Merge pull request #46 from balena/master

Adding options `connection_timeout`, `retry` and `retry_timeout`

src/eetcd.erl

@@ -38,6 +38,10 @@ open(Name, Hosts, Transport, TransportOpts) ->
 %% The pinned address is maintained until the client connection is closed.
 %% When the client receives an error, it randomly picks another normal endpoint.
 %%
+%% `{connect_timeout, Interval}' is the connection timeout. Defaults to one second (1000).
+%% `{retry, Attempts}' is the number of times it will try to reconnect on failure before giving up. Defaults to zero (disabled).
+%% `{retry_timeout, Interval}' is the time between retries in milliseconds.
+%%
 %% `{auto_sync_interval_ms, Interval}' sets the default `Interval' in milliseconds of auto-sync.
 %% Default is 0, which means no auto-sync. If enabled auto-sync, you can set `auto_sync_interval_ms'
 %% in application env to change the interval. If disabled, the `auto_sync_interval_ms' in application
@@ -50,7 +54,14 @@ open(Name, Hosts, Transport, TransportOpts) ->
 %% You can use `eetcd:info/0' to see the internal connection status.
 -spec open(name(),
     [string()],
-    [{mode, connect_all|random} |{name, string()} | {password, string()}],
+    [
+      {mode, connect_all | random}
+      | {name, string()}
+      | {password, string()}
+      | {retry, non_neg_integer()}
+      | {retry_timeout, pos_integer()}
+      | {connect_timeout, timeout()}
+    ],
     tcp | tls | ssl,
     [gen_tcp:connect_option()] | [ssl:connect_option()]) ->
     {ok, pid()} | {error, any()}.

src/eetcd_conn.erl

@@ -92,8 +92,10 @@ flush_token(Gun, Headers) ->
 init({Name, Hosts, Options, Transport, TransportOpts}) ->
     erlang:process_flag(trap_exit, true),
     GunOpts = #{protocols => [http2],
+        connect_timeout => proplists:get_value(connect_timeout, Options, 1000),
         http2_opts => #{keepalive => 45000},
-        retry => 0,
+        retry => proplists:get_value(retry, Options, 0),
+        retry_timeout => proplists:get_value(retry_timeout, Options, 5000),
         transport => Transport,
         transport_opts => TransportOpts
     },
@@ -228,7 +230,11 @@ fold_connect([Host | Hosts], Name, GunOpts, Auth, Ok, Fail) ->
 
 connect(Name, {IP, Port}, GunOpts, Auth) ->
     {ok, Gun} = gun:open(IP, Port, GunOpts),
-    case gun:await_up(Gun, 1000) of
+    Retries = maps:get(retry, GunOpts),
+    ConnectTimeout = maps:get(connect_timeout, GunOpts),
+    RetryTimeout = maps:get(retry_timeout, GunOpts),
+    AwaitTime = (Retries + 1) * ConnectTimeout + Retries * RetryTimeout,
+    case gun:await_up(Gun, AwaitTime) of
         {ok, http2} ->
             case check_health_remote(Gun) of
                 ok ->
@@ -590,4 +596,3 @@ put_in_authenticate(Data, Options) ->
 shuffle(List) ->
     Disorders = [begin {rand:uniform(), K} end||K <-List],
     [begin K end||{_, K} <- lists:keysort(1, Disorders)].
-