Starting a shell in the Docker Alpine container

Question

To start an interactive shell for the Ubuntu image we can run   ole T    docker run -it --rm ubuntu root 1a6721e1fb64    ls bin  boot  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var   But when this is run for the Alpine Docker image  the following results   ole T    docker run -it --rm alpine Error response from daemon  No command specified   What is the command for starting an interactive shell in an Alpine base container

User · Accepted Answer

ole T    docker run -it --rm alpine  bin ash  inside container         Options used above     bin ash is Ash  Almquist Shell  provided by BusyBox --rm Automatically remove the container when it exits  docker run --help  -i Interactive mode  Keep STDIN open even if not attached  -t Allocate a pseudo-TTY

User · Answer

Nowadays  Alpine images will boot directly into  bin sh by default  without having to specify a shell to execute     sudo docker run -it --rm alpine       echo  0    bin sh     This is since the alpine image Dockerfiles now contain a CMD command  that specifies the shell to execute when the container starts   CMD    bin sh     In older Alpine image versions  pre-2017   the CMD command was not used  since Docker used to create an additional layer for CMD which caused the image size to increase  This is something that the Alpine image developers wanted to avoid  In recent Docker versions  1 10    CMD no longer occupies a layer  and so it was added to alpine images  Therefore  as long as CMD is not overridden  recent Alpine images will boot into  bin sh   For reference  see the following commit to the official Alpine Dockerfiles by Glider Labs  https   github com gliderlabs docker-alpine commit ddc19dd95ceb3584ced58be0b8d7e9169d04c7a3 diff-db3dfdee92c17cf53a96578d4900cb5b

User · Answer

In case the container is already running   docker exec -it container id or name ash

User · Answer

Usually  an Alpine Linux image doesn t contain bash  Instead you can use  bin ash   bin sh  ash or only sh    bin ash  docker run -it --rm alpine  bin ash    bin sh  docker run -it --rm alpine  bin sh   ash  docker run -it --rm alpine ash   sh  docker run -it --rm alpine sh   I hope this information helps you

[linux] Starting a shell in the Docker Alpine container

Examples related to linux

Examples related to docker

Examples related to containers

Examples related to alpine