Support v2.2 Devfiles

[l0rd]

Is your enhancement related to a problem? Please describe

The OpenShift Developer Console will include some new examples that have Devfiles withouth placeholder outerloop component. But those Devfiles will use v2.2 of the spec.

Trying to start a workspace from this repo https://github.com/devfile-samples/devfile-sample-java-springboot-basic, on che next with devworkspace enabled, I faced the following problems:

1. Components of type image is considered invalid
2. Command build-image references the component of type image that is not supported
3. Commands of type composite are not supported
4. mvn commands fail because the default workingDir is /projects
5. (Related but not a problem with the devfile above): special variable $PROJECT_SOURCE is not supported

Describe the solution you'd like

• When DevWorkspace is enabled:

1. DevWorkspace supports image components ignoring them
2. DevWorkspace ignores commands associated to image components
3. DevWorkspace supports composite commands
4. DevWorkspace sets default working directory to first project folder (not /projects/)
5. DevWorkspace supports PROJECT_SOURCE (not PROJECTS_SOURCE)
6. DevWorkspace ignores placeholder outerloop component

• When DevWorkspace is disabled devfile library converter handling of v2.2 to v1 #20856

1. Devfile converter removes any image components during conversion
2. Devfile converter removes commands associated to image components
3. Devfile converter removes composite commands
4. Devfile converter sets default working directory to first project folder (not /projects/)
5. Devfile converter replaces PROJECT_SOURCE with the path to the first project /projects/
6. Devfile converter removes placeholder outerloop component

[l0rd]

Created this PR devfile-samples/devfile-sample-java-springboot-basic#2 to fix some issues with https://github.com/devfile-samples/devfile-sample-java-springboot-basic

[amisevsk]

One issue that has to be resolved first is that currently devfile/api versions have removed v1alpha1 DevWorkspaces. However, there are still some users of DevWorkspaces that depend on this API version, so DWO must continue to ship conversion webhooks for the time being. We need to consider reverting devfile/api#639

[benoitf]

part of che-server workspaces has been implemented and merged

[benoitf]

removed area/devfile-converter as this action has been done