Azure Pipeline File-based Trigger and Tags - azure

Question

Is it possible to make a build Pipeline with a file-based trigger?
Let's say I have the following Directory structure.
Microservices/
|_Service A
|_Test_Stage
|_Testing_Config
|_QA_Stage
|_QA_Config
|_Prod_stage
|_Prod_Config
|_Service B
|_Test_Stage
|_Testing_Config
|_QA_Stage
|_QA_Config
|_Prod_stage
|_Prod_Config
I want to have just one single YAML Build Pipeline File.
Based on the Variables $(Project) & $(Stage) different builds are created.
Is it possible to check what directory/file initiated the Trigger and set the variables accordingly?
Additionally it would be great if its possible to use those variables to set the tags to the artifact after the run.
Thanks
KR

Answer 1

Is it possible to check what directory/file initiated the Trigger and
set the variables accordingly?
Of course yes. But there's no direct way since we do not provide any pre-defined variables to store such message, so you need additional complex work around to get that.
#1:
Though there's no variable can direct stores the message like which folder and which file is modified, but you could get it by tracking the commit message Build.SourceVersion via api.
GET https://dev.azure.com/{organization}/{project}/_apis/git/repositories/{repositoryId}/commits/{commitId}/changes?api-version=5.1
From its response body, you can directly know its path and file:
Since the response body is JSON format, you could make use of some JSON function to parsing this path value. See this similar script as a reference.
Then use powershell script to set these value as pipeline variable which the next agent jobs/tasks could use them.
Also, in your scenario, all of these should be finished before all next job started. So, you could consider to create a simple extension with pipeline decorator. Define all above steps in decorator, so that it can be finished in the pre-job of every pipeline.
#2
Think you should feel above method is little complex. So I'd rather suggest you could make use of commit messge. For example, specify project name and file name in commit message, get them by using variable Build.SourceVersionMessage.
Then use the powershell script (I mentioned above) to set them as variable.
This is more convenient than using api to parse commits body.
Hope one of them could help.

Answer 2

Thanks for your reply.
I tried a different approach with a Bash Script.
Because I only use ubuntu Images.
I make "git log" with Filtering for the last commit of the Directory Microservices.
With some awk (not so a satisfying Solution) I get the Project & Stage and write them into Pipeline Variables.
The Pipeline just gets triggered when there is a change to the Microservices/* Path.
trigger:
batch: true
branches:
include:
- master
paths:
include:
- Microservices/*
The first job when the trigger activated, is the Dynamic_variables job.
This Job I only use to set the Variables $(Project) & $(Stage). Also the build tags are set with those Variables, so I'm able do differentiate the Artifacts in the Releases.
jobs:
- job: Dynamic_Variables
pool:
vmImage: 'ubuntu-latest'
steps:
- checkout: self
- task: Bash#3
name: Dynamic_Var
inputs:
filePath: './scripts/multi-usage.sh'
arguments: '$(Build.SourcesDirectory)'
displayName: "Set Dynamic Variables Project"
- task: Bash#3
inputs:
targetType: 'inline'
script: |
set +e
if [ -z $(Dynamic_Var.Dynamic_Project) ]; then
echo "target Project not specified";
exit 1;
fi
echo "Project is:" $(Dynamic_Var.Dynamic_Project)
displayName: 'Verify that the Project parameter has been supplied to pipeline'
- task: Bash#3
inputs:
targetType: 'inline'
script: |
set +e
if [ -z $(Dynamic_Var.Dynamic_Stage) ]; then
echo "target Stage not specified";
exit 1;
fi
echo "Stage is:" $(Dynamic_Var.Dynamic_Stage)
displayName: 'Verify that the Stage parameter has been supplied to pipeline'
The Bash Script I run in this Job looks like this:
#!/usr/bin/env bash
set -euo pipefail
WORKING_DIRECTORY=${1}
cd ${WORKING_DIRECTORY}
CHANGEPATH="$(git log -1 --name-only --pretty='format:' -- Microservices/)"
Project=$(echo $CHANGEPATH | awk -F[/] '{print $2}')
CHANGEFILE=$(echo $CHANGEPATH | awk -F[/] '{print $4}')
Stage=$(echo $CHANGEFILE | awk -F[-] '{print $1}')
echo "##vso[task.setvariable variable=Dynamic_Project;isOutput=true]${Project}"
echo "##vso[task.setvariable variable=Dynamic_Stage;isOutput=true]${Stage}"
echo "##vso[build.addbuildtag]${Project}"
echo "##vso[build.addbuildtag]${Stage}"
If someone has a better solution then the awk commands please let me know.
Thanks a lot.
KR