Add node documentation

Author: SimonBaeumer

README.md

@@ -10,6 +10,7 @@
 Define language independent tests for your command line scripts and programs in simple `yaml` files.
 
  - It runs on `windows`, `osx` and `linux` 
+ - It can validate local machines, ssh hosts and docker containers
  - It is a self-contained binary - no need to install a heavy lib or language
  - It is easy and fast to write
 
@@ -47,6 +48,10 @@ For more information take a look at the [quick start](#quick-start), the [exampl
     - [interval](#interval)
     - [retries](#retries)
     - [timeout](#timeout)
+    - [nodes](#nodes)
+  + [Nodes](#nodes)
+    - [local](#local)
+    - [ssh](#ssh)
   + [Development](#development)
 * [Misc](#misc)
 
@@ -625,6 +630,82 @@ If a tests exceeds the given `timeout` the test will fail.
 timeout: 600s
 ```
 
+### Nodes
+
+`Commander` has the option to execute tests against other hosts, i.e. via ssh.
+
+Available node types are currently:
+
+ - `local`, execute tests locally
+ - `ssh`, execute tests viá ssh
+
+```yaml
+nodes: # define nodes in the node section
+  ssh-host:
+    type: ssh # define the type of the connection 
+    user: root # set the user which is used by the connection
+    pass: password # set password for authentication
+    addr: 192.168.0.100:2222 # target host address
+    identity-file: ~/.ssh/id_rsa # auth with private key
+tests:
+  echo hello:
+    config:
+      nodes: # define on which host the test should be executed
+        - ssh-host
+    stdout: hello
+    exit-code: 0
+```
+
+You can identify on which node a test failed by inspecting the test output.
+The `[local]` and `[ssh-host]` represent the node name on which the test were executed.
+
+```
+✗ [local] it should test ssh host
+✗ [ssh-host] it should fail if env could not be set
+```
+
+#### local
+
+The `local` node is the default execution and will be applied if nothing else was configured.
+It is always pre-configured and available, i.e. if you want to execute tests on a node and locally.
+
+```yaml
+nodes:
+  ssh-host:
+    addr: 192.168.1.100
+    user: ...
+tests:
+  echo hello:
+    config:
+      nodes: # will be executed on local and ssh-host
+        - ssh-host
+        - local
+    exit-code: 0
+```
+
+#### ssh
+
+The `ssh` will execute tests against a configured node using ssh.
+
+**Limitations:** The `inhereit-env` config is disabled for ssh hosts, nevertheless it is possible to set env variables
+
+```yaml
+nodes: # define nodes in the node section
+  ssh-host:
+    type: ssh # define the type of the connection 
+    user: root # set the user which is used by the connection
+    pass: password # set password for authentication
+    addr: 192.168.0.100:2222 # target host address
+    identity-file: ~/.ssh/id_rsa # auth with private key
+tests:
+  echo hello:
+    config:
+      nodes: # define on which host the test should be executed
+        - ssh-host
+    stdout: hello
+    exit-code: 0
+```
+
 ### Development
 
 ```
@@ -640,6 +721,9 @@ $ make test
 # Coverage
 $ make test-coverage
 
+# Coverage with more complex tests like ssh execution
+$ make test-coverage-all
+
 # Integration tests
 $ make integration