Git Fileserver Backend Walkthrough¶

安装依赖¶

Beginning with version 2014.7.0, both pygit2 and Dulwich are supported as alternatives to GitPython. The desired provider can be configured using the gitfs_provider parameter in the master config file.

If gitfs_provider is not configured, then Salt will prefer pygit2 if a suitable version is available, followed by GitPython and Dulwich.

# yum install python-pygit2

# apt-get install python-pygit2

# yum install GitPython

# apt-get install python-git

# yum install python-dulwich

# apt-get install python-dulwich

salt-run fileserver.clear_cache backend=git

rm -rf /var/cache/salt/master{,/file_lists}/gitfs

基本配置¶

使用gitfs backend，只需要在master上修改两个配置：

1. Include git in the fileserver_backend list in the master config file:

   fileserver_backend:
     - git
   

2. Specify one or more git://, https://, file://, or ssh:// URLs in gitfs_remotes to configure which repositories to cache and search for requested files:

   gitfs_remotes:
     - https://github.com/saltstack-formulas/salt-formula.git
   

   SSH remotes can also be configured using scp-like syntax:

   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 here.

   注解

   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. 重启控制器来加载新的配置文件

多远程仓库¶

gitfs_remotes 选项接受一个有序的git remotes列表，该顺序列表用于缓存和搜索所请求的文件。

一个简单的场景说明了这种级联的查找行为：

如果 gitfs_remotes 选项指定了三个remotes：

gitfs_remotes:
  - git://github.com/example/first.git
  - https://github.com/example/second.git
  - file:///root/third

每个版本库包含一些文件：

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 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 salt://haproxy/init.sls will be served from the https://github.com/example/second.git git repo.
• A request for the file salt://haproxy/haproxy.conf will be served from the file:///root/third repo.

Per-remote Configuration Parameters¶

The following master config parameters are global (that is, they apply to all configured gitfs remotes):

• gitfs_base
• gitfs_root
• gitfs_mountpoint (new in 2014.7.0)
• gitfs_user (pygit2 only, new in 2014.7.0)
• gitfs_password (pygit2 only, new in 2014.7.0)
• gitfs_insecure_auth (pygit2 only, new in 2014.7.0)
• gitfs_pubkey (pygit2 only, new in 2014.7.0)
• gitfs_privkey (pygit2 only, new in 2014.7.0)
• 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:

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

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 not authenticating to insecure (non-HTTPS) remotes.

子目录¶

The 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.

假设下面的布局：

.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:

gitfs_remotes:
  - git://mydomain.com/stuff.git

gitfs_root: foo/baz

The root can also be configured on a per-remote basis.

Mountpoints¶

The 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.

gitfs_remotes:
  - https://mydomain.com/stuff.git

gitfs_mountpoint: salt://webapps/foo/files

Mountpoints can also be configured on a per-remote basis.

Using gitfs Alongside Other Backends¶

有时它可能会有意识的使用多个后端 ；例如，如果``sls`` 文件被存储在git上，而大多数文件被直接存储在master上。

级联的查找逻辑用于多remotes，也同样应用于多个backends。如果``fileserver_backend`` 选项包含多个backends：

fileserver_backend:
  - roots
  - git

那么 roots backend( 默认文件的backend在``/srv/salt``中)将会首先被请求文件搜索；然后，如果在master上没有找到，将会搜索每个配置的git remote。

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.

这里有一个例外： master branch 隐含映射到 base environment。

所以，一个典型的 base, qa, dev 设置中，以下的branches可以使用：

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.

要映射一个不同于``master``的 branch，使用 gitfs_base 参数。

gitfs_base: salt-base

The base can also be configured on a per-remote basis.

Environment Whitelist/Blacklist¶

The gitfs_env_whitelist and 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.

gitfs_env_whitelist:
  - base
  - v1.*
  - 'mybranch\d+'

The behavior of the blacklist/whitelist will differ depending on which combination of the two options is used:

• If only gitfs_env_whitelist is used, then only branches/tags which match the whitelist will be available as environments
• If only 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.

Authentication¶

gitfs_remotes:
  - https://domain.tld/myrepo.git:
    - user: git
    - password: mypassword

gitfs_remotes:
  - http://domain.tld/insecure_repo.git:
    - user: git
    - password: mypassword
    - insecure_auth: True

gitfs_remotes:
  - git@github.com:user/repo.git:
    - pubkey: /root/.ssh/id_rsa.pub
    - privkey: /root/.ssh/id_rsa
    - passphrase: myawesomepassphrase

gitfs_remotes:
  - ssh://git@github.com/example/salt-states.git

Host github.com
    IdentityFile /root/.ssh/id_rsa_gitfs

Host github.com
    IdentityFile /root/.ssh/id_rsa_gitfs
    StrictHostKeyChecking no

# 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

$ 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).

$ 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

$ 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¶

默认情况下，Salt每60秒更新remote文件服务器后端。但是，如果希望快速的刷新后端， Reactor System 可以用信号通知master来更新每个推送的文件服务器，这些服务器由git服务器来提供，它也可以是Salt minion。这一过程有三个步骤：

1. On the master, create a file /srv/reactor/update_fileserver.sls, with the following contents:

   update_fileserver:
     runner.fileserver.update
   

2. 添加下列反应器配置到master 配置文件：

   reactor:
     - 'salt/fileserver/gitfs/update':
       - /srv/reactor/update_fileserver.sls
   

3. 在git服务器上，添加一个 `post-receive hook`_包含以下内容：

   #!/usr/bin/env sh
   
   salt-call event.fire_master update salt/fileserver/gitfs/update
   

The update argument right after 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.

同样地，tag名称 salt/fileserver/gitfs/update 可以被任意替代，只要用法是一致的就可以。

使用Git作为一个外部Pillar来源¶

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 here.

For Salt releases before 2015.8.0, click here for documentation.

为什么自定义的模块/states等等不会同步到Minions上?¶

在0.16.3及之前的版本, 当使用 git文件服务后端 时，某些版本的GitPython可能会在fetch时产生错误, 导致Salt抓取失败。虽然对于fetch过程来说这并不致命，但是中断文件服务发生在自定义类型同步完成之前发生，这样会中断同步过程本身。请尝试关闭掉master配置中的git文件服务后端, 重启master并尝试再次同步.

这个问题在Salt 0.16.4及最新的版本已经得到解决.