In this lab we will learn how an application image binary can be promoted across the environments. As an example we will use development and QA environments as promotion to pre-prod and production will be very similar.
In this example we are using projects as means of separation of environments (development, qa, production).
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Create two projects (Development and Testing)
Using the knowledge you gained from the past create two projects. Name the first project development-UserName
$ oc new-project development-UserName
Name the second testing-UserName.
$ oc new-project testing-UserName
Remember to substitute the username!
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Provide ImagePuller Access to the QA Project from Development Project
The following command will allow the QA project to be able to pull the container images from the Development project.
$ oc policy add-role-to-group system:image-puller system:serviceaccounts:testing-UserName -n development-UserName
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Create an application in the development project
Switch over to the development-UserName project and deploy an application using the php s2i builder. You can use web console or
command line. The command line option is shown below.
Bonus points: Clone this application to your own github account and deploy it so that you can redeploy with changes later.
oc project development-UserName oc new-app openshift/php~https://github.com/RedHatWorkshops/welcome-php
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Tag the Container Image
Wait until the application gets built and deployed. Now if you check the imagestreams you will find the container image for this application.
Note You can find the imagestream name using the following command. is is the
short form for imageStream.
$ oc get is NAME IMAGE REPOSITORY TAGS UPDA TED welcome-php image-registry.openshift-image-registry.svc:5000/development-user1/welcome-php latest 12 s econds ago
Now describe this imagestream. It will show you full image id and the current tags assigned to that image. You’ll notice that only latest is assigned right now.
$ oc get is
NAME IMAGE REPOSITORY TAGS UPDA
TED
welcome-php image-registry.openshift-image-registry.svc:5000/development-user1/welcome-php latest Abou
t a minute ago
###
## Describe image stream
###
[user2@cli-2-b2pms ~]$ oc describe is welcome-php
Name: welcome-php
Namespace: development-user1
Created: 2 minutes ago
Labels: app=welcome-php
app.kubernetes.io/component=welcome-php
app.kubernetes.io/instance=welcome-php
Annotations: openshift.io/generated-by=OpenShiftNewApp
Image Repository: image-registry.openshift-image-registry.svc:5000/development-user1/welcome-php
Image Lookup: local=false
Unique Images: 1
Tags: 1
latest
no spec tag
* image-registry.openshift-image-registry.svc:5000/development-UserName/welcome-php@sha256:ba7dd4e757e2b20851
e7becc5fd2c2b38e1ee15165f2777fdc1c46ebd43c80a4
In general, when you are in development, you may be building your application multiple times,and test it. When a particular image passes your tests it will be promoted to QA.
Now let us assume that this container image is good and is ready to promote to QA. Let us tag this image using the oc tag command. We will pick up the latest image built and tested and add a tag to it as promote-qa as shown below:
Remember to substitute your UserName.
oc tag development-UserName/welcome-php:latest development-UserName/welcome-php:promote-qa Tag welcome-php:promote-qa set to development-user1/welcome-php@sha256:ba7dd4e757e2b20851e7becc5fd2c2b38e1ee 15165f2777fdc1c46ebd43c80a4.
Check the following commands and replace the values of UserName where needed:
$ oc tag image-registry.openshift-image-registry.svc:5000/development-UserName/welcome-php @sha256:99fd4920719fc8e7e9d4ff1c4e9a87b22ca802fdce006901a0cdd19fb9f2e14c development-UserName/welcome-php:promote-qa Tag welcome-php:promote-qa set to image-registry.openshift-image-registry.svc:5000/development-UserName/welcome -php@sha256:99fd4920719fc8e7e9d4ff1c4e9a87b22ca802fdce006901a0cdd19fb9f2e14c
Now describe the imagestream again to notice that a new tag promote-qa is applied now.
$ oc describe is welcome-php
Name: welcome-php
Namespace: development-user1
Created: 19 minutes ago
Labels: app=welcome-php
app.kubernetes.io/component=welcome-php
app.kubernetes.io/instance=welcome-php
Annotations: openshift.io/generated-by=OpenShiftNewApp
Image Repository: image-registry.openshift-image-registry.svc:5000/development-user1/welcome-php
Image Lookup: local=false
Unique Images: 1
Tags: 2
latest
no spec tag
* image-registry.openshift-image-registry.svc:5000/development-user1/welcome-php@sha256:ba7dd4e757e2b20851
e7becc5fd2c2b38e1ee15165f2777fdc1c46ebd43c80a4
18 minutes ago
promote-qa
tagged from welcome-php@sha256:ba7dd4e757e2b20851e7becc5fd2c2b38e1ee15165f2777fdc1c46ebd43c80a4
* image-registry.openshift-image-registry.svc:5000/development-user1/welcome-php@sha256:ba7dd4e757e2b20851
e7becc5fd2c2b38e1ee15165f2777fdc1c46ebd43c80a4
About a minute ago
Step 5: Deploy the application to QA
Now you can switch over to the QA project and deploy the container image that we tagged as promote-qa. Note that the image is still in the development project. You are able to deploy that into testing project, because we gave necessary permissions for the testing project to be able to pull an image from development project.
Also expose service to create route for this project and remember to substitute username.
oc project testing-UserName oc new-app development-UserName/welcome-php:promote-qa oc expose service welcome-php
Test this application in the QA project. Note that we deployed the container image (development-UserName/welcome-php:promote-qa) from the development project without rebuilding the code.
Bonus points: Make changes to your git repo (to index.php) and deploy it to development first. Notice that your changes are seen only in development project. Repeat the changes a couple of times. Now find the latest imagestream and tag it as promote-qa. Watch out that the QA project gets redeployed when you
update the new tag.
Watch this video for complete understanding.