reload config on new webhook request

Makefile

@@ -3,15 +3,17 @@ all: install
 clean:
 	rm -rf gohookr
 
-install:
-	go mod tidy
-	go build -o gohookr
+install: build
 	cp gohookr /usr/local/bin/
 	cp gohookr.service /usr/lib/systemd/system/
 	cp -n config.json /etc/gohookr.json
 	systemctl daemon-reload
 	systemctl enable --now gohookr
 
+build:
+	go mod tidy
+	go build -o gohookr
+
 uninstall:
 	systemctl disable --now gohookr
 	rm -rf /usr/local/bin/gohookr /usr/lib/systemd/system/gohookr.service

main.go

@@ -18,9 +18,10 @@ import (
 
 var config_filename = "/etc/gohookr.json"
 var checkSignature = true
-var c config.Config
 
 func main() {
+	var c config.Config
+
 	r := mux.NewRouter()
 	r.HandleFunc("/webhooks/{service}", webhookHandler)
 
@@ -32,23 +33,47 @@ func main() {
 		checkSignature = p != "true"
 	}
 
-	raw_config, err := ioutil.ReadFile(config_filename)
+	c, err := loadConfig(config_filename)
 	if err != nil {
 		panic(err.Error())
 	}
+	fmt.Printf("CONFIG OK: %s\n", config_filename)
+	fmt.Printf("LISTENING AT: %s\n", c.ListenAddress)
 
-	if err := json.Unmarshal(raw_config, &c); err != nil {
-		panic(err.Error())
-	}
-
-	if err := c.Validate(); err != nil {
-		panic(err.Error())
+	for _, v := range os.Args {
+		if v == "checkConfig" {
+			return
+		}
 	}
 
 	log.Fatal(http.ListenAndServe(c.ListenAddress, r))
 }
 
+func loadConfig(config_filename string) (config.Config, error) {
+	var c config.Config
+
+	raw_config, err := ioutil.ReadFile(config_filename)
+	if err != nil {
+		return config.Config{}, err
+	}
+
+	if err := json.Unmarshal(raw_config, &c); err != nil {
+		return config.Config{}, err
+	}
+
+	if err := c.Validate(); err != nil {
+		return config.Config{}, err
+	}
+
+	return c, nil
+
+}
+
 func webhookHandler(w http.ResponseWriter, r *http.Request) {
+	c, err := loadConfig(config_filename)
+	if err != nil {
+		writeResponse(w, 500, "Unable to read config file")
+	}
 	// Check what service is specified in URL (/webhooks/{service}) and if it exists
 	serviceName := string(mux.Vars(r)["service"])
 	service, ok := c.Services[serviceName]
@@ -85,7 +110,7 @@ func webhookHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Run tests and script as goroutine to prevent timing out
-	go func(){
+	go func() {
 		// Run tests, immediately stop if one fails
 		for _, test := range service.Tests {
 			if _, err := test.Execute(payload); err != nil {

readme.md

@@ -15,10 +15,17 @@ make
 Default config path is `/etc/gohookr.json`.
 It can be overriden by setting environment variable `CONFIG`.
 
+The config file will be re-read every request so service configs can be changed without restarting
+the service (unless you want to change the listening port).
+
 Check below for an example configuration, which should tell you most of the things you need to know
 to configure gohookr.
 
-Currently gohookr must be restarted after config changes.
+You can test your config file by running
+
+```
+gohookr checkConfig
+```
 
 ### Signature Verification
 
@@ -32,7 +39,8 @@ For GitHub it would be `sha256=`.
 
 #### Disable Signature Verification
 
-You can disable signature verification by setting `DisableSignatureVerification` for a service to `true`.
+You can disable signature verification by setting `DisableSignatureVerification` for a service to
+`true`.
 
 You can disable signature verification for all services by setting environment variable
 `NO_SIGNATURE_VERIFICATION` to `true`.