MINOR: add option to allow delay starting runtime

added AllowDelayedStartMax and AllowDelayedStartTick
to check allow slower starting of HAProxy, useful on limited machines.
these can be accessed with runtimeOptions.AllowDelayedStart(max, tick)

runtime/options/allow-delayed-start.go

@@ -0,0 +1,37 @@
+/*
+Copyright 2022 HAProxy Technologies
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package options
+
+import "time"
+
+type allowDelayedStart struct {
+	allowDelayedStartMax  time.Duration
+	allowDelayedStartTick time.Duration
+}
+
+func (d allowDelayedStart) Set(o *RuntimeOptions) error {
+	o.AllowDelayedStartMax = &d.allowDelayedStartMax
+	o.AllowDelayedStartTick = &d.allowDelayedStartTick
+	return nil
+}
+
+func AllowDelayedStart(allowDelayedStartMax, allowDelayedStartTick time.Duration) RuntimeOption {
+	return allowDelayedStart{
+		allowDelayedStartMax:  allowDelayedStartMax,
+		allowDelayedStartTick: allowDelayedStartTick,
+	}
+}

runtime/options/options.go

@@ -16,11 +16,15 @@ limitations under the License.
 
 package options
 
+import "time"
+
 type RuntimeOptions struct {
 	MapsDir                 *string
 	MasterSocketData        *masterSocketData
 	Sockets                 map[int]string
 	DoNotCheckRuntimeOnInit bool
+	AllowDelayedStartMax    *time.Duration
+	AllowDelayedStartTick   *time.Duration
 }
 
 type RuntimeOption interface {

runtime/runtime_single_client.go

@@ -71,9 +71,23 @@ func (s *SingleRuntime) Init(ctx context.Context, socketPath string, worker int,
 	s.process = process
 	go s.handleIncomingJobs(ctx)
 	if !runtimeOptions.DoNotCheckRuntimeOnInit {
-		// check if we have a valid socket
-		if _, err := s.ExecuteRaw("help"); err != nil {
-			return err
+		if runtimeOptions.AllowDelayedStartMax != nil {
+			now := time.Now()
+			var err error
+			for {
+				if _, err = s.ExecuteRaw("help"); err == nil {
+					break
+				}
+				time.Sleep(*runtimeOptions.AllowDelayedStartTick)
+				if time.Since(now) > *runtimeOptions.AllowDelayedStartMax {
+					return fmt.Errorf("cannot connect to runtime API %s within %s: %w", socketPath, *runtimeOptions.AllowDelayedStartMax, err)
+				}
+			}
+		} else {
+			// check if we have a valid socket
+			if _, err := s.ExecuteRaw("help"); err != nil {
+				return err
+			}
 		}
 	}
 	return nil