MultiSource

Topic Objectives

In this topic we will discuss:

  • What does multisource mean?

  • MultiSource status

  • User Experience

  • Next Steps

Using multiple-sources in our ArgoCD applications gives the Patterns framework a lot of flexibility in how applications are deployed. In the code snippet below we can see that we have a chart called acm where we have our normal values getting assigned, but also using values from another repository - in this case https://github.com/f00/multicloud-gitops

# MULTISOURCE
sources:
- ref: patternref
  repoURL: https://github.com/foo/multicloud-gitops
  targetRevision: test2
- chart: acm
  repoURL: https://charts.validatedpatterns.io/ # default
  targetRevision: 0.1.*
  helm:
	ignoreMissingValueFiles: true
	valueFiles:
	- $patternref/values-global.yaml
	- $patternref/values-hub.yaml
	- $patternref/values-AWS.yaml
	- $patternref/values-AWS-4.13.yaml
	- $patternref/values-AWS-hub.yaml
	- $patternref/values-4.13-hub.yaml
	parameters:
	...

With a single source we can only apply values files from within the repository, or declare them within the applications key. The primary issue with this approach is readability and reusability. The values file grows to a point where it is hard to follow the changes being made.

# SINGLE SOURCE
source:
  repoURL: https://github.com/foo/multicloud-gitops
  path: common/acm
  targetRevision: test2
  helm:
	valueFiles:
  	- /values-global.yaml
  	- /values-hub.yaml
  	- /values-AWS.yaml
  	- /values-AWS-4.13.yaml
  	- /values-AWS-hub.yaml
  	- /values-4.13-hub.yaml
	parameters:
	...

How it works

Multi-source needs to be enabled for the clusterGroup helm chart via: main.multiSourceConfig.enabled

Other applications stay as-is (e.g. single source like they have always been)

Switching an application to use the Patterns chart and multisource capability requires a small tweak in the values-*.yaml

Yes, you can change the default VP repository

Here’s what it would look like:

Original Configuration:

acm:
  name: acm
  path: common/acm

Updated Configuration:

acm:
  name: acm
  chart: acm
  chartVersion: 0.0.*
  # Tweak the default below to point to an alternative chart repo (OCI registries are
  # also supported)
  # repoURL: https://charts.validatedpatterns.io

Status

User Experience

multisource config

Helm Chart Repository

Example 1. How does it work?

  • common/ now has a github workflow which is triggered at every commit to main chart-branches.yaml

  • If any commit changes one of the charts (except operator-install) the corresponding branch in common for that chart will be updated (git subtree split)

  • This makes it so that the hashicorp-vault-main-single-chart branch only contains the code for the hashicorp-vault chart

  • Then it takes that hashicorp-vault-main-single-chart branch and pushes it out to the validatedpatterns/hashicorp-vault git repository

TL;DR

validatedpatterns/{acm,clustergroup,hashicorp-vault…​} repos are automatically kept up to date every time we push to common

Creating a chart release

  1. Change the version in common/(chart}/Chart.yaml (e.g. acm ver 0.0.2)

  2. Make sure the version propagated correctly in the vp/acm-chart repository

  3. From within the acm-chart repository, tag and push the new version v0.0.2

  4. In validatedpatterns/helm-charts, a github workflow is triggered that will:

    • build the helm chart

    • upload it in the assets of the helm-charts repository

    • update index.yaml

Next Steps

  • Continue to monitor for any issues in Argo

  • Expand the usage in other patterns

  • Create a simple way to test charts without pushing them to the main repo (dev/qa workflow)