Library versioning in Jenkins - Step-by-Step Execution

Process Flow - Library versioning

Start Jenkins Pipeline

↓

Load Library with Version

↓

Use Library Functions

↓

Execute Pipeline Steps

↓

Pipeline Completes

The Jenkins pipeline starts, loads a specific library version, uses its functions, executes steps, and then completes.

Execution Sample

Jenkins

library('my-shared-lib@v1.2')
node {
  stage('Build') {
    mySharedLib.buildApp()
  }
}

This Jenkins pipeline loads version v1.2 of a shared library and calls its buildApp function inside a build stage.

Process Table

Step	Action	Library Version	Function Called	Pipeline State
1	Start pipeline	none	none	Pipeline started
2	Load library	v1.2	none	Library v1.2 loaded
3	Enter node block	v1.2	none	Node allocated
4	Enter stage 'Build'	v1.2	none	Stage Build started
5	Call buildApp()	v1.2	buildApp	buildApp function executed
6	Stage 'Build' complete	v1.2	none	Stage Build finished
7	Pipeline complete	v1.2	none	Pipeline finished successfully

💡 Pipeline finishes after executing all stages using library version v1.2

Status Tracker

Variable	Start	After Step 2	After Step 5	Final
libraryVersion	none	v1.2	v1.2	v1.2
pipelineState	not started	started	running buildApp	finished

Key Moments - 2 Insights

Why do we specify '@v1.2' when loading the library?

Specifying '@v1.2' tells Jenkins exactly which version of the library to use, ensuring consistent behavior as shown in execution_table step 2.

What happens if we omit the version when loading the library?

Jenkins uses the default or latest library version, which might cause unexpected changes. The execution_table shows explicit version loading to avoid this.

Visual Quiz - 3 Questions

Look at the execution table, what is the library version loaded at step 2?

A latest

B v1.2

C v1.0

D none

💡 Hint

Check the 'Library Version' column at step 2 in the execution_table.

At which step does the buildApp function get executed?

A Step 5

B Step 3

C Step 6

D Step 7

💡 Hint

Look at the 'Function Called' column in the execution_table.

If we change the library version to '@v2.0', what changes in the execution table?

A Pipeline state changes to failed

B Function called changes to buildAppV2

C Library Version column shows v2.0 instead of v1.2

D No changes at all

💡 Hint

Changing version affects the 'Library Version' column in the execution_table.

Concept Snapshot

Jenkins Library Versioning:
- Use library('name@version') to load specific library version.
- Ensures consistent pipeline behavior.
- Call library functions after loading.
- Version controls shared code updates.
- Avoids unexpected changes from default/latest versions.

Full Transcript

This visual execution shows how Jenkins pipelines load a specific version of a shared library using the syntax library('my-shared-lib@v1.2'). The pipeline starts, loads version v1.2 of the library, then calls the buildApp function from that library inside a build stage. The execution table tracks each step, showing the library version loaded and pipeline state changes. Key moments clarify why specifying the version is important to avoid unexpected behavior. The quiz tests understanding of version loading and function execution steps. The snapshot summarizes the key points about library versioning in Jenkins pipelines.