Fixes export and execution of env variables for devfile commands

[mik-dass]

What type of PR is this?

/kind bug

What does does this PR do / why we need it:

Fixes export and execution of env variables for command in the devfile.

Which issue(s) this PR fixes:

Fixes #4232

PR acceptance criteria:

• Unit test

• Integration test

• Documentation

• I have read the test guidelines

How to test changes / Special notes to the reviewer:

• Use a devfile that defines a command spawning a new shell, for example like this:

  - id: run 
    exec:
      component: tools
      commandLine: "sh -c 'mkdir $foo'"
      group:
        kind: run
        isDefault: true
      env:
        - name: foo
          value: bar

• Check if the command is executed successfully.

[dharmit]

@mik-dass @kadel @adisky correct me if I'm doing something dumb here.

Here's the devfile that I used:

schemaVersion: 2.0.0
metadata:
  name: nodejs
  version: 1.0.0
  alpha.build-dockerfile: "https://raw.githubusercontent.com/odo-devfiles/registry/master/devfiles/nodejs/build/Dockerfile"
  alpha.deployment-manifest: "https://raw.githubusercontent.com/odo-devfiles/registry/master/devfiles/nodejs/deploy/deployment-manifest.yaml"
starterProjects:
  - name: nodejs-starter
    git:
      remotes:
        origin: "https://github.com/odo-devfiles/nodejs-ex.git"
components:
  - name: runtime
    container:
      image: registry.access.redhat.com/ubi8/nodejs-12:1-45
      memoryLimit: 1024Mi
      mountSources: true
      sourceMapping: /project
      endpoints:
        - name: http-3000
          targetPort: 3000
commands:
  - id: run 
    exec:
      component: runtime
      commandLine: "sh -c 'mkdir $foo'"
      group:
        kind: run
        isDefault: true
      env:
        - name: foo
          value: bar

And here's the odo push output:

$ odo push        

Validation
 ✓  Validating the devfile [34638ns]

Creating Kubernetes resources for component node-todo
 ✓  Waiting for component to start [6s]

Applying URL changes
 ✓  URL http-3000: http://http-3000-node-todo-buikmestmo.apps-crc.testing/ created

Syncing to component node-todo
 ✓  Checking files for pushing [680178ns]
 ✓  Syncing files to the component [243ms]

Executing devfile commands for component node-todo
 ✓  Executing run command "sh -c 'mkdir $foo'" [1s]

Pushing devfile component node-todo
 ✓  Changes successfully pushed to component

But if I spin up another shell, the env var doesn't seem to persist:

$ kubectl exec node-todo-5f5d5d5dd-7mcxm -- env | grep foo
ODO_COMMAND_RUN=export foo="bar" && sh -c 'mkdir $foo'

$ kubectl exec node-todo-5f5d5d5dd-7mcxm -- echo $foo

Am I doing or expecting something that's out of place or doing something wrong here?

[mik-dass]

But if I spin up another shell, the env var doesn't seem to persist:

These env vars are only used during the execution of run, debug etc commands from the devfile.

[dharmit]

/approve
/lgtm

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dharmit, mik-dass

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