Add Dockerfile healthcheck

WIP

1.1.21.2/Dockerfile

@@ -1,3 +1,17 @@
+FROM golang:1.22-alpine3.19 as builder
+
+WORKDIR /go/src/app
+
+# Copy the local package files to the container's workspace.
+COPY ./healthcheck .
+
+# Install Go dependencies and compile the static binary.
+RUN go mod init healthcheck && \
+    go get -d -v github.com/mikespook/gearman-go && \
+	go get -d -v github.com/mikespook/golib/signal && \
+    CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o ping_client client/ping.go && \
+    CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o pong_worker worker/pong.go
+
 FROM alpine:3.19.1
 
 ENV GEARMAND_VERSION 1.1.21
@@ -51,6 +65,14 @@ RUN set -x \
 	&& apk del .build-deps \
 	&& /usr/local/sbin/gearmand --version
 
+COPY --from=builder /go/src/app/ping_client /usr/local/bin/ping_client
+COPY --from=builder /go/src/app/pong_worker /usr/local/bin/pong_worker
+
+RUN chmod +x /usr/local/bin/ping_client /usr/local/bin/pong_worker
+
+HEALTHCHECK --interval=30s --timeout=3s --retries=2 \
+	CMD test $(/usr/local/bin/ping_client | grep -c 'pong') -eq 1 || exit 1
+
 COPY docker-entrypoint.sh /usr/local/bin/
 RUN apk add --no-cache bash \
     && touch /etc/gearmand.conf && chown gearman:gearman /etc/gearmand.conf \

1.1.21.2/docker-entrypoint.sh

@@ -102,4 +102,7 @@ function generate_config() {
 if ! [ -s "${CONFIG_FILE}" ]; then # dont genarate config if current config file is not empty
     generate_config
 fi
+
+/usr/local/bin/pong_worker &
+
 exec "$@"

1.1.21.2/healthcheck/client/go.mod

@@ -0,0 +1,5 @@
+module healthcheck
+
+go 1.22.1
+
+require github.com/mikespook/gearman-go v0.0.0-20220520031403-2a518e866145 // indirect

1.1.21.2/healthcheck/client/go.sum

@@ -0,0 +1,2 @@
+github.com/mikespook/gearman-go v0.0.0-20220520031403-2a518e866145 h1:6kTCi6p3Hd6JYROnq+1UOdewoXj90zKKDQPlsHYTSEs=
+github.com/mikespook/gearman-go v0.0.0-20220520031403-2a518e866145/go.mod h1:77Th6O6AZfMU6i5hLJnjN5xxUBoio7LN0aOyxGhqV1U=

1.1.21.2/healthcheck/client/ping.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"log"
+	"sync"
+
+	"github.com/mikespook/gearman-go/client"
+)
+
+func main() {
+	var wg sync.WaitGroup
+
+	c, err := client.New(client.Network, "127.0.0.1:4730")
+	if err != nil {
+		log.Fatalln(err)
+	}
+	defer c.Close()
+	c.ErrorHandler = func(e error) {
+		log.Println(e)
+	}
+	echo := []byte("ping")
+	wg.Add(1)
+
+	_, err = c.Echo(echo)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	wg.Done()
+	jobHandler := func(resp *client.Response) {
+		if string(resp.Data) == "pong" {
+			log.Println("Health check passed")
+		} else {
+			log.Println("Health check failed")
+		}
+		log.Printf("%s", resp.Data)
+		wg.Done()
+	}
+	handle, err := c.Do("ping", echo, client.JobNormal, jobHandler)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	wg.Add(1)
+	status, err := c.Status(handle)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	log.Printf("%v", *status)
+
+	wg.Wait()
+}

1.1.21.2/healthcheck/worker/go.mod

@@ -0,0 +1,9 @@
+module healthcheck
+
+go 1.22.1
+
+require (
+	github.com/mikespook/gearman-go v0.0.0-20220520031403-2a518e866145 // indirect
+	github.com/mikespook/golib v0.0.0-20151119134446-38fe6917d34b // indirect
+	gopkg.in/mgo.v2 v2.0.0-20190816093944-a6b53ec6cb22 // indirect
+)

1.1.21.2/healthcheck/worker/go.sum

@@ -0,0 +1,6 @@
+github.com/mikespook/gearman-go v0.0.0-20220520031403-2a518e866145 h1:6kTCi6p3Hd6JYROnq+1UOdewoXj90zKKDQPlsHYTSEs=
+github.com/mikespook/gearman-go v0.0.0-20220520031403-2a518e866145/go.mod h1:77Th6O6AZfMU6i5hLJnjN5xxUBoio7LN0aOyxGhqV1U=
+github.com/mikespook/golib v0.0.0-20151119134446-38fe6917d34b h1:v99/2GZfv/W/HuD17/QcHucnDtUsY9strTTwG82EuZY=
+github.com/mikespook/golib v0.0.0-20151119134446-38fe6917d34b/go.mod h1:3lBg8mdFpiF0C4ibbSFsxr+rgPWWkFlEVD/s11OG5k4=
+gopkg.in/mgo.v2 v2.0.0-20190816093944-a6b53ec6cb22 h1:VpOs+IwYnYBaFnrNAeB8UUWtL3vEUnzSCL1nVjPhqrw=
+gopkg.in/mgo.v2 v2.0.0-20190816093944-a6b53ec6cb22/go.mod h1:yeKp02qBN3iKW1OzL3MGk2IdtZzaj7SFntXj72NppTA=

1.1.21.2/healthcheck/worker/pong.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"log"
+	"os"
+	"time"
+
+	"github.com/mikespook/gearman-go/worker"
+	"github.com/mikespook/golib/signal"
+)
+
+func ping(job worker.Job) ([]byte, error) {
+	log.Printf("Received job: %s", job.Data())
+	return []byte("pong"), nil
+}
+
+func main() {
+	w := worker.New(worker.Unlimited)
+	defer w.Close()
+
+	connect := func() error {
+		return w.AddServer("tcp4", "localhost:4730")
+	}
+	for i := 0; i < 5; i++ {
+		err := connect()
+		if err == nil {
+			break
+		}
+		if i == 4 {
+			log.Fatalf("Failed to connect to gearman server after several retries: %v", err)
+		}
+		log.Printf("Could not connect to server: %v. Retrying in 5 seconds...", err)
+		time.Sleep(5 * time.Second)
+	}
+	w.AddFunc("ping", ping, worker.Unlimited)
+
+	if err := w.Ready(); err != nil {
+		log.Fatal(err)
+		return
+	}
+	go w.Work()
+	signal.Bind(os.Interrupt, func() uint { return signal.BreakExit })
+	signal.Wait()
+}