This adds CORS headers based on configuration.

README.md

@@ -27,6 +27,7 @@ scp temp-gopher <raspberrypi>:~/somepath
 Create a `config.yml` file like this:
 
 ```
+baseurl: http://<pihostname>:8080 # Base URL to find the app at. Usually your Pi's IP address or hostname, unless using a reverse proxy
 sensors:
 - id: 28-000008083108 # Id of the DS18b120 sensor
   alias: fermenter # An alias for the sensor

config.go

@@ -25,6 +25,7 @@ type Sensor struct {
 // Config contains the applications configuration
 type Config struct {
 	Sensors []Sensor `yaml:"sensors"`
+	BaseURL string   `yaml:"baseurl"`
 }
 
 // LoadConfig will loads a file and parses it into a Config struct

config_test.go

@@ -21,7 +21,10 @@ func Test_LoadConfig(t *testing.T) {
 		Verbose:     true,
 	}
 
-	testConfig := Config{Sensors: []Sensor{testSensor}}
+	testConfig := Config{
+		Sensors: []Sensor{testSensor},
+		BaseURL: "https://foo.bar",
+	}
 
 	loadedConfig, err := LoadConfig("tests/test_config.yml")
 	assert.Equal(t, nil, err)

tests/duplicate_alias.yml

@@ -21,3 +21,4 @@ sensors:
   coolinvert: false
   coolminutes: 10
   verbose: true
+baseurl: https://foo.bar

tests/duplicate_id.yml

@@ -21,3 +21,4 @@ sensors:
   coolinvert: false
   coolminutes: 10
   verbose: true
+baseurl: https://foo.bar

tests/test_config.yml

@@ -10,3 +10,4 @@ sensors:
   coolinvert: false
   coolminutes: 10
   verbose: true
+baseurl: https://foo.bar

web.go

@@ -10,6 +10,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/gin-contrib/cors"
 	"github.com/gin-gonic/gin"
 )
 
@@ -18,7 +19,7 @@ func PingHandler(c *gin.Context) {
 	c.String(http.StatusOK, "pong")
 }
 
-// ConfigHandler responds to get requests with the current configuration
+// ConfigHandler responds to get requests with the current configuration.
 func ConfigHandler(config *Config) gin.HandlerFunc {
 	fn := func(c *gin.Context) {
 		if c.Param("alias") != "/" && c.Param("alias") != "" {
@@ -57,9 +58,21 @@ func StatusHandler(states *map[string]State) gin.HandlerFunc {
 
 // SetupRouter initializes the gin router.
 func SetupRouter(config *Config, states *map[string]State) *gin.Engine {
+	// If not specified, put gin in release mode
+	if _, ok := os.LookupEnv("GIN_MODE"); !ok {
+		gin.SetMode(gin.ReleaseMode)
+	}
 	r := gin.Default()
 
-	gin.SetMode(gin.ReleaseMode)
+	// Midleware
+	r.Use(gin.Recovery())
+	if gin.Mode() != "release" {
+		r.Use(cors.Default())
+	} else {
+		corsconf := cors.DefaultConfig()
+		corsconf.AllowOrigins = []string{config.BaseURL}
+		r.Use(cors.New(corsconf))
+	}
 
 	// Ping
 	r.GET("/ping", PingHandler)