feat(backend): Add CORS headers to API responses

Gopkg.lock

@@ -65,6 +65,14 @@
   pruneopts = "UT"
   revision = "563b81fc02b75d664e54da31f787c2cc2186780b"
 
+[[projects]]
+  digest = "1:2b59aca2665ff804f6606c8829eaee133ddd3aefbc841014660d961b0034f888"
+  name = "github.com/gin-contrib/cors"
+  packages = ["."]
+  pruneopts = "UT"
+  revision = "cf4846e6a636a76237a28d9286f163c132e841bc"
+  version = "v1.2"
+
 [[projects]]
   branch = "master"
   digest = "1:944620dd72b65b9bac1b715134540e5546ffbf84876c3fe065ec594eef640eaf"
@@ -385,6 +393,7 @@
     "github.com/cnf/structhash",
     "github.com/elazarl/go-bindata-assetfs",
     "github.com/getsentry/raven-go",
+    "github.com/gin-contrib/cors",
     "github.com/gin-contrib/gzip",
     "github.com/gin-contrib/static",
     "github.com/gin-gonic/contrib/sentry",

Gopkg.toml

@@ -98,3 +98,7 @@
 [[constraint]]
   branch = "v2"
   name = "gopkg.in/yaml.v2"
+
+[[constraint]]
+  name = "github.com/gin-contrib/cors"
+  version = "1.2.0"

main.go

@@ -15,6 +15,7 @@ import (
 	"github.com/spf13/pflag"
 
 	"github.com/DeanThompson/ginpprof"
+	"github.com/gin-contrib/cors"
 	"github.com/gin-contrib/gzip"
 	"github.com/gin-contrib/static"
 	"github.com/gin-gonic/contrib/sentry"
@@ -53,6 +54,14 @@ func setupRouter(router *gin.Engine) {
 	router.Use(gzip.Gzip(gzip.DefaultCompression))
 	router.Use(static.Serve(getViewURL("/static"), newBinaryFileSystem("static")))
 
+	router.Use(cors.New(cors.Config{
+		AllowAllOrigins:  true,
+		AllowCredentials: true,
+		AllowMethods:     []string{"GET", "POST", "DELETE"},
+		AllowHeaders:     []string{"Origin"},
+		ExposeHeaders:    []string{"Content-Length"},
+	}))
+
 	router.GET(getViewURL("/favicon.ico"), favicon)
 	router.GET(getViewURL("/"), index)
 	router.GET(getViewURL("/help"), help)