Build pipeline basics in Azure - Step-by-Step Execution

Process Flow - Build pipeline basics

Start: Code Commit

↓

Trigger Build Pipeline

↓

Checkout Source Code

↓

Run Build Tasks

↓

Run Tests

↓

Publish Artifacts

↓

Build Pipeline Complete

This flow shows how a build pipeline starts from code commit, runs build and test tasks, then publishes artifacts.

Execution Sample

Azure

trigger:
  - main

pool:
  vmImage: 'ubuntu-latest'

steps:
  - script: echo Building project

A simple Azure build pipeline triggered on main branch that runs a build script on Ubuntu.

Process Table

Step	Action	Details	Result
1	Trigger pipeline	Code pushed to main branch	Pipeline starts
2	Checkout code	Get latest source from repo	Source code available
3	Run build script	Execute 'echo Building project'	Output: Building project
4	Run tests	No tests defined	Skipped
5	Publish artifacts	No artifacts defined	Skipped
6	Complete	Pipeline finished successfully	Success

💡 Pipeline ends after all steps complete successfully

Status Tracker

Variable	Start	After Step 2	After Step 3	After Step 6
pipeline_status	Not started	Running	Running	Succeeded
source_code	null	Checked out	Checked out	Checked out
build_output	null	null	Building project	Building project

Key Moments - 2 Insights

Why does the pipeline start automatically after code is pushed?

Because the trigger is set to the main branch, so any push to main starts the pipeline (see execution_table step 1).

What happens if no tests or artifacts are defined?

Those steps are skipped but the pipeline still completes successfully (see execution_table steps 4 and 5).

Visual Quiz - 3 Questions

Look at the execution table, what is the pipeline status after step 3?

A Running

B Succeeded

C Failed

D Not started

💡 Hint

Check the 'pipeline_status' variable in variable_tracker after Step 3

At which step does the source code become available?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look at the 'source_code' variable in variable_tracker after Step 2

If tests were added, which step would change in the execution table?

A Step 3

B Step 4

C Step 5

D Step 6

💡 Hint

Step 4 is where tests run according to the execution_table

Concept Snapshot

Build pipeline basics in Azure DevOps:
- Trigger on code push (e.g., main branch)
- Checkout source code
- Run build scripts
- Run tests (optional)
- Publish artifacts (optional)
- Pipeline ends with success or failure

Full Transcript

A build pipeline in Azure DevOps starts automatically when code is pushed to a specified branch, like main. The pipeline first checks out the latest source code, then runs build tasks such as scripts. If tests are defined, it runs them next. After that, it publishes build artifacts if configured. Finally, the pipeline completes successfully if all steps pass. If tests or artifacts are missing, those steps are skipped but the pipeline still finishes. Variables like pipeline status and build output change as the pipeline progresses through each step.

Practice

1. What is the main purpose of a build pipeline in Azure DevOps?

easy

A. To manually test code changes

B. To store code in a repository

C. To automate the process of preparing code for deployment

D. To monitor user activity on a website

Solution

1. Step 1: Understand the role of a build pipeline

   A build pipeline automates tasks like compiling code and running tests when code changes.

2. Step 2: Identify the main goal

   The main goal is to prepare code automatically for deployment or further steps.

3. Final Answer:

   To automate the process of preparing code for deployment -> Option C

4. Quick Check:

   Build pipeline purpose = automate code preparation [OK]

Hint: Build pipelines automate code prep, not manual tasks [OK]

Common Mistakes:

• Confusing build pipeline with code repository
• Thinking build pipelines monitor user activity
• Assuming build pipelines are for manual testing

2. Which YAML snippet correctly defines a trigger for a build pipeline on the 'main' branch?

easy

A. trigger:\n branches:\n - main

B. trigger:\n branches:\n exclude:\n - main

C. trigger:\n paths:\n include:\n - main

D. trigger:\n branches:\n include:\n - main

Solution

1. Step 1: Understand trigger syntax in YAML

   The trigger block uses 'branches' with 'include' to specify branches that start the pipeline.

2. Step 2: Check each option

   trigger:\n branches:\n include:\n - main correctly includes 'main' branch under 'branches' and 'include'. trigger:\n branches:\n exclude:\n - main excludes 'main', which disables trigger on it. trigger:\n paths:\n include:\n - main uses 'paths' which triggers on file changes, not branches. trigger:\n branches:\n - main misses 'include' keyword, so syntax is incorrect.

3. Final Answer:

   trigger:\n branches:\n include:\n - main -> Option D

4. Quick Check:

   Correct trigger syntax includes branches: include [OK]

Hint: Use 'branches: include:' to trigger on specific branches [OK]

Common Mistakes:

• Using 'exclude' instead of 'include' to trigger
• Confusing 'paths' with 'branches' in triggers
• Omitting 'include' keyword causing syntax errors

3. Given this YAML snippet in an Azure build pipeline, what will be the output of the script step?

steps:
- script: echo Hello, Azure DevOps!
  displayName: 'Print greeting'

medium

A. No output, script step is missing

B. Hello, Azure DevOps!

C. script: echo Hello, Azure DevOps!

D. Print greeting

Solution

1. Step 1: Understand the script step in YAML

   The 'script' keyword runs the command given, here 'echo Hello, Azure DevOps!'.

2. Step 2: Identify the output of the echo command

   The echo command prints the text 'Hello, Azure DevOps!' to the pipeline logs.

3. Final Answer:

   Hello, Azure DevOps! -> Option B

4. Quick Check:

   Script echo output = Hello, Azure DevOps! [OK]

Hint: Script runs commands; echo prints text to output [OK]

Common Mistakes:

• Confusing displayName with output
• Thinking script keyword prints itself
• Assuming no output if displayName is set

4. You wrote this YAML snippet for a build pipeline but it fails to trigger on the 'develop' branch:

trigger:
  branches:
    include:
      - main
steps:
- script: echo Build started

What is the likely cause?

medium

A. The trigger only includes the 'main' branch, not 'develop'

B. The script step is missing a displayName

C. The echo command is incorrect syntax

D. The YAML indentation is invalid

Solution

1. Step 1: Analyze the trigger branches

   The trigger includes only the 'main' branch, so changes in 'develop' won't start the pipeline.

2. Step 2: Check other parts for errors

   The script step is valid without displayName, echo syntax is correct, and indentation looks fine.

3. Final Answer:

   The trigger only includes the 'main' branch, not 'develop' -> Option A

4. Quick Check:

   Trigger branches must include target branch [OK]

Hint: Check trigger branches include all needed branches [OK]

Common Mistakes:

• Assuming script needs displayName to run
• Thinking echo command syntax causes trigger failure
• Ignoring trigger branch filters

5. You want to create a build pipeline that triggers only when files in the 'src/' folder change on the 'release' branch. Which YAML snippet correctly sets this up?

hard

A. trigger:\n branches:\n include:\n - release\n paths:\n include:\n - src/**

B. trigger:\n branches:\n include:\n - release\n paths:\n exclude:\n - src/**

C. trigger:\n branches:\n exclude:\n - release\n paths:\n include:\n - src/**

D. trigger:\n branches:\n include:\n - main\n paths:\n include:\n - src/**

Solution

1. Step 1: Understand branch and path filters

   To trigger on 'release' branch and only when files in 'src/' change, include 'release' in branches and 'src/**' in paths.

2. Step 2: Evaluate each option

   trigger:\n branches:\n include:\n - release\n paths:\n include:\n - src/** correctly includes 'release' branch and 'src/**' path. trigger:\n branches:\n include:\n - release\n paths:\n exclude:\n - src/** excludes 'src/**' so it won't trigger on those files. trigger:\n branches:\n exclude:\n - release\n paths:\n include:\n - src/** excludes 'release' branch, so no trigger on it. trigger:\n branches:\n include:\n - main\n paths:\n include:\n - src/** triggers on 'main' branch, not 'release'.

3. Final Answer:

   trigger:\n branches:\n include:\n - release\n paths:\n include:\n - src/** -> Option A

4. Quick Check:

   Include branch and path filters to trigger correctly [OK]

Hint: Use both branches and paths include to filter triggers [OK]

Common Mistakes:

• Using exclude instead of include for paths
• Triggering on wrong branch
• Forgetting to specify paths filter