Chore: refactor auth proxy (#16504)

* Chore: refactor auth proxy

Introduced the helper struct for auth_proxy middleware.
Added couple unit-tests, but it seems "integration" tests already cover
most of the code paths.

Although it might be good idea to test every bit of it, hm.
Haven't refactored the extraction of the header logic that much

Fixes #16147

* Fix: make linters happy

pkg/middleware/auth_proxy/auth_proxy_test.go

@@ -0,0 +1,124 @@
+package authproxy
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	"github.com/grafana/grafana/pkg/infra/remotecache"
+	"github.com/grafana/grafana/pkg/login"
+	models "github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/setting"
+	. "github.com/smartystreets/goconvey/convey"
+	"gopkg.in/macaron.v1"
+)
+
+type TestLDAP struct {
+	login.ILdapAuther
+	ID         int64
+	syncCalled bool
+}
+
+func (stub *TestLDAP) SyncUser(query *models.LoginUserQuery) error {
+	stub.syncCalled = true
+	query.User = &models.User{
+		Id: stub.ID,
+	}
+	return nil
+}
+
+func TestMiddlewareContext(t *testing.T) {
+	Convey("auth_proxy helper", t, func() {
+		req, _ := http.NewRequest("POST", "http://example.com", nil)
+		setting.AuthProxyHeaderName = "X-Killa"
+		name := "markelog"
+
+		req.Header.Add(setting.AuthProxyHeaderName, name)
+
+		ctx := &models.ReqContext{
+			Context: &macaron.Context{
+				Req: macaron.Request{
+					Request: req,
+				},
+			},
+		}
+
+		Convey("gets data from the cache", func() {
+			store := remotecache.NewFakeStore(t)
+			key := fmt.Sprintf(CachePrefix, name)
+			store.Set(key, int64(33), 0)
+
+			auth := New(&Options{
+				Store: store,
+				Ctx:   ctx,
+				OrgID: 4,
+			})
+
+			id, err := auth.GetUserID()
+
+			So(err, ShouldBeNil)
+			So(id, ShouldEqual, 33)
+		})
+
+		Convey("LDAP", func() {
+			Convey("gets data from the LDAP", func() {
+				login.LdapCfg = login.LdapConfig{
+					Servers: []*login.LdapServerConf{
+						{},
+					},
+				}
+
+				setting.LdapEnabled = true
+
+				store := remotecache.NewFakeStore(t)
+
+				auth := New(&Options{
+					Store: store,
+					Ctx:   ctx,
+					OrgID: 4,
+				})
+
+				stub := &TestLDAP{
+					ID: 42,
+				}
+
+				auth.LDAP = func(server *login.LdapServerConf) login.ILdapAuther {
+					return stub
+				}
+
+				id, err := auth.GetUserID()
+
+				So(err, ShouldBeNil)
+				So(id, ShouldEqual, 42)
+				So(stub.syncCalled, ShouldEqual, true)
+			})
+
+			Convey("gets nice error if ldap is enabled but not configured", func() {
+				setting.LdapEnabled = false
+
+				store := remotecache.NewFakeStore(t)
+
+				auth := New(&Options{
+					Store: store,
+					Ctx:   ctx,
+					OrgID: 4,
+				})
+
+				stub := &TestLDAP{
+					ID: 42,
+				}
+
+				auth.LDAP = func(server *login.LdapServerConf) login.ILdapAuther {
+					return stub
+				}
+
+				id, err := auth.GetUserID()
+
+				So(err, ShouldNotBeNil)
+				So(id, ShouldNotEqual, 42)
+				So(stub.syncCalled, ShouldEqual, false)
+			})
+
+		})
+	})
+}