Upgrading Concourse with Helm

Introduction

Helm is the package manager for Kubernetes, a tool that streamlines installing and managing Kubernetes applications. It creates Kubernetes objects that can be submitted to Kubernetes clusters, and materialized into a Concourse deployment using Kubernetes constructs (Deployments, StatefulSets, PersistentVolumeClaims, etc).

A Helm Chart is a versioned package of pre-configured Kubernetes resources. Deploying Concourse via Helm Chart makes it easy to deploy, scale, maintain, or upgrade your deployment in the future. This guide aims to walk an operator through the step by step process of deploying with Helm.

Once you've deployed Concourse to a Kubernetes cluster, you can use the following process to keep it up to date as new releases arrive on the Broadcom Support portal.

Backup

In the case of a Helm-deployed Concourse pointed to a Postgres database that has been deployed and managed with BOSH, you can use BBR to perform a backup.

Otherwise, use the pg_dump utility to backup your Postgres database. For more information on the tool, click here to view a guide on postgresql.org.

Next, download, tag, and push images to the internal registry.

Download Concourse Helm Chart and load images into Docker

If you have not already done so, visit the Broadcom Support portal and download the Concourse Helm Chart.
Unarchive the Helm Chart tarball to a local directory. For example, with version v7.9.1, the tarball will be called concourse-7.9.1.tgz.
```
mkdir concourse-helm
```
```
tar xvzf ./concourse-7.9.1.tgz -C ./concourse-helm
```
```
cd ./concourse-helm
```
Load the container images into a local Docker client by running the following docker load commands one at a time:
```
docker load -i ./images/concourse.tar
docker load -i ./images/postgres.tar
```
If you are using Helm v2 (i.e. Concourse versions < v6.7.x) you'll also need to load the helm image:
```
docker load -i ./images/helm.tar
```
These images are quite large, and there will be no output until Docker is done loading.

Success: After the loading finishes, you'll see:
```
Loaded image: IMAGE-NAME
```

Tag and push the loaded images to internal registry

This step assumes that the current docker client has already authenticated against the internal registry through a regular docker login.

In addition to logging in, if you're using a registry with self-signed certificates, you should also make sure your registry has been added to the Insecure Registries section of the Daemon tab in the Docker settings ui for your current workstation.

For more information about certificates and secure registry concerns, see this article: Test an insecure registry.

Begin by exporting a pair of variables to your shell to be reused throughout this process. In your terminal, run the following commands.
- If using Harbor (internal registry):
```
export INTERNAL_REGISTRY=INTERNAL-REGISTRY
export PROJECT=PROJECT-NAME
```
  Where:
  - INTERNAL-REGISTRY is the domain of your internal registry - if you are using Harbor, this must correspond to the URL (without scheme)
  - PROJECT-NAME is the name of the project in your registry. If the project does not exist already you will need to make it.
- If using Docker Hub:
```
export USERNAME=DOCKERHUB-USERNAME
```
  Where:
  - DOCKERHUB-USERNAME is your username on hub.docker.io
The .tar file you downloaded contains a directory called images. You need to extract the tag of each image so that you can appropriately tag the images with the internal registry and project name details from the last step.

To do this, run the following commands:
```
export CONCOURSE_IMAGE_TAG=$(cat ./images/concourse.tar.name | cut -d ':' -f 2)
export POSTGRES_IMAGE_TAG=$(cat ./images/postgres.tar.name | cut -d ':' -f 2)
```
If you are using Helm v2 (i.e. Concourse versions < v6.7.x) you'll also need to tag the helm image:
```
export HELM_IMAGE_TAG=$(cat ./images/helm.tar.name | cut -d ':' -f 2)
```

Tag the images so their names include the internal registry address.

If using Harbor (internal registry):

docker tag concourse/concourse:$CONCOURSE_IMAGE_TAG $INTERNAL_REGISTRY/$PROJECT/concourse:$CONCOURSE_IMAGE_TAG
docker tag dev.registry.pivotal.io/concourse/postgres:$POSTGRES_IMAGE_TAG $INTERNAL_REGISTRY/$PROJECT/postgres:$POSTGRES_IMAGE_TAG

If using Docker Hub:

docker tag concourse/concourse:$CONCOURSE_IMAGE_TAG $USERNAME/concourse:$CONCOURSE_IMAGE_TAG
docker tag dev.registry.pivotal.io/concourse/postgres:$POSTGRES_IMAGE_TAG $USERNAME/postgres:$POSTGRES_IMAGE_TAG

If you are using Helm v2 (i.e. Concourse versions < v6.7.x) you'll also need to tag the helm image.

If using Harbor (internal registry):

docker tag dev.registry.pivotal.io/concourse/helm:$HELM_IMAGE_TAG $INTERNAL_REGISTRY/$PROJECT/helm:$HELM_IMAGE_TAG

If using Docker Hub:

docker tag dev.registry.pivotal.io/concourse/helm:$HELM_IMAGE_TAG $USERNAME/helm:$HELM_IMAGE_TAG

Push the images to the internal registry by running the following commands in your terminal.
- If using Harbor (internal registry):
```
docker push $INTERNAL_REGISTRY/$PROJECT/concourse:$CONCOURSE_IMAGE_TAG
docker push $INTERNAL_REGISTRY/$PROJECT/postgres:$POSTGRES_IMAGE_TAG
```
- If using Docker Hub:
```
docker push $USERNAME/concourse:$CONCOURSE_IMAGE_TAG
docker push $USERNAME/postgres:$POSTGRES_IMAGE_TAG
```
If you are using Helm v2 (i.e. Concourse versions < v6.7.x) you'll also need to tag the helm image.
- If using Harbor (internal registry):
```
docker push $INTERNAL_REGISTRY/$PROJECT/helm:$HELM_IMAGE_TAG
```
- If using Docker Hub:
```
docker push $USERNAME/helm:$HELM_IMAGE_TAG
```
Important You must have the necessary credentials (and authorization) to push to the targeted project.

Get previous deployment values

Helm uses a set of configuration values to template the different Kubernetes objects that Concourse requires into a release. To ensure you maintain the exact same configuration between the current version of Concourse and the upgraded version you are about to deploy, it is important to know what configuration is already deployed.

Note VMware recommends checking in these configuration values to a source control management (SCM) system like git so that you can track changes over time. If you have your configuration values in to an SCM system, check them out to your local machine so that they can be updated now.

If you're unsure of what has been deployed, and don't have access to the values files locally, you can fetch the deployment values that your existing release is using by running the helm get values command. This will allow you to recreate the exact configuration with your upgraded release.

Get your previous deployment-values.yml file from SCM, or download it using this command:
```
helm get values RELEASE-NAME > deployment-values.yml
```
Where:
- RELEASE-NAME is the name of your existing Concourse release. Discover this by running the helm list command and looking for a chart that starts with concourse.
Open the file in your favorite text editor. For example, with vim:
```
vim deployment-values.yml
```
Change the imageTag value to match the new version of Concourse. For example, using the v6.3.1 Helm Chart, this image tag will be 6.3.1-ubuntu.

The following is a sample snippet; make sure the rest of the file you edit reflects your existing Concourse deployment:
```
---
image: INTERNAL-REGISTRY/PROJECT/concourse
imageTag: CONCOURSE-IMAGE-TAG
imagePullSecrets: ["regcred"] #remove this line for public image registry
postgresql:
    image:
        registry: INTERNAL-REGISTRY
        repository: PROJECT/postgres
        tag: POSTGRES-IMAGE-TAG
        pullSecrets: ["regcred"] # remove for public image registry
```
Where:
- INTERNAL-REGISTRY/PROJECT is your registry address and project.
- CONCOURSE-IMAGE-TAG is the output of
```
cat ./images/concourse.tar.name | cut -d ':' -f 2
```
  For example, 6.3.1-ubuntu.
- imagePullSecrets is the pull secret listed under the key spec.template.spec in the following file:
```
helm init --tiller-image $INTERNAL_REGISTRY/$PROJECT/helm:IMAGE-TAG --service-account tiller --dry-run --debug > tiller.yml
```
  Remove if using a public repository.
- POSTGRES-IMAGE-TAG is the output of
```
cat ./images/postgres.tar.name | cut -d ':' -f 2
```
- pullSecrets is the pull secret created in step 6a. Remove if using a public repository.

Upgrade

Now that the deployment values are updated, use the helm upgrade command to upgrade your existing release using the new values.

Upgrade your release:

helm upgrade RELEASE-NAME ./charts/ --values ./deployment-values.yml

Where:

RELEASE-NAME is the name of your existing Concourse release. Discover this by running the helm list command and looking for a chart that starts with concourse.

Test for successful deployment

If Kubernetes has accepted the manifest correctly, then you will see the following response followed by more information about your cluster:

NAME: DEPLOYMENT-NAME
LAST DEPLOYED: DEPLOYMENT-DATE
NAMESPACE: default
STATUS: DEPLOYED
...

To determine whether your pods are up and running correctly, use the following command:

kubectl get pods

This will show you a list of deployed pods as well as their current status. It should look something like this:

$ kubectl get pods
NAME                             READY   STATUS    RESTARTS   AGE
concourse-postgresql-0           1/1     Running   0          15m
concourse-web-57ccf57f46-zsd25   1/1     Running   0          9m52s
concourse-worker-0               1/1     Running   0          8m45s
concourse-worker-1               1/1     Running   0          9m45s