updated README to reflect current state of the project

README.md

@@ -3,58 +3,99 @@ A DNS record updater for [Gandi's LiveDNS](https://api.gandi.net/docs/livedns/)
 This script is heavily inspired by [dyn-gandi](https://github.com/Danamir/dyn-gandi).
 
 ## How it works
-This script determines the your server's current IP by querying the resolvers defined in the config file.
-After that it reads the current state of the domains and subdomains you specified of Gandi.
-Should the IP address of a subdomain not match your current IP it will be updated.
-The subdomain will be created should it not already exist.
+This script determines the the current IP address by querying the resolvers defined in the config file.
+It then queries the subdomains' A records off of Gandi and compares their IP addresses to the current IP address.
+Should the IP address of a subdomain's A record not match your current IP address it will be updated. The subdomain's A record will be created should it not already exist.
 
-## Note
-The current implementation only allows for one entry per subdomain.
-Meaning that should you have a TXT and a CNAME record for a subdomain that is in the config file, then both these entries will be deleted and replaced by a single A name record.
+## Notes
+Every invocation of the script causes at least 1 request to a resolver specified and 1 API call to Gandi per domain.
+Updating a subdomain's A record is 1 API request per subdomain, even if they share the same domain.  
+Resolvers are queried in the order specified until one returns a valid IP address.  
+It is also possible to define a path to a file with the API key written in it. This is good for environments where the config file has to be shared like in a nix project.
 
 ## How to use
 First, get your API key from https://account.gandi.net/en/users/USER/security where `USER` is your Gandi username.
-On first run the program will create a minimal, yet complete `config.json` in the same directory it is being run in.  
-Next, enter the API key into the configuration file and assign domains to it.
-The domains are keys to a list of subdomain for a given domain you wish to monitor.
-The below example is complete and should explain itself.
-Resolvers are queried one after another until one returns a valid IP.
 
-`config.json`
+The script looks for a config file at `$HOME/.config/dyn-gandi/config.log` or `/etc/dyn-gandi.conf` in that order. So create a file at one of these locations according to the schema below.
+
 ```json
 {
   "api": {
     "<Your-API-Key>": {
       "example.com": [ "@", "www", "sub1" ],
       "example.org": [ "@", "www", "sub1", "sub2" ]
+    },
+    "/path/to/a/file/containing/api_key": {
+      "example.at": [ "sub1" ],
+      "example.au": [ "sub1" "sub2" ]
     }
   },
-  "ttl": 3600,
   "resolvers": [
     "https://ifconfig.me/ip",
     "https://me.gandi.net"
   ],
+  "ttl": 3600,
   "log_path": "./log.txt"
 }
 ```
 
+## Nix
+Add this to the modules.
+```nix
+
+inputs = {
+  nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05";
+  dyn-gandi.url = "/home/kristian/dyn-gandi";
+};
+
+outputs = {
+  self,
+  nixpkgs,
+  dyn-gandi
+}: {
+  ...
+  modules = [
+    dyn-gandi.nixosModules.default
+    {
+      dyn-gandi.enable = true;
+      dyn-gandi.settings = {
+        api = {
+          "/path/to/a/file/containing/api_key" = {
+            "example.com" = ["@" "www"];
+          };
+        };
+        resolvers = [
+          "https://ifconfig.me/ip"
+          "https://me.gandi.net"
+        ];
+        ttl = 3600;
+        log_path = "/path/to/log/file";
+      };
+      dyn-gandi.timer = 300;
+    }
+    ...
+  ];
+  ...
+}
+```
+Use `dyn-gandi.nixosModules.default` for a NixOs module and `dyn-gandi.homeManagerModules.default` for home-manager
+
+`dyn-gandi.timer` specifies a timer in seconds when the script should be repeated.
+
+
 ## Features
-* Support for arbitrarily many domains and records through a nested data structure.
-* Small codebase.
+* Support for arbitrarily many domains and subdomains through a nested data structure.
+* Small codebase
 * Logging
+* NixOS and home-manager modules
 
 ## Limitations
-* Right now only IPv4 addresses are supported
-* Every record is only allowed one A record.
-* Extra records (TXT, CNAME and such) will get deleted on update. 
+* Only IPv4 addresses are supported
 
 ## TODO
 * Testing
 * Command line options controlling: dry-run, config, log, verbosity, force
+* Support IPv6
 * Per subdomain TTL
-* Nix Flake support with exported config and service options
 * Better documentation
 * Better logging
-* Support IPv6
-* Remember other record types (TXT, etc.)
-* Detect TTL change and update even when the IP is the same