Build Jenkins Container with Terraform and Ansible

I thought it might be interesting to show how to build a Docker container running Jenkins and tools like Terraform and Ansible. I am planning to use a Jenkins pipeline to deploy my OpenShift 3.11 example on AWS using Terraform and Ansible but more about this in the next post.

I am using the source Dockerfile from Jenkins and modified it, and added Ansible and Terraform: Below you see a few variables you might need to change depending on the version you are trying to use or where to place the volume mount. Have a look here for the latest Jenkins version:

Here is my Dockerfile:

ARG JENKINS_HOME=/var/jenkins_home
ARG JENKINS_SHA=a4335cc626c1f64da61a20174af654283d171b255a928bbacb6402a315e213d7

Let’s start and clone my Jenkins Docker repository  and run docker build:

git clone && cd ./jenkins-docker/
docker build -t berndonline/jenkins .

The docker build will take a few minutes, just wait and look out for error you might have with the build:

[email protected]:~/jenkins-docker$ docker build -t berndonline/jenkins .
Sending build context to Docker daemon  141.3kB
Step 1/51 : FROM openjdk:8-jdk
8-jdk: Pulling from library/openjdk
54f7e8ac135a: Pull complete
d6341e30912f: Pull complete
087a57faf949: Pull complete
5d71636fb824: Pull complete
9da6b28682cf: Pull complete
203f1094a1e2: Pull complete
ee38d9f85cf6: Pull complete
7f692fae02b6: Pull complete
eaa976dc543c: Pull complete
Digest: sha256:94bbc3357f995dd37986d8da0f079a9cd4b99969a3c729bad90f92782853dea7
Status: Downloaded newer image for openjdk:8-jdk
 ---> c14ba9d23b3a
Step 2/51 : USER root
 ---> Running in c78f75ca3d5a
Removing intermediate container c78f75ca3d5a
 ---> f2c6bb7538ea
Step 3/51 : RUN apt-get update && apt-get install -y git curl && rm -rf /var/lib/apt/lists/*
 ---> Running in 4cc857e12f50
Ign:1 stretch InRelease
Get:2 stretch/updates InRelease [94.3 kB]
Get:3 stretch-updates InRelease [91.0 kB]
Get:4 stretch Release [118 kB]
Get:5 stretch/updates/main amd64 Packages [459 kB]
Get:6 stretch Release.gpg [2434 B]
Get:7 stretch-updates/main amd64 Packages [5152 B]
Get:8 stretch/main amd64 Packages [7089 kB]
Fetched 7859 kB in 1s (5540 kB/s)
Reading package lists...
Reading package lists...
Building dependency tree...


Step 49/51 : ENTRYPOINT ["/sbin/tini", "--", "/usr/local/bin/"]
 ---> Running in 28da7c4bf90a
Removing intermediate container 28da7c4bf90a
 ---> f380f1a6f06f
Step 50/51 : COPY /usr/local/bin/
 ---> 82871f0df0dc
Step 51/51 : COPY /usr/local/bin/
 ---> feea9853af70
Successfully built feea9853af70
Successfully tagged berndonline/jenkins:latest
[email protected]:~/jenkins-docker$

The Docker container is successfully build:

[email protected]:~/jenkins-docker$ docker images
REPOSITORY                  TAG                 IMAGE ID            CREATED             SIZE
berndonline/jenkins         latest              cd1742c317fa        6 days ago          1.28GB

Let’s start the Docker container:

docker run -d -v /var/jenkins_home:/var/jenkins_home -p 32771:8080 -p 32770:50000 berndonline/jenkins

Quick check that the container is successfully created:

[email protected]:~/jenkins-docker$ docker ps
CONTAINER ID        IMAGE                 COMMAND                  CREATED             STATUS              PORTS                                               NAMES
7073fa9c0cd4        berndonline/jenkins   "/sbin/tini -- /usr/…"   5 days ago          Up 7 seconds>8080/tcp,>50000/tcp   jenkins

Afterwards you can connect to http://<your-ip-address>:32771/ and do the initial Jenkins configuration, like changing admin password and install needed plugins. I recommend putting an Nginx reverse proxy with SSL infront to secure Jenkins properly.

So what about updates or changing the configuration? – Pretty easy; because we are using a Docker bind mount to /var/jenkins_home/, all the Jenkins related data is stored on the local file system of your server and you can re-create or re-build the container at anytime.

I hope you like this article about how to create your down Jenkins Docker container. In my next post I will create a very simple Jenkins pipeline to deploy OpenShift 3.11 on AWS using Terraform.

Please share your feedback and leave a comment.

Getting started with OpenShift Container Platform

In the recent month I have spend a lot of time around networking and automation but I want to shift more towards running modern container platforms like Kubernetes or OpenShift which both are using networking services and as I have shared in one of my previous article about AVI software load balancer, it all fits nicely into networking in my opinion.

But before we start, please have a look at my previous article about Deploying OpenShift Origin Cluster using Ansible to create a small OpenShift platform for testing.

Create a bash completion file for oc commands:

[[email protected] ~]# oc completion bash > /etc/bash_completion.d/oc
[[email protected] ~]# . /etc/bash_completion.d/oc
  • Let’s start and login to OpenShift as a normal user account
[[email protected] ~]# oc login
The server is using a certificate that does not match its hostname: x509: certificate is valid for, not
You can bypass the certificate check, but any data you send to the server could be intercepted by others.
Use insecure connections? (y/n): y

Authentication required for (openshift)
Username: demo
Login successful.

[[email protected] ~]#

Instead of username and password use token which you can get from the web console:

oc login --token=***hash token***
  • Now create the project where we want to run our web application:
[[email protected] ~]# oc new-project webapp
Now using project "webapp" on server "".

You can add applications to this project with the 'new-app' command. For example, try:

    oc new-app centos/ruby-22-centos7~

to build a new example application in Ruby.
[[email protected] ~]#

Afterwards we need to create a build configuration, in my example we use an external Dockerfile without starting the build directly:

[[email protected] ~]#  oc new-build --name webapp-build --binary
warning: Cannot find git. Ensure that it is installed and in your path. Git is required to work with git repositories.
    * A Docker build using binary input will be created
      * The resulting image will be pushed to image stream "webapp-build:latest"
      * A binary build was created, use 'start-build --from-dir' to trigger a new build

--> Creating resources with label build=webapp-build ...
    imagestream "webapp-build" created
    buildconfig "webapp-build" created
--> Success
[[email protected] ~]#

Create Dockerfile:

[[email protected] ~]# vi Dockerfile

Copy and paste the line below into the Dockerfile:

FROM openshift/hello-openshift

Let’s continue and start the build from the Dockerfile we specified previously

[[email protected] ~]#  oc start-build webapp-build --from-file=Dockerfile --follow
Uploading file "Dockerfile" as binary input for the build ...
build "webapp-build-1" started
Receiving source from STDIN as file Dockerfile
Pulling image openshift/hello-openshift ...
Step 1/3 : FROM openshift/hello-openshift
 ---> 7af3297a3fb4
Step 2/3 : ENV "OPENSHIFT_BUILD_NAME" "webapp-build-1" "OPENSHIFT_BUILD_NAMESPACE" "webapp"
 ---> Running in 422f63f69364
 ---> 2cd93085ec93
Removing intermediate container 422f63f69364
Step 3/3 : LABEL "" "webapp-build-1" "" "webapp"
 ---> Running in 0c3e6cce6f0b
 ---> cf178dda8238
Removing intermediate container 0c3e6cce6f0b
Successfully built cf178dda8238
Pushing image docker-registry.default.svc:5000/webapp/webapp-build:latest ...
Push successful
[[email protected] ~]#

Alternatively you can directly inject the Dockerfile options in a single command and the build would start immediately:

[[email protected] ~]#  oc new-build --name webapp-build -D $'FROM openshift/hello-openshift'
  • Create the web application
[[email protected] ~]# oc new-app webapp-build
warning: Cannot find git. Ensure that it is installed and in your path. Git is required to work with git repositories.
--> Found image cf178dd (4 minutes old) in image stream "webapp/webapp-build" under tag "latest" for "webapp-build"

    * This image will be deployed in deployment config "webapp-build"
    * Ports 8080/tcp, 8888/tcp will be load balanced by service "webapp-build"
      * Other containers can access this service through the hostname "webapp-build"

--> Creating resources ...
    deploymentconfig "webapp-build" created
    service "webapp-build" created
--> Success
    Application is not exposed. You can expose services to the outside world by executing one or more of the commands below:
     'oc expose svc/webapp-build'
    Run 'oc status' to view your app.
[[email protected] ~]#

As you see below, we are currently running a single pod:

[[email protected] ~]#  oc get pod -o wide
NAME                   READY     STATUS      RESTARTS   AGE       IP            NODE
webapp-build-1-build   0/1       Completed   0          8m   origin-node-1
webapp-build-1-znk98   1/1       Running     0          3m   origin-node-1
[[email protected] ~]#

Let’s check out endpoints and services:

[[email protected] ~]# oc get ep
NAME           ENDPOINTS                           AGE
webapp-build,   1m
[[email protected] ~]# oc get svc
NAME           CLUSTER-IP     EXTERNAL-IP   PORT(S)             AGE
webapp-build           8080/TCP,8888/TCP   1m
[[email protected] ~]#

Running a single pod is not great for redundancy, let’s scale out:

[[email protected] ~]# oc scale --replicas=5 dc/webapp-build
deploymentconfig "webapp-build" scaled
[[email protected] ~]#  oc get pod -o wide
NAME                   READY     STATUS      RESTARTS   AGE       IP            NODE
webapp-build-1-4fb98   1/1       Running     0          15s   origin-node-2
webapp-build-1-build   0/1       Completed   0          9m   origin-node-1
webapp-build-1-dw6ww   1/1       Running     0          15s   origin-node-1
webapp-build-1-lswhg   1/1       Running     0          15s   origin-node-1
webapp-build-1-z4nk9   1/1       Running     0          15s   origin-node-2
webapp-build-1-znk98   1/1       Running     0          4m   origin-node-1
[[email protected] ~]#

We can check our endpoints and services again, and see that we have more endpoints and still one service:

[[email protected] ~]# oc get ep
NAME           ENDPOINTS                                                        AGE
webapp-build,, + 7 more...   4m
[[email protected] ~]# oc get svc
NAME           CLUSTER-IP     EXTERNAL-IP   PORT(S)             AGE
webapp-build           8080/TCP,8888/TCP   4m
[[email protected] ~]#

OpenShift uses an internal DNS service called SkyDNS to expose services for internal communication:

[[email protected] ~]# dig webapp-build.webapp.svc.cluster.local

; <<>> DiG 9.9.4-RedHat-9.9.4-61.el7 <<>> webapp-build.webapp.svc.cluster.local
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20933
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;webapp-build.webapp.svc.cluster.local. IN A

webapp-build.webapp.svc.cluster.local. 30 IN A

;; Query time: 1 msec
;; WHEN: Sat Jun 30 08:58:19 UTC 2018
;; MSG SIZE  rcvd: 71

[[email protected] ~]#
  • Let’s expose our web application so that it is accessible from the outside world:
[[email protected] ~]# oc expose svc webapp-build
route "webapp-build" exposed
[[email protected] ~]#

Connect with a browser to the URL you see under routes:

Modify the WebApp and inject variables via a config map into our application:

[[email protected] ~]# oc create configmap webapp-map --from-literal=RESPONSE="My first OpenShift WebApp"
configmap "webapp-map" created
[[email protected] ~]#

Afterwards we need to add the previously created config map to our environment

[[email protected] ~]# oc env dc/webapp-build --from=configmap/webapp-map
deploymentconfig "webapp-build" updated
[[email protected] ~]#

Now when we check our web application again you see that the new variables are injected into the pod and displayed:

I will share more about running OpenShift Container Platform and my experience in the coming month. I hope you find this article useful and please share your feedback and leave a comment.