Can't pass source variables to the exec arguments list

[carolynvs]

This was first implemented in #31 but doesn't seem to work anymore.

When you run this, replace TODO with your username.

mixins:
  - exec

name: HELLO
version: 0.1.0
description: "An example Porter configuration"
invocationImage: TODO/porter-hello:latest

parameters:
  - name: cmd
    type: string
    default: "echo hello world"

install:
  - description: "Install Hello World"
    exec:
      command: bash
      arguments:
        - -c
        - source: bundle.parameters.cmd

uninstall:
  - description: "Uninstall Hello World"
    exec:
      command: bash
      arguments:
        - -c
        - echo Goodbye World

$ porter build && duffle install FOO -f bundle.json --insecure
Executing install action...
executing porter install configuration from /cnab/app/porter.yaml
Install Hello World
Error: yaml: unmarshal errors:
  line 6: cannot unmarshal !!map into string
err: yaml: unmarshal errors:
  line 6: cannot unmarshal !!map into string

[nunix]

just for information, I got the exact same issue by running with porter only:

porter run --action install --file ./porter.yaml --debug

really looking forward to this fix :)

[jeremyrickard]

This turns out not to be a problem with the way the parameter sourcing is working exactly..., it's a "how go is parsing YAML and reflection" problem. You can pass the params, with slightly different YAML right now.

The yaml above fails (here it is again):

install:
  - description: "Install Hello World"
    exec:
      command: bash
      arguments:
        - -c
        - source: bundle.parameters.cmd

However.....this does work

install:
  - description: "Install Hello World"
    exec:
      command: bash
      arguments:
        - -c
        - "source: bundle.parameters.cmd"

When the YAML blob gets loaded to process, it's failing to handle that correctly. Working on a fix now.

[nunix]

I tried the workaround and the values are empty (still based on my yaml file). Which I think it's because I do directly the command porter run --action install --file ./porter.yaml --debug instead of piping it like Carolyn did in her example.

My porter version is:

[carolynvs]

I think I know what you are running into!

Short answer:

Set an environment variable named after the parameter that you are trying to access (or matching the destination env var used) before running porter run. So to match my porter.yaml above, I would set $env:CMD = "echo hello world".

Long answer:

porter is intended to execute inside of a CNAB environment. From the spec, parameters are either exported as environment variables in the environment or as files (depending on how they are defined in the bundle). Porter reads parameters and credentials not from the porter.yaml but from the CNAB environment. That's why you saw in my examples that I was running a duffle install. If you do a porter run directly, you'll need to provide those environment variables or files yourself.