Updated Oink to accept environment variables to override global API keys

README.md

@@ -101,3 +101,19 @@ systemctl start oink_ddns
 ```
 - You are done! Your domain DNS record should update automatically
 
+---
+### CLI options
+**Oink!** also provides a CLI interface for manual DNS updates and debugging. The CLI options are the following:
+
+> Type `oink -h` to display this help message
+```
+Usage of oink:
+  -c string
+    	Path to oink_ddns configuration file (default "/etc/oink_ddns/config.json")
+  -u	Update the DNS records immediately and exit
+  -v	Enable verbose output
+```
+
+---
+### Overriding API keys
+For certain specific use cases, you might want to override the global API keys of your configuration file using environment variables. To do so, **both** `OINK_OVERRIDE_SECRETAPIKEY` and `OINK_OVERRIDE_APIKEY` must be set. These environment variables will take precedence over the global API keys set in the configuration file.

src/main.go

@@ -371,6 +371,15 @@ func main() {
 		cfg.Global.Interval = 60
 	}
 
+	// If environment variables for the API keys are set, override the global API keys of the config file
+	if os.Getenv("OINK_OVERRIDE_SECRETAPIKEY") != "" && os.Getenv("OINK_OVERRIDE_APIKEY") != "" {
+		if *verbose {
+			log.Printf("Overriding secretapikey and apikey with environment variables")
+		}
+		cfg.Global.Secretapikey = os.Getenv("OINK_OVERRIDE_SECRETAPIKEY")
+		cfg.Global.Apikey = os.Getenv("OINK_OVERRIDE_APIKEY")
+	}
+
 	// Run the update loop
 	for {
 		// Update domains