How to loop through user-defined variables in a YAML pipeline? - azure

Question

I am trying to loop through user-defined variables in an Azure DevOps YAML pipeline.
The variables have been created through the UI:
Below the YAML pipeline code that I'm using:
trigger:
- dev
- main
pr:
- dev
pool:
vmImage: ubuntu-latest
stages:
- stage:
jobs:
- job: TestVars
steps:
- ${{ each var in variables }}:
- script: |
echo ${{ var.key }}
echo ${{ var.value }}
displayName: ${{ var.key }}
When running the above pipeline only system and build variables are listed (e.g. system, system.hostType, build.queuedBy, etc.).
Any help to loop through user-defined variables would be much appreciated.

Answer 1

Unfortunately, no luck fetching the variables defined in UI. However, if your variables are non-secrets, you can bring them over into the YAML, and they will show up in the loop.
- stage:
variables:
myyamlvar: 1000 # this will show up in the loop
jobs:
- job: TestVars
steps:
- ${{ each var in variables }}:
- script: |
echo ${{ var.key }}
echo ${{ var.value }}
displayName: ${{ var.key }}
Alternatively, instead of using a compile time expression, you can list variables using a runtime construct, for example:
- job: TestRuntimeVars
steps:
- script: |
for var in $(compgen -e); do
echo $var ${!var};
done
This will list all variables including ones defined in the UI.

Answer 2

From the Microsoft docs link you provided, it specifies that:
"Unlike a normal variable, they are not automatically decrypted into
environment variables for scripts. You need to explicitly map secret
variables."
However, one workaround could potentially be to run an azure cli task and get the pipeline variables using az pipelines variable list
Assuming your intention is to get the actual values, in which case maybe that won't suffice. Having said that, you should consider a variable group even if you're not using them in other pipelines since the group can be linked to an Azure KeyVault and map the secrets as variables. You can store your sensitive values in a KeyVault and link it to the variable group which can be used like regular variables in your pipeline.
Or you can access KeyVault secrets right from the AzureKeyVault pipeline task.

Answer 3

To expand on the awnser below. It is a bit round about but you can use the azure devopps CLI. This may be a bit overkill but it does do the job.
trigger:
- main
pool:
vmImage: ubuntu-latest
steps:
- bash: az --version
displayName: 'Show Azure CLI version'
- bash: az devops configure --defaults organization=$(System.TeamFoundationCollectionUri) project=$(System.TeamProject) --use-git-aliases true
displayName: 'Set default Azure DevOps organization and project'
- bash: |
az pipelines variable list --pipeline-id $(System.DefinitionId)
displayName: 'Show build list varibales'
env:
AZURE_DEVOPS_EXT_PAT: $(System.AccessToken)
This approach was taken from a combination of:
https://learn.microsoft.com/en-us/azure/devops/pipelines/process/variables?view=azure-devops&tabs=yaml%2Cbatch#list-variables
and
https://learn.microsoft.com/en-us/azure/devops/pipelines/process/variables?view=azure-devops&tabs=yaml%2Cbatch#list-variables
If the agent is self hosted you may need to install the dev opps cli.