GitOps Stack Technical Reference

Stack Components

Core Technologies

• Docker: Container runtime with Alpine Linux/glibc compatibility issues
• Kubernetes: Container orchestration with complex debugging requirements
• ArgoCD: GitOps controller with sync reliability challenges
• Prometheus Stack: Monitoring with high resource consumption

Implementation Approaches

Approach	Setup Time	Production Ready	Customization	Best For
GitOps Playground	15-30 min	Development only	Limited	Learning/prototyping
Helm-Based	2-4 hours	Yes with customization	High	Small-medium production
Custom Manifests	8-16 hours	Fully customizable	Complete control	Large enterprise
Enterprise Platform	1-2 hours	Enterprise-grade	Platform-specific	Enterprise with budget

Critical Failure Modes

ArgoCD "Too Long" Annotation Error

• Cause: Prometheus CRDs exceed 262KB Kubernetes annotation limit
• Symptoms: metadata.annotations: Too long: must have at most 262144 bytes
• Solution: Deploy CRDs separately with Replace=true, use skipCrds: true for main chart
• Time Cost: 4+ hours debugging if unknown

Dependency Hell

• Cause: ArgoCD deploys resources in random order by default
• Symptoms: Apps crash with "ConfigMap not found" errors
• Solution: Use sync waves - infrastructure -1, services 0, apps 1+
• Implementation: argocd.argoproj.io/sync-wave: "-1"

Secret Management Failures

• Never: Put secrets in Git repositories
• Use: External Secrets Operator with Vault/AWS/Azure
• Risk: Vault unreachable = complete system failure
• Mitigation: Separate monitoring for secret providers

Resource Requirements (Production)

Minimum Resource Allocation

• ArgoCD: 2-4 cores, 4-8GB RAM (scales with application count)
• Prometheus: 4-8 cores, 8-16GB RAM (scales with cardinality)
• Grafana: 1-2 cores, 2-4GB RAM
• Total Monitoring: 15+ cores, 30+ GB RAM for 50+ services

Performance Thresholds

• ArgoCD: Performance degrades at 50+ applications
• Prometheus: Memory doubles with high-cardinality labels
• UI Responsiveness: Becomes unusable with single ArgoCD at scale

Production Breaking Points

Scale Limits

• Single ArgoCD: Unusable UI and sync timeouts at 50+ apps
• Solution: Shard ArgoCD or deploy per environment
• Alternative: ApplicationSets for templating across clusters

Memory Consumption

• Prometheus: Consumes more RAM than monitored applications
• Cardinality Impact: Labels like user_id, request_id double memory usage
• Mitigation: 30-day retention, reduced scrape intervals, recording rules

Repository Structure Failures

• Monorepo: Becomes unmaintainable at scale
• Solution: Separate repos per environment
• Tools: Kustomize for environment configs, Helm for templates

Common Troubleshooting

ArgoCD Stuck Syncing

Root Causes:

• Competing operators fighting over resources
• Admission webhooks timing out (OPA)
• RBAC permission failures
• Jobs stuck in Running state

Resolution: argocd app sync --force + identify root cause

False OutOfSync Status

Cause: ArgoCD confused by status fields added by controllers
Solution: Enable Server-Side Apply with ServerSideApply=true

Secret Provider Dependencies

Problem: External Secrets Operator fails when vault unreachable
Impact: Complete system startup failure
Monitoring: Separate health checks for secret providers

Security Implementation

Default Security Risks

• ArgoCD runs with cluster-admin privileges by default
• No RBAC configured out-of-box
• No audit logging enabled

Production Security Requirements

• Implement RBAC policies
• Enable audit logging
• Use OPA for policy enforcement
• Separate monitoring for GitOps infrastructure

Disaster Recovery Requirements

Backup Components

1. Git repositories: Multiple remotes, mirror everything
2. ArgoCD configuration: Namespace, CRDs, secrets backup
3. etcd cluster state: Automated backups
4. Prometheus data: Remote write to external storage

Recovery Testing

• Document all procedures
• Test regularly (not during outages)
• Verify backup integrity
• Practice restoration workflows

Anti-Patterns to Avoid

Configuration Anti-Patterns

• Storing secrets in Git repositories
• Single ArgoCD for all environments
• High-cardinality Prometheus labels
• Monorepo for all configurations

Operational Anti-Patterns

• Manual kubectl commands in production
• No backup/recovery procedures
• Default security configurations
• Untested disaster recovery plans

Production Readiness Checklist

Pre-Deployment

• Separate secret management implemented
• Resource quotas calculated and allocated
• Repository structure designed for scale
• RBAC policies defined
• Backup procedures documented and tested

Post-Deployment Monitoring

• ArgoCD sync success rate monitoring
• Prometheus resource usage tracking
• Secret provider health checks
• Multi-cluster connectivity monitoring

Operational Procedures

• Incident response runbooks
• Disaster recovery testing schedule
• Security audit procedures
• Capacity planning processes

Cost Considerations

Hidden Costs

• Human Time: 6+ hours debugging sync issues common
• Infrastructure: Monitoring uses more resources than applications
• Expertise: Advanced Kubernetes knowledge required
• Maintenance: Ongoing Helm chart version management

Total Cost of Ownership

• Learning Curve: 2-4 weeks for team proficiency
• Implementation: 1-3 months for production-ready setup
• Operations: 20-40% overhead for GitOps infrastructure maintenance
• Tooling: Free open-source + infrastructure costs

Success Metrics

Technical Metrics

• Deployment frequency increase
• Mean time to recovery reduction
• Configuration drift detection coverage
• Automated rollback success rate

Operational Metrics

• Reduced manual interventions
• Faster environment provisioning
• Improved change auditability
• Enhanced disaster recovery capability