How to resolve "unexpected value 'stages' azure pipelines" in Azure devops pipeline yml

Question

I am new to Azure devops. as part of poc, i am trying to build a java based docker image.

so i have following pipeline yaml file

# Maven
# Build your Java project and run tests with Apache Maven.
# Add steps that analyze code, save build artifacts, deploy, and more:
# https://learn.microsoft.com/azure/devops/pipelines/languages/java

trigger:
- master

pool:
  vmImage: 'ubuntu-latest'

steps:
- task: Maven@3
  inputs:
    mavenPomFile: 'pom.xml'
    mavenOptions: '-Xmx3072m'
    javaHomeOption: 'JDKVersion'
    jdkVersionOption: '1.8'
    jdkArchitectureOption: 'x64'
    publishJUnitResults: true
    testResultsFiles: '**/surefire-reports/TEST-*.xml'
    goals: 'package'

resources:
- repo: self

variables:
  tag: '$(Build.BuildId)'

stages:
- stage: Build
  displayName: Build image
  jobs:  
  - job: Build
    displayName: Build
    pool:
      vmImage: 'ubuntu-latest'
    steps:
    - task: Docker@2
      displayName: Build an image
      inputs:
        command: build
        dockerfile: '$(Build.SourcesDirectory)/Dockerfile'
        tags: |
          $(tag)

Expected

What i expected, this pipeline need to create a java application (jar file) and then it should create a docker image using this jar

Actual:

i am getting below error

unexpected value 'stages' azure pipelines

I didnt understand the issue...

Appreciated if anybody can help on this..?

Thanks

Answer 1

Please move this into job before your first task - task: Docker@2

steps:
- task: Maven@3
  inputs:
    mavenPomFile: 'pom.xml'
    mavenOptions: '-Xmx3072m'
    javaHomeOption: 'JDKVersion'
    jdkVersionOption: '1.8'
    jdkArchitectureOption: 'x64'
    publishJUnitResults: true
    testResultsFiles: '**/surefire-reports/TEST-*.xml'
    goals: 'package'

This is simply syntax issue. If you use steps you cant use stages on the root level. Here you may check syntax.

If you want to have jar creation as separate stage/job you have to define explicitly this as another stage or job. However in that way you need to publish and then download your jar as pipeline artifact.

If you stay with one single job you may just use:

trigger:
- master

pool:
  vmImage: 'ubuntu-latest'

variables:
  tag: '$(Build.BuildId)'

steps:
- task: Maven@3
  inputs:
    mavenPomFile: 'pom.xml'
    mavenOptions: '-Xmx3072m'
    javaHomeOption: 'JDKVersion'
    jdkVersionOption: '1.8'
    jdkArchitectureOption: 'x64'
    publishJUnitResults: true
    testResultsFiles: '**/surefire-reports/TEST-*.xml'
    goals: 'package'
- task: Docker@2
  displayName: Build an image
  inputs:
    command: build
    dockerfile: '$(Build.SourcesDirectory)/Dockerfile'
    tags: |
      $(tag)