NAME

git-annex-shell - Restricted login shell for git-annex only SSH access

SYNOPSIS

git-annex-shell [-c] command [params ...]

DESCRIPTION

git-annex-shell is a restricted shell, similar to git-shell, which can be used as a login shell for SSH accounts.

Since its syntax is identical to git-shell's, it can be used as a drop-in replacement anywhere git-shell is used. For example it can be used as a user's restricted login shell.

COMMANDS

Any command not listed below is passed through to git-shell.

Note that the directory parameter should be an absolute path, otherwise it is assumed to be relative to the user's home directory. Also the first "/~/" or "/~user/" is expanded to the specified home directory.

  • configlist directory

    This outputs a subset of the git configuration, in the same form as git config --list. This is used to get the annex.uuid of the remote repository.

    When run in a repository that does not yet have an annex.uuid, one will be created, as long as a git-annex branch has already been pushed to the repository, or if the autoinit= flag is used to indicate initialization is desired.

  • inannex directory [key ...]

    This checks if all specified keys are present in the annex, and exits zero if so.

    Exits 1 if the key is certainly not present in the annex. Exits 100 if it's unable to tell (perhaps the key is in the process of being removed from the annex).

  • lockcontent directory key

    This locks a key's content in place in the annex, preventing it from being dropped.

    Once the content is successfully locked, outputs "OK". Then the content remains locked until a newline is received from the caller or the connection is broken.

    Exits nonzero if the content is not present, or could not be locked.

  • dropkey directory [key ...]

    This drops the annexed data for the specified keys.

  • recvkey directory key

    This runs rsync in server mode to receive the content of a key, and stores the content in the annex.

  • sendkey directory key

    This runs rsync in server mode to transfer out the content of a key.

  • transferinfo directory key

    This is typically run at the same time as sendkey is sending a key to the remote. Using it is optional, but is used to update progress information for the transfer of the key.

    It reads lines from standard input, each giving the number of bytes that have been received so far.

  • commit directory

    This commits any staged changes to the git-annex branch. It also runs the annex-content hook.

  • notifychanges directory

    This is used by git-annex remotedaemon to be notified when refs in the remote repository are changed.

  • gcryptsetup directory gcryptid

    Sets up a repository as a gcrypt repository.

OPTIONS

Most options are the same as in git-annex. The ones specific to git-annex-shell are:

  • --uuid=UUID

    git-annex uses this to specify the UUID of the repository it was expecting git-annex-shell to access, as a sanity check.

  • -- fields=val fields=val.. --

    Additional fields may be specified this way, to retain compatibility with past versions of git-annex-shell (that ignore these, but would choke on new dashed options).

    Currently used fields include remoteuuid=, associatedfile=, unlocked=, direct=, and autoinit=

HOOK

After content is received or dropped from the repository by git-annex-shell, it runs a hook, .git/hooks/annex-content (or hooks/annex-content on a bare repository). The hook is not currently passed any information about what changed.

ENVIRONMENT

  • GIT_ANNEX_SHELL_READONLY

    If set, disallows any command that could modify the repository.

    Note that this does not prevent passing commands on to git-shell. For that, you also need ...

  • GIT_ANNEX_SHELL_LIMITED

    If set, disallows running git-shell to handle unknown commands.

  • GIT_ANNEX_SHELL_DIRECTORY

    If set, git-annex-shell will refuse to run commands that do not operate on the specified directory.

EXAMPLES

To make a ~/.ssh/authorized_keys file that only allows git-annex-shell to be run, and not other commands, pass the original command to the -c option:

command="git-annex-shell -c \"$SSH_ORIGINAL_COMMAND\"",no-agent-forwarding,no-port-forwarding,no-X11-forwarding ssh-rsa AAAAB3NzaC1y[...] user@example.com

To further restrict git-annex-shell to a particular repository, and fully lock it down to read-only mode:

command="GIT_ANNEX_SHELL_DIRECTORY=/srv/annex GIT_ANNEX_SHELL_LIMITED=true GIT_ANNEX_SHELL_READONLY=true git-annex-shell -c \"$SSH_ORIGINAL_COMMAND\"",no-agent-forwarding,no-port-forwarding,no-X11-forwarding ssh-rsa AAAAB3NzaC1y[...] user@example.com

Obviously, ssh-rsa AAAAB3NzaC1y[...] user@example.com needs to replaced with your SSH key. The above also assumes git-annex-shell is available in your $PATH, use an absolute path if it is not the case.

SEE ALSO

git-annex(1)

git-shell(1)

AUTHOR

Joey Hess id@joeyh.name

http://git-annex.branchable.com/

Warning: Automatically converted into a man page by mdwn2man. Edit with care