feat(skill): add structured workflow to k8s-helm-charts-dev (#817)

Add Research → Planning → Implementation workflow with approval gates,
issue mapping, and extend/contribute strategy for complex Helm chart
development.

### Added

**Reference Files:**
- extend-contribute-strategy.md - Fork vs copy decision, contribution workflow
- research-phase-workflow.md - Structured research with approval gates
- planning-phase-workflow.md - High-level and phase planning with issue mapping
- implementation-workflow.md - Implementation with sanity checks and review stops
- research-strategy.md - Expanded decision table, workflow selection
- chart-complexity.md - Chart complexity classification
- external-services.md - Common ports, env vars, connection strings

**Templates:**
- research-summary.md - Research findings documentation
- high-level-plan.md - High-level chart plan
- phase-plan.md - Per-phase implementation plan
- issue-structure.md - GitHub issue hierarchy

**Patterns:**
- external-database.yaml - MySQL/PostgreSQL configuration
- external-search.yaml - Elasticsearch/OpenSearch configuration
- external-messaging.yaml - Airflow/Kafka/RabbitMQ/Redis configuration
- multi-port-service.yaml - Multiple ports pattern
- jvm-application.yaml - JVM heap/GC/JMX configuration
- health-probes-multiport.yaml - Probes on different ports

### Changed
- SKILL.md - Added "Structured Development Workflow" section
- SKILL.md - Updated Reference Files list

Closes #816
Closes #696

🤖 Generated with [Claude Code](https://claude.ai/claude-code)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: aRustyDev

components/skills/k8s-helm-charts-dev/SKILL.md

@@ -21,6 +21,95 @@ Use this skill when you need to:
 - Set up Helm chart repositories
 - Follow Helm best practices and conventions
 
+## Chart Complexity Classification
+
+Before starting, classify your chart to determine the appropriate approach:
+
+| Level | Characteristics | CI Handling | Example |
+|-------|-----------------|-------------|---------|
+| **Simple** | Single container, no external deps, standard probes | Full lint + install | Static site, simple API |
+| **Standard** | Multiple resources, ConfigMaps/Secrets, optional deps | Full lint + install | Web app with ingress |
+| **Complex** | External services required, multi-port, JVM config | Lint only, skip install | OpenMetadata, data platforms |
+| **Operator** | CRDs, webhooks, cluster-wide resources | Lint only, manual test | Prometheus Operator |
+
+**Quick Decision:**
+- Needs database/search/messaging at runtime? → **Complex** (exclude from install tests)
+- Has admin port separate from main port? → Check `assets/patterns/multi-port-service.yaml`
+- JVM application? → Check `assets/patterns/jvm-application.yaml`
+
+> **Details**: See `references/chart-complexity.md` for full classification guide and CI configuration.
+
+## Research Strategy
+
+Before creating a chart, research the application:
+
+1. **Check for official chart** - Many projects maintain their own Helm charts
+2. **Review Docker documentation** - Container entrypoint, environment variables, ports
+3. **Identify external dependencies** - What services does the app need?
+
+**If documentation scraping fails**, use alternative methods:
+- Search GitHub for existing implementations
+- Check Docker Hub for environment variable documentation
+- Review Kubernetes deployment examples in project repos
+
+> **Details**: See `references/research-strategy.md` for complete fallback strategies and information gathering checklist.
+
+## Structured Development Workflow
+
+For complex charts or when contributing to existing projects, use a structured approach:
+
+### Workflow Selection
+
+| Chart Complexity | Official Chart Exists | Workflow |
+|------------------|----------------------|----------|
+| Simple/Standard | No | **Fast Path** - Quick research, create, validate |
+| Simple/Standard | Yes (use as-is) | **Skip** - Use existing chart |
+| Complex/Operator | No | **Full Workflow** - Research → Plan → Implement |
+| Any | Yes (extend) | **Full Workflow** with contribution strategy |
+
+### Research Phase
+
+Systematically investigate the application before creating templates:
+1. Check for existing charts (official, community)
+2. Gather configuration details (image, ports, env vars)
+3. Document findings in structured format
+4. Get approval for complex applications
+
+> **Details**: See `references/research-phase-workflow.md`
+
+### Planning Phase
+
+Translate research into actionable implementation plan:
+1. Create high-level plan with target features
+2. Break down into atomic components (phases)
+3. Draft phase plans for each component
+4. Get sequential approvals
+5. Map plans to GitHub issues (optional)
+
+> **Details**: See `references/planning-phase-workflow.md`
+
+### Implementation Phase
+
+Execute with quality gates and review checkpoints:
+1. Create worktree and draft PR immediately
+2. Implement following phase plan
+3. Run sanity checks (lint, template, security)
+4. Pause for external review when needed
+5. Submit PR when complete, clean up worktree
+
+> **Details**: See `references/implementation-workflow.md`
+
+### Extending Existing Charts
+
+When an official chart exists but needs improvements:
+1. Decide: fork repo vs copy locally
+2. Review upstream patterns and values schema
+3. Maintain compatibility for contribution
+4. Document differences and improvements
+5. Prepare upstream contribution (PR or patch)
+
+> **Details**: See `references/extend-contribute-strategy.md`
+
 ## Helm Overview
 
 **Helm** is the package manager for Kubernetes that:
@@ -499,6 +588,37 @@ global:
 image: {{ .Values.global.imageRegistry }}/{{ .Values.image.repository }}
 ```
 
+## Pattern Templates
+
+Ready-to-use patterns for common scenarios. Copy values and template sections to your chart.
+
+### External Services
+
+| Pattern | Use When | File |
+|---------|----------|------|
+| Database | Chart connects to MySQL or PostgreSQL | `assets/patterns/external-database.yaml` |
+| Search | Chart connects to Elasticsearch or OpenSearch | `assets/patterns/external-search.yaml` |
+| Messaging | Chart connects to Airflow, Kafka, RabbitMQ, or Redis | `assets/patterns/external-messaging.yaml` |
+
+All patterns include:
+- Values structure with `existingSecret` support
+- Helper template functions
+- Environment variable configuration
+- Example configurations
+
+### Application Architecture
+
+| Pattern | Use When | File |
+|---------|----------|------|
+| Multi-Port Service | App has main + admin/metrics ports | `assets/patterns/multi-port-service.yaml` |
+| JVM Application | Java/Kotlin/Scala app needing heap/GC config | `assets/patterns/jvm-application.yaml` |
+| Health Probes (Multi-Port) | Different probes on different ports | `assets/patterns/health-probes-multiport.yaml` |
+
+### Quick Reference
+
+For port numbers, environment variables, and connection strings:
+- `references/external-services.md` - Common services reference table
+
 ## Best Practices
 
 1. **Use semantic versioning** for chart and app versions
@@ -533,10 +653,36 @@ kubectl get events --sort-by='.lastTimestamp'
 
 ## Reference Files
 
+### Chart Templates
 - `assets/Chart.yaml.template` - Chart metadata template
 - `assets/values.yaml.template` - Values structure template
-- `scripts/validate-chart.sh` - Validation script
+
+### Pattern Files
+- `assets/patterns/external-database.yaml` - MySQL/PostgreSQL configuration
+- `assets/patterns/external-search.yaml` - Elasticsearch/OpenSearch configuration
+- `assets/patterns/external-messaging.yaml` - Airflow/Kafka/RabbitMQ/Redis configuration
+- `assets/patterns/multi-port-service.yaml` - Multiple ports pattern
+- `assets/patterns/jvm-application.yaml` - JVM heap/GC/JMX configuration
+- `assets/patterns/health-probes-multiport.yaml` - Probes on different ports
+
+### Workflow Templates
+- `assets/templates/research-summary.md` - Research findings documentation
+- `assets/templates/high-level-plan.md` - High-level chart plan
+- `assets/templates/phase-plan.md` - Per-phase implementation plan
+- `assets/templates/issue-structure.md` - GitHub issue hierarchy
+
+### References
 - `references/chart-structure.md` - Detailed chart organization
+- `references/chart-complexity.md` - Chart complexity classification guide
+- `references/research-strategy.md` - Documentation research and fallback strategies
+- `references/external-services.md` - Common ports, env vars, connection strings
+- `references/extend-contribute-strategy.md` - Extending and contributing to existing charts
+- `references/research-phase-workflow.md` - Research phase structured workflow
+- `references/planning-phase-workflow.md` - Planning phase structured workflow
+- `references/implementation-workflow.md` - Implementation phase with checkpoints
+
+### Scripts
+- `scripts/validate-chart.sh` - Validation script
 
 ## Related Skills
 

components/skills/k8s-helm-charts-dev/assets/patterns/external-database.yaml

@@ -0,0 +1,220 @@
+# =============================================================================
+# External Database Configuration Pattern
+# =============================================================================
+# Use this pattern when chart connects to an EXISTING external database
+# rather than deploying a database as a subchart dependency.
+#
+# Supports: MySQL, PostgreSQL, MariaDB
+#
+# Usage:
+#   1. Copy the values section to your values.yaml
+#   2. Copy the helper templates to your _helpers.tpl
+#   3. Copy the environment variable section to your deployment.yaml
+# =============================================================================
+
+# -----------------------------------------------------------------------------
+# VALUES.YAML SECTION
+# -----------------------------------------------------------------------------
+# Copy this to your values.yaml under a 'database:' key
+
+database:
+  # -- Database type: mysql, postgres, or mariadb
+  type: mysql
+
+  # -- External database host (required)
+  host: ""
+
+  # -- Database port (3306 for MySQL/MariaDB, 5432 for PostgreSQL)
+  port: 3306
+
+  # -- Database name
+  name: "app_db"
+
+  # -- Database username
+  username: ""
+
+  # -- Database password (use existingSecret in production)
+  password: ""
+
+  # -- Use existing Kubernetes secret for database credentials
+  # If set, password field is ignored
+  existingSecret: ""
+
+  # -- Key in existing secret containing the password
+  existingSecretKey: "password"
+
+  # -- Additional JDBC connection parameters
+  # MySQL example: "useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true"
+  # PostgreSQL example: "sslmode=require"
+  params: ""
+
+  # -- Connection pool settings (if supported by application)
+  pool:
+    # -- Minimum pool size
+    minSize: 5
+    # -- Maximum pool size
+    maxSize: 20
+    # -- Connection timeout in milliseconds
+    connectionTimeout: 30000
+
+# -----------------------------------------------------------------------------
+# HELPERS.TPL SECTION
+# -----------------------------------------------------------------------------
+# Copy these helper templates to your templates/_helpers.tpl
+
+# {{/*
+# Database JDBC URL
+# */}}
+# {{- define "<chart>.databaseUrl" -}}
+# {{- $params := "" }}
+# {{- if .Values.database.params }}
+# {{- $params = printf "?%s" .Values.database.params }}
+# {{- end }}
+# {{- if eq .Values.database.type "mysql" }}
+# {{- printf "jdbc:mysql://%s:%d/%s%s" .Values.database.host (int .Values.database.port) .Values.database.name $params }}
+# {{- else if eq .Values.database.type "mariadb" }}
+# {{- printf "jdbc:mariadb://%s:%d/%s%s" .Values.database.host (int .Values.database.port) .Values.database.name $params }}
+# {{- else if eq .Values.database.type "postgres" }}
+# {{- printf "jdbc:postgresql://%s:%d/%s%s" .Values.database.host (int .Values.database.port) .Values.database.name $params }}
+# {{- end }}
+# {{- end }}
+
+# {{/*
+# Database driver class name
+# */}}
+# {{- define "<chart>.databaseDriver" -}}
+# {{- if eq .Values.database.type "mysql" }}
+# {{- "com.mysql.cj.jdbc.Driver" }}
+# {{- else if eq .Values.database.type "mariadb" }}
+# {{- "org.mariadb.jdbc.Driver" }}
+# {{- else if eq .Values.database.type "postgres" }}
+# {{- "org.postgresql.Driver" }}
+# {{- end }}
+# {{- end }}
+
+# {{/*
+# Database dialect (for ORMs like Hibernate)
+# */}}
+# {{- define "<chart>.databaseDialect" -}}
+# {{- if eq .Values.database.type "mysql" }}
+# {{- "org.hibernate.dialect.MySQL8Dialect" }}
+# {{- else if eq .Values.database.type "mariadb" }}
+# {{- "org.hibernate.dialect.MariaDB103Dialect" }}
+# {{- else if eq .Values.database.type "postgres" }}
+# {{- "org.hibernate.dialect.PostgreSQL10Dialect" }}
+# {{- end }}
+# {{- end }}
+
+# -----------------------------------------------------------------------------
+# DEPLOYMENT.YAML ENVIRONMENT SECTION
+# -----------------------------------------------------------------------------
+# Copy this to your deployment.yaml container env section
+
+# env:
+#   # Database connection details
+#   - name: DB_TYPE
+#     value: {{ .Values.database.type | quote }}
+#   - name: DB_HOST
+#     value: {{ .Values.database.host | quote }}
+#   - name: DB_PORT
+#     value: {{ .Values.database.port | quote }}
+#   - name: DB_NAME
+#     value: {{ .Values.database.name | quote }}
+#   - name: DB_USER
+#     value: {{ .Values.database.username | quote }}
+#   - name: DB_PASSWORD
+#     {{- if .Values.database.existingSecret }}
+#     valueFrom:
+#       secretKeyRef:
+#         name: {{ .Values.database.existingSecret }}
+#         key: {{ .Values.database.existingSecretKey }}
+#     {{- else }}
+#     value: {{ .Values.database.password | quote }}
+#     {{- end }}
+#   # Optional: JDBC URL (if application uses single URL)
+#   - name: DB_URL
+#     value: {{ include "<chart>.databaseUrl" . | quote }}
+#   - name: DB_DRIVER
+#     value: {{ include "<chart>.databaseDriver" . | quote }}
+
+# -----------------------------------------------------------------------------
+# ALTERNATIVE: DATABASE_URL STYLE (Node.js, Rails, etc.)
+# -----------------------------------------------------------------------------
+# Some applications prefer a single connection URL
+
+# env:
+#   - name: DATABASE_URL
+#     {{- if .Values.database.existingSecret }}
+#     valueFrom:
+#       secretKeyRef:
+#         name: {{ .Values.database.existingSecret }}
+#         key: database-url
+#     {{- else }}
+#     {{- if eq .Values.database.type "postgres" }}
+#     value: "postgresql://{{ .Values.database.username }}:{{ .Values.database.password }}@{{ .Values.database.host }}:{{ .Values.database.port }}/{{ .Values.database.name }}"
+#     {{- else }}
+#     value: "mysql://{{ .Values.database.username }}:{{ .Values.database.password }}@{{ .Values.database.host }}:{{ .Values.database.port }}/{{ .Values.database.name }}"
+#     {{- end }}
+#     {{- end }}
+
+# -----------------------------------------------------------------------------
+# NOTES.TXT SECTION
+# -----------------------------------------------------------------------------
+# Add database connection info to NOTES.txt
+
+# {{- if .Values.database.host }}
+# Database Configuration:
+#   Type: {{ .Values.database.type }}
+#   Host: {{ .Values.database.host }}:{{ .Values.database.port }}
+#   Database: {{ .Values.database.name }}
+#   User: {{ .Values.database.username }}
+# {{- else }}
+# WARNING: Database host is not configured!
+# Set database.host in your values to connect to your database.
+# {{- end }}
+
+# -----------------------------------------------------------------------------
+# COMMON PORTS REFERENCE
+# -----------------------------------------------------------------------------
+# | Database   | Default Port |
+# |------------|--------------|
+# | MySQL      | 3306         |
+# | PostgreSQL | 5432         |
+# | MariaDB    | 3306         |
+# | MongoDB    | 27017        |
+# | Cassandra  | 9042         |
+# | CockroachDB| 26257        |
+
+# -----------------------------------------------------------------------------
+# EXAMPLE VALUES FOR DIFFERENT SCENARIOS
+# -----------------------------------------------------------------------------
+
+# MySQL in same cluster:
+# database:
+#   type: mysql
+#   host: mysql.database.svc.cluster.local
+#   port: 3306
+#   name: myapp
+#   username: myapp
+#   existingSecret: myapp-db-credentials
+#   existingSecretKey: password
+
+# PostgreSQL with SSL:
+# database:
+#   type: postgres
+#   host: postgres.example.com
+#   port: 5432
+#   name: myapp
+#   username: myapp
+#   existingSecret: myapp-db-credentials
+#   params: "sslmode=require"
+
+# AWS RDS MySQL:
+# database:
+#   type: mysql
+#   host: myapp.xxxxx.us-east-1.rds.amazonaws.com
+#   port: 3306
+#   name: myapp
+#   username: admin
+#   existingSecret: rds-credentials
+#   params: "useSSL=true&requireSSL=true"