oauth: provide more logging for failed oauth requests

pkg/api/login_oauth.go

@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
-	"log"
 	"net/http"
 	"net/url"
 
@@ -16,6 +15,7 @@ import (
 	"golang.org/x/oauth2"
 
 	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/log"
 	"github.com/grafana/grafana/pkg/metrics"
 	"github.com/grafana/grafana/pkg/middleware"
 	m "github.com/grafana/grafana/pkg/models"
@@ -29,6 +29,7 @@ var (
 	ErrSignUpNotAllowed      = errors.New("Signup is not allowed for this adapter")
 	ErrUsersQuotaReached     = errors.New("Users quota reached")
 	ErrNoEmail               = errors.New("Login provider didn't return an email address")
+	oauthLogger              = log.New("oauth.login")
 )
 
 func GenStateString() string {
@@ -50,10 +51,11 @@ func OAuthLogin(ctx *middleware.Context) {
 		return
 	}
 
-	error := ctx.Query("error")
-	if error != "" {
+	errorParam := ctx.Query("error")
+	if errorParam != "" {
 		errorDesc := ctx.Query("error_description")
-		redirectWithError(ctx, ErrProviderDeniedRequest, "error", error, "errorDesc", errorDesc)
+		oauthLogger.Error("failed to login ", "error", errorParam, "errorDesc", errorDesc)
+		redirectWithError(ctx, ErrProviderDeniedRequest, "error", errorParam, "errorDesc", errorDesc)
 		return
 	}
 
@@ -90,7 +92,7 @@ func OAuthLogin(ctx *middleware.Context) {
 	if setting.OAuthService.OAuthInfos[name].TlsClientCert != "" || setting.OAuthService.OAuthInfos[name].TlsClientKey != "" {
 		cert, err := tls.LoadX509KeyPair(setting.OAuthService.OAuthInfos[name].TlsClientCert, setting.OAuthService.OAuthInfos[name].TlsClientKey)
 		if err != nil {
-			log.Fatal(err)
+			log.Fatal(1, "Failed to setup TlsClientCert", "oauth provider", name, "error", err)
 		}
 
 		tr.TLSClientConfig.Certificates = append(tr.TLSClientConfig.Certificates, cert)
@@ -99,7 +101,7 @@ func OAuthLogin(ctx *middleware.Context) {
 	if setting.OAuthService.OAuthInfos[name].TlsClientCa != "" {
 		caCert, err := ioutil.ReadFile(setting.OAuthService.OAuthInfos[name].TlsClientCa)
 		if err != nil {
-			log.Fatal(err)
+			log.Fatal(1, "Failed to setup TlsClientCa", "oauth provider", name, "error", err)
 		}
 		caCertPool := x509.NewCertPool()
 		caCertPool.AppendCertsFromPEM(caCert)