DL4003: Multiple CMD instructions found
Warning Reliability
Why This Matters
Only the last CMD instruction takes effect. Multiple CMD instructions in a stage are almost always a mistake because the earlier ones are silently ignored. This leads to confusion when developers expect a specific CMD to run but Docker quietly uses only the last one. Keep a single CMD per stage.
How to Fix
Remove duplicate CMD instructions, keep only the final one
Before (incorrect)
CMD ["echo", "first"]
CMD ["echo", "second"]After (correct)
CMD ["echo", "second"]Rule Details
- Rule Code
- DL4003
- Severity
- Warning
- Category
- Reliability