query: Add support for ArgoCD: Define replace action in servicemonitor

[francescsanjuanmrf]

The relabelings block of the serviceMonitor configuration for the query component does not include the action field.

The default value for action is replace.

• https://github.com/prometheus-operator/prometheus-operator/blob/e2ce57ad6c383a886a7d5fb518a677e1dd6a6115/example/prometheus-operator-crd/monitoring.coreos.com_servicemonitors.yaml#L179-L189
• https://github.com/prometheus-operator/prometheus-operator/blob/e2ce57ad6c383a886a7d5fb518a677e1dd6a6115/example/prometheus-operator-crd/monitoring.coreos.com_servicemonitors.yaml#L360-L373

Having this field undefined makes ArgoCD always unsynced.

The definitions in this repo code lack the action field, but when the object is created in Kubernetes, the field is written in the Kubernetes object with the default value (replace). Then, ArgoCD compares with the code in the repo and tries to sync again (removing the action field). This causes an infinite loop of adding and removing the action field.

Setting the action field to the default value (replace) in the code solves this problem and does not change the behavior of serviceMonitor.

• [x] I added CHANGELOG entry for this change.
• [X] Change is not relevant to the end user.

Changes

• query: Added default action 'replace' to serviceMonitor

Verification

I've tested it by modifying the chart and testing locally.

[francescsanjuanmrf]

Added modified YAMLs

[francescsanjuanmrf]

I've just modified all the ServiceMonitors, but I haven't all of them deployed, and I haven't tested them. Initially, I only added the action field in one because I've just tested one.

[francescsanjuanmrf]

Sure! I've just added the missing template.

Thanks for your help!