How to use instance command aliases
See also: Alias, How to use command aliases, Instance.
This guide demonstrates how to create, list, run and remove aliases for commands running inside an instance.
Create an alias
See also:
alias
To create an alias that runs a command on a given instance, use the command multipass alias. The code below uses this command to create an alias lscc that will run the command ls inside an instance crazy-cat:
multipass alias crazy-cat:ls lscc
After running this command, the alias lscc is defined as running the command ls on the instance crazy-cat. If the alias name lscc is omitted, the alias name defaults to the name of the command to run (ls in this case).
Working directory mapping
By default, if the host folder on which you are running an alias is mounted on the instance, the working directory on the instance is changed to the mounted directory. To avoid this behaviour, use the option --no-map-working-directory when defining the alias; for example:
multipass alias crazy-cat:pwd pwdcc --no-map-working-directory
Alias contexts
See also:
prefer
Contexts are sets of aliases. While one can safely work with one context, named default, contexts can be useful in some scenarios; for example, to define aliases with the same name in different instances.
You can switch to using another context with multipass prefer secondary. Then, defining an alias in the new context is done in the usual way. The name of the alias can coincide with an already defined one. For example, multipass alias cozy-canary:ls lscc.
List the existing aliases
See also:
aliases
To see the list of aliases defined so far, use the multipass aliases command.
The output will be similar to the following:
Alias Instance Command Context Working directory
lscc crazy-cat ls default map
pwdcc crazy-cat pwd default default
lscc cozy-canary ls secondary* map
The current context is marked with an asterisk.
The column Working directory tells us on which directory of the host the alias will be run. The value default means that the alias will be run in the instance default working directory (normally, /home/ubuntu). The value map means that, in case the host directory from which the user calls the alias is mounted on the instance, the alias will be run on the mounted directory on the instance. The value will be default only if the --no-map-working-directory argument is present at alias creation.
Run an alias
There are two ways to run an alias:
multipass <alias><alias>
multipass <alias>
The first way of running an alias is invoking it with multipass <alias>, for example:
multipass lscc
This command opens a shell into the instance cozy-canary, runs ls and returns to the host command line, as if it was an exec command. Since we have defined two aliases with the same name, lscc, the one in the current context will be run.
If you want to run an alias outside the current context, you can use a fully-qualified alias name:
multipass default.lscc
Arguments are also supported, provided you separate any options with --:
multipass lscc -- -l
or:
multipass default.lscc -- -l
<alias>
The second way of running an alias is a two-step process:
- Add the Multipass alias script folder to the system path.
- Run the alias.
Add the Multipass alias script folder to the system path
The instructions to add the Multipass alias script folder to the system path are displayed the first time you create an alias, and vary for each platform. For instance, when you run the command:
multipass alias crazy-cat:ls lscc
the following output is displayed:
You'll need to add this to your shell configuration (.bashrc, .zshrc or so) for
aliases to work without prefixing with `multipass`:
PATH="$PATH:/home/user/snap/multipass/common/bin"
On Linux, you’ll have to edit the shell configuration file. In most Linux distributions, the shell used by default is bash. You can configure this option by editing the file .bashrc in the user’s home directory using a text editor; for example:
nano ~/.bashrc
You can modify the path by appending a line to the .bashrc file, such as:
export PATH="$PATH:/home/user/snap/multipass/common/bin"
Remember to replace the correct folder, as indicated in the output of the Multipass command above, and to restart the shell when done.
If your shell is zsh and not bash, the file to modify is .zshrc instead of .bashrc. The procedure is the same.
On macOS, you’ll have to edit the shell configuration file. The shell used by default is zsh. You can configure this option by editing the file .zshrc in the user’s home directory using a text editor.
You can modify the path by appending a line to the .zshrc file, such as:
export PATH="$PATH:/Users/<username>/Library/Application Support/multipass/bin"
Remember to replace the correct folder, as indicated in the output of the Multipass command above, and to restart the shell when done.
On Windows, to make the change permanent, use PowerShell to store the old system path, add the alias folder to it, and store the new path:
$old_path = (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment' -Name PATH).path
$new_path = “$old_path;C:\Users\<user>\AppData\Local\Multipass\bin”
Set-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment' -Name PATH -Value $new_path
Don’t forget to restart your terminal. The folder is now permanently added to your path, and Multipass can now run aliases just invoking their name.
Run the alias
Once you’ve added the alias folder to the system path, you can run it directly from the command line, without the need to also mention multipass; for example:
lscc
or:
default.lscc
Since the path has been added to the system path, this command is equivalent to multipass lscc. Arguments are also supported, without the need for --:
lscc -l
Remove an alias
See also:
unalias
Finally, to remove the alias lscc, run the following command:
multipass unalias lscc
or:
multipass unalias default.lscc
The unalias command accepts many arguments, specifying more than one alias to remove. For example, you can remove both aliases lscc and pwdcc at once:
multipass unalias lscc pwdcc
You can also use the --all option to remove all the defined aliases in the current context at once:
multipass unalias --all
Aliases are also removed when the instance for which they were defined is deleted and purged. This means that multipass delete crazy-cat --purge will also remove the aliases lscc and pwdcc.
Errors or typos? Topics missing? Hard to read? Let us know or open an issue on GitHub.
Contributors: @luisp , @saviq , @tmihoc , @andreitoterman , @itecompro , @ricab , @gzanchi , @sharder996