You add the official redis image to a Compose file, and your app logs Could not connect to Redis at 127.0.0.1:6379: Connection refused . Or it gets DENIED Redis is running in protected mode , or NOAUTH Authentication required . Or Redis works until its first snapshot, and then every write fails with MISCONF Redis is configured to save RDB snapshots, but it's currently unable to persist to disk .

This guide reproduces each of those errors with redis:8.10.3 in Docker Compose and fixes them. Every error message and log line below comes from that lab run on October 31, 2026, when redis:latest pulled the same 8.10.3 image. These errors are common. The Stack Overflow question MISCONF Redis is configured to save RDB snapshots had 646,097 views that day, Connecting to Redis running in Docker Container from Host machine had 306,329, and the image repo issue Set password and other options via ENV variable has 53 comments.

The short version:

From another container, localhost is that container.…