Support composite commands

[elsony]

/kind user-story

User Story

As a stack creator, I want to define composite commands to chain multiple commands together when running in odo.

Acceptance Criteria

• It should follow the corresponding settings specified in the devfile 2.0 specification: Composite commands label and id devfile/api#18
• It should support running composite command for all command groups that odo supports, e.g. build, run, etc.
• If parallel flag is set to true, the commands should be executed sequentially based on the order specified in the composite command; otherwise, the command will be executed in parallel.

This item will only cover the composite command for the build, not including the run command.

Links

• Related issue: Composite commands label and id devfile/api#18

/kind user-story
/area devfile
/area devfilev2

[johnmcollier]

Sample Devfile 2.0 with composite commands:

schemaVersion: 2.0.0
metadata:
  name: openLiberty
  version: 1.0.0
  description: Java application stack using Open Liberty runtime
projects:
  - name: user-app
    git:
      location: 'https://github.com/odo-devfiles/openliberty-ex.git'
      branch: master
components:
  - chePlugin:
      id: redhat/java/latest
      memoryLimit: 1512Mi
  - container:
      name: appsodyrun
      image: 'ajymau/java-openliberty-dev:latest'
      memoryLimit: 1024Mi
      mountSources: true
      endpoints:
        - name: 9080/tcp
          configuration:
            discoverable: false
            public: true
            protocol: tcp
            scheme: http
          targetPort: 9080
      env:
        - name: MODE2
          value: TEST2
        - name: myprop2
          value: myval2
commands:
  - exec:
      id: build
      component: appsodyrun
      commandLine: mvn -DhotTests=true -DappsDirectory=apps -Dmaven.repo.local=/mvn/repository liberty:dev
      workingDir: /projects/user-app
      attributes:
        restart: "false"
      group:
        kind: run
        isDefault: true
   - exec:
       id: run
       commandLine: "./run.sh"
       component: tooling
       group: 
          kind: run
   - composite:
       id: buildAndRun
       label: Build and Run
       commands:
         - build
         - run
       parallel: false
       group: 
          kind: run

Based on the second point, it sounds like this PR depends on support for command groups in devfiles (#2938)

[johnmcollier]

Some questions on composite commands that I couldn't find answers for in the schema:

1. Can a composite command reference other composite commands?
2. When parallel: true, does odo need to wait for all of the commands to finish executing?
3. If yes to 2, do we wait indefinitely or should there be a timeout?

[elsony]

1. Yes, from spec perspective, there is nothing prevent someone to reference a composite command to another composite command
2. yes
3. Similar to push command today, there is no timeout for command execution.

[johnmcollier]

@kadel Based on our discussion on the odo contributor's call on Tuesday about composite run commands, @elsony and I chatted and we decided to scope this story down to just suppoorting composite build/init/test commands, rather than partially supporting non-long running composite commands.

We'll open up a separate story for suppoorting composite run commands (both long running and non-long running)