DigitalOcean App Platform Deploy Failed or 502 After Deploy

How to fix it

Try these in order — the most common fix is first.

1. 1. Bind to the right address and port

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   1. Listen on 0.0.0.0 and use the PORT environment variable (default 8080)
   2. If you hardcode a port, set HTTP Port in the component Settings tab to match; http_port in the app spec overrides PORT
   Did this fix it? Yes No

2. 2. Fix the health check

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   1. Check the last health check result in the app
   2. Make sure the configured route returns a 200 quickly
   Did this fix it? Yes No

3. 3. Check memory and restarts

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   1. Open Insights and check CPU, memory and the Restart Count metric (a crash loop can hide a normal memory graph)
   2. Move to a larger instance size or enable autoscaling on dedicated containers
   Did this fix it? Yes No

4. 4. Check env vars and database access

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   1. Confirm required environment variables exist at runtime
   2. App Platform sets DATABASE_URL for attached managed databases; remove trusted-source restrictions that block it
   3. Use the console to open a shell in the container for debugging
   Did this fix it? Yes No

Symptoms

Deployment fails with ContainerHealthChecksFailed, ContainerExitNonZero or ContainerOutOfMemory, or the live app shows 502/503.

Why it happens

• App binds to localhost or 127.0.0.1
• Hardcoded port differs from the HTTP Port setting
• Health check route returns an error or is too slow
• Container exits with non-zero code (missing env vars, crash on start)
• Container out of memory (exit code 137)
• Database restricts trusted sources so the app cannot connect

This guide also covers

• digitalocean app platform 502
• app platform health check failed
• containerhealthchecksfailed
• app platform deploy failed

Other DigitalOcean errors

• DigitalOcean Droplet SSH Permission Denied (publickey)
• DigitalOcean Droplet SSH Connection Refused or Timed Out
• DigitalOcean Droplet 502 Bad Gateway (Nginx)
• DigitalOcean Droplet Out of Memory (OOM Killer)
• DigitalOcean App Platform Build Failed
• DigitalOcean Account Locked or Verification Required
• DigitalOcean Unexpected Bill: Charged for Deleted or Powered-Off Droplets
• DigitalOcean Droplet Locked Out: Reset Root Password and Recovery Console