Update README

Signed-off-by: Atanas Dinov <[email protected]>

README.md

@@ -1,12 +1,12 @@
 # nm-configurator
 
-nm-configurator (or NMC) is a CLI tool which makes it easy to generate and apply NetworkManager configurations.
+nm-configurator (or nmc) is a CLI tool which makes it easy to generate and apply NetworkManager configurations.
 
 ## How to install it?
 
 ### Download from release
 
-Each release is published with NMC already built for `amd64` and `arm64` Linux systems:
+Each release is published with nmc already built for `amd64` and `arm64` Linux systems:
 
 ```shell
 $ curl -o nmc -L https://github.com/suse-edge/nm-configurator/releases/latest/download/nmc-linux-$(uname -m)
@@ -25,13 +25,21 @@ $ cargo build --release # only supports Linux based systems
 
 ### Generate config
 
-NMC depends on having the desired network state for all known nodes beforehand.
+nmc depends on having the desired network state for all known nodes beforehand.
 
 [NetworkManager](https://documentation.suse.com/sle-micro/5.5/html/SLE-Micro-all/cha-nm-configuration.html)
 is using connection profiles defined as files stored under `/etc/NetworkManager/system-connections`.
-In order to generate these config (*.nmconnection) files, NMC uses the
+
+In order to generate these config (*.nmconnection) files, nmc uses the
 [nmstate](https://github.com/nmstate/nmstate) library and requires a configuration directory as an input.
-This directory must contain the desired network state for all hosts in a <i>hostname</i>.yaml file format.
+This directory must contain the desired network state in one of the following file formats:
+
+1. A single or multiple `<hostname>.yaml` files containing the different configurations per host.
+This method requires specifying the MAC addresses of all Ethernet interfaces for each host
+in order to properly identify the relevant configurations when applying those.
+
+2. A single `_all.yaml` file containing the configurations to be applied to all hosts.
+This method does not depend on MAC address matching.
 
 #### Prepare desired states
 
@@ -89,7 +97,7 @@ EOF
 
 Please refer to the official nmstate docs for more extensive [examples](https://nmstate.io/examples.html).
 
-#### Run NMC
+#### Run nmc
 
 ```shell
 $ ./nmc generate --config-dir desired-states --output-dir network-config
@@ -119,7 +127,7 @@ There are separate directories for each host (identified by their input <i>hostn
 Each of these contains the configuration files for the desired network interfaces (e.g. `eth0`).
 
 The `host_config.yaml` file on the root level maps the hosts to all of their preconfigured interfaces.
-This is necessary in order for NMC to identify which host it is running on when applying the network configurations later.
+This is necessary in order for nmc to identify which host it is running on when applying the network configurations later.
 
 ```yaml
 - hostname: node1
@@ -139,9 +147,11 @@ This is necessary in order for NMC to identify which host it is running on when
       interface_type: ethernet
 ```
 
+**NOTE:** The `host_config.yaml` file will not be present if the input configurations are the same for all provisioned hosts (specified in `_all.yaml`).
+
 ### Apply config
 
-NMC will use the previously generated configurations to identify and store the relevant NetworkManager settings for a given host.
+nmc will use the previously generated configurations to identify and store the relevant NetworkManager settings for a given host.
 
 Typically used with [Combustion](https://documentation.suse.com/sle-micro/5.5/single-html/SLE-Micro-deployment/#cha-images-combustion)
 in order to bootstrap multiple nodes using the same provisioning artefact instead of depending on different custom images per machine.
@@ -160,6 +170,6 @@ $ ./nmc apply --config-dir network-config/
 ```
 
 **NOTE:** Interface names during the installation of nodes might differ from the preconfigured logical ones.
-This is expected and NMC will rely on the MAC addresses and use the actual names for the NetworkManager
+This is expected and nmc will rely on the MAC addresses and use the actual names for the NetworkManager
 configurations instead e.g. settings for interface with a predefined logical name `eth0` but actually named
 `eth2` will automatically be adjusted and stored to `/etc/NetworkManager/eth2.nmconnection`.