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Validate Auto Reload of your Application#

Managing application deployments and keeping configurations up-to-date can be challenging. Changes to secrets or configmaps for instance, often require manual intervention to update the application and trigger a redeployment. This can lead to operational inefficiencies and potential downtime.

To address this challenge, Stakater has Reloader—a powerful tool that automates the process of reloading deployments when related resources, such as secrets or configmaps, change. In this tutorial, we will explore how to set up Reloader in your SAAP and configure it to automatically trigger the reload of a deployment whenever a secret changes.

Objectives#

  • Enable Reloader to monitor changes in the secret and reload the deployment.
  • Verify the changes in the secret triggers an automatic reload of the deployment.

Key Results#

  • Test the automatic deployment reloading by updating the secret and observing the changes.

Tutorial#

Let's take a look at the secret before any change.

The secret we created for our deployment earlier, notice the details and the value of mongodb-password which is 123456789.

secret details before change

  1. Add this YAML to your deploy/values.yaml file.

    ## Enable reloader on changes
reloadOnChange: true

    It should look like this:

    Reloader values

    Note

    The indentation should be application.deployment.reloadOnChange: true.

  2. Save and run tilt up at the root of your directory. Hit the space bar and the browser with TILT logs will be shown. If everything is green then the changes will be deployed on the cluster.

  3. Now go to the Deployments, and see if it has updated with the Reloader annotation:

    deployment reload annotation

    Let's change one of the values of review-mongodb-creds secret.

  4. Log in to Vault and got to your-tenant/kv, click on the secret review-mongodb-creds, then click on create new version.

    Vault secret new version

  5. You can now edit the values of your secret which will be considered a new version of your external secret. Edit mongodb-password and set the value to 123456780. Hit Save.

    edit-secret

  6. Let's go to SAAP to see if the new version of the external secret has been deployed. Go to review-mongodb-creds, and scroll down to see Data. On the right corner you will see Reveal values, hit on it and see the value for mongodb-password.

    updated secret

  7. Now let's go to Pods and see if the pod of our review application has reloaded. You will see the new pod review is deploying and once it's in a Running state and Ready 1/1, the older pod will be terminated.

    deployment pod restarted older pod terminated.

To see more information related to Stakater's Reloader project, click here.

And voila! now you don't have to redeploy your application manually for each change, Reloader to the Rescue!

Let's move on to the next tutorial to know how to set up alerts for any downtime.