.. _tutorial-gitfs: ================================== Git Fileserver Backend Walkthrough ================================== .. note:: This walkthrough assumes basic knowledge of Salt. To get up to speed, check out the :doc:`Salt Walkthrough `. The gitfs backend allows Salt to serve files from git repositories. It can be enabled by adding ``git`` to the :conf_master:`fileserver_backend` list, and configuring one or more repositories in :conf_master:`gitfs_remotes`. Branches and tags become Salt fileserver environments. .. _gitfs-dependencies: Installing Dependencies ======================= Beginning with version 2014.7.0, both pygit2_ and Dulwich_ are supported as alternatives to GitPython_. The desired provider can be configured using the :conf_master:`gitfs_provider` parameter in the master config file. If :conf_master:`gitfs_provider` is not configured, then Salt will prefer pygit2_ if a suitable version is available, followed by GitPython_ and Dulwich_. .. note:: It is recommended to always run the most recent version of any the below dependencies. Certain features of gitfs may not be available without the most recent version of the chosen library. .. _pygit2: https://github.com/libgit2/pygit2 .. _Dulwich: https://www.samba.org/~jelmer/dulwich/ .. _GitPython: https://github.com/gitpython-developers/GitPython pygit2 ------ The minimum supported version of pygit2_ is 0.20.3. Availability for this version of pygit2_ is still limited, though the SaltStack team is working to get compatible versions available for as many platforms as possible. For the Fedora/EPEL versions which have a new enough version packaged, the following command would be used to install pygit2_: .. code-block:: bash # yum install python-pygit2 Provided a valid version is packaged for Debian/Ubuntu (which is not currently the case), the package name would be the same, and the following command would be used to install it: .. code-block:: bash # apt-get install python-pygit2 If pygit2_ is not packaged for the platform on which the Master is running, the pygit2_ website has installation instructions here__. Keep in mind however that following these instructions will install libgit2 and pygit2_ without system packages. Additionally, keep in mind that :ref:`SSH authentication in pygit2 ` requires libssh2_ (*not* libssh) development libraries to be present before libgit2 is built. On some distros (debian based) ``pkg-config`` is also required to link libgit2 with libssh2. .. warning:: pygit2_ is actively developed and :ref:`frequently makes non-backwards-compatible API changes `, even in minor releases. It is not uncommon for pygit2_ upgrades to result in errors in Salt. Please take care when upgrading pygit2_, and pay close attention to the :ref:`changelog `, keeping an eye out for API changes. Errors can be reported on the :ref:`SaltStack issue tracker `. .. _pygit2-version-policy: http://www.pygit2.org/install.html#version-numbers .. _pygit2-changelog: https://github.com/libgit2/pygit2#changelog .. _saltstack-issue-tracker: https://github.com/saltstack/salt/issues .. __: http://www.pygit2.org/install.html .. _libssh2: http://www.libssh2.org/ GitPython --------- GitPython_ 0.3.0 or newer is required to use GitPython for gitfs. For RHEL-based Linux distros, a compatible version is available in EPEL, and can be easily installed on the master using yum: .. code-block:: bash # yum install GitPython Ubuntu 14.04 LTS and Debian Wheezy (7.x) also have a compatible version packaged: .. code-block:: bash # apt-get install python-git If your master is running an older version (such as Ubuntu 12.04 LTS or Debian Squeeze), then you will need to install GitPython using either pip_ or easy_install (it is recommended to use pip). Version 0.3.2.RC1 is now marked as the stable release in PyPI, so it should be a simple matter of running ``pip install GitPython`` (or ``easy_install GitPython``) as root. .. _`pip`: http://www.pip-installer.org/ .. warning:: Keep in mind that if GitPython has been previously installed on the master using pip (even if it was subsequently uninstalled), then it may still exist in the build cache (typically ``/tmp/pip-build-root/GitPython``) if the cache is not cleared after installation. The package in the build cache will override any requirement specifiers, so if you try upgrading to version 0.3.2.RC1 by running ``pip install 'GitPython==0.3.2.RC1'`` then it will ignore this and simply install the version from the cache directory. Therefore, it may be necessary to delete the GitPython directory from the build cache in order to ensure that the specified version is installed. Dulwich ------- Dulwich 0.9.4 or newer is required to use Dulwich as backend for gitfs. Dulwich is available in EPEL, and can be easily installed on the master using yum: .. code-block:: bash # yum install python-dulwich For APT-based distros such as Ubuntu and Debian: .. code-block:: bash # apt-get install python-dulwich .. important:: If switching to Dulwich from GitPython/pygit2, or switching from GitPython/pygit2 to Dulwich, it is necessary to clear the gitfs cache to avoid unpredictable behavior. This is probably a good idea whenever switching to a new :conf_master:`gitfs_provider`, but it is less important when switching between GitPython and pygit2. Beginning in version 2015.5.0, the gitfs cache can be easily cleared using the :mod:`fileserver.clear_cache ` runner. .. code-block:: bash salt-run fileserver.clear_cache backend=git If the Master is running an earlier version, then the cache can be cleared by removing the ``gitfs`` and ``file_lists/gitfs`` directories (both paths relative to the master cache directory, usually ``/var/cache/salt/master``). .. code-block:: bash rm -rf /var/cache/salt/master{,/file_lists}/gitfs Simple Configuration ==================== To use the gitfs backend, only two configuration changes are required on the master: 1. Include ``git`` in the :conf_master:`fileserver_backend` list in the master config file: .. code-block:: yaml fileserver_backend: - git 2. Specify one or more ``git://``, ``https://``, ``file://``, or ``ssh://`` URLs in :conf_master:`gitfs_remotes` to configure which repositories to cache and search for requested files: .. code-block:: yaml gitfs_remotes: - https://github.com/saltstack-formulas/salt-formula.git SSH remotes can also be configured using scp-like syntax: .. code-block:: yaml gitfs_remotes: - git@github.com:user/repo.git - ssh://user@domain.tld/path/to/repo.git Information on how to authenticate to SSH remotes can be found :ref:`here `. .. note:: Dulwich does not recognize ``ssh://`` URLs, ``git+ssh://`` must be used instead. Salt version 2015.5.0 and later will automatically add the ``git+`` to the beginning of these URLs before fetching, but earlier Salt versions will fail to fetch unless the URL is specified using ``git+ssh://``. 3. Restart the master to load the new configuration. .. note:: In a master/minion setup, files from a gitfs remote are cached once by the master, so minions do not need direct access to the git repository. Multiple Remotes ================ The ``gitfs_remotes`` option accepts an ordered list of git remotes to cache and search, in listed order, for requested files. A simple scenario illustrates this cascading lookup behavior: If the ``gitfs_remotes`` option specifies three remotes: .. code-block:: yaml gitfs_remotes: - git://github.com/example/first.git - https://github.com/example/second.git - file:///root/third And each repository contains some files: .. code-block:: yaml first.git: top.sls edit/vim.sls edit/vimrc nginx/init.sls second.git: edit/dev_vimrc haproxy/init.sls third: haproxy/haproxy.conf edit/dev_vimrc Salt will attempt to lookup the requested file from each gitfs remote repository in the order in which they are defined in the configuration. The :strong:`git://github.com/example/first.git` remote will be searched first. If the requested file is found, then it is served and no further searching is executed. For example: * A request for the file :strong:`salt://haproxy/init.sls` will be served from the :strong:`https://github.com/example/second.git` git repo. * A request for the file :strong:`salt://haproxy/haproxy.conf` will be served from the :strong:`file:///root/third` repo. .. note:: This example is purposefully contrived to illustrate the behavior of the gitfs backend. This example should not be read as a recommended way to lay out files and git repos. The :strong:`file://` prefix denotes a git repository in a local directory. However, it will still use the given :strong:`file://` URL as a remote, rather than copying the git repo to the salt cache. This means that any refs you want accessible must exist as *local* refs in the specified repo. .. warning:: Salt versions prior to 2014.1.0 are not tolerant of changing the order of remotes or modifying the URI of existing remotes. In those versions, when modifying remotes it is a good idea to remove the gitfs cache directory (``/var/cache/salt/master/gitfs``) before restarting the salt-master service. .. _gitfs-per-remote-config: Per-remote Configuration Parameters =================================== .. versionadded:: 2014.7.0 The following master config parameters are global (that is, they apply to all configured gitfs remotes): * :conf_master:`gitfs_base` * :conf_master:`gitfs_root` * :conf_master:`gitfs_mountpoint` (new in 2014.7.0) * :conf_master:`gitfs_user` (**pygit2 only**, new in 2014.7.0) * :conf_master:`gitfs_password` (**pygit2 only**, new in 2014.7.0) * :conf_master:`gitfs_insecure_auth` (**pygit2 only**, new in 2014.7.0) * :conf_master:`gitfs_pubkey` (**pygit2 only**, new in 2014.7.0) * :conf_master:`gitfs_privkey` (**pygit2 only**, new in 2014.7.0) * :conf_master:`gitfs_passphrase` (**pygit2 only**, new in 2014.7.0) These parameters can now be overridden on a per-remote basis. This allows for a tremendous amount of customization. Here's some example usage: .. code-block:: yaml gitfs_provider: pygit2 gitfs_base: develop gitfs_remotes: - https://foo.com/foo.git - https://foo.com/bar.git: - root: salt - mountpoint: salt://foo/bar/baz - base: salt-base - http://foo.com/baz.git: - root: salt/states - user: joe - password: mysupersecretpassword - insecure_auth: True .. important:: There are two important distinctions which should be noted for per-remote configuration: 1. The URL of a remote which has per-remote configuration must be suffixed with a colon. 2. Per-remote configuration parameters are named like the global versions, with the ``gitfs_`` removed from the beginning. In the example configuration above, the following is true: 1. The first and third gitfs remotes will use the ``develop`` branch/tag as the ``base`` environment, while the second one will use the ``salt-base`` branch/tag as the ``base`` environment. 2. The first remote will serve all files in the repository. The second remote will only serve files from the ``salt`` directory (and its subdirectories), while the third remote will only serve files from the ``salt/states`` directory (and its subdirectories). 3. The files from the second remote will be located under ``salt://foo/bar/baz``, while the files from the first and third remotes will be located under the root of the Salt fileserver namespace (``salt://``). 4. The third remote overrides the default behavior of :ref:`not authenticating to insecure (non-HTTPS) remotes `. Serving from a Subdirectory =========================== The :conf_master:`gitfs_root` parameter allows files to be served from a subdirectory within the repository. This allows for only part of a repository to be exposed to the Salt fileserver. Assume the below layout: .. code-block:: text .gitignore README.txt foo/ foo/bar/ foo/bar/one.txt foo/bar/two.txt foo/bar/three.txt foo/baz/ foo/baz/top.sls foo/baz/edit/vim.sls foo/baz/edit/vimrc foo/baz/nginx/init.sls The below configuration would serve only the files under ``foo/baz``, ignoring the other files in the repository: .. code-block:: yaml gitfs_remotes: - git://mydomain.com/stuff.git gitfs_root: foo/baz The root can also be configured on a :ref:`per-remote basis `. Mountpoints =========== .. versionadded:: 2014.7.0 The :conf_master:`gitfs_mountpoint` parameter will prepend the specified path to the files served from gitfs. This allows an existing repository to be used, rather than needing to reorganize a repository or design it around the layout of the Salt fileserver. Before the addition of this feature, if a file being served up via gitfs was deeply nested within the root directory (for example, ``salt://webapps/foo/files/foo.conf``, it would be necessary to ensure that the file was properly located in the remote repository, and that all of the the parent directories were present (for example, the directories ``webapps/foo/files/`` would need to exist at the root of the repository). The below example would allow for a file ``foo.conf`` at the root of the repository to be served up from the Salt fileserver path ``salt://webapps/foo/files/foo.conf``. .. code-block:: yaml gitfs_remotes: - https://mydomain.com/stuff.git gitfs_mountpoint: salt://webapps/foo/files Mountpoints can also be configured on a :ref:`per-remote basis `. Using gitfs Alongside Other Backends ==================================== Sometimes it may make sense to use multiple backends; for instance, if ``sls`` files are stored in git but larger files are stored directly on the master. The cascading lookup logic used for multiple remotes is also used with multiple backends. If the ``fileserver_backend`` option contains multiple backends: .. code-block:: yaml fileserver_backend: - roots - git Then the ``roots`` backend (the default backend of files in ``/srv/salt``) will be searched first for the requested file; then, if it is not found on the master, each configured git remote will be searched. Branches, Environments, and Top Files ===================================== When using the gitfs backend, branches, and tags will be mapped to environments using the branch/tag name as an identifier. There is one exception to this rule: the ``master`` branch is implicitly mapped to the ``base`` environment. So, for a typical ``base``, ``qa``, ``dev`` setup, the following branches could be used: .. code-block:: yaml master qa dev ``top.sls`` files from different branches will be merged into one at runtime. Since this can lead to overly complex configurations, the recommended setup is to have a separate repository, containing only the ``top.sls`` file with just one single ``master`` branch. To map a branch other than ``master`` as the ``base`` environment, use the :conf_master:`gitfs_base` parameter. .. code-block:: yaml gitfs_base: salt-base The base can also be configured on a :ref:`per-remote basis `. .. _gitfs-whitelist-blacklist: Environment Whitelist/Blacklist =============================== .. versionadded:: 2014.7.0 The :conf_master:`gitfs_env_whitelist` and :conf_master:`gitfs_env_blacklist` parameters allow for greater control over which branches/tags are exposed as fileserver environments. Exact matches, globs, and regular expressions are supported, and are evaluated in that order. If using a regular expression, ``^`` and ``$`` must be omitted, and the expression must match the entire branch/tag. .. code-block:: yaml gitfs_env_whitelist: - base - v1.* - 'mybranch\d+' .. note:: ``v1.*``, in this example, will match as both a glob and a regular expression (though it will have been matched as a glob, since globs are evaluated before regular expressions). The behavior of the blacklist/whitelist will differ depending on which combination of the two options is used: * If only :conf_master:`gitfs_env_whitelist` is used, then **only** branches/tags which match the whitelist will be available as environments * If only :conf_master:`gitfs_env_blacklist` is used, then the branches/tags which match the blacklist will **not** be available as environments * If both are used, then the branches/tags which match the whitelist, but do **not** match the blacklist, will be available as environments. .. _gitfs-authentication: Authentication ============== pygit2 ------ .. versionadded:: 2014.7.0 Both HTTPS and SSH authentication are supported as of version 0.20.3, which is the earliest version of pygit2_ supported by Salt for gitfs. .. note:: The examples below make use of per-remote configuration parameters, a feature new to Salt 2014.7.0. More information on these can be found :ref:`here `. HTTPS ~~~~~ For HTTPS repositories which require authentication, the username and password can be provided like so: .. code-block:: yaml gitfs_remotes: - https://domain.tld/myrepo.git: - user: git - password: mypassword .. _gitfs-insecure-auth: If the repository is served over HTTP instead of HTTPS, then Salt will by default refuse to authenticate to it. This behavior can be overridden by adding an ``insecure_auth`` parameter: .. code-block:: yaml gitfs_remotes: - http://domain.tld/insecure_repo.git: - user: git - password: mypassword - insecure_auth: True .. _pygit2-authentication-ssh: SSH ~~~ SSH repositories can be configured using the ``ssh://`` protocol designation, or using scp-like syntax. So, the following two configurations are equivalent: * ``ssh://git@github.com/user/repo.git`` * ``git@github.com:user/repo.git`` Both :conf_master:`gitfs_pubkey` and :conf_master:`gitfs_privkey` (or their :ref:`per-remote counterparts `) must be configured in order to authenticate to SSH-based repos. If the private key is protected with a passphrase, it can be configured using :conf_master:`gitfs_passphrase` (or simply ``passphrase`` if being configured :ref:`per-remote `). For example: .. code-block:: yaml gitfs_remotes: - git@github.com:user/repo.git: - pubkey: /root/.ssh/id_rsa.pub - privkey: /root/.ssh/id_rsa - passphrase: myawesomepassphrase Finally, the SSH host key must be :ref:`added to the known_hosts file `. GitPython --------- With GitPython_, only passphrase-less SSH public key authentication is supported. **The auth parameters (pubkey, privkey, etc.) shown in the pygit2 authentication examples above do not work with GitPython.** .. code-block:: yaml gitfs_remotes: - ssh://git@github.com/example/salt-states.git Since GitPython_ wraps the git CLI, the private key must be located in ``~/.ssh/id_rsa`` for the user under which the Master is running, and should have permissions of ``0600``. Also, in the absence of a user in the repo URL, GitPython_ will (just as SSH does) attempt to login as the current user (in other words, the user under which the Master is running, usually ``root``). If a key needs to be used, then ``~/.ssh/config`` can be configured to use the desired key. Information on how to do this can be found by viewing the manpage for ``ssh_config``. Here's an example entry which can be added to the ``~/.ssh/config`` to use an alternate key for gitfs: .. code-block:: text Host github.com IdentityFile /root/.ssh/id_rsa_gitfs The ``Host`` parameter should be a hostname (or hostname glob) that matches the domain name of the git repository. It is also necessary to :ref:`add the SSH host key to the known_hosts file `. The exception to this would be if strict host key checking is disabled, which can be done by adding ``StrictHostKeyChecking no`` to the entry in ``~/.ssh/config`` .. code-block:: text Host github.com IdentityFile /root/.ssh/id_rsa_gitfs StrictHostKeyChecking no However, this is generally regarded as insecure, and is not recommended. .. _gitfs-ssh-fingerprint: Adding the SSH Host Key to the known_hosts File ----------------------------------------------- To use SSH authentication, it is necessary to have the remote repository's SSH host key in the ``~/.ssh/known_hosts`` file. If the master is also a minion, this can be done using the :mod:`ssh.set_known_host ` function: .. code-block:: bash # salt mymaster ssh.set_known_host user=root hostname=github.com mymaster: ---------- new: ---------- enc: ssh-rsa fingerprint: 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48 hostname: |1|OiefWWqOD4kwO3BhoIGa0loR5AA=|BIXVtmcTbPER+68HvXmceodDcfI= key: AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ== old: None status: updated If not, then the easiest way to add the key is to su to the user (usually ``root``) under which the salt-master runs and attempt to login to the server via SSH: .. code-block:: bash $ su Password: # ssh github.com The authenticity of host 'github.com (192.30.252.128)' can't be established. RSA key fingerprint is 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'github.com,192.30.252.128' (RSA) to the list of known hosts. Permission denied (publickey). It doesn't matter if the login was successful, as answering ``yes`` will write the fingerprint to the known_hosts file. Verifying the Fingerprint ~~~~~~~~~~~~~~~~~~~~~~~~~ To verify that the correct fingerprint was added, it is a good idea to look it up. One way to do this is to use nmap: .. code-block:: bash $ nmap github.com --script ssh-hostkey Starting Nmap 5.51 ( http://nmap.org ) at 2014-08-18 17:47 CDT Nmap scan report for github.com (192.30.252.129) Host is up (0.17s latency). Not shown: 996 filtered ports PORT STATE SERVICE 22/tcp open ssh | ssh-hostkey: 1024 ad:1c:08:a4:40:e3:6f:9c:f5:66:26:5d:4b:33:5d:8c (DSA) |_2048 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48 (RSA) 80/tcp open http 443/tcp open https 9418/tcp open git Nmap done: 1 IP address (1 host up) scanned in 28.78 seconds Another way is to check one's own known_hosts file, using this one-liner: .. code-block:: bash $ ssh-keygen -l -f /dev/stdin <<<`ssh-keyscan -t rsa github.com 2>/dev/null` | awk '{print $2}' 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48 Refreshing gitfs Upon Push ========================== By default, Salt updates the remote fileserver backends every 60 seconds. However, if it is desirable to refresh quicker than that, the :ref:`Reactor System ` can be used to signal the master to update the fileserver on each push, provided that the git server is also a Salt minion. There are three steps to this process: 1. On the master, create a file **/srv/reactor/update_fileserver.sls**, with the following contents: .. code-block:: yaml update_fileserver: runner.fileserver.update 2. Add the following reactor configuration to the master config file: .. code-block:: yaml reactor: - 'salt/fileserver/gitfs/update': - /srv/reactor/update_fileserver.sls 3. On the git server, add a `post-receive hook`_ with the following contents: .. code-block:: bash #!/usr/bin/env sh salt-call event.fire_master update salt/fileserver/gitfs/update The ``update`` argument right after :mod:`event.fire_master ` in this example can really be anything, as it represents the data being passed in the event, and the passed data is ignored by this reactor. Similarly, the tag name ``salt/fileserver/gitfs/update`` can be replaced by anything, so long as the usage is consistent. .. _`post-receive hook`: http://www.git-scm.com/book/en/Customizing-Git-Git-Hooks#Server-Side-Hooks .. _git-as-ext_pillar Using Git as an External Pillar Source ====================================== The git external pillar (a.k.a. git_pillar) has been rewritten for the 2015.8.0 release. This rewrite brings with it pygit2_ support (allowing for access to authenticated repositories), as well as more granular support for per-remote configuration. To make use of the new features, changes to the git ext_pillar configuration must be made. The new configuration schema is detailed :ref:`here `. For Salt releases before 2015.8.0, click :ref:`here ` for documentation. .. _faq-gitfs-bug: Why aren't my custom modules/states/etc. syncing to my Minions? =============================================================== In versions 0.16.3 and older, when using the :doc:`git fileserver backend `, certain versions of GitPython may generate errors when fetching, which Salt fails to catch. While not fatal to the fetch process, these interrupt the fileserver update that takes place before custom types are synced, and thus interrupt the sync itself. Try disabling the git fileserver backend in the master config, restarting the master, and attempting the sync again. This issue is worked around in Salt 0.16.4 and newer.