Recently, a customer asked me how to pass several custom objects to an Azure DevOps YAML pipeline and index into each object.
They wanted to index into 3 object arrays being passed to the template file, similar to below.
- template: builds.yml
parameters:
imageNames:
- app1Api
- app2api
pathToSolutionFiles:
- App1API/App1API.sln
- App2API/App2Api.sln
pathToDockerfiles:
- App1API/App1API/Dockerfile
- App2API/App2API/Dockerfileparameters:
- name: imageNames
type: object
- name: pathToSolutionFiles
type: object
- name: pathToDockerfiles
type: object
steps:
- ${{ each imageName in parameters.imageNames }}:
- task: DotNetCoreCLI@2
displayName: 'dotnet build'
inputs:
projects: "$(pathToSolutionFiles)"
- task: Docker@1
displayName: 'Build Image $(imageName)'
inputs:
dockerFile: $(pathToDockerfiles)
...Unfortunately, ADO YAML syntax doesn’t let you index into 3 objects at the same time the way you might in C# (pseudocode).
for (int i = 0; i < parameters.imageNames.length; i++) {
var imageName = parameters.imageNames[i];
var pathToSolutionFile = parameters.pathToSolutionFiles[i];
var pathToDockerfile = parameters.pathToDockerfiles[i];
...
}Therefore, you need to change how you are passing in the array of objects.
You need to combine the object arrays together.
You can either choose a sequential or parallel approach to generating the correct YAML.
Sequential
In the sequential version of this method, you will use the each command to have the ADO YAML generated for you. Each set of commands will be copy-pasted after the previous set of commands (one for each entry in the array).
template-build.yml
parameters:
- name: builds
type: object
steps:
- ${{ each build in parameters.builds }} :
- task: DotNetCoreCLI@2
displayName: dotnet build
inputs:
projects: '${{ build.pathToSolutionFile }}'
- task: Docker@1
displayName: Build Image ${{ build.imageName }}
inputs:
dockerFile: '${{ build.pathToDockerfile }}'
...You write the YAML assuming what the 3 properties of each array object will be.
In the calling script, you pass in a complex object. This object will be an array of objects. Each entry in the object array will contain 3 properties (imageName, pathToSolutionFile, pathToDockerfile).
azure-pipeline.yml
- job: jobSequential
steps:
- template: template-build.yml
parameters:
builds:
- imageName: app1Api
pathToSolutionFile: App1API/App1API.sln
pathToDockerfile: App1API/App1API/Dockerfile
- imageName: app2Api
pathToSolutionFile: App2API/App2API.sln
pathToDockerfile: App2API/App2API/DockerfileParallel
In this option, instead of writing the each loop yourself, you can use the matrix build to have the ADO YAML generated that will execute in parallel instead of sequentially.
template-build.yml
parameters:
- name: imageName
type: string
- name: pathToSolutionFile
type: string
- name: pathToDockerfile
type: string
steps:
- task: DotNetCoreCLI@2
displayName: dotnet build
inputs:
projects: '${{ parameters.pathToSolutionFile }}'
- task: Docker@1
displayName: Build Image ${{ parameters.imageName }}
inputs:
dockerFile: '${{ parameters.pathToDockerfile }}'In this option, the template-build.yml file has the specific steps for 1 job.
azure-pipeline.yml
- job: jobMatrix
strategy:
matrix:
buildApp1:
imageName: app1Api
pathToSolutionFile: App1API/App1API.sln
pathToDockerfile: App1API/App1API/Dockerfile
buildApp2:
imageName: app2Api
pathToSolutionFile: App2API/App2API.sln
pathToDockerfile: App2API/App2API/Dockerfile
steps:
- template: template-build.yml
parameters:
imageName: $(imageName)
pathToSolutionFile: $(pathToSolutionFile)
pathToDockerfile: $(pathToDockerfile)The calling script will use the matrix keyword to generate duplicate jobs, one for each object in the array. Each entry in the array will contain the 3 properties we need.