Functional tests for LDAP Connection Pool

functional/ldap_test.go

@@ -7,9 +7,12 @@ import (
 	"net/url"
 	"os"
 	"strconv"
+	"sync"
 	"testing"
+	"time"
 
 	"github.com/coreos/dex/connector"
+	"golang.org/x/net/context"
 	"gopkg.in/ldap.v2"
 )
 
@@ -123,3 +126,57 @@ func TestConnectorLDAPHealthy(t *testing.T) {
 		}
 	}
 }
+
+func TestLDAPPoolHighWatermarkAndLockContention(t *testing.T) {
+	server := ldapServer(t)
+	ldapPool := &connector.LDAPPool{
+		MaxIdleConn: 30,
+		ServerHost:  server.Host,
+		ServerPort:  server.Port,
+		UseTLS:      false,
+		UseSSL:      false,
+	}
+
+	// Excercise pool operations with MaxIdleConn + 10 concurrent goroutines.
+	// We are testing both pool high watermark code and lock contention
+	numRoutines := ldapPool.MaxIdleConn + 10
+	var wg sync.WaitGroup
+	wg.Add(numRoutines)
+	ctx, _ := context.WithTimeout(context.Background(), 5*time.Second)
+	for i := 0; i < numRoutines; i++ {
+		go func() {
+			defer wg.Done()
+			for {
+				select {
+				case <-ctx.Done():
+					return
+				default:
+					ldapConn, err := ldapPool.Acquire()
+					if err != nil {
+						t.Errorf("Unable to acquire LDAP Connection: %v", err)
+					}
+					s := ldap.NewSearchRequest("", ldap.ScopeBaseObject, ldap.NeverDerefAliases, 0, 0, false, "(objectClass=*)", []string{}, nil)
+					_, err = ldapConn.Search(s)
+					if err != nil {
+						t.Errorf("Search request failed. Dead/invalid LDAP connection from pool?: %v", err)
+						ldapConn.Close()
+					} else {
+						ldapPool.Put(ldapConn)
+					}
+					_, _ = ldapPool.CheckConnections()
+				}
+			}
+		}()
+	}
+
+	// Wait for all operations to complete and check status.
+	// There should be MaxIdleConn connections in the pool. This confirms:
+	// 1. The tests was indeed executed concurrently
+	// 2. Even though we ran more routines than the configured MaxIdleConn the high
+	//    watermark code did its job and closed surplus connections
+	wg.Wait()
+	alive, killed := ldapPool.CheckConnections()
+	if alive < ldapPool.MaxIdleConn {
+		t.Errorf("expected %v connections, got alive=%v killed=%v", ldapPool.MaxIdleConn, alive, killed)
+	}
+}