如何在构建时为 Windows 2019 在 AWS-codebuild 中设置环境变量？

Question

It seems that in AWS-codebuild variables are not propagated between commands for the windows 2019 environment.

With this buildspec.yml

version: 0.2

env:
  variables:
    MY_VAR_0: $(git log -n 1 --date=short --pretty=format:%cd_%h)

phases:
  build:
    commands:
      - $Env:MY_VAR_1 = & git log -n 1 --date=short --pretty=format:%cd_%h
      - Get-ChildItem Env:MY_VAR_*
      # build commands here

artifacts:
  name: $MY_VAR_0

I get in the logs:

[Container] 2020/12/14 11:41:27 Entering phase BUILD
[Container] 2020/12/14 11:41:27 Running command $Env:MY_VAR_1 = & git log -n 1 --date=short --pretty=format:%cd_%h

[Container] 2020/12/14 11:41:27 Running command Get-ChildItem Env:MY_VAR_*

Name                           Value                                           
----                           -----                                           
MY_VAR_0                       $(git log -n 1 --date=short --pretty=format:%...

[Container] 2020/12/14 11:41:28 Phase complete: BUILD State: SUCCEEDED

The problem here are

• MY_VAR_0 is set to the string $(git log... and not the output of the command.
• MY_VAR_1 is not propagated to following commands in phases.build.commands
• and of course my artifacts end in the wrong place.

---

Up to now the only way I found to solve this problem is

version: 0.2

phases:
  build:
    commands:
      - |
        $Env:MY_VAR_0 = & git log -n 1 --date=short --pretty=format:%cd_%h
        $Env:MY_VAR_1 = & git log -n 1 --date=short --pretty=format:%cd_%h
        Get-ChildItem Env:MY_VAR_*
        # first build command here
      - |
        $Env:MY_VAR_0 = & git log -n 1 --date=short --pretty=format:%cd_%h
        $Env:MY_VAR_1 = & git log -n 1 --date=short --pretty=format:%cd_%h
        Get-ChildItem Env:MY_VAR_*
        # second build command here

artifacts:
  name: $(git log -n 1 --date=short --pretty=format:%cd_%h)

with the following log:

[Container] 2020/12/14 12:25:18 Entering phase BUILD
[Container] 2020/12/14 12:25:18 Running command $Env:MY_VAR_0 = & git log -n 1 --date=short --pretty=format:%cd_%h
$Env:MY_VAR_1 = & git log -n 1 --date=short --pretty=format:%cd_%h
Get-ChildItem Env:MY_VAR_*
# first build command here


Name                           Value                                           
----                           -----                                           
MY_VAR_1                       2020-12-14_eccfb77                              
MY_VAR_0                       2020-12-14_eccfb77                              

[Container] 2020/12/14 12:25:19 Running command $Env:MY_VAR_0 = & git log -n 1 --date=short --pretty=format:%cd_%h
$Env:MY_VAR_1 = & git log -n 1 --date=short --pretty=format:%cd_%h
Get-ChildItem Env:MY_VAR_*
# second build command here


Name                           Value                                           
----                           -----                                           
MY_VAR_1                       2020-12-14_eccfb77                              
MY_VAR_0                       2020-12-14_eccfb77                              

[Container] 2020/12/14 12:25:20 Phase complete: BUILD State: SUCCEEDED

What I do not like in this approach is that I have to repeat the code for computing the MY_VAR_* values at the begin of each build command. (And no, I do not consider feasible to have a single, multiline huge build command.) Moreover the same code has to be repeated in artifacts.name

questions

1. How do I propagate environment variables computed at build-time between different phases.*.commands ?
2. Why is $(...) expanded in artifacts.name but not in env.variables.MY_VAR_0 ?

Answer 1

Answer to #1:

it looks like setting Environment variables in Env: drive silently fails. However, using local variable syntax $Foo = "bar" seems to work between commands as well as phases.

For example, in the following:

version: 0.2
env:
  shell: powershell.exe
phases:
  pre_build: 
    commands:
      - $foo = "bar"
      - echo $foo
  build:
    commands:
      - echo $foo

both echo commands print bar .

Answer to #2:

artifacts.name always uses the shell language (unix), where when setting a variable you are in either cmd.exe or powershell.exe depending on what you have env.shell set to in the buildspec. Reference