Drop the dependency on clientutil for the ldap package

Just use backoff.Retry() straight away without a wrapper.

ldap/pool.go

@@ -7,11 +7,30 @@ import (
 	"net/url"
 	"time"
 
-	"git.autistici.org/ai3/go-common/clientutil"
 	"github.com/cenkalti/backoff"
 	"gopkg.in/ldap.v2"
 )
 
+// Parameters that define the exponential backoff algorithm used.
+var (
+	ExponentialBackOffInitialInterval = 100 * time.Millisecond
+	ExponentialBackOffMultiplier      = 1.4142
+)
+
+// newExponentialBackOff creates a backoff.ExponentialBackOff object
+// with our own default values.
+func newExponentialBackOff() *backoff.ExponentialBackOff {
+	b := backoff.NewExponentialBackOff()
+	b.InitialInterval = ExponentialBackOffInitialInterval
+	b.Multiplier = ExponentialBackOffMultiplier
+
+	// Set MaxElapsedTime to 0 because we expect the overall
+	// timeout to be dictated by the request Context.
+	b.MaxElapsedTime = 0
+
+	return b
+}
+
 // ConnectionPool provides a goroutine-safe pool of long-lived LDAP
 // connections that will reconnect on errors.
 type ConnectionPool struct {
@@ -129,14 +148,14 @@ func NewConnectionPool(uri, bindDN, bindPw string, cacheSize int) (*ConnectionPo
 }
 
 func (p *ConnectionPool) doRequest(ctx context.Context, fn func(*ldap.Conn) error) error {
-	return clientutil.Retry(func() error {
+	return backoff.Retry(func() error {
 		conn, err := p.Get(ctx)
 		if err != nil {
 			// Here conn is nil, so we don't need to Release it.
 			if isTemporaryLDAPError(err) {
-				return clientutil.TempError(err)
+				return err
 			}
-			return err
+			return backoff.Permanent(err)
 		}
 
 		if deadline, ok := ctx.Deadline(); ok {
@@ -144,13 +163,12 @@ func (p *ConnectionPool) doRequest(ctx context.Context, fn func(*ldap.Conn) erro
 		}
 
 		err = fn(conn)
-		if err != nil && isTemporaryLDAPError(err) {
-			p.Release(conn, err)
-			return clientutil.TempError(err)
-		}
 		p.Release(conn, err)
+		if err != nil && !isTemporaryLDAPError(err) {
+			err = backoff.Permanent(err)
+		}
 		return err
-	}, backoff.WithContext(clientutil.NewExponentialBackOff(), ctx))
+	}, backoff.WithContext(newExponentialBackOff(), ctx))
 }
 
 // Search performs the given search request. It will retry the request