test: update go example

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

Author: crazy-max

test/go/Dockerfile

@@ -1,16 +1,19 @@
-FROM golang:1.19-alpine AS base
+# syntax=docker/dockerfile:1
+
+FROM golang:alpine AS base
 ENV CGO_ENABLED=0
 RUN apk add --no-cache file git
 WORKDIR /src
 
-FROM base as build
-COPY go.mod go.sum ./
-RUN go mod download -x
-COPY . .
-RUN go build -ldflags "-s -w" -o /usr/bin/app .
+FROM base AS build
+RUN --mount=type=bind,target=/src \
+    --mount=type=cache,target=/root/.cache/go-build \
+    go build -ldflags "-s -w" -o /usr/bin/app .
 
 FROM scratch AS binary
 COPY --from=build /usr/bin/app /bin/app
 
-FROM alpine:3.17 AS image
+FROM alpine AS image
 COPY --from=build /usr/bin/app /bin/app
+EXPOSE 8080
+ENTRYPOINT ["/bin/app"]

test/go/go.mod

@@ -1,19 +1,3 @@
 module github.com/docker/build-push-action/test/go
 
 go 1.18
-
-require github.com/labstack/echo/v4 v4.9.1
-
-require (
-	github.com/golang-jwt/jwt v3.2.2+incompatible // indirect
-	github.com/labstack/gommon v0.4.0 // indirect
-	github.com/mattn/go-colorable v0.1.11 // indirect
-	github.com/mattn/go-isatty v0.0.14 // indirect
-	github.com/valyala/bytebufferpool v1.0.0 // indirect
-	github.com/valyala/fasttemplate v1.2.1 // indirect
-	golang.org/x/crypto v0.0.0-20210817164053-32db794688a5 // indirect
-	golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f // indirect
-	golang.org/x/sys v0.0.0-20211103235746-7861aae1554b // indirect
-	golang.org/x/text v0.3.7 // indirect
-	golang.org/x/time v0.0.0-20201208040808-7e3f01d25324 // indirect
-)

test/go/go.sum

@@ -1,31 +1,14 @@
 package main
 
 import (
+	"fmt"
+	"log"
 	"net/http"
-	"os"
-
-	"github.com/labstack/echo/v4"
-	"github.com/labstack/echo/v4/middleware"
 )
 
 func main() {
-	e := echo.New()
-
-	e.Use(middleware.Logger())
-	e.Use(middleware.Recover())
-
-	e.GET("/", func(c echo.Context) error {
-		return c.HTML(http.StatusOK, "Hello World")
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintf(w, "Hello, Go!")
 	})
-
-	e.GET("/ping", func(c echo.Context) error {
-		return c.JSON(http.StatusOK, struct{ Status string }{Status: "OK"})
-	})
-
-	httpPort := os.Getenv("HTTP_PORT")
-	if httpPort == "" {
-		httpPort = "8080"
-	}
-
-	e.Logger.Fatal(e.Start(":" + httpPort))
+	log.Fatal(http.ListenAndServe(":8080", nil))
 }