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