Set GOMAXPROCS automatically

This is required in containerised environments to properly set
GOMAXPROCS to actual container limits set and not the whole underlying node's CPUs

See:
https://github.com/uber-go/automaxprocs

go.mod

@@ -11,11 +11,12 @@ require (
 	github.com/orcaman/concurrent-map v1.0.0
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.12.2
-	github.com/stretchr/testify v1.7.0
+	github.com/stretchr/testify v1.7.5
 	github.com/twmb/franz-go v1.6.0
 	github.com/twmb/franz-go/pkg/kmsg v1.1.0
 	github.com/twmb/franz-go/pkg/sasl/kerberos v1.0.0
 	go.uber.org/atomic v1.9.0
+	go.uber.org/automaxprocs v1.5.1
 	go.uber.org/zap v1.21.0
 	golang.org/x/sync v0.0.0-20220601150217-0de741cfad7f
 )

go.sum

@@ -269,6 +269,7 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/posener/complete v1.1.1/go.mod h1:em0nMJCgc9GFtwrmVmEMR/ZL6WyhyjMBndrE9hABlRI=
+github.com/prashantv/gostub v1.1.0 h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5FsnadC4Ky3P0J6CfImo=
 github.com/prometheus/client_golang v1.7.1/go.mod h1:PY5Wy2awLA44sXw4AOSfFBetzPP4j5+D6mVACh+pe2M=
@@ -304,12 +305,16 @@ github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.5 h1:s5PTfem8p8EbKQOctVV53k6jCJt3UX4IEJzwh+C324Q=
+github.com/stretchr/testify v1.7.5/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/twmb/franz-go v1.5.0/go.mod h1:ZKQ5AtqBbdc783bLCay7nDc21lJnIIA8mFJYhLMF19E=
 github.com/twmb/franz-go v1.6.0 h1:yri7YsVBe/k1LKcoZSLILgUI3U14e82qtD9i4VOcs9c=
 github.com/twmb/franz-go v1.6.0/go.mod h1:xdMwpUIQL/JDKKwerc5qJQG8TU1SNIddfjKJJyqRJIg=
@@ -332,6 +337,8 @@ go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/atomic v1.9.0 h1:ECmE8Bn/WFTYwEW/bpKD3M8VtR/zQVbavAoalC1PYyE=
 go.uber.org/atomic v1.9.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
+go.uber.org/automaxprocs v1.5.1 h1:e1YG66Lrk73dn4qhg8WFSvhF0JuFQF0ERIp4rpuV8Qk=
+go.uber.org/automaxprocs v1.5.1/go.mod h1:BF4eumQw0P9GtnuxxovUd06vwm1o18oMzFtK66vU6XU=
 go.uber.org/goleak v1.1.10/go.mod h1:8a7PlsEVH3e/a/GLqe5IIrQx6GzcnRmZEufDUTk4A7A=
 go.uber.org/goleak v1.1.11 h1:wy28qYRKZgnJTxGxvye5/wgWr1EKjmUDGYox5mGlRlI=
 go.uber.org/goleak v1.1.11/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=

main.go

@@ -3,20 +3,20 @@ package main
 import (
 	"context"
 	"fmt"
-	"net"
-	"net/http"
-	"os"
-	"os/signal"
-	"strconv"
-
 	"github.com/cloudhut/kminion/v2/e2e"
 	"github.com/cloudhut/kminion/v2/kafka"
 	"github.com/cloudhut/kminion/v2/logging"
 	"github.com/cloudhut/kminion/v2/minion"
 	"github.com/cloudhut/kminion/v2/prometheus"
 	promclient "github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"go.uber.org/automaxprocs/maxprocs"
 	"go.uber.org/zap"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"strconv"
 )
 
 var (
@@ -42,14 +42,17 @@ func main() {
 	if err != nil {
 		startupLogger.Fatal("failed to parse config", zap.Error(err))
 	}
-
 	logger := logging.NewLogger(cfg.Logger, cfg.Exporter.Namespace).Named("main")
-	if err != nil {
-		startupLogger.Fatal("failed to create new logger", zap.Error(err))
-	}
-
 	logger.Info("started kminion", zap.String("version", version), zap.String("built_at", builtAt))
 
+	// set GOMAXPROCS automatically
+	l := func(format string, a ...interface{}) {
+		logger.Info(fmt.Sprintf(format, a...))
+	}
+	if _, err = maxprocs.Set(maxprocs.Logger(l)); err != nil {
+		logger.Fatal("failed to set GOMAXPROCS automatically", zap.Error(err))
+	}
+
 	// Setup context that cancels when the application receives an interrupt signal
 	ctx, cancel := context.WithCancel(context.Background())
 	c := make(chan os.Signal, 1)