ApplicationSet templatePatch list merge with template #16800
Description
Checklist:
- I've searched in the docs and FAQ for my answer: https://bit.ly/argocd-faq.
- I've included steps to reproduce the bug.
- I've pasted the output of
argocd version.
Describe the bug
The new ApplicationSet templatePatch introduced in #14893 does not merge lists from template. It will override a list field entirely. An example is when using sources to list multiple sources. Consider the following example which produces the error
InvalidSpecError: spec.source.repoURL and either source.path, source.chart, or source.ref are required for source...
To Reproduce
apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
name: guestbook
namespace: argocd
spec:
goTemplate: true
generators:
- list:
elements:
- cluster: ops-dev
kustomizeComponents:
- components/pod-disruption-budget
templatePatch: |
spec:
sources:
- repoURL: https://github.com/LS80/kustomize-examples.git
kustomize:
components:
{{- range .kustomizeComponents }}
- {{ . }}
{{- end }}
template:
metadata:
name: 'guestbook-{{.cluster}}'
namespace: argocd
spec:
sources:
- repoURL: https://github.com/argoproj/argocd-example-apps.git
path: helm-guestbook
helm:
valuesObject:
nameOverride: guestbook
replicaCount: 2
- repoURL: https://github.com/LS80/kustomize-examples.git
path: guestbook
kustomize:
commonLabels:
app: guestbook
project: default
destination:
name: '{{.cluster}}'
namespace: defaultPutting all sources in templatePatch does work, but is not ideal as it could be a very large string that doesn't work as nicely in IDEs as an object would. Here is the equivalent example that works:
apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
name: guestbook
namespace: argocd
spec:
goTemplate: true
generators:
- list:
elements:
- cluster: ops-dev
kustomizeComponents:
- components/pod-disruption-budget
templatePatch: |
spec:
sources:
- repoURL: https://github.com/argoproj/argocd-example-apps.git
path: helm-guestbook
helm:
valuesObject:
nameOverride: guestbook
replicaCount: 2
- repoURL: https://github.com/LS80/kustomize-examples.git
path: guestbook
kustomize:
components:
{{- range .kustomizeComponents }}
- {{ . }}
{{- end }}
commonLabels:
app: guestbook
template:
metadata:
name: 'guestbook-{{.cluster}}'
namespace: argocd
spec:
project: default
destination:
name: '{{.cluster}}'
namespace: defaultExpected behavior
The sources in the templatePatch will be deep merged with the sources in template, using repoURL or perhaps ref as a merge key.
That might not be feasible because while repoURL is required, it is not necessarily unique. ref is unique but not required. Perhaps ref could be required in the case where a source merge is desired.
This behaviour would be similar to how a Kustomize strategic merge patch patches Container fields within a Pod spec, using the Container name as a unique merge key.
If not then at least additional sources in templatePatch could be appended to the existing list of sources in template?
Version
argocd: v2.9.3+6eba5be.dirty
BuildDate: 2023-12-02T00:37:14Z
GitCommit: 6eba5be864b7e031871ed7698f5233336dfe75c7
GitTreeState: dirty
GoVersion: go1.21.4
Compiler: gc
Platform: darwin/arm64
argocd-server: v2.10.0-rc1+d919606
BuildDate: 2023-12-18T20:45:12Z
GitCommit: d9196060c2d8ea3eadafe278900e776760c5fcc6
GitTreeState: clean
GoVersion: go1.21.3
Compiler: gc
Platform: linux/arm64
Kustomize Version: v5.2.1 2023-10-19T20:13:51Z
Helm Version: v3.13.2+g2a2fb3b
Kubectl Version: v0.26.11
Jsonnet Version: v0.20.0