Implement better logging and error handling and update the tests

Signed-off-by: Doğukan Teber <[email protected]>

Author: dogukanteber

gateway/gateway_test.go

@@ -266,7 +266,7 @@ func TestStartGateway(t *testing.T) {
 		{
 			name:        "invalid distributor proxy",
 			config:      &Config{},
-			expectedErr: errors.New("invalid URL scheme:"),
+			expectedErr: errors.New("invalid URL scheme"),
 		},
 		{
 			name: "invalid frontend proxy",
@@ -276,7 +276,7 @@ func TestStartGateway(t *testing.T) {
 					Paths: []string{},
 				},
 			},
-			expectedErr: errors.New("invalid URL scheme:"),
+			expectedErr: errors.New("invalid URL scheme"),
 		},
 		{
 			name: "invalid alertmanager proxy",
@@ -290,7 +290,7 @@ func TestStartGateway(t *testing.T) {
 					Paths: []string{},
 				},
 			},
-			expectedErr: errors.New("invalid URL scheme:"),
+			expectedErr: errors.New("invalid URL scheme"),
 		},
 		{
 			name: "invalid ruler proxy",
@@ -308,7 +308,7 @@ func TestStartGateway(t *testing.T) {
 					Paths: []string{},
 				},
 			},
-			expectedErr: errors.New("invalid URL scheme:"),
+			expectedErr: errors.New("invalid URL scheme"),
 		},
 	}
 

gateway/proxy.go

@@ -8,11 +8,9 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"net/url"
-	"os"
 	"time"
 
 	"github.com/cortexproject/auth-gateway/utils"
-	"github.com/sirupsen/logrus"
 )
 
 const (
@@ -65,7 +63,11 @@ func NewProxy(targetURL string, upstream Upstream, component string) (*Proxy, er
 	}
 
 	reverseProxy := httputil.NewSingleHostReverseProxy(url)
-	reverseProxy.Transport = customTransport(component, upstream)
+	transport, err := customTransport(component, upstream)
+	if err != nil {
+		return nil, err
+	}
+	reverseProxy.Transport = transport
 	originalDirector := reverseProxy.Director
 	reverseProxy.Director = customDirector(url, originalDirector)
 	reverseProxy.ErrorLog = log.New(utils.LogrusErrorWriter{}, "", 0)
@@ -88,7 +90,7 @@ func customDirector(targetURL *url.URL, originalDirector func(*http.Request)) fu
 	}
 }
 
-func customTransport(component string, upstream Upstream) http.RoundTripper {
+func customTransport(component string, upstream Upstream) (http.RoundTripper, error) {
 	dialerTimeout := upstream.HTTPClientDialerTimeout * time.Second
 	if dialerTimeout == 0 {
 		dialerTimeout = defaultTimeoutValues[component].HTTPClientDialerTimeout
@@ -108,14 +110,13 @@ func customTransport(component string, upstream Upstream) http.RoundTripper {
 
 	url, err := url.Parse(upstream.URL)
 	if err != nil {
-		logrus.Errorf("unexpected error when parsing the upstream url: %v", err)
-		os.Exit(1)
+		return nil, fmt.Errorf("unexpected error when parsing the upstream url: %v", err)
 	}
 
 	resolver := DefaultDNSResolver{}
 	lb, err := newRoundRobinLoadBalancer(url.Hostname(), resolver.LookupIP)
 	if err != nil {
-		logrus.Errorf("unexpected error when creating the load balancer: %v", err)
+		return nil, fmt.Errorf("unexpected error when creating the load balancer: %v", err)
 	}
 	t := &CustomTransport{
 		Transport: *http.DefaultTransport.(*http.Transport).Clone(),
@@ -130,7 +131,7 @@ func customTransport(component string, upstream Upstream) http.RoundTripper {
 	t.TLSHandshakeTimeout = TLSHandshakeTimeout
 	t.ResponseHeaderTimeout = responseHeaderTimeout
 
-	return t
+	return t, nil
 }
 
 func (p *Proxy) Handler(w http.ResponseWriter, r *http.Request) {

gateway/proxy_test.go

@@ -11,26 +11,37 @@ func TestNewProxy(t *testing.T) {
 	testCases := []struct {
 		name       string
 		targetURL  string
+		upstream   Upstream
 		expectErr  bool
 		expectHost string
 	}{
 		{
-			name:       "invalid URL",
-			targetURL:  "invalid url",
+			name:      "invalid URL",
+			targetURL: "invalid url",
+			upstream: Upstream{
+				URL:   "",
+				Paths: []string{},
+			},
 			expectErr:  true,
 			expectHost: "",
 		},
 		{
-			name:       "valid URL",
-			targetURL:  "http://localhost:8080",
+			name: "valid URL",
+			upstream: Upstream{
+				URL: "http://localhost:8080",
+				Paths: []string{
+					"/api/v1",
+					"/api/v1/push",
+				},
+			},
 			expectErr:  false,
 			expectHost: "localhost:8080",
 		},
 	}
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			p, err := NewProxy(tc.targetURL, Upstream{}, "")
+			p, err := NewProxy(tc.upstream.URL, tc.upstream, DISTRIBUTOR)
 			if (err != nil) != tc.expectErr {
 				t.Errorf("unexpected error: %v", err)
 				return