test-the-pipeline.md

Test the Pipeline

In this section you will test the Drone CI build pipeline by making modifications to the pipeline application and observing how each change propogates through the staging, qa, and production environments.

Retrieve the Kubernetes cluster pods

Set the list of environments:

ENVIRONMENTS=(
  staging
  qa
  production
)

Verify no pods are currently running in any environment:

for e in ${ENVIRONMENTS[@]}; do
  kubectl get pods --context ${e}
done

Modify the Pipeline Application

In this section you will modify the pipeline application and push the changes to a new branch on your pipeline-application GitHub repository.

Configure git to ensure the hub command line utility uses the HTTPS protocol when working with GitHub repositories:

git config --global hub.protocol https

Configure a git credential helper to use the hub-credential-helper utility when authenticating to GitHub:

git config --global credential.https://github.com.helper /usr/local/bin/hub-credential-helper

Clone the pipeline-application GitHub repository to the current directory:

hub clone ${GITHUB_USERNAME}/pipeline-application

Change into the pipeline-application directory and create a new branch named new-message:

cd pipeline-application

git checkout -b new-message

Modify the message return for HTTP requests to the pipeline application:

sed "s/world/${GITHUB_USERNAME}/g" main.go > main.go.new

mv main.go.new main.go

The syntax for in-place sed updates does not work consistently across operating systems so we are forced to create a temporary file and use it to overwrite the target of our changes.

Review the changes to the pipeline application:

git diff

diff --git a/main.go b/main.go
index 2f76589..0b08a59 100644
--- a/main.go
+++ b/main.go
@@ -21,7 +21,7 @@ func main() {
        log.Println("Starting pipeline application...")

        http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-               fmt.Fprintf(w, "Hello world!\n")
+               fmt.Fprintf(w, "Hello dellintosh!\n")
        })

        http.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {

Commit the changes and push the new-message branch to the pipeline-application GitHub repository:

git add main.go && git commit -m "change message" && git push origin new-message

Review the current builds:

drone build last ${GITHUB_USERNAME}/pipeline-application
for e in ${ENVIRONMENTS[@]}; do
  drone build last ${GITHUB_USERNAME}/pipeline-application-infra-${e}
done

You can also view the build history using the Drone CI Console:

Pushing a new branch to the pipeline-application GitHub repository will trigger the staging-build pipeline, which will in turn trigger the staging-infra build:

The staging-infra build step pushes a commit to the pipeline-application-infra-staging GitHub repository.

List the pods created by the staging-deployment build trigger:

kubectl get pods \
  --context staging

NAME                                   READY     STATUS    RESTARTS   AGE
pipeline-application-389525417-68nxn   1/1       Running   0          1m

Verify the changes:

SERVICE_IP_ADDRESS=$(kubectl get svc pipeline-application \
  --context staging \
  -o jsonpath="{.status.loadBalancer.ingress[0].ip}")

curl http://${SERVICE_IP_ADDRESS}

Tag the pipeline-application Repo

In this section you will merge the new-message and master branches, then create a new tag on the pipeline-application GitHub repository, which will trigger a new pipeline container image to be built and deployed to the QA Kubernetes cluster.

Checkout the master branch:

git checkout master

Merge the new-message and master branches and push the changes to the pipeline-applicaiton GitHub repository:

git merge new-message && git push origin master

Create a new v1.0.0 tag and push it to the pipeline-applicaiton GitHub repository:

git tag v1.0.0 && git push origin --tags

Pushing a new tag to the pipeline-applicaiton GitHub repository will trigger the qa-build build trigger, which will in turn trigger the qa-infra build.

The qa-infra build step pushes a commit to the pipeline-application-infra-qa GitHub repository.

Review the current builds:

Notice a new Docker image was created based on the v1.0.0 tag pushed to the pipeline-application GitHub repository.

List the pods created by the qa-deployment build trigger:

kubectl get pods \
  --context qa

NAME                                   READY     STATUS    RESTARTS   AGE
pipeline-application-685432654-h4zhc   1/1       Running   0          1m

Hit the pipeline application in the QA cluster:

SERVICE_IP_ADDRESS=$(kubectl get svc pipeline-application \
  --context qa \
  -o jsonpath="{.status.loadBalancer.ingress[0].ip}")

curl http://${SERVICE_IP_ADDRESS}

Once the pipeline application is deployed to the QA cluster a pull request is sent to the pipeline-application-infra-production GitHub repository. Review and merge the PR on GitHub:

Merging the pull-request on the pipeline-application-infra-production GitHub repository will trigger the production-deployment build trigger.

List the pods created by the production-deployment build trigger:

kubectl get pods \
  --context production

NAME                                   READY     STATUS    RESTARTS   AGE
pipeline-application-685432654-gndw1   1/1       Running   0          35s

Hit the pipeline application in the production cluster:

SERVICE_IP_ADDRESS=$(kubectl get svc pipeline-application \
  --context production \
  -o jsonpath="{.status.loadBalancer.ingress[0].ip}")

curl http://${SERVICE_IP_ADDRESS}

At this point the pipeline-application:v1.0.0 container image has been propagated across each environment and is now running in the production Kubernetes cluster.