$PROJECT_SOURCE env variable

[kadel]

/kind user-story

User Story

As a Devfile author, I always want to know the exact location of the project source code So that I can execute commands in a current diretory

Acceptance Criteria

• ${PROJECT_SOURCE} env variable should be available in every container of the component so it can be used in commandLine or workingDir fields inside Devfiles
• ${PROJECT_SOURCE} should point to a directory that contains project source code
  • if there are multiple projects in devfile ${PROJECT_SOURCE} will point to the source code of the first one
  • if there are no projects in devfile ${PROJECT_SOURCE} will be equal to the value of ${PROJECTS_ROOT}

Notes

• ${PROJECT_SOURCE} can be different for each container because it depends on sourceMapping value and on ${PROJECTS_ROOT} value both are set per container.
• Projects source code location inside ${PROJECTS_ROOT} depends on clonePath value (defaults to project name) (clonePath should be supported in odo #3729)

Links

• add PROJECTS_ROOT and PROJECT_SOURCE description to CommandLine and WorkingDir devfile/api#116
• Parent Devfiles and workingDir vs clonePath issue devfile/api#109 (comment)

/kind user-story
/priority high

[girishramnani]

so wouldn't this be blocked on #3729 @kadel ?

[kadel]

so wouldn't this be blocked on #3729 @kadel ?

not sure, it could but it also might not :-) It depends how it is handled in odo codebase.

[girishramnani]

Prioritise this #3729

[girishramnani]

$PROJECT_SOURCE is required for using parent without this env varibale parent devfiles are unusable, but we are not using it anywhere yet

[girishramnani]

so it would be ok to implement it after GA

[maysunfaisal]

I had a question regarding a use case and wanted to see how we should respond to it. Consider the situation:

devfile snippet:

projects:
  - name: myproj1
    clonePath: myapp1/
    git:
      remotes:
        origin: https://github.com/odo-devfiles/springboot-ex
components:
- name: dummy
  container:
    image: quay.io/eclipse/che-java11-maven:nightly
    memoryLimit: 768Mi
    mountSources: true
    sourceMapping: /test
    command: ['tail']
    args: [ '-f', '/dev/null']
    env:
    - name: PROJECT_SOURCE
      value: /mycustom/path/

explanation:

When a user overwrites PROJECT_SOURCE via devfile env. That would mean it would take precedence over a component container's sourceMapping and project's clonePath and we would need to overwrite the container's volume mount path to this custom PROJECT_SOURCE value now for the project volume and sync to this location.

When this happens, the sourceMapping, clonePath and the existing ENV PROJECTS_ROOT(which is decided by sourceMapping and in the above snippet it would be /test, /projects otherwise), becomes pointless.

1. Is this the correct expected behavior?
2. what should be PROJECTS_ROOT in this case? (Note that PROJECT_SOURCE is /mycustom/path/ and PROJECTS_ROOT is /test)
3. Ignore this 3rd ques, it is invalid (DELETED)

cc: @kadel @elsony @johnmcollier

[johnmcollier]

@maysunfaisal So, here are my thoughts:

I actually don't think we should allow $PROJECT_SOURCE to be customized by the user for two reasons:

• As per the schema, its value directly depends on the value of $PROJECT_ROOT, so it doesn't make sense for the two to be completely different values (say /test and /somedir)
• The project root* is used by odo to determine where to mount the source code volume on the container and the parent folder of where to sync. So if $PROJECT_SOURCE is overridden to some other value, then it won't point to where the source code is located.

* Odo uses the following logic to determine the project root (in order):

1. The value of sourceMapping, if set
2. The value of the $PROJECT_ROOT env, if overridden in the container
3. Defaults to /project otherwise

[elsony]

+1 on no point for user to override the $PROJECT_SOURCE. By doing that, the user is introducing inconsistent configuration within the devfile. Source mapping and the clone path decide where to do sync code and while $PROJECT_SOURCE give you the final value on where you can find the source. If you override $PROJECT_SOURCE to a different value, the config basically say clone my source to one location and then telling the build that uses $PROJECT_SOURCE to find the source in another location.

On high level, there is no different from someone specify a clone path but then their build scripts are trying to build the source from a different location. It is an inconsistent config that the user provides. Having said that, it will be nice to flag that as a warning during devfile validation to avoid the user accidentally change the value of those variables.

If you take a look at the spec under the command section

Special variables that can be used:
$PROJECTS_ROOT: A path where projects sources are mounted

$PROJECT_SOURCE: A path to a project source ($PROJECTS_ROOT/). If there are multiple projects, this will point to the directory of the first one.

The spec already say those are special variables. We can consider to update the spec to say those are reserved variables (+ the devfile validation warning that I mentioned earlier) to make it clear.