Architecture Smells Analysis

Source: Garcia et al., Lippert & Roock, Sharma

Context: System-level structural issues affecting maintainability, evolution, and deployment.

Table of Contents

1. Considered Architecture Smells

1.1 Garcia et al. (Connector/Component Perspective)

Type Issue Type Description Applicable Reason
Connector Envy Structure Components handle communication logic that should be in a dedicated connector ✗ No connector concept in Jenkins Pipeline
Extraneous Connector Structure Two components communicate through a connector when direct call suffices ✗ Same as above
Ambiguous Interface Structure Interface offers only single, overly general entry point ✗ Weak interface concept in Helper functions

1.2 Lippert & Roock (Symptom-Based)

Type Issue Type Description Applicable Reason
Cyclic Dependency Dependency Components/Packages form a dependency cycle ✓ Sequence diagram analysis confirms unidirectional dependencies only
Unstable Dependency Dependency Stable component depends on less stable component ✗ No change frequency data available

Cyclic Dependency Analysis Method: Jenkins Pipeline is procedural code, so call flow was traced via sequence diagrams. Analysis confirms Jenkinsfile → Helper → External (Python/CLI) unidirectional dependencies only. No inter-Helper dependencies found.

See: pipeline-sequence-diagrams/domain-mapping.md

1.3 Sharma (Dependency Perspective)

Type Issue Type Description Applicable Reason
Hub-like Dependency Dependency Component with too many incoming/outgoing dependencies ✓ generalHelper → all 5 pipelines depend on it
Scattered Functionality Structure Single concern implemented across multiple components ✓ Same functionality scattered across helper and inline
Dense Structure Structure Dependency graph is too dense ✗ Density measurement meaningless with only 8 files
Implicit Cross-module Dependency Dependency Hidden dependencies not visible in architecture ✓ Python scripts, env vars, Jenkins APIs

Note: Hub-like Dependency is classified as Design Smell (class level) in Sharma's taxonomy. However, in Jenkins Pipeline context, Helper files serve as core system components, so it is included in Architecture level analysis.

2. Applied Architecture Smells Analysis

2.1 Hub-like Dependency

Data Sources:

Component Source Extracted Data
Pipelines Pipeline Sequence Diagrams Call counts extracted from Delegation Pattern tables
generalHelper Software Smells Analysis (Hub-like Modularization) Existing count data used
jsHelper jsHelper.groovy source code External calls counted directly
unityHelper unityHelper.groovy source code External calls counted directly

Incoming Dependencies (Pipeline → Helper):

Pipeline generalHelper jsHelper unityHelper Total
DLX CI 5 - 5 10
DLX CD 3 - 4 7
JS CI 6 4 - 10
JS CD 3 6 - 9
Jenkins CI 4 - - 4
Total 21 10 9 40

Outgoing Dependencies (Helper → External):

External Type generalHelper jsHelper unityHelper
Git CLI 18 - -
Linux CLI 11 3 1
SSH 6 - -
SCP 4 - -
Python 2 1 4
SonarQube API 2 - -
Node.js CLI - 2 -
npm CLI - 6 -
Unity CLI - - 1
Unity Hub CLI - - 2
Total Calls 43 12 8
Total Types 6 4 4

Dependency Diagram:

Numbers on edges represent call counts. Solid lines (→) indicate calls through Helper, dashed lines (⇢) indicate direct External calls.

flowchart LR subgraph Pipelines DLX_CI[DLX CI] DLX_CD[DLX CD] JS_CI[JS CI] JS_CD[JS CD] Jenkins_CI[Jenkins CI] end subgraph Helpers GH[generalHelper
21 calls in] JH[jsHelper
10 calls in] UH[unityHelper
9 calls in] end subgraph External Git[Git CLI] Python[Python Scripts] SSH[SSH/SCP] SonarQube[SonarQube] npm[npm CLI] Unity[Unity CLI] Docker[Docker CLI] Azure[Azure CLI] end %% Pipeline → Helper DLX_CI -->|5| GH DLX_CI -->|5| UH DLX_CD -->|3| GH DLX_CD -->|4| UH JS_CI -->|6| GH JS_CI -->|4| JH JS_CD -->|3| GH JS_CD -->|6| JH Jenkins_CI -->|4| GH %% Helper → External GH -->|18| Git GH -->|10| SSH GH -->|2| Python GH -->|2| SonarQube JH -->|6| npm JH -->|1| Python UH -->|4| Python UH -->|3| Unity %% Pipeline → External (Direct) DLX_CD -.->|4| Git DLX_CD -.->|8| SSH JS_CD -.->|4| Git JS_CD -.->|8| Docker JS_CD -.->|8| Azure

Analysis: - generalHelper: All 5 pipelines depend on it (100%), 43 outgoing calls to 6 external types → Hub - jsHelper, unityHelper: Only 2 pipelines each depend on them, 12/8 outgoing calls to 4 types - Dashed lines: Pipeline → External direct calls (Helper bypass) → inconsistent abstraction

2.2 Scattered Functionality

Data Sources:

Source Extracted Data
Pipeline Sequence Diagrams Pipeline Comparison tables

Evidence:

Concern Implementation Location Issue
Git operations generalHelper (CI) vs Jenkinsfile direct calls (CD) Same functionality, different implementation
Build status sending Via initializeEnvironment (CI) vs direct sendBuildStatus call (CD) Same functionality, different call pattern
Bitbucket reporting unityHelper (sendTestReport), Jenkinsfile direct Python calls Same domain, scattered across multiple locations
Web Server deployment generalHelper (CI) vs Jenkinsfile direct SSH/SCP (CD) Same functionality, different implementation

Analysis: - Same concern implemented differently depending on CI/CD pipeline type - Changes require modifications in multiple locations → triggers Shotgun Surgery

2.3 Implicit Cross-module Dependency

Data Sources:

Source Extracted Data
2.1 Hub-like Dependency Dependency Diagram, Outgoing Dependencies table
Pipeline Sequence Diagrams Delegation Pattern tables (direct External calls)
Helper source code Environment variable usage list

Hidden Dependencies via sh calls:

All External calls are made through sh command. Dependencies only revealed at runtime without import in Groovy code.

Source External Types Total Calls
Helpers 10 63
Pipelines (direct) 10 50
Total - 113

Hidden Dependencies via Environment Variables:

Environment Variable Used In Set In
WORKSPACE jsHelper Jenkins (automatic)
COMMIT_HASH jsHelper Jenkinsfile
PR_BRANCH unityHelper Jenkinsfile
CI_PIPELINE unityHelper Jenkinsfile
SSH_KEY generalHelper Jenkins credentials
DLX_WEB_HOST_URL generalHelper Jenkins configuration
UNITY_EXECUTABLE unityHelper Jenkinsfile
PROJECT_DIR unityHelper Jenkinsfile
REPORT_DIR unityHelper Jenkinsfile
BUILD_URL unityHelper Jenkins (automatic)

Analysis: - All 113 external calls are implicit dependencies via sh - Cannot determine required external tools by reading Helper code alone - Tracing environment variable origins requires examining Jenkinsfile

References