feat: add configurable ldap connection timeout

conf/hydra-werther.conf

@@ -117,3 +117,9 @@ WERTHER_LDAP_ROLE_BASEDN=ou=groups,dc=myorg,dc=com
   # [type]        String
   # [default]     /
   # [required]
+
+#WERTHER_LDAP_CONNECTION_TIMEOUT=
+  # [description] LDAP server connection timeout
+  # [type]        Duration
+  # [default]     60s
+  # [required]

internal/ldapclient/ldapclient.go

@@ -61,6 +61,7 @@ type Config struct {
 	CacheSize         int               `envconfig:"cache_size" default:"512" desc:"a user info cache's size in KiB"`
 	CacheTTL          time.Duration     `envconfig:"cache_ttl" default:"30m" desc:"a user info cache TTL"`
 	IsTLS             bool              `envconfig:"is_tls" default:"false" desc:"should LDAP connection be established via TLS"`
+	ConnectionTimeout time.Duration     `envconfig:"connection_timeout" default:"60s" desc:"LDAP server connection timeout"`
 }
 
 // Client is a LDAP client (compatible with Active Directory).
@@ -80,6 +81,7 @@ func New(cnf Config) *Client {
 			RoleBaseDN:        cnf.RoleBaseDN,
 			IsTLS:             cnf.IsTLS,
 			RoleSearchQuery:   cnf.RoleSearchQuery,
+			ConnectionTimeout: cnf.ConnectionTimeout,
 		},
 		cache: freecache.NewCache(cnf.CacheSize * 1024),
 	}
@@ -296,10 +298,11 @@ type ldapConnector struct {
 	IsTLS             bool
 	UserSearchQuery   string
 	RoleSearchQuery   string
+	ConnectionTimeout time.Duration
 }
 
 func (c *ldapConnector) Connect(ctx context.Context, addr string) (conn, error) {
-	d := net.Dialer{Timeout: ldap.DefaultTimeout}
+	d := net.Dialer{Timeout: c.ConnectionTimeout}
 	tcpcn, err := d.DialContext(ctx, "tcp", addr)
 	if err != nil {
 		return nil, err