Skip to content
This repository was archived by the owner on Oct 10, 2025. It is now read-only.

Commit cb944e0

Browse files
committed
docs: integrate provisioning strategy analysis across redesign phases
- Enhanced phase2-analysis/02-automation-and-tooling.md with comprehensive provisioning strategy comparison (cloud-init vs Ansible approaches) - Added technology stack simplification analysis (4-tech to 3-tech stack) - Enhanced phase2-analysis/04-testing-strategy.md with container-based testing strategy and VM testing limitations analysis - Created phase3-design/provisioning-strategy-adr.md documenting architectural decision for minimal cloud-init + Ansible hybrid approach - Integrated Ansible molecule testing methodology and implementation strategy - Documented rationale, consequences, and alternative approaches considered Strategic content distribution across analysis (technical comparison) and design (architectural decision) phases while maintaining documentation patterns and markdown compliance.
1 parent 96954c5 commit cb944e0

File tree

3 files changed

+318
-0
lines changed

3 files changed

+318
-0
lines changed

docs/redesign/phase2-analysis/02-automation-and-tooling.md

Lines changed: 65 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -58,3 +58,68 @@ ensuring consistency and reproducibility.
5858
- Jinja2 (if using Python).
5959
- Go's `text/template` package (if using Go).
6060
- Tools like Ansible for more complex configuration and orchestration tasks.
61+
62+
## Provisioning Strategy Analysis
63+
64+
### Current Approach: Cloud-init + Shell Scripts
65+
66+
The current PoC uses cloud-init for initial VM provisioning combined with shell scripts
67+
for application deployment. This hybrid approach has both strengths and limitations:
68+
69+
**Strengths**:
70+
71+
- **Fast Initial Setup**: Cloud-init provides rapid system initialization
72+
- **Provider Agnostic**: Works consistently across libvirt, Hetzner, AWS
73+
- **Minimal Dependencies**: Uses standard Linux tools and Docker
74+
75+
**Limitations**:
76+
77+
- **Complex Debugging**: Cloud-init failures are difficult to diagnose
78+
- **Limited Flexibility**: Hard to implement complex conditional logic
79+
- **Testing Challenges**: Requires full VM lifecycle for validation
80+
81+
### Recommendation: Minimal Cloud-init + Ansible Hybrid
82+
83+
Based on analysis of production requirements and testing constraints, the recommended
84+
approach for the redesign is:
85+
86+
**Cloud-init Role (Minimal)**:
87+
88+
- Basic system setup (users, SSH keys, packages)
89+
- Docker and essential service installation
90+
- Network and security configuration
91+
- Ansible prerequisites installation
92+
93+
**Ansible Role (Primary)**:
94+
95+
- Application configuration and deployment
96+
- Service orchestration and health checks
97+
- Environment-specific customization
98+
- Operational procedures (backups, monitoring)
99+
100+
### Benefits of This Approach
101+
102+
1. **Improved Testability**: Ansible playbooks can be tested with molecule and Docker,
103+
eliminating the need for VM-based testing in most scenarios
104+
2. **Better Debugging**: Ansible provides clear output, logging, and error handling
105+
3. **Enhanced Maintainability**: Ansible's declarative syntax is more maintainable than
106+
shell scripts
107+
4. **CI/CD Compatibility**: Ansible tests run efficiently in standard CI environments
108+
5. **Reduced Complexity**: Eliminates 4-technology stack (Terraform + cloud-init + Docker + shell)
109+
in favor of 3-technology stack (Terraform + Ansible + Docker)
110+
111+
### Technology Stack Simplification
112+
113+
**Current Stack**:
114+
115+
- **Infrastructure**: OpenTofu/Terraform
116+
- **Provisioning**: Cloud-init + shell scripts
117+
- **Services**: Docker Compose
118+
- **Automation**: Complex shell script orchestration
119+
120+
**Recommended Stack**:
121+
122+
- **Infrastructure**: OpenTofu/Terraform
123+
- **Configuration Management**: Ansible
124+
- **Services**: Docker Compose
125+
- **Automation**: Simplified orchestration with proper error handling

docs/redesign/phase2-analysis/04-testing-strategy.md

Lines changed: 74 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -91,3 +91,77 @@ well-thought-out, providing a solid foundation for ensuring reliability and qual
9191
provider to run the tests.
9292
- **Alternative Virtualization**: Exploring technologies like Docker-in-Docker if
9393
they can adequately simulate the target environment.
94+
95+
## Container-Based Testing Strategy
96+
97+
### Current Challenge: VM-Dependent Testing
98+
99+
The current PoC requires full VM lifecycle testing for validation, which creates significant
100+
CI/CD friction:
101+
102+
**VM-Based Testing Limitations**:
103+
104+
- **Long Execution Time**: 8-12 minutes per test cycle including VM provisioning
105+
- **Resource Intensive**: Requires KVM/libvirt support, significant CPU/memory
106+
- **CI/CD Incompatibility**: Standard CI runners don't support nested virtualization
107+
- **Debugging Complexity**: Infrastructure failures obscure application issues
108+
- **Cost and Complexity**: Requires specialized runners or cloud resources
109+
110+
### Recommended: Container-First Testing Approach
111+
112+
The redesign should prioritize Docker-based testing strategies that eliminate VM dependencies
113+
for most test scenarios:
114+
115+
**Container Testing Benefits**:
116+
117+
1. **Speed**: Container startup in seconds vs. minutes for VMs
118+
2. **CI/CD Native**: All major CI platforms support Docker containers
119+
3. **Resource Efficiency**: Lower CPU, memory, and storage requirements
120+
4. **Reproducibility**: Consistent environment across local and CI systems
121+
5. **Debugging**: Direct access to application logs and state
122+
123+
### Three-Layer Testing Architecture (Enhanced)
124+
125+
#### Layer 1: Unit Tests (Container-Based)
126+
127+
- **Scope**: Individual component testing in isolated containers
128+
- **Tools**: pytest, jest, cargo test, etc.
129+
- **Execution**: Seconds, runs on every commit
130+
- **Environment**: Docker containers with minimal dependencies
131+
132+
#### Layer 2: Integration Tests (Container-Based)
133+
134+
- **Scope**: Multi-service testing with Docker Compose
135+
- **Tools**: Docker Compose, Testcontainers, pytest-docker
136+
- **Execution**: 1-3 minutes, runs on every commit
137+
- **Environment**: Full application stack in containers
138+
139+
#### Layer 3: E2E Tests (Minimal VM Usage)
140+
141+
- **Scope**: Full deployment validation (reserved for critical scenarios)
142+
- **Tools**: Terraform + cloud providers for real infrastructure testing
143+
- **Execution**: 5-10 minutes, runs on PR merge or nightly
144+
- **Environment**: Actual cloud infrastructure (staging environments)
145+
146+
### Implementation Strategy
147+
148+
**Ansible + Molecule Testing**:
149+
150+
- Use Ansible molecule with Docker driver for configuration testing
151+
- Test playbooks against various OS distributions in containers
152+
- Validate service configuration and health checks
153+
- Eliminate VM dependency for configuration management testing
154+
155+
**Application Integration Testing**:
156+
157+
- Docker Compose environments for full stack testing
158+
- Test tracker functionality with containerized MySQL, Nginx, monitoring
159+
- Validate API endpoints, UDP/HTTP tracker protocols
160+
- Use testcontainers for database and external service mocking
161+
162+
**Infrastructure Validation**:
163+
164+
- Reserve VM/cloud testing for infrastructure-specific scenarios
165+
- Use staging environments for periodic full integration validation
166+
- Implement blue-green deployment testing in production-like environments
167+
- Focus VM testing on provider-specific networking, security, and performance
Lines changed: 179 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,179 @@
1+
# ADR: Provisioning Strategy - Minimal Cloud-init + Ansible
2+
3+
## Status
4+
5+
**Proposed** - Based on comprehensive analysis of current PoC limitations and production requirements
6+
7+
## Context
8+
9+
The current PoC uses a cloud-init + shell script approach for VM provisioning and application
10+
deployment. While this approach works for demonstration purposes, it presents significant
11+
challenges for production use and testing automation:
12+
13+
### Current Approach Limitations
14+
15+
**Cloud-init Heavy Approach**:
16+
17+
- Complex debugging when provisioning fails
18+
- Limited conditional logic capabilities
19+
- Difficult to test without full VM lifecycle
20+
- Shell script brittleness and maintenance overhead
21+
- Poor CI/CD integration due to VM dependencies
22+
23+
**Testing Challenges**:
24+
25+
- 8-12 minute test cycles including VM provisioning
26+
- Requires KVM/libvirt support for testing
27+
- Standard CI runners don't support nested virtualization
28+
- Infrastructure failures obscure application issues
29+
- High resource requirements (CPU, memory, storage)
30+
31+
**Technology Stack Complexity**:
32+
33+
- 4-technology stack: Terraform + Cloud-init + Docker + Shell scripts
34+
- Complex orchestration between different tooling approaches
35+
- Inconsistent error handling and logging across tools
36+
37+
## Decision
38+
39+
**Adopt a minimal cloud-init + Ansible hybrid approach** for the production redesign:
40+
41+
### Cloud-init Role (Minimal)
42+
43+
Cloud-init will handle only essential system initialization:
44+
45+
- Basic system setup (users, SSH keys, network)
46+
- Package manager configuration and essential packages
47+
- Docker installation and daemon configuration
48+
- Security configuration (firewall, fail2ban, SSH hardening)
49+
- Ansible prerequisites (Python, pip, ansible-core)
50+
51+
### Ansible Role (Primary)
52+
53+
Ansible will handle all application-level configuration and deployment:
54+
55+
- Application configuration management
56+
- Service deployment and orchestration
57+
- Health checks and validation
58+
- Environment-specific customization
59+
- Operational procedures (backups, monitoring, updates)
60+
61+
### Technology Stack Simplification
62+
63+
**Target Stack**:
64+
65+
- **Infrastructure**: OpenTofu/Terraform
66+
- **Configuration Management**: Ansible
67+
- **Services**: Docker Compose
68+
- **Testing**: Container-first with minimal VM validation
69+
70+
## Rationale
71+
72+
### 1. Improved Testability
73+
74+
**Container-Based Testing**: Ansible playbooks can be tested using molecule with Docker driver,
75+
eliminating VM dependencies for most test scenarios:
76+
77+
- **Speed**: Container startup in seconds vs. minutes for VMs
78+
- **CI/CD Native**: Standard CI platforms support Docker containers
79+
- **Resource Efficiency**: Lower CPU, memory, and storage requirements
80+
- **Debugging**: Direct access to application logs and state
81+
82+
### 2. Enhanced Maintainability
83+
84+
**Declarative Configuration**: Ansible's YAML-based declarative syntax is more maintainable
85+
than shell scripts:
86+
87+
- Clear, readable configuration management
88+
- Built-in idempotency guarantees
89+
- Comprehensive error handling and logging
90+
- Large ecosystem of community modules
91+
92+
### 3. Production Readiness
93+
94+
**Operational Excellence**: Ansible provides production-grade capabilities:
95+
96+
- Role-based organization for reusability
97+
- Inventory management for multi-environment deployments
98+
- Vault integration for secret management
99+
- Comprehensive logging and audit trails
100+
101+
### 4. CI/CD Compatibility
102+
103+
**Testing Strategy**: Container-first approach enables efficient CI/CD pipelines:
104+
105+
- Unit tests: Individual components in containers (seconds)
106+
- Integration tests: Multi-service Docker Compose (1-3 minutes)
107+
- E2E tests: Reserved for critical scenarios with real infrastructure (5-10 minutes)
108+
109+
## Implementation Strategy
110+
111+
### Phase 1: Core Infrastructure
112+
113+
1. **Minimal Cloud-init Templates**: Create lean cloud-init configurations focused on system initialization
114+
2. **Ansible Playbook Structure**: Develop role-based playbooks for application deployment
115+
3. **Container Testing**: Implement molecule-based testing for Ansible roles
116+
117+
### Phase 2: Application Integration
118+
119+
1. **Service Orchestration**: Migrate Docker Compose management to Ansible
120+
2. **Configuration Management**: Replace envsubst templating with Ansible Jinja2
121+
3. **Health Checks**: Implement comprehensive service validation
122+
123+
### Phase 3: Testing and Validation
124+
125+
1. **Container Test Suite**: Comprehensive Docker-based testing
126+
2. **Integration Validation**: Multi-service container testing
127+
3. **Minimal E2E**: Strategic VM testing for infrastructure validation
128+
129+
## Consequences
130+
131+
### Positive
132+
133+
- **Faster Development Cycles**: Container-based testing reduces feedback loops
134+
- **Better CI/CD Integration**: Standard CI platforms support Docker natively
135+
- **Improved Debugging**: Clear error messages and logging from Ansible
136+
- **Enhanced Maintainability**: Declarative configuration over imperative scripts
137+
- **Production Readiness**: Industry-standard configuration management practices
138+
- **Reduced Complexity**: 3-technology stack vs. current 4-technology approach
139+
140+
### Negative
141+
142+
- **Learning Curve**: Team needs Ansible expertise
143+
- **Migration Effort**: Requires refactoring existing shell script logic
144+
- **Initial Complexity**: Setting up molecule testing framework
145+
146+
### Risks and Mitigation
147+
148+
**Risk**: Ansible playbook complexity could become unwieldy
149+
**Mitigation**: Use role-based organization and follow Ansible best practices
150+
151+
**Risk**: Container testing might miss infrastructure-specific issues
152+
**Mitigation**: Maintain strategic E2E testing for critical infrastructure scenarios
153+
154+
## Alternative Approaches Considered
155+
156+
### 1. Pure Cloud-init Approach
157+
158+
**Rejected**: Maintains testing challenges and limited flexibility for complex logic
159+
160+
### 2. Ansible-Only (No Cloud-init)
161+
162+
**Rejected**: Requires more complex initial connectivity setup and provider-specific handling
163+
164+
### 3. Shell Script Enhancement
165+
166+
**Rejected**: Doesn't address fundamental testing and maintainability issues
167+
168+
## References
169+
170+
- [Ansible Best Practices](https://docs.ansible.com/ansible/latest/user_guide/playbooks_best_practices.html)
171+
- [Molecule Testing Framework](https://molecule.readthedocs.io/)
172+
- [Testcontainers Documentation](https://www.testcontainers.org/)
173+
- [Docker Compose Testing Strategies](https://docs.docker.com/compose/)
174+
175+
## Related Decisions
176+
177+
- **Testing Strategy**: Three-layer architecture with container-first approach
178+
- **Configuration Management**: Ansible Jinja2 templating over envsubst
179+
- **Technology Stack**: Simplified 3-component architecture

0 commit comments

Comments
 (0)