feat(argo-cd): Add support for application controller dynamic cluster distribution. (#2539)

* Add support for application controller dynamic cluster distribution.

Signed-off-by: Oscar Wieman <oscar@oscarr.nl>

* Added env variables to handle the non-standard names generated by the helm chart.
https://argo-cd.readthedocs.io/en/release-2.9/user-guide/environment-variables/
99723143b9/common/common.go (L252)

Signed-off-by: Oscar Wieman <oscar@oscarr.nl>

---------

Signed-off-by: Oscar Wieman <oscar@oscarr.nl>

charts/argo-cd/values.yaml

@@ -577,8 +577,22 @@ controller:
 
   # -- The number of application controller pods to run.
   # Additional replicas will cause sharding of managed clusters across number of replicas.
+  ## With dynamic cluster distribution turned on, sharding of the clusters will gracefully
+  ## rebalance if the number of replica's changes or one becomes unhealthy. (alpha)
   replicas: 1
 
+  # -- Enable dynamic cluster distribution (alpha)
+  # Ref: https://argo-cd.readthedocs.io/en/stable/operator-manual/dynamic-cluster-distribution
+  ## This is done using a deployment instead of a statefulSet
+  ## When replicas are added or removed, the sharding algorithm is re-run to ensure that the
+  ## clusters are distributed according to the algorithm. If the algorithm is well-balanced,
+  ## like round-robin, then the shards will be well-balanced.
+  dynamicClusterDistribution: false
+
+  # -- Application controller heartbeat time
+  # Ref: https://argo-cd.readthedocs.io/en/stable/operator-manual/dynamic-cluster-distribution/#working-of-dynamic-distribution
+  heartbeatTime: 10
+
   # -- Maximum number of controller revisions that will be maintained in StatefulSet history
   revisionHistoryLimit: 5
 
@@ -662,6 +676,9 @@ controller:
   # -- Annotations for the application controller StatefulSet
   statefulsetAnnotations: {}
 
+  # -- Annotations for the application controller Deployment
+  deploymentAnnotations: {}
+
   # -- Annotations to be added to application controller pods
   podAnnotations: {}