Instrument Canary Rollout Health Checks for multi-tenant services with DeployClaw Infrastructure Specialist Agent

Automate Canary Rollout Health Checks in Docker + TypeScript

The Pain

Managing canary deployments across multi-tenant services without automated health instrumentation is a coordination nightmare. Your development team ships a TypeScript service containerized in Docker, but operations has to manually configure health check endpoints, define thresholds for each tenant, and correlate metrics across load balancers and orchestrators. The handoff introduces configuration drift—what your Dockerfile specifies diverges from what Kubernetes or Docker Swarm actually enforces. You're left debugging why canary rollouts fail silently: health checks timeout, tenant isolation breaks under load, or metrics don't reflect actual service behavior. Manual verification of readiness probes and liveness probes introduces latency into your deployment pipeline. One misconfigured tenant container can poison the entire canary, yet identifying which tenant's sidecar is the culprit requires digging through logs across three different systems. This is operational toil that scales poorly.

The DeployClaw Advantage

The Infrastructure Specialist Agent executes canary health check instrumentation using OS-level operations defined in internal SKILL.md protocols. This is not template generation or ChatGPT-style suggestions—the agent directly modifies your Dockerfile, TypeScript service configuration, and orchestration manifests, then validates the changes against your actual runtime environment. It analyzes your Docker network topology, detects multi-tenant isolation boundaries, and instruments health check endpoints with tenant-aware logic. The agent synthesizes health check configurations for both container-level probes (Docker health checks) and orchestrator-level checks (Kubernetes readiness/liveness probes), ensuring consistency across your deployment stack.

Technical Proof

Before: Manual, Inconsistent Health Checks

// app.ts - No health instrumentation
app.get('/api/data', (req, res) => {
  res.json({ status: 'ok' });
});
// No tenant isolation, no canary metrics

# Dockerfile - Missing health checks
FROM node:18
WORKDIR /app
COPY . .
RUN npm install
CMD ["node", "dist/app.js"]

After: Automated, Tenant-Aware Canary Instrumentation

// app.ts - Instrumented with canary health checks
import { metricsRegistry, tenantHealthStore } from './instrumentation';

app.get('/health/ready', (req, res) => {
  const tenantId = req.headers['x-tenant-id'] as string;
  const isReady = tenantHealthStore.checkTenantReadiness(tenantId);
  res.status(isReady ? 200 : 503).json({ 
    status: isReady ? 'ready' : 'initializing',
    tenant: tenantId,
    canaryRolloutPhase: process.env.CANARY_PHASE 
  });
});

app.get('/health/live', (req, res) => {
  const tenantId = req.headers['x-tenant-id'] as string;
  metricsRegistry.recordHealthCheckLatency(tenantId);
  const isAlive = tenantHealthStore.checkTenantAliveness(tenantId);
  res.status(isAlive ? 200 : 503).json({ alive: isAlive });
});

export const canaryMetrics = metricsRegistry;

# Dockerfile - Instrumented with multi-stage build and health checks
FROM node:18 AS builder
WORKDIR /app
COPY . .
RUN npm ci && npm run build

FROM node:18-slim
WORKDIR /app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/package.json .
RUN npm ci --omit=dev

HEALTHCHECK --interval=10s --timeout=3s --start-period=15s --retries=3 \
  CMD node -e "require('http').get('http://localhost:3000/health/live', (r) => process.exit(r.statusCode === 200 ? 0 : 1))"

ENV CANARY_PHASE=stable
CMD ["node", "dist/app.js"]

Agent Execution Log

{
  "task": "instrument_canary_rollout_health_checks",
  "execution_start": "2025-01-15T14:23:47.312Z",
  "agent": "Infrastructure Specialist",
  "steps": [
    {
      "step": 1,
      "action": "analyze_service_topology",
      "status": "completed",
      "details": {
        "detected_tenants": 7,
        "detected_docker_services": 3,
        "orchestrator": "kubernetes",
        "namespace": "production"
      }
    },
    {
      "step": 2,
      "action": "scan_dockerfile",
      "status": "completed",
      "details": {
        "missing_health_checks": true,
        "base_image": "node:18",
        "entry_point": "node dist/app.js"
      }
    },
    {
      "step": 3,
      "action": "analyze_typescript_service",
      "status": "completed",
      "details": {
        "framework": "express",
        "tenant_isolation_headers": ["x-tenant-id"],
        "existing_health_endpoints": 0,
        "required_instrumentation": ["readiness", "liveness", "metrics"]
      }
    },
    {
      "step": 4,
      "action": "instrument_canary_health_module",
      "status": "completed",
      "details": {
        "module_created": "instrumentation.ts",
        "health_store_initialized": true,
        "metrics_registry_bound": true,
        "tenant_isolation_enforced": true
      }
    },
    {
      "step": 5,
      "action": "inject_health_endpoints",
      "status": "completed",
      "details": {
        "endpoints_added": 2,
        "endpoint_paths": ["/health/ready", "/health/live"],
        "tenant_awareness": true,
        "canary_phase_env_set": true
      }
    },
    {
      "step": 6,
      "action": "update_dockerfile_health_check",
      "status": "completed",
      "details": {
        "healthcheck_instruction_added": true,
        "interval_seconds": 10,
        "timeout_seconds": 3,
        "start_period_seconds": 15,
        "retries": 3
      }
    },
    {
      "step": 7,
      "action": "generate_k8s_probe_manifests",
      "status": "completed",
      "details": {
        "readiness_probe": {
          "http_get_path": "/health/ready",
          "port": 3000,
          "initial_delay": 15,
          "period": 10,
          "timeout": 3
        },
        "liveness_probe": {
          "http_get_path": "/health/live",
          "port": 3000,
          "initial_delay": 30,
          "period": 10,
          "timeout": 3
        }
      }
    },
    {
      "step": 8,
      "action": "validate_canary_isolation",
      "status": "completed",
      "details": {
        "tenant_segregation_verified": true,
        "metrics_cardinality_acceptable": true,
        "canary_phase_routing_ready": true
      }
    },
    {
      "step": 9,
      "action": "test_health_endpoints_local",
      "status": "completed",
      "details": {
        "ready_endpoint_test": "passed",
        "live_endpoint_test": "passed",
        "tenant_isolation_test": "passed",
        "response_latency_ms": 12
      }
    },
    {
      "step": 10,
      "action": "execution_complete",
      "status": "