Docker and CI/CD · Junior · Question 71 of 75

`docker run -p 5432:5432 postgres` fails with "port is already allocated". Why?

✓Correct answer: Something on the host already uses port 5432
2Postgres can't run on its default port in Docker
3The image was built for a different port

Explanation

Perhaps a local Postgres or another container. Map a different host port, like -p 5433:5432; the container side stays the same.

Further reading

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