add headers mw

README.md

@@ -1,3 +1,36 @@
 # docker-proxy
 
 Simple edge HTTP(s) proxy for docker containers
+
+```
+Application Options:
+  -l, --listen=          listen on host:port (default: 127.0.0.1:8080) [$LISTEN]
+  -t, --timeout=         proxy timeout (default: 5s) [$TIMEOUT]
+      --max=             max response size (default: 64000) [$MAX_SIZE]
+  -g, --gzip             enable gz compression [$GZIP]
+  -x, --header=          proxy headers [$HEADER]
+      --dbg              debug mode [$DEBUG]
+
+assets:
+  -a, --assets.location= assets location [$ASSETS_LOCATION]
+      --assets.root=     assets web root (default: /) [$ASSETS_ROOT]
+
+docker:
+      --docker.enabled   enable docker provider [$DOCKER_ENABLED]
+      --docker.host=     docker host (default: unix:///var/run/docker.sock) [$DOCKER_HOST]
+      --docker.exclude=  excluded containers [$DOCKER_EXCLUDE]
+
+file:
+      --file.enabled     enable file provider [$FILE_ENABLED]
+      --file.name=       file name (default: dpx.conf) [$FILE_NAME]
+      --file.interval=   file check interval (default: 3s) [$FILE_INTERVAL]
+      --file.delay=      file event delay (default: 500ms) [$FILE_DELAY]
+
+static:
+      --static.enabled   enable static provider [$STATIC_ENABLED]
+      --static.rule=     routing rules [$STATIC_RULES]
+
+Help Options:
+  -h, --help             Show this help message
+
+```

app/main.go

@@ -20,10 +20,11 @@ import (
 )
 
 var opts struct {
-	Listen      string        `short:"l" long:"listen" env:"LISTEN" default:"127.0.0.1:8080" description:"listen on host:port"`
-	TimeOut     time.Duration `short:"t" long:"timeout" env:"TIMEOUT" default:"5s" description:"proxy timeout"`
-	MaxSize     int64         `long:"m" long:"max" env:"MAX_SIZE" default:"64000" description:"max response size"`
-	GzipEnabled bool          `short:"g" long:"gzip" env:"GZIP" description:"enable gz compression"`
+	Listen       string        `short:"l" long:"listen" env:"LISTEN" default:"127.0.0.1:8080" description:"listen on host:port"`
+	TimeOut      time.Duration `short:"t" long:"timeout" env:"TIMEOUT" default:"5s" description:"proxy timeout"`
+	MaxSize      int64         `long:"m" long:"max" env:"MAX_SIZE" default:"64000" description:"max response size"`
+	GzipEnabled  bool          `short:"g" long:"gzip" env:"GZIP" description:"enable gz compression"`
+	ProxyHeaders []string      `short:"x" long:"header" env:"HEADER" description:"proxy headers"`
 
 	Assets struct {
 		Location string `short:"a" long:"location" env:"LOCATION" default:"" description:"assets location"`
@@ -44,7 +45,7 @@ var opts struct {
 	} `group:"file" namespace:"file" env-namespace:"FILE"`
 
 	Static struct {
-		Enabled bool     `long:"enabled" env:"ENABLED" description:"enable file provider"`
+		Enabled bool     `long:"enabled" env:"ENABLED" description:"enable static provider"`
 		Rules   []string `long:"rule" env:"RULES" description:"routing rules"`
 	} `group:"static" namespace:"static" env-namespace:"STATIC"`
 

app/proxy/middleware/headers.go

@@ -0,0 +1,25 @@
+package middleware
+
+import (
+	"net/http"
+	"strings"
+)
+
+// Headers middleware adds headers to request
+func Headers(headers []string) func(http.Handler) http.Handler {
+
+	return func(h http.Handler) http.Handler {
+
+		fn := func(w http.ResponseWriter, r *http.Request) {
+			for _, h := range headers {
+				elems := strings.Split(h, ":")
+				if len(elems) != 2 {
+					continue
+				}
+				r.Header.Set(strings.TrimSpace(elems[0]), strings.TrimSpace(elems[1]))
+			}
+			h.ServeHTTP(w, r)
+		}
+		return http.HandlerFunc(fn)
+	}
+}

app/proxy/middleware/headers_test.go

@@ -0,0 +1,23 @@
+package middleware
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHeaders(t *testing.T) {
+	req := httptest.NewRequest("GET", "/something", nil)
+	w := httptest.NewRecorder()
+
+	h := Headers([]string{"h1:v1", "bad", "h2:v2"})(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+	h.ServeHTTP(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusOK, resp.StatusCode)
+	t.Logf("%+v", req.Header)
+	assert.Equal(t, "v1", req.Header.Get("h1"))
+	assert.Equal(t, "v2", req.Header.Get("h2"))
+	assert.Equal(t, 2, len(req.Header))
+}

app/proxy/proxy.go

@@ -21,6 +21,7 @@ type Http struct {
 	AssetsWebRoot  string
 	MaxBodySize    int64
 	GzEnabled      bool
+	ProxyHeaders   []string
 	Version        string
 }
 
@@ -41,6 +42,7 @@ func (h *Http) Do(ctx context.Context) error {
 			rest.Ping,
 			logger.New(logger.Prefix("[DEBUG] PROXY")).Handler,
 			rest.SizeLimit(h.MaxBodySize),
+			middleware.Headers(h.ProxyHeaders),
 			h.gzipHandler(),
 		),
 		ReadHeaderTimeout: 5 * time.Second,