Build history and logs in Jenkins - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of build history in Jenkins?

Build history in Jenkins keeps a record of all past builds, showing their status, duration, and time. It helps track what happened in each build over time.

beginner

Where can you find the logs for a specific Jenkins build?

You can find the logs by clicking on the build number in the build history, then selecting 'Console Output'. This shows detailed steps and messages from that build.

beginner

What information does the Jenkins console output provide?

The console output shows step-by-step messages, errors, warnings, and success messages from the build process. It helps diagnose problems or confirm success.

intermediate

How can build history help in troubleshooting Jenkins jobs?

Build history shows which builds failed or succeeded and when. By reviewing logs from failed builds, you can find errors and fix issues faster.

intermediate

What happens to build logs when Jenkins is configured to discard old builds?

When old builds are discarded, their logs and details are deleted to save space. Only recent builds remain accessible in the build history.

Where do you click to see the logs of a Jenkins build?

A On the build number in the build history

B On the Jenkins dashboard logo

C On the system settings

D On the user profile

Clicking the build number in the build history opens details including the console output logs.

What does the Jenkins console output NOT show?

A User login history

B Errors and warnings

C Step-by-step build messages

D Success messages

Console output shows build details, not user login history.

Why is build history important in Jenkins?

A To add new users

B To change Jenkins system settings

C To edit source code

D To track past build results and durations

Build history helps track what happened in previous builds.

What happens if Jenkins is set to discard old builds?

A Build history is duplicated

B Old build logs are deleted

C New builds are ignored

D Builds run faster

Discarding old builds deletes their logs to save space.

How can you use build logs to fix a failed Jenkins job?

A By deleting the job

B By restarting Jenkins server

C By reading error messages in the console output

D By changing user permissions

Error messages in logs help identify what went wrong.

Explain how Jenkins build history and logs help in managing and troubleshooting builds.

Think about how you would check what happened if a build failed.

Describe what happens to build logs when Jenkins discards old builds and why this might be useful.

Consider storage limits and system performance.

Practice

1. What does the Build History section in Jenkins primarily show?

easy

A. The configuration settings of the Jenkins server

B. The detailed logs of the current build

C. A list of past builds with their results and status

D. The list of users who accessed Jenkins

Solution

1. Step 1: Understand the purpose of Build History

   The Build History section shows a timeline of previous builds with their success or failure status.

2. Step 2: Differentiate from build logs and settings

   Build logs show detailed steps, not the summary list. Configuration and user lists are separate sections.

3. Final Answer:

   A list of past builds with their results and status -> Option C

4. Quick Check:

   Build History = past build results [OK]

Hint: Build History = summary of past builds, not logs [OK]

Common Mistakes:

• Confusing Build History with build logs
• Thinking Build History shows Jenkins settings
• Assuming Build History lists users

2. Which Jenkins UI element do you click to view the detailed logs of a specific build?

easy

A. The build number link in Build History

B. The 'Configure' button on the job page

C. The 'New Item' button on the dashboard

D. The 'Manage Jenkins' link

Solution

1. Step 1: Identify where build logs are accessed

   Clicking the build number in Build History opens that build's details including logs.

2. Step 2: Exclude unrelated UI elements

   'Configure' edits job settings, 'New Item' creates jobs, 'Manage Jenkins' is for admin tasks.

3. Final Answer:

   The build number link in Build History -> Option A

4. Quick Check:

   Build logs accessed via build number link [OK]

Hint: Click build number in history to see logs [OK]

Common Mistakes:

• Clicking 'Configure' instead of build number
• Trying 'New Item' to see logs
• Using 'Manage Jenkins' for build logs

3. Given a Jenkins job with three builds: #1 (SUCCESS), #2 (FAILURE), #3 (SUCCESS). What will the Build History show after build #3 completes?

medium

A. Build #3 FAILURE, Build #2 SUCCESS, Build #1 FAILURE

B. Build #1 SUCCESS, Build #2 FAILURE, Build #3 SUCCESS

C. Build #2 FAILURE only

D. Build #3 SUCCESS, Build #2 FAILURE, Build #1 SUCCESS

Solution

1. Step 1: Understand Build History order

   Build History lists builds in reverse order: newest first.

2. Step 2: Match build statuses and order

   Build #3 is latest and successful, then #2 failed, then #1 successful.

3. Final Answer:

   Build #3 SUCCESS, Build #2 FAILURE, Build #1 SUCCESS -> Option D

4. Quick Check:

   Newest builds appear first in history [OK]

Hint: Build History shows newest builds first [OK]

Common Mistakes:

• Reading builds oldest to newest
• Mixing up build statuses
• Assuming only failed builds show

4. You try to view build logs but see an empty page. What is the most likely cause?

medium

A. You clicked the wrong build number

B. The build has not started or produced logs yet

C. Jenkins server is offline

D. You lack permission to view logs

Solution

1. Step 1: Consider build status and logs availability

   If the build is queued or just started, logs may be empty.

2. Step 2: Exclude other causes

   Wrong build number still shows logs if build exists; server offline shows error; permission issues show access denied.

3. Final Answer:

   The build has not started or produced logs yet -> Option B

4. Quick Check:

   Empty logs usually mean build not started [OK]

Hint: Empty logs = build not started or no output yet [OK]

Common Mistakes:

• Assuming server offline causes empty logs
• Thinking wrong build number shows empty logs
• Ignoring permission errors

5. You want to analyze why a Jenkins build failed by checking logs but the logs are very long. Which Jenkins feature helps you quickly find errors in the logs?

hard

A. The 'Console Output' search box to filter keywords

B. The 'Build History' to rerun the build

C. The 'Configure' page to edit build steps

D. The 'Manage Jenkins' to restart the server

Solution

1. Step 1: Identify how to search logs

   Jenkins Console Output page often has a search/filter box to find keywords like 'error'.

2. Step 2: Exclude unrelated features

   Build History shows past builds but no search; Configure edits jobs; Manage Jenkins is for admin tasks.

3. Final Answer:

   The 'Console Output' search box to filter keywords -> Option A

4. Quick Check:

   Use Console Output search to find errors fast [OK]

Hint: Use Console Output search box to find errors fast [OK]

Common Mistakes:

• Trying to find errors via Build History
• Editing job instead of checking logs
• Restarting Jenkins unnecessarily