Create tutorial for git backend for salt

GITSALT.md

+
+## Git backend tutorial
+
+### 1. Install salt master and register minion
+
+```bash
+sudo apt-get install salt-minion
+sudo apt-get install salt-master
+```
+
+#### Edit /etc/salt/minion to set master to 127.0.0.1
+#### Open 4505 and 4506 with ufw allow.
+#### Restart master and minion. Accept minion key with salt-key -A.
+#### Use -l debug option to show debug messages.
+
+### 2. Install pygit2
+
+#### 2.1 Without adding the repo, installing pygit is a bit difficult. Use this:
+
+```bash
+sudo add-apt-repository ppa:dennis/python
+sudo apt-get update
+sudo apt-get install python-pygit2
+```
+
+#### 2.2 Copy keys.
+
+### 3. Modify the *master* config file:
+
+```yaml
+fileserver_backend:
+  - git
+
+gitfs_remotes:
+  - git@git.ik.bme.hu:circle/salt.git:
+    - pubkey: /root/.ssh/git.pub
+    - privkey: /root/.ssh/git
+
+pillar_roots:
+  base:
+    - /home/cloud/salt/pillar
+
+gitfs_root: salt 
+```
+
+### 4. Clone pillar to /home/cloud/
+```bash
+git clone `https://git.ik.bme.hu/circle/salt.git
+```
+
+### 5. Finish: call salt '*' state.sls allinone (or whatever you need)
+
+###  the *master* config file:
+
+#### The default git provider is pygit2. You can change that to dulwich ot gitpython.
+
+```yaml
+gitfs_provider: dulwich
+```
+
+#### Include git in the fileserver_backend list:
+
+```yaml
+fileserver_backend:
+  - git
+```
+
+#### Specify one or more git://, https://, file://, or ssh:// URLs in gitfs_remotes to configure which repositories to cache and search for requested files:
+
+```yaml
+gitfs_remotes:
+  - git@git.ik.bme.hu:circle/salt.git
+```
+
+> The gitfs_remotes option accepts an ordered list of git remotes to cache and search, in listed order, for requested files.
+
+#### Serving from subdirectory
+
+```yaml
+gitfs_root: foo/baz
+```
+
+#### Other options
+
+Its possible to change branches, enviroments
+
+Change branch:
+
+```yaml
+gitfs_base: salt-base
+```
+
+
+### Tutorial with more information:
+http://docs.saltstack.com/en/latest/topics/tutorials/gitfs.html
+
+### Local gitfs issue:
+https://github.com/saltstack/salt/issues/6660