Update readme and add generate-config command

README.md

@@ -1,71 +1,95 @@
 # Gnome appindicator dns switcher
 https://pypi.org/project/gnome-dns-switcher/
 
+Gnome appindicator (toolbar icon) tool to quickly switch between different DNS servers
+- Easily available in your toolbox
+- Config file to specify DNS servers
+Supports multiple connections and switching them separately
+- Utility button to restart NetworkManager
+
+![Screenshot of menu with DNS servers](./screenshots/menu.png)
+
+<details>
+<summary>💻 More screenshots</summary>
+
+#### Easily available in your toolbar
+![](./screenshots/appindicator.png)
+
+#### Shows you what it's done, no surprises
+![](./screenshots/notification.png)
+
+#### Supports multiple connections and switching them separately
+![](./screenshots/menu_multiple_connections.png)
+
+</details>
+
 ## Setup
+Install dependencies
 ```shell
-# In case you don't have pip3:
+# If you don't yet have pip3:
 sudo apt install python3-pip
 
+# Install dependencies to run this application
+sudo apt install python3-gi python3-gi-cairo gir1.2-gtk-3.0 gir1.2-appindicator3-0.1
+```
+
+Install gnome-dns-switcher
+```shell
 # sudo so the script is added to $PATH, you can also install normally and fix $PATH :)
 sudo pip3 install gnome-dns-switcher
 
-# See config explanation
-edit ~/.config/gnome-dns-switcher.yml
+# Generate a default configuration
+gnome-dns-switcher generate-config
 
-# Start the app in the background
-gnome-dns-switcher --config ~/.config/gnome-dns-switcher.yml &
+# Modify the config to your needs. See config documentation below
+edit ~/.config/gnome-dns-switcher.yml
 ```
 
-
-Add to startup applications:
+## Usage
+### Start the app in the background
+Simply add ` &` after your command
 ```shell
-# Sleep 10 to prevent starting up before network connections have been made
-bash -c 'sleep 10 && gnome-dns-switcher --config ~/.config/gnome-dns-switcher.yml'```
-
-- Create a config.yml, see [Config](#config)
-
-## Running
+gnome-dns-switcher &
+```
 
+### Specify a different configuration file (default is `~/.config/gnome-dns-switcher.yml`)
 ```shell
 gnome-dns-switcher --config /path/to/config.yml
 ```
 
-## Config
+### Add to startup applications
+```shell
+# Sleep 10 seconds before starting to prevent starting up 
+# before network connections have been made
+bash -c 'sleep 10 && gnome-dns-switcher --config ~/.config/gnome-dns-switcher.yml'
+```
 
-### Sample:
+## Config
+The config file allows you to specify which DNS servers to show and what devices are visible.
+By default, gnome-dns-switcher looks for a config file at `~/.config/gnome-dns-switcher.yml`
 
+To generate and example configuration, you can run `gnome-dns-switcher generate-config`
+### The generated configuration will look like this:
 ```yaml
-servers:
-  CloudFlare: 1.1.1.1
+servers: # DNS Server options to show
+  # DHCP is always shown as the first option
+  Quad9: 9.9.9.9
+  CloudFlare: [1.1.1.1, 1.0.0.1]
   Google DNS:
     - 8.8.8.8
     - 8.8.4.4
-  localhost: 127.0.0.1, 127.0.1.1
-devices:
-  - wlp2s0
+devices: [] # Specify device names here if you want to hide certain devices (ip link show)
 ```
 
-### Explanation
-
-#### `servers:`
+#### `servers` A list of servers that can be switched between
+- The name is only used for displaying
+- You can define one or more ips, as a yaml array or as a comma-seperated string
 
-- A list of servers that can be switched between
-- Name is just used for displaying
-- You can define one or more ips
-- On launch, we'll try to detect if the current settings match any of the servers
-
-#### `devices:`
-
-- optional, will display all non-bridge connections otherwise
+#### `devices` Which devices to show (optional)
+- optional, will display all non-bridge connections if not present or empty
 - one or more devices to show in the switcher
     - List all your devices by running `ip link show` in a terminal
 
-### You possibly need to install these dependencies
-
-```shell
-sudo apt install python3-gi python3-gi-cairo gir1.2-gtk-3.0 gir1.2-appindicator3-0.1
-```
-
 ## Development
 
 ### Setup

gnome_dns_switcher/__main__.py

@@ -1,4 +1,5 @@
 import argparse
+import os
 from os.path import isfile
 from typing import List
 
@@ -7,23 +8,61 @@
 from .gnome_helpers import get_connections
 from .switcher import Server, DnsSwitcher
 
+CONFIG_PATH = os.path.expanduser("~/.config/gnome-dns-switcher.yml")
+
 APPINDICATOR_ID = 'gnome_dns_switcher'
 
+# language=yaml
+DEFAULT_CONFIG = '''
+servers:
+  # DHCP is always shown as the first option
+  Quad9: 9.9.9.9
+  CloudFlare: [1.1.1.1, 1.0.0.1]
+  Google DNS:
+    - 8.8.8.8
+    - 8.8.4.4
+devices: [] # Specify device names here if you want to hide certain devices (ip link show)
+'''
+
 
 def main():
     parser = argparse.ArgumentParser(description='Gnome Dns Switcher')
-    parser.add_argument("--config", dest="config", required=False, default="./config.yml",
-                        help="Path to config yaml", metavar="FILE",
-                        type=lambda x:
-                        x if isfile(x)
-                        else parser.error("Specified config file ({}) is not a file. "
-                                          "Create it or specify a different path with --config".format(x)))
+    subcommands = parser.add_subparsers()
+    parser.set_defaults(subcommand=None)
+
+    parser.add_argument(
+        "--config",
+        dest="config",
+        required=False,
+        default=CONFIG_PATH,
+        help="Path to config yaml",
+        metavar="FILE",
+    )
+
+    generate_config_command = subcommands.add_parser(
+        'generate-config',
+        help=f'Generate an example configuration file in {CONFIG_PATH}'
+    )
+    generate_config_command.set_defaults(subcommand='generate-config')
 
     args = parser.parse_args()
-
-    config_path = args.config
-
-    result = 42 # 42 === reload
+    config_path = os.path.expanduser(args.config)
+
+    if args.subcommand == 'generate-config':
+        if isfile(config_path):
+            print(f'A file already exists at {config_path}')
+            exit(1)
+        print(f'Generating config at {config_path}')
+        os.umask(0o077)
+        os.makedirs(os.path.dirname(config_path), 0o700, exist_ok=True)
+        with open(config_path, 'x') as config_file:
+            config_file.write(DEFAULT_CONFIG)
+        print(f'Config file written!')
+        if (config_path != CONFIG_PATH):
+            print(f'To use this config file, run this program with --config {config_path}')
+        exit(0)
+
+    result = 42  # 42 === reload
     while result == 42:
         connections, servers = load_config(config_path)
         menu = DnsSwitcher(APPINDICATOR_ID, servers, connections)
@@ -33,6 +72,13 @@ def main():
 
 
 def load_config(config_path):
+    if not isfile(config_path):
+        print(
+            f"There is no file at the specified config path ({config_path}).\n"
+            f"Create it by running `gnome-dns-switcher generate-config` or specify a different path with --config"
+        )
+        exit(1)
+
     with open(config_path, 'r') as config_file:
         config = yaml.safe_load(config_file)
         servers: List[Server] = [Server('DHCP', None, True)]