fastly-compute-deployment-debugging

Fastly Compute Deployment Debugging

Problem

After deploying to Fastly Compute, requests return stale content or 404s even though:

• fastly compute publish reported success
• The new version shows as "active" in fastly service-version list
• The code is correct and works locally

Context / Trigger Conditions

• Version endpoint returns old version string after deployment
• New routes/features return 404
• fastly purge --all doesn't fix the issue
• Requests with cache buster (?v=random) work but regular requests don't
• fastly domain list doesn't show your custom domain
• Different POPs return different results

Solution

1. Verify Code is Actually Deployed

# Check the direct edgecompute.app URL (bypasses custom domain config)
curl https://your-service.edgecompute.app/version

# Compare to custom domain
curl https://your-custom-domain.com/version

If edgecompute.app works but custom domain doesn't, it's a domain configuration issue.

2. Diagnose Cached Error Responses

The most common issue: 404s get cached at edge POPs before new code propagates.

# Test with cache buster
curl "https://your-domain.com/endpoint?bust=$RANDOM"

# Test without
curl "https://your-domain.com/endpoint"

If cache-busted works but regular doesn't = cached error response.

Fix: Wait 2-5 minutes for full propagation, then purge:

fastly purge --all --service-id YOUR_SERVICE_ID

3. Check Domain Configuration (Two APIs!)

Fastly has TWO domain management systems:

System	CLI Command	API Endpoint
Classic Domains	fastly domain list	/service/{id}/version/{ver}/domain
Versionless Domains	(not shown in CLI)	/domain-management/v1/domains

If fastly domain list doesn't show your domain, check the versionless API:

# Get your API token
TOKEN=$(fastly profile token)

# Query domain-management API
curl -s -H "Fastly-Key: $TOKEN" \
  "https://api.fastly.com/domain-management/v1/domains?filter%5Bfqdn%5D=your-domain.com"