propellor - property-based host configuration management in haskell


propellor [options]


propellor is a property-based host configuration management program written and configured in haskell.


  • propellor --init

    Get started by initializing a ~/.propellor/ repository.

    After this, you'll edit ~/.propellor/config.hs to configure propellor.

  • propellor

    Once propellor is configured, running it without any options will take action as needed to satisfy the configured properties of the local host.

    If there's a central git repository, it will first fetch from it, check the gpg signature and merge, and rebuild propellor, so that any configuration changes will immediately take effect.

    If propellor is run by a non-root user without any options, this is the same as running propellor --spin with the hostname of the local host.

  • propellor --spin targethost [targethost ...] [--via relayhost]

    Causes propellor to automatically install itself on the specified target host, or if it's already installed there, push any updates. Propellor is then run on the target host, to satisfy its configured properties.

    A signed git commit is made by --spin, so that any changes you have made get propagated to the target host.

    Multiple target hosts can be specified; propellor will run on each of them in sequence.

    When run with --via, propellor sshes to the relay host and runs propellor --spin hostname from there. This can be useful when propellor is installing itself, since most of the data transfer is done between relay host and target host. Note that propellor uses ssh agent forwarding to make this work, and the relay host sees any privdata belonging to the target host.

    Propellor configuration typically uses the FQDN of hosts. The hostname given to --spin can be a short name, which is then looked up in the DNS to find the FQDN.

  • propellor --build

    Causes propellor to build itself, checking that your config.hs, etc are valid.

    You do not need to run this as a separate step; propellor automatically builds itself when using things like --spin.

  • propellor --add-key keyid

    Adds a gpg key, which is used to encrypt the privdata.

    Multiple gpg keys can be added; the privdata will be encrypted so that all of them can decrypt it.

    If the gpg secret key is present, git is configured to sign commits using this key. Propellor requires signed commits when pulling from a central git repository.

  • propellor --rm-key keyid

    Stops encrypting the privdata to a gpg key.

  • propellor --list-fields

    Lists all privdata fields that are used by your propellor configuration. The first 2 columns are the field name and context, and are followed by a list of the hosts that use that privdata value.

  • propellor --set field context

    Sets a field of privdata. The content is read in from stdin.

  • propellor --unset field context

    Removes a value from the privdata store.

  • propellor --unset-unused

    Removes all values from the privdata store that are not currently in use.

  • propellor --dump field context

    Outputs the privdata value to stdout.

  • propellor --edit field context

    Opens $EDITOR on the privdata value.

  • propellor --merge

    Combine multiple --spin commits into a single, more useful commit.

    When using propellor, you may find yourself repeatedly running propellor --spin until you get things working the way you like. This results in a lot of git commits being made, with incremental changes.

    To clean that up to a single commit, use propellor --merge. A normal interactive git commit will then be made, consisting of all changes that have been previously committed by --spin, since the last time a normal git commit was made.

    (This will result in a trapezoid pattern in gitk.)

  • propellor --check

    If propellor is able to run, this simply exits successfully.

  • propellor hostname

    When run with a hostname and no other options, propellor will provision the local host with the configuration of that hostname. This is useful when the local host doesn't yet have its hostname set correctly.


  • ~/.propellor/config.hs

    This is the default config file used by propellor.

  • ./config.hs

    If propellor is run in a directory containing a config.hs, it assumes that the current directory is a propellor repository, and uses the configuration from the current directory, rather tnan ~/.propellor/


Set PROPELLOR_DEBUG=1 to make propellor output each command it runs and other debugging information.


git config propellor.debug 1 will configure propellor to output debugging information.

git config propellor.spin-branch foo will configure propellor to refuse to spin when the foo branch is not checked out.

git config propellor.forbid-dirty-spin true will configure propellor to refuse to spin when there are uncommitted changes in the ~/.propellor repository.

git config propellor.buildsystem stack makes propellor use stack for building itself, rather than the default cabal. This only controls the local build of propellor; Hosts can have properties set to control how propellor is built on them.

The usual git configuration controls which centralized repository (if any) propellor pushes and pulls from.

Additionally, the url of a remote named "deploy", if it exists in your ~/.propellor/ repository, is used as the origin url for the other repositories.


Joey Hess

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