[#135] Allow specifying the mount path for ConfigMaps

[yersan]

This PR will allow the configuration of ConfigMpas by defining a MountPath in addition to the Name

The MountPath could be a relative or an absolute path. If it is a relative path, then it is treated as relative to JBOSS_HOME. The MountPath is optional, and if it is not specified then it defaults to /etc/configmaps/

This fixes #135

[jmesnil]

The new feature itself looks good, thanks!

I've requested change to keep the code consistent but I'm fine with the new code.

[jmesnil]

could you please move the comment about the mount path from ConfigMapSpec to here so that is is correctly picked when the openapi and k8s resources are generated?

[yersan]

Do you mean this one? https://github.com/wildfly/wildfly-operator/pull/136/files#diff-553a69f3eee8fa0585c8bfe19a47a871R43-R45

[pkremens]

@yersan @jmesnil @mchoma @jbliznak I don't think we can do it that way. This is a way we use to setup the configMaps field in EAP Operator (registry-proxy.engineering.redhat.com/rh-osbs/jboss-eap-7-eap73-rhel8-operator:1.0-8)

  configMaps:
  - config-map-name

After the change, the same setup would be

    configMaps:
    - name: config-map-name

Trying to use the old style config with this version of operator gives me

# * spec.configMaps: Invalid value: "string": spec.configMaps in body must be of type object: "string"

thus we're breaking the backward compatibility with this one.

[jmesnil]

That's correct, this feature would break backwards compatibility.
Note that the CRD apiVersion is wildfly.org/v1alpha1. We have clearly identified that our API is in an alpha state and might be changed without backwards compatibility.

We should strive to preserve backwards compatibility when introducing a new feature but in that specific case, I prefer we provide a clean representation of a config map (with a name and an optional location) rather than preserve the backwards compatibility with a clunky api.
When we discussed this feature with @yersan we could not find a correct representation for that feature that would preserve backwards compatibility so I ok-ed to break it.

[jmesnil]

let's close this PR as we will need first to have a conversion web hook to introduce this change without breaking compatibility