How to install bash shell in Alpine Linux

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How do I install bash shell in Alpine Linux?

How do I install bash shell in my Alpine Linux LXD (Linux Container) or virtual machine (VM)?Alpine Linux comes with BusyBox. It is described as “The Swiss Army Knife of Embedded Linux.” BusyBox combines tiny versions of many standard UNIX utilities into a single small executable, including /bin/sh. By default, bash is not included with BusyBox and Alpine Linux. The postmarketOS project, which is designed to run on mobile devices, is based on Alpine Linux. Many Docker images are also based upon Alpine, and you may install bash shell in Docker-based images too. This page shows how to install a bash shell in Alpine Linux using the apk command

It is easy to have bash installed but this does not mean the symlinks to busybox are gone. The syntax is as follows with apk command:

# apk update

# apk upgrade

# apk add bash

Sample outputs:

(1/4) Installing ncurses-terminfo-base (6.1_p20200118-r4) (2/4) Installing ncurses-libs (6.1_p20200118-r4) (3/4) Installing readline (8.0.1-r0) (4/4) Installing bash (5.0.11-r1) Executing bash-5.0.11-r1.post-install Executing busybox-1.31.1-r9.trigger OK: 11 MiB in 23 packages

Get a list of valid login shells on Alpine Linux using the cat command:

# cat /etc/shells

Outputs:

# valid login shells /bin/sh /bin/ash /bin/bash

How to install bash man pages and other docs

To install bash documentation, enter:

# apk add bash-doc

To install bash automatic command line completion install, run:

# apk add bash-completion

Sample session:



How to set bash as login shell

To use bash as a shell just type bash:

$ bash

To login to alpine Linux LXD vm from host, enter:

$ lxc exec alpine-lxd-vm-name-here bash

One can change root shell to bash shell using the following method:

# vi /etc/passwd

Find user name and the default shell such as /bin/ash:

root:x:0:0:root:/root:/bin/ash

Replace it with /bin/bash:

root:x:0:0:root:/root:/bin/bash

Customize bash shell

Here is a sample file displayed using the cat command cat ~/.bashrc

Sample outputs:

alias update = 'apk update && apk upgrade' export HISTTIMEFORMAT = "%d/%m/%y %T " export PS1 = '\u@\h:\W \$ ' alias l = 'ls -CF' alias la = 'ls -A' alias ll = 'ls -alF' alias ls = 'ls --color=auto' source / etc / profile.d / bash_completion.sh export PS1 = "\[\e[31m\][\[\e[m\]\[\e[38;5;172m\]\u\[\e[m\]@\[\e[38;5;153m\]\h\[\e[m\] \[\e[38;5;214m\]\W\[\e[m\]\[\e[31m\]]\[\e[m\]\ \$ " alias update='apk update && apk upgrade' export HISTTIMEFORMAT="%d/%m/%y %T " export PS1='\u@\h:\W \$ ' alias l='ls -CF' alias la='ls -A' alias ll='ls -alF' alias ls='ls --color=auto' source /etc/profile.d/bash_completion.sh export PS1="\[\e[31m\][\[\e[m\]\[\e[38;5;172m\]\u\[\e[m\]@\[\e[38;5;153m\]\h\[\e[m\] \[\e[38;5;214m\]\W\[\e[m\]\[\e[31m\]]\[\e[m\]\\$ "

See Customize the bash shell environments wiki page for more info.



How to find bash shell version

One can type the following command:

bash --version

Sample outputs:

GNU bash, version 5.0.11(1)-release (x86_64-alpine-linux-musl) Copyright (C) 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later This is free software; you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

Adding bash to Alpine Docker image

Add the following command to your Docker config file to install bash shell:

RUN apk add --no-cache bash

Conclusion

You learned how to install bash shell on Alpine Linux along with documents, man pages and configure the bash shell as per your needs. I suggest you read bash man pages/docs here online for more info.