Exported vars are not evaluated recursively in the context of nested params

[civitaspo]

summary

Exported vars are not evaluated recursively in the context of nested params

the dig file to reproduce

_export:
  a: aaa
  b: bbb
  c: ccc

+a:
  _export:
    d: ${a}-${b}-${c}

  +b:
    _export:
      e: ${d}
      f:
        g: ${d}
    +c:
      echo>: ${d}
    +d:
      echo>: ${e}
    +e:
      echo>: ${f.g}

the result of the dig file

You can see that only the nested param ${f.g} is not evaluated recursively.

$ digdag run ./var.dig --no-save
2018-09-14 13:18:02 +0900: Digdag v0.9.27
2018-09-14 13:18:03 +0900 [WARN] (main): Using a new session time 2018-09-14T00:00:00+00:00.
2018-09-14 13:18:03 +0900 [INFO] (main): Starting a new session project id=1 workflow name=var session_time=2018-09-14T00:00:00+00:00
2018-09-14 13:18:04 +0900 [INFO] (0016@[0:default]+var+a+b+c): echo>: aaa-bbb-ccc
aaa-bbb-ccc
2018-09-14 13:18:05 +0900 [INFO] (0016@[0:default]+var+a+b+d): echo>: aaa-bbb-ccc
aaa-bbb-ccc
2018-09-14 13:18:05 +0900 [INFO] (0016@[0:default]+var+a+b+e): echo>: ${a}-${b}-${c}
${a}-${b}-${c}
Success.
  * Use --session <daily | hourly | "yyyy-MM-dd[ HH:mm:ss]"> to not reuse the last session time.
  * Use --rerun, --start +NAME, or --goal +NAME argument to rerun skipped tasks.

Ref

• This issue may be the same cause as A moment.js parameter which defined in _export part, cannot reference properly. #678 .

[civitaspo]

This issue is happend when operators requires nested params.

_export:
  staging_bucket: mybucket
  project: aaa
  workspace_s3_uri_prefix: s3://${staging_bucket}/${project}/${session_uuid}

+create_cluster:
  emr_fleet.create_cluster>:
  ...<snip>...
  bootstrap_acitons:
    - name: "install datadog"
      script: ${workspace_s3_uri_prefix}/install_dd_agent.sh
      content: |
        ...<snip>...

In the above case, the script option gets s3://${staging_bucket}/${project}/${session_uuid}/install_dd_agent.sh, not like s3://mybucket/aaa/28d1743c-2f66-44a2-983d-c14a8f133auc/install_dd_agent.sh.

[civitaspo]

I implemented param_eval> operator as a workaround for this issue.