Attribute enableServiceLinks can be now configured in PodSpec so that environment variables are not injected in function pods and DNS is used for discovery
The pod template is embedded inside the deployment. So if
the pod annotation contains instance-id, the deployment
will get updated and thus triggers a rolling update whenever
a new executor starts which is unwanted.
After this PR, poolmanager will patches instance-id when a
pod is chosen for a function.
For newdeploy, unlike poolmanager manages the lifecycle
of function pod directly, newdeploy is only responsible
to create the deployment so we append instance-id to top-
level controller (deployment) only.
The merge function executor used wasn't merge container correctly, and it
didn't merge all fields in spec except volumeMount & Env which confused people.
To apply the user-configured container correctly, this PR changes the way of merge
and follows rules:
1. Slices are merged and return an error if the elements in the slice have name conflicts.
2. Maps are merged, the value of map of dst container are overridden if the key is the same.
3. The rest of the fields of dst container are overridden directly.
