#troubleshooting

Fixes for "Cannot connect to the Docker daemon at unix:///var/run/docker.sock" and "permission denied while trying to connect to the Docker daemon socket".

A container that stops right after docker run, or loops in "Restarting", almost always has a main process that exits or crashes. The exit code tells you why.

"Connection refused", "could not translate host name" or timeouts when one container calls another. Almost always a network, hostname or port mix-up.

A top-down routine for any "my container is not working" moment: status, logs, config, inside, network, resources. Work down the list and stop at the first thing that looks wrong.

Builds, pulls or containers fail with "no space left on device". Docker keeps old images, stopped containers, volumes, build cache and logs until you remove them.

Fix "Bind for 0.0.0.0:8080 failed: port is already allocated" and "address already in use" when starting a container.

"exec format error" or "no matching manifest for linux/arm64": the image was built for a different CPU architecture than the machine running it (amd64 vs arm64, e.g. Apple Silicon or AWS Graviton).