deploy-guide: add seed (#155)

Signed-off-by: Christian Berendt <[email protected]>

docs/guides/deploy-guide/seed.md

@@ -4,3 +4,56 @@ sidebar_position: 10
 ---
 
 # Seed
+
+The seed node is used once for the initial bootstrap of the manager node. It is sufficient
+to use the local workstation. It doesn't have to be a dedicated system. The seed node is
+no longer needed in the further process. The seed node must be able to reach the manager
+node via SSH.
+
+The use of Linux on the seed node is recommended. Other operating systems should also
+work without problems.
+
+## Install required packages
+
+```
+sudo apt-get install git python3-pip python3-virtualenv sshpass
+```
+
+## Get a copy of the configuration repository
+
+Each environment managed with OSISM is based on a configuration repository. This was
+previously created with Cookiecutter and the cfg-cookiecutter repository.
+
+A configuration repository is stored on a Git server (e.g. GitHub, Gitlab, ...). The
+configuration repository is individual for each environment and is therefore not provided
+by us.
+
+The configuration repository to be used must be available on the seed node. In the following
+example, replace `YOUR_ORG` and `YOUR_NEW_CONFIGURATION_REPOSITORY` accordingly.
+
+```
+git clone ssh://[email protected]:YOUR_ORG/YOUR_NEW_CONFIGURATION_REPOSITORY.git
+```
+
+Examples:
+
+* The repository is located in the `regiocloud` organisation on GitHub, has the name
+  configuration and can be accessed via SSH: `ssh://[email protected]:regiocloud/configuration.git`
+* The repository is located in the `regiocloud` organisation on Gitlab, has the name configuration
+  and can be accessed via SSH: `ssh://[email protected]:regiocloud/configuration.git`
+* The repository is located in the `regiocloud` organisation on an internal Gitlab, has the name
+  configuration and can be accessed via SSH: `ssh://[email protected]:regiocloud/configuration.git`
+
+If necessary, the configuration SSH key can be used for the initial transfer of the repository.
+
+For this, the following content is added in `~/.ssh/config` and the SSH privte key is stored in
+`~/.ssh/id_rsa.configuration`.
+
+
+```
+Host github.com
+  HostName github.com
+  User git
+  Port 22
+  IdentityFile ~/.ssh/id_rsa.configuration
+```