Troubleshooting Docker Containers: Works Locally, Fails in Production

Investigation and remediation process when a container runs perfectly in a local environment but fails in production despite using the exact same image.

Symptom: The Docker container functions smoothly on a local machine, but throws errors or crashes upon deployment to production, even though the image digests match entirely.

Root Cause: Discrepancies in the external execution environment outside the container (host OS, hardware, resource constraints), network configurations, environment variables, or file system permissions.

Key Factors to Investigate

Environment Variables & Configurations:
- Verify if .env files or runtime environment variables in production are missing, misformatted, or differing from local settings.
Resource Limits:
- Production environments may enforce strict CPU or RAM constraints (cgroup limits) leading to OOM (Out Of Memory) kills or resource starvation.
CPU Architecture / OS Differences:
- Architecture mismatches (e.g., building images on Apple Silicon ARM64 Macs and deploying to Linux AMD64/x86_64 servers).
Volumes & File System Mounts:
- Permission issues, missing mount volumes, or file system behavior differences (e.g., case sensitivity between macOS/Windows and Linux).
Networking & Firewall Settings:
- Discrepancies in port binding, internal database connectivity, or DNS resolution configurations on production servers.