Run Nginx as a Docker Container

Task:

Nautilus DevOps team is testing some applications deployment on some of the application servers. They need to deploy a nginx container on Application Server 3. Please complete the task as per details given below:

On Application Server 3 create a container named nginx_3 using image nginx with alpine tag and make sure container is in running state.

Solution:

thor@jump_host /$ ssh banner@stapp03

The authenticity of host 'stapp03 (172.16.238.12)' can't be established.

ECDSA key fingerprint is SHA256:AJF2x1pj8Ms5Xff85dXW3eULtBP32HV5LdA0H98Uqms.

ECDSA key fingerprint is MD5:ab:7d:52:1c:6b:49:cd:ee:4b:35:e8:43:2f:1b:93:2e.

Are you sure you want to continue connecting (yes/no)? yes

Warning: Permanently added 'stapp03,172.16.238.12' (ECDSA) to the list of known hosts.

banner@stapp03's password: 

[banner@stapp03 ~]$ sudo su -

We trust you have received the usual lecture from the local System

Administrator. It usually boils down to these three things:

    #1) Respect the privacy of others.

    #2) Think before you type.

    #3) With great power comes great responsibility.

[sudo] password for banner: 

[root@stapp03 ~]# pwd

/root

[root@stapp03 ~]# docker run -it --name nginx_3 -p 80:80 -d nginx:alpine

Unable to find image 'nginx:alpine' locally

alpine: Pulling from library/nginx

540db60ca938: Pull complete 

197dc8475a23: Pull complete 

39ea657007e5: Pull complete 

37afbf7d4c3d: Pull complete 

0c01f42c3df7: Pull complete 

d590d87c9181: Pull complete 

Digest: sha256:07ab71a2c8e4ecb19a5a5abcfb3a4f175946c001c8af288b1aa766d67b0d05d2

Status: Downloaded newer image for nginx:alpine

4c273c6a7f1b12e58dd2cb5e105172d53cc19494c20cb7a368d14089bd021af8

[root@stapp03 ~]# docker ps

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES

4c273c6a7f1b        nginx:alpine        "/docker-entrypoint.…"   11 seconds ago      Up 10 seconds       0.0.0.0:80->80/tcp   nginx_3

[root@stapp03 ~]# 

Create Replicaset in Kubernetes Cluster

Task: 

The Nautilus DevOps team is going to deploy some applications on kubernetes cluster as they are planning to migrate some of their applications there. Recently one of the team members has been assigned a task to write a template as per details mentioned below:

Create a ReplicaSet using nginx image with latest tag only and remember to mention tag i.e nginx:latest and name it as nginx-replicaset.

Labels app should be nginx_app, labels type should be front-end. The container should be named as nginx-container; also make sure replicas counts are 4.

Note: The kubectl utility on jump_host has been configured to work with the kubernetes cluster.

Solution:

Step 1) Create a yaml file

thor@jump_host /$ cat /tmp/rs.yaml 

apiVersion: apps/v1

kind: ReplicaSet

metadata:

  name: nginx-replicaset

  labels:

    type: front-end

    app: nginx_app

spec:

  replicas: 4

  selector:

    matchLabels:

      type: front-end

      app: nginx_app

  template:

    metadata:

      labels:

        type: front-end

        app: nginx_app

    spec:

      containers:

      - name: nginx-container

        image: nginx:latest

thor@jump_host /$ 

Step 2) Execute the yaml file to create a ReplicaSet

thor@jump_host /$ kubectl create -f /tmp/rs.yaml 

replicaset.apps/nginx-replicaset created

Build a ubuntu image and run apache instance using Dockerfile

 As per recent requirements shared by the Nautilus application development team, they need custom images created for one of their projects. Several of the initial testing requirements are already been shared with DevOps team. Therefore, create a docker file /opt/docker/Dockerfile (please keep D capital of Dockerfile) on App server 3 in Stratos DC and configure to build an image with the following requirements:

a. Use ubuntu as the base image.

b. Install apache2 and configure it to work on 8086 port. (do not update any other Apache configuration settings like document root etc).

Step 1) Create a Dockerfile

[root@stapp03 docker]# cd /opt/docker

[root@stapp03 docker]# cat Dockerfile 

FROM ubuntu

ENV DEBIAN_FRONTEND=noninteractive

RUN apt-get update -y

RUN apt-get install apache2 -y 

RUN apt-get install apache2-utils -y 

RUN apt-get clean 

RUN sed -i 's/80/8086/g' /etc/apache2/ports.conf

EXPOSE 8086 

ENTRYPOINT ["/usr/sbin/apache2ctl"]

CMD ["-D","FOREGROUND","-k", "start"]

Step 2) Build the docker file

[root@stapp03 docker]# docker build . 

Build an Apache Instance using a Dockerfile

Step 1) Create a Dockerfile

 [root@stapp03 docker]# ls -rtl

total 12

drwxr-xr-x 2 root root 4096 Apr 11 02:53 html

drwxr-xr-x 2 root root 4096 Apr 11 02:53 certs

-rw-r--r-- 1 root root  518 Apr 11 02:53 Dockerfile

[root@stapp03 docker]# cat Dockerfile 

FROM httpd:2.4.43

RUN sed -i "s/Listen 80/Listen 8080/g" /usr/local/apache2/conf/httpd.conf

RUN sed -i '/LoadModule\ ssl_module modules\/mod_ssl.so/s/^#//g' conf/httpd.conf

RUN sed -i '/LoadModule\ socache_shmcb_module modules\/mod_socache_shmcb.so/s/^#//g' conf/httpd.conf

RUN sed -i '/Include\ conf\/extra\/httpd-ssl.conf/s/^#//g' conf/httpd.conf

COPY certs/server.crt /usr/local/apache2/conf/server.crt

COPY certs/server.key /usr/local/apache2/conf/server.key

COPY html/index.html /usr/local/apache2/htdocs/

Step 2) Build the docker file.

[root@stapp03 docker]# docker build . 

Sending build context to Docker daemon  9.216kB

Step 1/8 : FROM httpd:2.4.43

2.4.43: Pulling from library/httpd

bf5952930446: Pull complete 

3d3fecf6569b: Pull complete 

b5fc3125d912: Pull complete 

3c61041685c0: Pull complete 

34b7e9053f76: Pull complete 

Digest: sha256:cd88fee4eab37f0d8cd04b06ef97285ca981c27b4d685f0321e65c5d4fd49357

Status: Downloaded newer image for httpd:2.4.43

 ---> f1455599cc2e

Step 2/8 : RUN sed -i "s/Listen 80/Listen 8080/g" /usr/local/apache2/conf/httpd.conf

 ---> Running in 8a15fb135929

Removing intermediate container 8a15fb135929

 ---> 68a60d63d706

Step 3/8 : RUN sed -i '/LoadModule\ ssl_module modules\/mod_ssl.so/s/^#//g' conf/httpd.conf

 ---> Running in 4428dc0a8f75

Removing intermediate container 4428dc0a8f75

 ---> 120807ee4b24

Step 4/8 : RUN sed -i '/LoadModule\ socache_shmcb_module modules\/mod_socache_shmcb.so/s/^#//g' conf/httpd.conf

 ---> Running in 16a20cd89c06

Removing intermediate container 16a20cd89c06

 ---> adccf5d023cc

Step 5/8 : RUN sed -i '/Include\ conf\/extra\/httpd-ssl.conf/s/^#//g' conf/httpd.conf

 ---> Running in 20517b5c3139

Removing intermediate container 20517b5c3139

 ---> eb9a29e245f6

Step 6/8 : COPY certs/server.crt /usr/local/apache2/conf/server.crt

 ---> 778c38d0b9e8

Step 7/8 : COPY certs/server.key /usr/local/apache2/conf/server.key

 ---> a296ecb733bf

Step 8/8 : COPY html/index.html /usr/local/apache2/htdocs/

 ---> f8770710ddf9

Successfully built f8770710ddf9

Step 3) Verify if the image is running. 

[root@stapp03 docker]# docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

<none>              <none>              f8770710ddf9        6 seconds ago       166MB

httpd               2.4.43              f1455599cc2e        8 months ago        166MB

Ansible playbook loop with condition example

[osboxes@master ansible-playbooks]$ cat loopwithcondition.yml

- hosts: all

  tasks:

  - name: Ansible loop with conditional example

    debug:

      msg: "{{ item }}"

    loop:

      - "hello1"

      - "hello2"

      - "hello3"

    when: ansible_distribution == "CentOS"

[osboxes@master ansible-playbooks]$ ansible-playbook loopwithcondition.yml -i inventory.txt

PLAY [all] **************************************************************************************************************************************************

TASK [Gathering Facts] **************************************************************************************************************************************

ok: [192.168.1.182]

TASK [Ansible loop with conditional example] ****************************************************************************************************************

ok: [192.168.1.182] => (item=hello1) => {

    "msg": "hello1"

}

ok: [192.168.1.182] => (item=hello2) => {

    "msg": "hello2"

}

ok: [192.168.1.182] => (item=hello3) => {

    "msg": "hello3"

}

PLAY RECAP **************************************************************************************************************************************************

192.168.1.182              : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Ansible when condition with "in" keyword

Task: Check the disk space of the file system When the operating system is "RedHat" or  "CentOS" or "Debian" using "when" condition and "in" keyword

[osboxes@master ansible-playbooks]$ cat conditions-in.yml

---

- name: check the disk space on the file system

  hosts: all

  vars:

    distributions:

      - RedHat

      - CentOS

      - Debian

  tasks:

    - name: Check the disk space on the each server

      shell: df -h

      register: result

    - debug:

        var: result.stdout_lines

      when: ansible_distribution in distributions

[osboxes@master ansible-playbooks]$ ansible-playbook conditions-in.yml -i inventory.txt

PLAY [check the disk space on the file system] **************************************************************************************************************

TASK [Gathering Facts] **************************************************************************************************************************************

ok: [192.168.1.182]

TASK [Check the disk space on the each server] **************************************************************************************************************

changed: [192.168.1.182]

TASK [debug] ************************************************************************************************************************************************

ok: [192.168.1.182] => {

    "result.stdout_lines": [

        "Filesystem      Size  Used Avail Use% Mounted on",

        "devtmpfs        887M     0  887M   0% /dev",

        "tmpfs           914M     0  914M   0% /dev/shm",

        "tmpfs           914M  9.2M  905M   1% /run",

        "tmpfs           914M     0  914M   0% /sys/fs/cgroup",

        "/dev/sda2       236G  6.9G  230G   3% /",

        "/dev/sda5       254G  1.9G  252G   1% /home",

        "/dev/sda1       976M  188M  722M  21% /boot",

        "tmpfs           183M  1.2M  182M   1% /run/user/42",

        "tmpfs           183M  4.0K  183M   1% /run/user/1000"

    ]

}

PLAY RECAP **************************************************************************************************************************************************

192.168.1.182              : ok=3    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Deploy an App on Docker Containers using docker-compose

Task:

The Nautilus Application development team recently finished development of one of the apps that they want to deploy on a containerized platform. The Nautilus Application development and DevOps teams met to discuss some of the basic pre-requisites and requirements to complete the deployment. The team wants to test the deployment on one of the app servers before going live and set up a complete containerized stack using a docker compose fie. Below are the details of the task:

On App Server 3 in Stratos Datacenter create a docker compose file /opt/finance/docker-compose.yml (should be named exactly).

The compose should deploy two services (web and DB), and each service should deploy a container as per details below:

For web service:

a. Container name must be php_host.

b. Use image php with any apache tag. Check here for more details https://hub.docker.com/_/php?tab=tags.

c. Map php_host container's port 80 with host port 5001

d. Map php_host container's /var/www/html volume with host volume /var/www/html.

For DB service:

a. Container name must be mysql_host.

b. Use image mariadb with any tag (preferably latest). Check here for more details https://hub.docker.com/_/mariadb?tab=tags.

c. Map mysql_host container's port 3306 with host port 3306

d. Map mysql_host container's /var/lib/mysql volume with host volume /var/lib/mysql.

e. Set MYSQL_DATABASE=database_host and use any custom user ( except root ) with some complex password for DB connections.

After running docker-compose up you can access the app with curl command curl <server-ip or hostname>:5001/

For more details check here: https://hub.docker.com/_/mariadb?tab=description

Step 1) Login to Application server 3 and switch to root user.

thor@jump_host /$ ssh banner@stapp03

banner@stapp03's password: 

[banner@stapp03 ~]$ sudo su -

Step 2) Create a docker-compose.yml file with the specifications given in the task.

[root@stapp03 ~]# cd /opt/finance/

[root@stapp03 finance]# ls -rlt

total 0

[root@stapp03 finance]# vi docker-compose.yml

  web:

     container_name: php_host

     image: php:apache

     ports:

       - 5001:80

     volumes:

       - /var/www/html:/var/www/html     

  db:

    container_name: mysql_host

    image: mariadb:latest

    ports:

    - 3306:3306

    volumes:

      - /var/lib/mysql:/var/lib/mysql

    environment:

      MYSQL_DATABASE: database_host

      MYSQL_ROOT_PASSWORD: abc#123

      MYSQL_USER: pavan

      MYSQL_PASSWORD: Wordpress#134

Step 3) Run the following command

[root@stapp03 finance]# docker-compose up

Pulling web (php:apache)...

apache: Pulling from library/php

6f28985ad184: Pull complete

db883aae18bc: Pull complete

ffae70ea03a9: Pull complete

1e8027612378: Pull complete

3ec32e53dce5: Pull complete

3bb74037bf77: Pull complete

feda0fbd85b1: Pull complete

08cbfcace66f: Pull complete

90e59842632d: Pull complete

5a29d8ab032c: Pull complete

5435aacb3255: Pull complete

57f9bba5897a: Pull complete

7c89fe480eda: Pull complete

Pulling db (mariadb:latest)...

latest: Pulling from library/mariadb

5d3b2c2d21bb: Pull complete

3fc2062ea667: Pull complete

75adf526d75b: Pull complete

62aa2722e098: Pull complete

756d25563a9f: Pull complete

2022ea4dab77: Pull complete

0ab4098b0f7c: Pull complete

d03413915fdf: Pull complete

fb8e671b1408: Pull complete

5e2452f3fb5c: Pull complete

c2da3a6fe532: Pull complete

153b7df268e7: Pull complete

Creating php_host   ... done

Creating mysql_host ... done

Attaching to mysql_host, php_host

mysql_host | 2021-03-16 01:43:25+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 1:10.5.9+maria~focal started.

mysql_host | 2021-03-16 01:43:25+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'

mysql_host | 2021-03-16 01:43:25+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 1:10.5.9+maria~focal started.

mysql_host | 2021-03-16 01:43:25+00:00 [Note] [Entrypoint]: Initializing database files

php_host | AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 172.17.0.3. Set the 'ServerName' directive globally to suppress this message

php_host | AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 172.17.0.3. Set the 'ServerName' directive globally to suppress this message

php_host | [Tue Mar 16 01:43:28.007827 2021] [mpm_prefork:notice] [pid 1] AH00163: Apache/2.4.38 (Debian) PHP/8.0.3 configured -- resuming normal operations

php_host | [Tue Mar 16 01:43:28.007869 2021] [core:notice] [pid 1] AH00094: Command line: 'apache2 -D FOREGROUND'

mysql_host | 

mysql_host | 

mysql_host | PLEASE REMEMBER TO SET A PASSWORD FOR THE MariaDB root USER !

mysql_host | To do so, start the server, then issue the following commands:

mysql_host | 

mysql_host | '/usr/bin/mysqladmin' -u root password 'new-password'

mysql_host | '/usr/bin/mysqladmin' -u root -h  password 'new-password'

mysql_host | 

mysql_host | Alternatively you can run:

mysql_host | '/usr/bin/mysql_secure_installation'

mysql_host | 

mysql_host | which will also give you the option of removing the test

mysql_host | databases and anonymous user created by default.  This is

mysql_host | strongly recommended for production servers.

mysql_host | 

mysql_host | See the MariaDB Knowledgebase at https://mariadb.com/kb or the

mysql_host | MySQL manual for more instructions.

mysql_host | 

mysql_host | Please report any problems at https://mariadb.org/jira

mysql_host | 

mysql_host | The latest information about MariaDB is available at https://mariadb.org/.

mysql_host | You can find additional information about the MySQL part at:

mysql_host | https://dev.mysql.com

mysql_host | Consider joining MariaDB's strong and vibrant community:

mysql_host | https://mariadb.org/get-involved/

mysql_host | 

mysql_host | 2021-03-16 01:43:28+00:00 [Note] [Entrypoint]: Database files initialized

mysql_host | 2021-03-16 01:43:28+00:00 [Note] [Entrypoint]: Starting temporary server

mysql_host | 2021-03-16 01:43:28+00:00 [Note] [Entrypoint]: Waiting for server startup

mysql_host | 2021-03-16  1:43:28 0 [Note] mysqld (mysqld 10.5.9-MariaDB-1:10.5.9+maria~focal) starting as process 96 ...

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Uses event mutexes

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Compressed tables use zlib 1.2.11

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Number of pools: 1

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Using crc32 + pclmulqdq instructions

mysql_host | 2021-03-16  1:43:28 0 [Note] mysqld: O_TMPFILE is not supported on /tmp (disabling future attempts)

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Using Linux native AIO

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Initializing buffer pool, total size = 134217728, chunk size = 134217728

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Completed initialization of buffer pool

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: 128 rollback segments are active.

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Creating shared tablespace for temporary tables

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: 10.5.9 started; log sequence number 45130; transaction id 20

mysql_host | 2021-03-16  1:43:28 0 [Note] Plugin 'FEEDBACK' is disabled.

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool

mysql_host | 2021-03-16  1:43:28 0 [Note] InnoDB: Buffer pool(s) load completed at 210316  1:43:28

mysql_host | 2021-03-16  1:43:28 0 [Warning] 'user' entry 'root@35db7c5d0517' ignored in --skip-name-resolve mode.

mysql_host | 2021-03-16  1:43:28 0 [Warning] 'proxies_priv' entry '@% root@35db7c5d0517' ignored in --skip-name-resolve mode.

mysql_host | 2021-03-16  1:43:28 0 [Note] Reading of all Master_info entries succeeded

mysql_host | 2021-03-16  1:43:28 0 [Note] Added new Master_info '' to hash table

mysql_host | 2021-03-16  1:43:28 0 [Note] mysqld: ready for connections.

mysql_host | Version: '10.5.9-MariaDB-1:10.5.9+maria~focal'  socket: '/run/mysqld/mysqld.sock'  port: 0  mariadb.org binary distribution

mysql_host | 2021-03-16 01:43:29+00:00 [Note] [Entrypoint]: Temporary server started.

mysql_host | Warning: Unable to load '/usr/share/zoneinfo/leap-seconds.list' as time zone. Skipping it.

mysql_host | Warning: Unable to load '/usr/share/zoneinfo/leapseconds' as time zone. Skipping it.

mysql_host | Warning: Unable to load '/usr/share/zoneinfo/tzdata.zi' as time zone. Skipping it.

mysql_host | 2021-03-16  1:43:31 5 [Warning] 'proxies_priv' entry '@% root@35db7c5d0517' ignored in --skip-name-resolve mode.

mysql_host | 2021-03-16 01:43:31+00:00 [Note] [Entrypoint]: Creating database database_host

mysql_host | 2021-03-16 01:43:31+00:00 [Note] [Entrypoint]: Creating user pavan

mysql_host | 2021-03-16 01:43:31+00:00 [Note] [Entrypoint]: Giving user pavan access to schema database_host

mysql_host | 

mysql_host | 2021-03-16 01:43:31+00:00 [Note] [Entrypoint]: Stopping temporary server

mysql_host | 2021-03-16  1:43:31 0 [Note] mysqld (initiated by: root[root] @ localhost []): Normal shutdown

mysql_host | 2021-03-16  1:43:31 0 [Note] Event Scheduler: Purging the queue. 0 events

mysql_host | 2021-03-16  1:43:31 0 [Note] InnoDB: FTS optimize thread exiting.

mysql_host | 2021-03-16  1:43:31 0 [Note] InnoDB: Starting shutdown...

mysql_host | 2021-03-16  1:43:31 0 [Note] InnoDB: Dumping buffer pool(s) to /var/lib/mysql/ib_buffer_pool

mysql_host | 2021-03-16  1:43:31 0 [Note] InnoDB: Buffer pool(s) dump completed at 210316  1:43:31

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Removed temporary tablespace data file: "ibtmp1"

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Shutdown completed; log sequence number 45142; transaction id 21

mysql_host | 2021-03-16  1:43:32 0 [Note] mysqld: Shutdown complete

mysql_host | 

mysql_host | 2021-03-16 01:43:32+00:00 [Note] [Entrypoint]: Temporary server stopped

mysql_host | 

mysql_host | 2021-03-16 01:43:32+00:00 [Note] [Entrypoint]: MySQL init process done. Ready for start up.

mysql_host | 

mysql_host | 2021-03-16  1:43:32 0 [Note] mysqld (mysqld 10.5.9-MariaDB-1:10.5.9+maria~focal) starting as process 1 ...

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Uses event mutexes

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Compressed tables use zlib 1.2.11

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Number of pools: 1

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Using crc32 + pclmulqdq instructions

mysql_host | 2021-03-16  1:43:32 0 [Note] mysqld: O_TMPFILE is not supported on /tmp (disabling future attempts)

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Using Linux native AIO

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Initializing buffer pool, total size = 134217728, chunk size = 134217728

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Completed initialization of buffer pool

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: 128 rollback segments are active.

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Creating shared tablespace for temporary tables

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: 10.5.9 started; log sequence number 45142; transaction id 20

mysql_host | 2021-03-16  1:43:32 0 [Note] Plugin 'FEEDBACK' is disabled.

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool

mysql_host | 2021-03-16  1:43:32 0 [Note] InnoDB: Buffer pool(s) load completed at 210316  1:43:32

mysql_host | 2021-03-16  1:43:33 0 [Note] Server socket created on IP: '::'.

mysql_host | 2021-03-16  1:43:33 0 [Warning] 'proxies_priv' entry '@% root@35db7c5d0517' ignored in --skip-name-resolve mode.

mysql_host | 2021-03-16  1:43:33 0 [Note] Reading of all Master_info entries succeeded

mysql_host | 2021-03-16  1:43:33 0 [Note] Added new Master_info '' to hash table

mysql_host | 2021-03-16  1:43:33 0 [Note] mysqld: ready for connections.

mysql_host | Version: '10.5.9-MariaDB-1:10.5.9+maria~focal'  socket: '/run/mysqld/mysqld.sock'  port: 3306  mariadb.org binary distribution

php_host | 172.16.238.3 - - [16/Mar/2021:01:49:57 +0000] "GET / HTTP/1.1" 200 358 "-" "curl/7.29.0"

 

Ansible when condition examples

 Task: Install http package using yum module and load services, enable services, start services when Operating system is "CentOS"

[osboxes@master ansible-playbooks]$ cat conditions.yml

---

- name: Install packages

  hosts: all

  become: true

  become_user: root

  tasks:

    - name: Install httpd

      yum:

        name: httpd

        state: present

    - name: load apache service

      systemd: daemon_reload=yes name=httpd

      when: (ansible_distribution == "CentOS")

    - name: enable apache service

      service: name=httpd enabled=yes

      when: (ansible_distribution == "CentOS")

    - name: start apache service

      service: name=httpd state=started

      when: (ansible_distribution == "CentOS")

[osboxes@master ansible-playbooks]$ ansible-playbook conditions.yml -i inventory.txt --syntax-check

playbook: conditions.yml

[osboxes@master ansible-playbooks]$ ansible-playbook conditions.yml -i inventory.txt

PLAY [Install packages] *************************************************************************************************************************************

TASK [Gathering Facts] **************************************************************************************************************************************

ok: [192.168.1.182]

TASK [Install httpd] ****************************************************************************************************************************************

ok: [192.168.1.182]

TASK [load apache service] **********************************************************************************************************************************

changed: [192.168.1.182]

TASK [enable apache service] ********************************************************************************************************************************

ok: [192.168.1.182]

TASK [start apache service] *********************************************************************************************************************************

changed: [192.168.1.182]

PLAY RECAP **************************************************************************************************************************************************

192.168.1.182              : ok=5    changed=2    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Puppet Setup NTP Server

 Task:

While troubleshooting one of the issue on app servers in Stratos Datacenter DevOps team identified the root cause that the time isn't synchronized properly among all app servers which cause issues sometimes. So team has decided to use a specific time server for all app servers so that they all remain in sync. This task needs to be done using Puppet so as per details mentioned below please compete the task:

Create a puppet programming file apps.pp under /etc/puppetlabs/code/environments/production/manifests directory on puppet master node i.e on Jump Server. Within the programming file define a custom class ntpconfig to install and configure ntp server on all app servers.

Also add NTP Server server 1.africa.pool.ntp.org in default configuration file on all app servers.

Please note that do not try to start/restart/stop ntp service as we already have a scheduled restart for this service tonight and we don't want these changes to be applied right now.

Note: Please perform this task using apps.pp only, do not try to create any separate inventory file.

Step 1) Create puppet class file apps.pp on jump host where puppet master is running

root@jump_host /etc/puppetlabs/code/environments/production/manifests# cat apps.pp 

class ntpconfig {

#Installing NTP Package

package {"ntp":

        ensure => 'present',

        }

#Add content to ntp configuration file

file {"/etc/ntp.conf":

     ensure => "present",

     content => "server 1.africa.pool.ntp.org",

     }

#Start NTP Services

service {"ntpd":

        ensure => "running",

        }

}

node 'stapp01.stratos.xfusioncorp.com', 'stapp02.stratos.xfusioncorp.com', 'stapp03.stratos.xfusioncorp.com' {

include ntpconfig

}

Step 2) Validate the syntax 

root@jump_host /etc/puppetlabs/code/environments/production/manifests# puppet parser validate apps.pp

Step 3) Run puppet agent -tv on app server 1, Server 2 and Server 3 and validate if ntp server is running.

[root@stapp01 ~]# puppet agent -tv

[root@stapp01 ~]# ps -ef | grep ntp

ntp        413     1  0 00:50 ?        00:00:00 /usr/sbin/ntpd -u ntp:ntp -g

root       416   164  0 00:50 pts/0    00:00:00 grep --color=auto ntp

[root@stapp02 ~]# puppet agent -tv

[root@stapp02 ~]# ps -ef | grep ntp

ntp        413     1  0 00:50 ?        00:00:00 /usr/sbin/ntpd -u ntp:ntp -g

root       416   164  0 00:50 pts/0    00:00:00 grep --color=auto ntp

[root@stapp03 ~]# puppet agent -tv

[root@stapp03 ~]# ps -ef | grep ntp

ntp        413     1  0 00:50 ?        00:00:00 /usr/sbin/ntpd -u ntp:ntp -g

root       416   164  0 00:50 pts/0    00:00:00 grep --color=auto ntp

Rolling Updates in Kunbernetes

 Task:

We have an application running on Kubernetes cluster using nginx web server. The Nautilus application development team has pushed some of the latest features to prod branch and those need be deployed. The Nautilus DevOps team has created an image nginx:1.18 with latest changes.

Perform a rolling update for this application and incorporate nginx:1.18 image. The deployment name is nginx-deployment

Make sure all pods are up and running after the update.
Note: The kubectl utility on jump_host has been configured to work with the kubernetes cluster.

Step 1) Check if the deployment nginx-deployment is present

thor@jump_host ~$ kubectl get deployment 

NAME               READY   UP-TO-DATE   AVAILABLE   AGE

nginx-deployment   3/3     3            3           8m19s

Step 2) Check if the pods are running

thor@jump_host ~$ kubectl get pods

NAME                                READY   STATUS    RESTARTS   AGE

nginx-deployment-74fb588559-7447s   1/1     Running   0          8m37s

nginx-deployment-74fb588559-ch6mm   1/1     Running   0          8m37s

nginx-deployment-74fb588559-g9cm7   1/1     Running   0          8m37s

Step 3) Check what deployment version is running on the container

thor@jump_host ~$ kubectl get deployment -o wide

NAME               READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS        IMAGES       SELECTOR

nginx-deployment   3/3     3            3           8m56s   nginx-container   nginx:1.16   app=nginx-app

Step 4) Update the image version to nginx:1.18 from nginx:1.16

thor@jump_host ~$ kubectl set image deployment/nginx-deployment nginx-container=nginx:1.18 --record=true

deployment.apps/nginx-deployment image updated

Step 5)  Check the status of the pods and wait until they come back to running state

thor@jump_host ~$ kubectl get pods 

NAME                                READY   STATUS              RESTARTS   AGE

nginx-deployment-74fb588559-7447s   1/1     Running             0          14m

nginx-deployment-74fb588559-ch6mm   0/1     Terminating         0          14m

nginx-deployment-74fb588559-g9cm7   1/1     Running             0          14m

nginx-deployment-7b6877b9b5-6qcw6   0/1     ContainerCreating   0          2s

nginx-deployment-7b6877b9b5-l8v6c   1/1     Running             0          9s

thor@jump_host ~$ kubectl get pods

NAME                                READY   STATUS    RESTARTS   AGE

nginx-deployment-7b6877b9b5-6qcw6   1/1     Running   0          46s

nginx-deployment-7b6877b9b5-776br   1/1     Running   0          44s

nginx-deployment-7b6877b9b5-l8v6c   1/1     Running   0          53s

thor@jump_host ~$ kubectl get pods -o wide

NAME                                READY   STATUS    RESTARTS   AGE    IP           NODE     NOMINATED NODE   READINESS GATES

nginx-deployment-7b6877b9b5-6qcw6   1/1     Running   0          109s   10.244.1.7   node01   <none>           <none>

nginx-deployment-7b6877b9b5-776br   1/1     Running   0          107s   10.244.1.8   node01   <none>           <none>

nginx-deployment-7b6877b9b5-l8v6c   1/1     Running   0          116s   10.244.1.6   node01   <none>           <none>

Step 6) Check the rollout history 

thor@jump_host ~$ kubectl rollout history deployment 

deployment.apps/nginx-deployment 

REVISION  CHANGE-CAUSE

1         <none>

2         kubectl set image deployment/nginx-deployment nginx-container=nginx:1.18 --record=true

Step 7) Check the image version now

thor@jump_host ~$ kubectl get deployment -o wide

NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS        IMAGES       SELECTOR

nginx-deployment   3/3     3            3           16m   nginx-container   nginx:1.18   app=nginx-app

GIT - Working with Remote repository GITHUB

Setup SSH Authentication with GITHUB Repository

Generate ssh keys on your linux machine

[osboxes@master ansible-playbooks]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/osboxes/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/osboxes/.ssh/id_rsa.
Your public key has been saved in /home/osboxes/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:iDSkhURVA9g/UILBIkV4mAdjdkr6QpF2iHFMhCPsrqk osboxes@linuxhost
The key's randomart image is:
+---[RSA 3072]----+
|*^%O*++          |
|/B%=o. .         |
|*Bo oo           |
|.o . oo.         |
|o . . ..S        |
| o               |
|..               |
|o                |
|E                |
+----[SHA256]-----+

[osboxes@master ansible-playbooks]$ cat ~/.ssh/id_rsa.pub

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQDHsN99astKP+jnHdSu6EtiY072Rllo4ILiZ4wwU5KISwjKVnUy9XGjVmMbFdQAJOczBRtw7AVmuo1vh5ieKa+BRvdJe1Sa7fZQVyHWqKxk+wkA1Mt6sSIkz3zzdte8hE9Ojmuqrqw3evjcwBywzf2Tz03JqSN2hhaXeQl8eK/DbO4y+NQXM2nOhVAGhpj1JWSCwXS9a1hWBF2OSHpJsmvcqVyDDWZvpjDoAwvJjd+n2XuZqyns/PVTy1WPq7AfWBigiGI8OTi/K97MKtDrSv0JgjX/aTVz5sirWxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxqIzrPkq+MfpKDMtORfjjbzIdwuRgngZLUtPDI1EywCy2gNhaWwoeG3CTQ/aR1OsMDs/74u/S5ECcQTYW7Vpb/slQhm8I+yvyfqUky7M9zuLMaMZyfRwdawrMExtU= osboxes@master

Create a new github account if you don't have one 

https://github.com

Go to Settings -> SSH and GPG keys -> SSH keys -> Click on New SSH Key

Copy the id_rsa.pub key from linux machine and paste it here 

Enter the following command on your Linux Machine

[osboxes@master ansible-playbooks]$ ssh -T git@github.com

The authenticity of host 'github.com (140.82.114.4)' can't be established.
RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'github.com,140.82.114.4' (RSA) to the list of known hosts.
Hi pavanbandaru! You've successfully authenticated, but GitHub does not provide shell access.

Create a repository on your local system and commit the changes to local repository before pushing your code to GITHUB

[osboxes@master ansible-playbooks]$ git init

Initialized empty Git repository in /home/osboxes/ansible-playbooks/.git/

[osboxes@master ansible-playbooks]$ git add .

[osboxes@master ansible-playbooks]$ git commit -m "My First commit to ansible playbooks"

[master (root-commit) e8f579c] My First commit to ansible playbooks

 15 files changed, 236 insertions(+)

 create mode 100644 addusers.yml

 create mode 100644 apache-install.yml

 create mode 100644 create_dir.yml

 create mode 100644 dict.yml

 create mode 100644 install-packages.yml

 create mode 100644 install-packages_1.yml

 create mode 100644 inventory-loops.yml

 create mode 100644 inventory.txt

 create mode 100644 iterating-loops.yml

 create mode 100644 limit-output.yml

 create mode 100644 linux-user.yml

 create mode 100644 mynewplaybook

 create mode 100644 new_inventory.txt

 create mode 100644 password.txt

 create mode 100644 register.yml

[osboxes@master ansible-playbooks]$ git status

On branch master

nothing to commit, working tree clean

Create a new repository on GITHUB and click on Code -> SSH and copy the URL link.

Go to your Linux machine and execute the following commands

[osboxes@master ansible-playbooks]$ git remote add origin git@github.com:pavanbandaru/ansible-playbooks.git

[osboxes@master ansible-playbooks]$ git remote -v

origin  git@github.com:pavanbandaru/ansible-playbooks.git (fetch)

origin  git@github.com:pavanbandaru/ansible-playbooks.git (push)

[osboxes@master ansible-playbooks]$ git push -u origin master

Warning: Permanently added the RSA host key for IP address '140.82.112.4' to the list of known hosts.

Enumerating objects: 17, done.

Counting objects: 100% (17/17), done.

Compressing objects: 100% (15/15), done.

Writing objects: 100% (17/17), 3.34 KiB | 285.00 KiB/s, done.

Total 17 (delta 2), reused 0 (delta 0), pack-reused 0

remote: Resolving deltas: 100% (2/2), done.

remote:

remote: Create a pull request for 'master' on GitHub by visiting:

remote:      https://github.com/pavanbandaru/ansible-playbooks/pull/new/master

remote:

To github.com:pavanbandaru/ansible-playbooks.git

 * [new branch]      master -> master

Branch 'master' set up to track remote branch 'master' from 'origin'.

Go to GITHUB and verify the changes

Make some changes to our local repository and push the changes to remote repository

( I have made changes to inventory-loops.yml file and I am going to push these changes to remote repository)

Check the status

[osboxes@master ansible-playbooks]$ git status

On branch master

Your branch is up to date with 'origin/master'.

Changes not staged for commit:

  (use "git add <file>..." to update what will be committed)

  (use "git restore <file>..." to discard changes in working directory)

        modified:   inventory-loops.yml

no changes added to commit (use "git add" and/or "git commit -a")

Check the difference

[osboxes@master ansible-playbooks]$ git diff

diff --git a/inventory-loops.yml b/inventory-loops.yml

index dba93c1..d50904f 100644

--- a/inventory-loops.yml

+++ b/inventory-loops.yml

@@ -1,5 +1,5 @@

 ---

-- name:  looping over inventory

+- name:  looping over inventory example

   hosts: all

   become: true

   become_user: root

Add file and commit the changes

[osboxes@master ansible-playbooks]$ git commit -am "updated inventory-loops.yml"

[master 10207db] updated inventory-loops.yml

 1 file changed, 1 insertion(+), 1 deletion(-)

Pull the remote repository to local before pushing into remote as a best practice. Changes would have been made to the remote repository by others. So to avoid conflicts, pull the repository before pushing it to remote. 

[osboxes@master ansible-playbooks]$ git pull origin master

warning: Pulling without specifying how to reconcile divergent branches is

discouraged. You can squelch this message by running one of the following

commands sometime before your next pull:

  git config pull.rebase false  # merge (the default strategy)

  git config pull.rebase true   # rebase

  git config pull.ff only       # fast-forward only

You can replace "git config" with "git config --global" to set a default

preference for all repositories. You can also pass --rebase, --no-rebase,

or --ff-only on the command line to override the configured default per

invocation.

Warning: Permanently added the RSA host key for IP address '140.82.114.3' to the list of known hosts.

From github.com:pavanbandaru/ansible-playbooks

 * branch            master     -> FETCH_HEAD

Already up to date.

Now push the changes to remote repository

[osboxes@master ansible-playbooks]$ git push origin master

Enumerating objects: 5, done.

Counting objects: 100% (5/5), done.

Compressing objects: 100% (3/3), done.

Writing objects: 100% (3/3), 314 bytes | 314.00 KiB/s, done.

Total 3 (delta 2), reused 0 (delta 0), pack-reused 0

remote: Resolving deltas: 100% (2/2), completed with 2 local objects.

To github.com:pavanbandaru/ansible-playbooks.git

   e8f579c..10207db  master -> master

We can see the changes on the remote repository

Install and configure GIT on Linux and working with local repository

Install git 

 [root@linuxhost ~]# yum install git -y

Step 2) Configure global configurations for any repository that we use in future.

[osboxes@linuxhost ~]$ git config --global user.name "Pavan Bandaru"

[osboxes@linuxhost ~]$ git config --global user.email "pavankumarbandaru@hotmail.com"

[osboxes@linuxhost ~]$ git config --global --list

user.name=Pavan Bandaru

user.email=pavankumarbandaru@hotmail.com

It created a config file under user home directory

[osboxes@linuxhost ~]$  cat ~/.gitconfig

[user]

        name = Pavan Bandaru

        email = pavankumarbandaru@hotmail.com

You can also check what Git thinks a specific key’s value is by typing git config <key>:

[osboxes@linuxhost ansible-playbooks]$ git config user.name

Pavan Bandaru

.

Create a projects directory

[osboxes@linuxhost ~]$ pwd

/home/osboxes

[osboxes@linuxhost ~]$ cd projects/

[osboxes@linuxhost projects]$ ls -rlt

total 0

Initialize a git repository

Create a new repository: By default Git will create a branch called master when you create a new repository with git init

[osboxes@linuxhost projects]$ git init sample-repo

Initialized empty Git repository in /home/osboxes/projects/sample-repo/.git/

[osboxes@linuxhost projects]$ ls -rlt

total 0

drwxrwxr-x. 3 osboxes osboxes 18 Mar  5 15:47 sample-repo

[osboxes@linuxhost projects]$ cd sample-repo/

[osboxes@linuxhost sample-repo]$ ls -rlt

total 0

[osboxes@linuxhost sample-repo]$ pwd

/home/osboxes/projects/sample-repo

[osboxes@linuxhost sample-repo]$ ls -lart

total 0

drwxrwxr-x. 3 osboxes osboxes  25 Mar  5 15:47 ..

drwxrwxr-x. 3 osboxes osboxes  18 Mar  5 15:47 .

drwxrwxr-x. 7 osboxes osboxes 119 Mar  5 15:47 .git

[osboxes@linuxhost sample-repo]$

Initialize git repository on existing project: I have an existing project ansible-playbooks and I wanted to create a repository with an existing project name. Run "git init" command under your project name directory.

/home/osboxes/projects/ansible-playbooks

[osboxes@linuxhost ansible-playbooks]$ ls -rlt

total 52

-rw-------. 1 osboxes osboxes    0 Feb 27 09:41 linux-user.yml.txt

-rw-------. 1 osboxes osboxes   10 Mar  3 15:59 password.txt

-rw-------. 1 osboxes osboxes  355 Mar  3 15:59 mynewplaybook

-rw-------. 1 osboxes osboxes 1197 Mar  3 15:59 linux-user.yml

-rw-------. 1 osboxes osboxes  259 Mar  3 15:59 install-packages.yml

-rw-------. 1 osboxes osboxes  491 Mar  3 15:59 create_dir.yml

-rw-------. 1 osboxes osboxes  654 Mar  3 15:59 apache-install.yml

-rw-------. 1 osboxes osboxes   14 Mar  3 15:59 inventory.txt

-rw-------. 1 osboxes osboxes  311 Mar  3 15:59 install-packages_1.yml

-rw-------. 1 osboxes osboxes  342 Mar  3 15:59 addusers.yml

-rw-------. 1 osboxes osboxes  295 Mar  3 16:19 dict.yml

-rw-------. 1 osboxes osboxes  716 Mar  3 19:39 register.yml

-rw-------. 1 osboxes osboxes  429 Mar  3 20:15 limit-output.yml

-rw-------. 1 osboxes osboxes  508 Mar  3 20:18 inventory-loops.yml

[osboxes@linuxhost ansible-playbooks]$ git init

Initialized empty Git repository in /home/osboxes/projects/ansible-playbooks/.git/

Check the status of your files (We are on the master branch and have not added any files)

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

No commits yet

Untracked files:

  (use "git add <file>..." to include in what will be committed)

        addusers.yml

        apache-install.yml

        create_dir.yml

        dict.yml

        install-packages.yml

        install-packages_1.yml

        inventory-loops.yml

        inventory.txt

        limit-output.yml

        linux-user.yml

        linux-user.yml.txt

        mynewplaybook

        password.txt

        register.yml

nothing added to commit but untracked files present (use "git add" to track)

Add the file to the git repository and commit the changes.  ( Now we added a file addusers.yml file and did not commit the changes. git status will track the changes)

[osboxes@linuxhost ansible-playbooks]$ git add addusers.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

No commits yet

Changes to be committed:

  (use "git rm --cached <file>..." to unstage)

        new file:   addusers.yml

Untracked files:

  (use "git add <file>..." to include in what will be committed)

        apache-install.yml

        create_dir.yml

        dict.yml

        install-packages.yml

        install-packages_1.yml

        inventory-loops.yml

        inventory.txt

        limit-output.yml

        linux-user.yml

        linux-user.yml.txt

        mynewplaybook

        password.txt

        register.yml

commit the changes

[osboxes@linuxhost ansible-playbooks]$ git commit -m "First commit"

[master (root-commit) 51a789e] First commit

 1 file changed, 15 insertions(+)

 create mode 100644 addusers.yml

Use git add *  or git add . incase if you want to add all the files

[osboxes@linuxhost ansible-playbooks]$ git add *

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes to be committed:

  (use "git restore --staged <file>..." to unstage)

        new file:   apache-install.yml

        new file:   create_dir.yml

        new file:   dict.yml

        new file:   install-packages.yml

        new file:   install-packages_1.yml

        new file:   inventory-loops.yml

        new file:   inventory.txt

        new file:   limit-output.yml

        new file:   linux-user.yml

        new file:   linux-user.yml.txt

        new file:   mynewplaybook

        new file:   password.txt

        new file:   register.yml

Untracked files:

  (use "git add <file>..." to include in what will be committed)

        .remote-sync.json

commit the changes 

[osboxes@linuxhost ansible-playbooks]$ git commit -m "Second commit - Added all the files"

[master 2debee7] Second commit - Added all the files

 13 files changed, 191 insertions(+)

 create mode 100644 apache-install.yml

 create mode 100644 create_dir.yml

 create mode 100644 dict.yml

 create mode 100644 install-packages.yml

 create mode 100644 install-packages_1.yml

 create mode 100644 inventory-loops.yml

 create mode 100644 inventory.txt

 create mode 100644 limit-output.yml

 create mode 100644 linux-user.yml

 create mode 100644 linux-user.yml.txt

 create mode 100644 mynewplaybook

 create mode 100644 password.txt

 create mode 100644 register.yml

Check the status now. There are no new file to commit.

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

nothing to commit, working tree clean

Modify an existing file and check the status ( I have modified a file addusers.yml )

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes not staged for commit:

  (use "git add <file>..." to update what will be committed)

  (use "git restore <file>..." to discard changes in working directory)

        modified:   addusers.yml

no changes added to commit (use "git add" and/or "git commit -a")

Now you have two options to add and commit the changes

1) git add adduser.yml 

     git commit -m "Second commit on addusers"

2) git commit -am "Second commit on addusers" ( -a is for adding, -m is for commit message )

I used option 2 for adding and commit  my changes

[osboxes@linuxhost ansible-playbooks]$ git commit -am "Second commit on addusers"

[master ea3b865] Second commit on addusers

 1 file changed, 1 insertion(+), 1 deletion(-)

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

nothing to commit, working tree clean

Now modify an existing file and create a new file and check the status

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes not staged for commit:

  (use "git add <file>..." to update what will be committed)

  (use "git restore <file>..." to discard changes in working directory)

        modified:   addusers.yml

Untracked files:

  (use "git add <file>..." to include in what will be committed)

        dictionary.yml

no changes added to commit (use "git add" and/or "git commit -a")

Now add a file adduser.yml and don't add the new file and check the status ( Here one file addusers.yml is in staging area )

[osboxes@linuxhost ansible-playbooks]$ git add addusers.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes to be committed:

  (use "git restore --staged <file>..." to unstage)

        modified:   addusers.yml

Untracked files:

  (use "git add <file>..." to include in what will be committed)

        dictionary.yml

Add the second file and check the status ( Both the file are in  "to be commited" state which is staging area )

[osboxes@linuxhost ansible-playbooks]$ git add dictionary.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes to be committed:

  (use "git restore --staged <file>..." to unstage)

        modified:   addusers.yml

        new file:   dictionary.yml

commit the change

[osboxes@linuxhost ansible-playbooks]$ git commit -m "Changes to adduser and added new file dictionar"

[master 34f1071] Changes to adduser and added new file dictionar

 2 files changed, 15 insertions(+), 1 deletion(-)

 create mode 100644 dictionary.yml

[osboxes@linuxhost ansible-playbooks]$

Un stage the added file ( Now I have modified the file and added but I don't want to commit the changes rather I wanted to un stage the file from Staging area. Use git restore --staged <file> command to revert the change )

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes not staged for commit:

  (use "git add <file>..." to update what will be committed)

  (use "git restore <file>..." to discard changes in working directory)

        modified:   addusers.yml

no changes added to commit (use "git add" and/or "git commit -a")

[osboxes@linuxhost ansible-playbooks]$ git add addusers.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes to be committed:

  (use "git restore --staged <file>..." to unstage)

        modified:   addusers.yml

Unstage the changes

[osboxes@linuxhost ansible-playbooks]$ git restore --staged addusers.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes not staged for commit:

  (use "git add <file>..." to update what will be committed)

  (use "git restore <file>..." to discard changes in working directory)

        modified:   addusers.yml

no changes added to commit (use "git add" and/or "git commit -a")

[osboxes@linuxhost ansible-playbooks]$

Use the following command incase if you want to discard the changes in your working directory:

git restore <file>

[osboxes@linuxhost ansible-playbooks]$ git restore addusers.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

nothing to commit, working tree clean

Display the history of commits are part of the current  repository. ( User git log command )

[osboxes@linuxhost ansible-playbooks]$ git log

commit 34f107160fd8ded3fd8a0e8edbd2088faa6570f6 (HEAD -> master)

Author: Pavan Bandaru <pavankumarbandaru@hotmail.com>

Date:   Fri Mar 5 16:51:49 2021 -0500

    Changes to adduser and added new file dictionar

commit ea3b86521585d7406d7d85e5448f9ea94dee3290

Author: Pavan Bandaru <pavankumarbandaru@hotmail.com>

Date:   Fri Mar 5 16:35:04 2021 -0500

    Second commit on addusers

commit 2debee75efcf276445cadbe2937e646c13166e6e

Author: Pavan Bandaru <pavankumarbandaru@hotmail.com>

Date:   Fri Mar 5 16:23:39 2021 -0500

    Second commit - Added all the files

commit 51a789e2399329a799245f90d63327f4a9b4715b

Author: Pavan Bandaru <pavankumarbandaru@hotmail.com>

Date:   Fri Mar 5 16:19:50 2021 -0500

    First commit

[osboxes@linuxhost ansible-playbooks]$ git log --oneline --graph --decorate --color

* 34f1071 (HEAD -> master) Changes to adduser and added new file dictionar

* ea3b865 Second commit on addusers

* 2debee7 Second commit - Added all the files

* 51a789e First commit

Revert already committed changes or remove files from git repository ( File has been deleted when we enter git rm <file> how ever the changes are is still in staging area. So commit the changes you have made )

[osboxes@linuxhost ansible-playbooks]$ git rm dictionary.yml

rm 'dictionary.yml'

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes to be committed:

  (use "git restore --staged <file>..." to unstage)

        deleted:    dictionary.yml

[osboxes@linuxhost ansible-playbooks]$ git commit -m "remove the file dictionary"

[master 1dc84bb] remove the file dictionary

 1 file changed, 14 deletions(-)

 delete mode 100644 dictionary.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

nothing to commit, working tree clean

Another way of removing the files using git add -u

[osboxes@linuxhost ansible-playbooks]$ rm dict.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes not staged for commit:

  (use "git add/rm <file>..." to update what will be committed)

  (use "git restore <file>..." to discard changes in working directory)

        deleted:    dict.yml

no changes added to commit (use "git add" and/or "git commit -a")

osboxes@linuxhost ansible-playbooks]$ git add -u

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes to be committed:

  (use "git restore --staged <file>..." to unstage)

        deleted:    dict.yml

[osboxes@linuxhost ansible-playbooks]$ git commit -m " remove file dict.yml "

[master dbdb1e4]  remove file dict.yml

 1 file changed, 14 deletions(-)

 delete mode 100644 dict.yml

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

nothing to commit, working tree clean

Moving files using git mv command

[osboxes@linuxhost ansible-playbooks]$ git mv addusers.yml new

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes to be committed:

  (use "git restore --staged <file>..." to unstage)

        renamed:    addusers.yml -> new/addusers.yml

[osboxes@linuxhost ansible-playbooks]$ git commit -m " addusers file moved to a different location "

[master 8f5dcd5]  addusers file moved to a different location

 1 file changed, 0 insertions(+), 0 deletions(-)

 rename addusers.yml => new/addusers.yml (100%)

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

nothing to commit, working tree clean

[osboxes@linuxhost ansible-playbooks]$

Ignoring Files

The rules for the patterns you can put in the .gitignore file are as follows:

• Blank lines or lines starting with # are ignored.
• Standard glob patterns work, and will be applied recursively throughout the entire working tree.
• You can start patterns with a forward slash (/) to avoid recursivity.
• You can end patterns with a forward slash (/) to specify a directory.
• You can negate a pattern by starting it with an exclamation point (!).

Glob patterns are like simplified regular expressions that shells use. An asterisk (*) matches zero or more characters; [abc] matches any character inside the brackets (in this case a, b, or c); a question mark (?) matches a single character; and brackets enclosing characters separated by a hyphen ([0-9]) matches any character between them (in this case 0 through 9). You can also use two asterisks to match nested directories; a/**/z would match a/z, a/b/z, a/b/c/z, and so on.

Here is another example .gitignore file:

# ignore all .a files

*.a

# but do track lib.a, even though you're ignoring .a files above

!lib.a

# only ignore the TODO file in the current directory, not subdir/TODO

/TODO

# ignore all files in any directory named build

build/

# ignore doc/notes.txt, but not doc/server/arch.txt

doc/*.txt

# ignore all .pdf files in the doc/ directory and any of its subdirectories

doc/**/*.pdf

Example: I want to ignore files ending with .log

[osboxes@linuxhost ansible-playbooks]$ cat .gitignore

*.log

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Untracked files:

  (use "git add <file>..." to include in what will be committed)

        .gitignore

nothing added to commit but untracked files present (use "git add" to track)

[osboxes@linuxhost ansible-playbooks]$ git add .gitignore

[osboxes@linuxhost ansible-playbooks]$ git commit -m "added gitignore file"

[master 8e582b3] added gitignore file

 1 file changed, 1 insertion(+)

 create mode 100644 .gitignore

Viewing Your Staged and Unstaged Changes using git diff command ( git status will not show you exactly what is changed. git diff --staged command compares your staged changes to your last commit )

[osboxes@linuxhost ansible-playbooks]$ git status

On branch master

Changes to be committed:

  (use "git restore --staged <file>..." to unstage)

        modified:   register-new.yml

[osboxes@linuxhost ansible-playbooks]$ git diff --staged

diff --git a/register-new.yml b/register-new.yml

index 96dea29..8986d05 100644

--- a/register-new.yml

+++ b/register-new.yml

@@ -1,6 +1,6 @@

 ---

-- name: Register loop variable results

+- name: Register loop example^M

   hosts: all

   become: true

   become_user: root

I have remove few lines of code in loop.yml in working directory. use git diff to see the changes in the file that are staged and the changes that are unstaged.

[osboxes@linuxhost ansible-playbooks]$ git diff

diff --git a/loops.yml b/loops.yml

index dba93c1..a628e21 100644

--- a/loops.yml

+++ b/loops.yml

@@ -13,8 +13,3 @@

       debug:

         msg: "{{ item }}"

       loop: "{{ ansible_play_batch }}"

-

-    - name: Show all the hosts in the inventory

-      debug:

-        msg: "{{ item }}"

-      loop: "{{ query('inventory_hostnames', 'all') }}"