Problem Statement

The WINC test suite currently uses 35+ static YAML template files in test/extended/testdata/winc/. Many of these files are near-duplicates with minor variations:

Windows Web Server variants (7 files):

• windows_web_server.yaml
• windows_web_server_no_taint.yaml
• windows_web_server_pvc.yaml
• windows_web_server_scaler.yaml
• windows_webserver_secondary_os.yaml
• windows_webserver_projected_volume.yaml
• windows_web_server_disconnected.yaml

Machineset templates (10 files):

• 5 platform-specific Windows machinesets (AWS, Azure, GCP, vSphere, Nutanix)
• 5 BYOH machinesets (being removed in WINC-1508)

Note: windows_web_server_byoh.yaml and the 5 BYOH machineset templates will be removed by WINC-1508 and are excluded from this consolidation effort.

This creates significant maintenance overhead:

• Changes to common structure must be duplicated across multiple files
• Easy to introduce inconsistencies between variants
• Difficult to understand what differentiates each template
• Hard to create new test variants
• Increases file count and repository size

Proposed Solution

Implement a Go template-based system using Go's text/template package to consolidate test templates. This will reduce file count by ~70% while maintaining full backward compatibility.

Scope: Focus on Windows web server templates (Phase 1) with optional expansion to machinesets (Phase 3), coordinating with WINC-1508 for BYOH removal.

Objectives

1. Reduce Windows web server template file count from 7 to 1 consolidated template
2. Improve maintainability through centralized template definitions
3. Add type safety to template configuration
4. Enable easier creation of new test variants
5. Support both file-based and stdin-based (oc apply -f -) deployment
6. Maintain backward compatibility with existing tests
7. Coordinate with WINC-1508 to avoid conflicts with BYOH template removal

Proposed Approach

Phase 1: Infrastructure Setup (Windows Web Server Templates)

1. Create Consolidated Template

• Create windows_web_server_template.yaml using Go text/template syntax
• Support 7 existing Windows web server variants through configuration (excluding BYOH)
• Use conditional blocks ({{ {\{if\}}

  ..{{

  {\{end\}}

  }}) for optional sections

• Support dynamic values through template variables

2. Add Type-Safe Configuration

• Create WindowsWebServerConfig struct in test/extended/winc/utils.go
• Add fields for all configuration options:
  • Service inclusion
  • Tolerations
  • Security context
  • Replica count
  • PVC mounting
  • Resource limits
  • Node selectors
  • Image pull secrets
  • PowerShell version
  • OS label styles
• Add NewDefaultWindowsWebServerConfig() helper function
• Import text/template package

3. Implement Template Functions

• Create createWorkloadFromTemplate() function for file-based deployment
• Create createWorkloadFromTemplateWithStdin() function for stdin-based deployment
• Handle template parsing, execution, and error checking
• Support waiting for workload readiness

4. Documentation

• Create migration guide with before/after examples
• Document all configuration options
• Provide usage examples for each template variant
• Include troubleshooting guide

Phase 2: Migration (Optional - Future Ticket)

• Update test/extended/winc/winc.go to use new template system
• Update test/extended/winc/storage.go to use new template system
• Update other test files using Windows web server templates
• Verify all tests pass in CI
• Remove old static YAML files (coordinate with WINC-1508)

Phase 3: Expansion to Machinesets (Future Ticket)

• Wait for WINC-1508 BYOH removal to complete
• Apply same pattern to remaining machineset templates (5 platforms, Windows only)
• Create per-platform consolidated templates
• Further reduce file count

Technical Design

Template System Architecture

Test Code (*.go)
    ↓
WindowsWebServerConfig (typed configuration)
    ↓
createWorkloadFromTemplate[WithStdin]()
    ↓
text/template.Execute()
    ↓
windows_web_server_template.yaml
    ↓
Generated YAML
    ↓
oc apply -f <file> OR oc apply -f -

Configuration Example

Current approach (map of strings):

createWorkload(oc, namespace, "windows_web_server_pvc.yaml",
    map[string]string{
        "<id>": pvc,
        "<pvc-name>": pvc,
        "<windows_container_image>": image,
        "<node-selector>": nodeSelector,
    },
    false, windowsWorkloads+"-"+pvc)

Proposed approach (type-safe struct):

config := NewDefaultWindowsWebServerConfig()
config.ImageName = image
config.NameSuffix = pvc
config.PVCName = pvc
config.Replicas = 3
config.AdditionalNodeSelector = nodeSelector

createWorkloadFromTemplateWithStdin(oc, namespace,
    "windows_web_server_template.yaml", config, false, windowsWorkloads+"-"+pvc)

Template Consolidation Mapping

Expected Benefits

1. Reduced Maintenance: Common changes only need to be made once in the template
2. Type Safety: Configuration validated at compile time, preventing typos in placeholder strings
3. Improved Clarity: Explicit configuration shows what makes each test variant different
4. Easier Testing: Create new test variants without creating new files
5. Better Efficiency: Stdin mode eliminates temp file I/O overhead
6. Supports OTE Migration: Cleaner codebase makes framework migration easier (WINC-1536)
7. No Conflicts with BYOH Removal: Work is coordinated with WINC-1508

Implementation Tasks

Required Work (Phase 1)

1. Create windows_web_server_template.yaml with Go template syntax
2. Add WindowsWebServerConfig struct to utils.go
3. Add text/template import to utils.go
4. Implement createWorkloadFromTemplate() function
5. Implement createWorkloadFromTemplateWithStdin() function
6. Add NewDefaultWindowsWebServerConfig() helper function
7. Create comprehensive migration guide
8. Create usage examples for all 7 template variants (excluding BYOH)
9. Add testing utilities
10. Validate template syntax and rendering

Coordination Required

1. Verify WINC-1508 status and timeline for BYOH removal
2. Ensure no conflicts with BYOH template removal work
3. Document that BYOH templates are excluded from this effort

Optional Follow-up Work (Future Tickets)

1. Migrate existing test code to use new template system
2. Remove old static YAML files (after WINC-1508 completes)
3. Create machineset templates for each cloud provider (5 platforms)
4. Consolidate other resource templates

Acceptance Criteria

Phase 1: Infrastructure (Core Deliverable)

• [ ] windows_web_server_template.yaml created with Go template syntax supporting 7 variants
• [ ] WindowsWebServerConfig struct implemented with all required fields
• [ ] createWorkloadFromTemplate() function implemented and tested
• [ ] createWorkloadFromTemplateWithStdin() function implemented and tested
• [ ] NewDefaultWindowsWebServerConfig() helper function created
• [ ] Template syntax validated (no parsing errors)
• [ ] Documentation created:
  • Migration guide with before/after examples
  • Usage examples for all template variants
  • Configuration reference
  • Troubleshooting guide
• [ ] Can generate YAML equivalent to all 7 original template files (excluding BYOH)
• [ ] No breaking changes to existing tests
• [ ] No conflicts with WINC-1508 BYOH removal work

Phase 2: Migration (Optional - Future Ticket)

• [ ] All test files migrated to use new template system
• [ ] All tests pass in CI
• [ ] Old static YAML files removed (coordinate timing with WINC-1508)
• [ ] Code review completed

Phase 3: Expansion (Future Ticket - After WINC-1508)

• [ ] WINC-1508 BYOH removal completed
• [ ] Machineset templates created for 5 platforms (Windows only)
• [ ] Additional resource templates consolidated
• [ ] Template best practices documented

Success Metrics

• Windows web server file count reduction: 7 files → 1 template (86% reduction)
• Potential overall reduction after Phase 3: ~29 files → ~8-10 templates (65-70% reduction)
• Zero test failures introduced by migration
• Improved code review velocity (less duplication to review)
• Easier for team members to create new test variants
• Clean coordination with WINC-1508 (no merge conflicts)

Dependencies and Related Work

Dependencies

• None - this work is independent and can proceed immediately
• However, Phase 3 (machineset consolidation) should wait for WINC-1508 to complete

Related Issues

• WINC-1536 (Epic): Stabilize and Migrate WINC Tests to OpenShift Tests Extension (OTE)
  • This work supports test stabilization and cleaner codebase for OTE migration

• WINC-1508: Remove BYOH template support
  • Affects 6 files: windows_web_server_byoh.yaml + 5 BYOH machineset templates
  • This consolidation effort excludes BYOH templates to avoid conflicts
  • Phase 3 machineset consolidation should wait for WINC-1508 completion

Coordination Plan

1. Phase 1 (this ticket): Focus only on Windows web server templates (excludes BYOH)
2. WINC-1508: Removes BYOH templates independently
3. Phase 2 (future): Migrate code to use new templates (after both efforts stabilize)
4. Phase 3 (future): Consolidate remaining machineset templates (after WINC-1508 completes)

Risks and Mitigations

Risk: Conflicts with WINC-1508 BYOH removal
Mitigation: Explicitly exclude BYOH templates from consolidation scope

Risk: Breaking existing tests during migration
Mitigation: Keep old templates until migration is complete and verified in CI

Risk: Template syntax errors
Mitigation: Validate templates before use, add unit tests for template rendering

Risk: Team unfamiliarity with Go templates
Mitigation: Provide comprehensive documentation and examples

Timeline Estimate

• Phase 1 (Infrastructure): 3-5 days
• Phase 2 (Migration): 3-5 days (future ticket, coordinate with WINC-1508)
• Phase 3 (Expansion): 5-8 days (future ticket, after WINC-1508)

Story Points

Recommended: 5 Story Points (Phase 1 only)

• Medium complexity
• Clear requirements
• Well-defined scope
• Excludes migration and expansion work

Resources

• Go text/template documentation: https://pkg.go.dev/text/template
• Existing test files: test/extended/testdata/winc/
• Existing utilities: test/extended/winc/utils.go
• Related epic: https://issues.redhat.com/browse/WINC-1536
• Related issue: https://issues.redhat.com/browse/WINC-1508