nginx-golang: add dev envs support (#273)

* Add Docker Desktop Developer Environments config
* Upgrade from Go 1.13 (🙀) to 1.18
* Rename `frontend` -> `proxy` for clarity & consistency
  with other samples
* Add Chi as a dependency to provide an example of Go
  module dependencies for parity with other samples

Signed-off-by: Milas Bowman <milas.bowman@docker.com>

nginx-golang/backend/Dockerfile

@@ -1,11 +1,41 @@
-FROM golang:1.13 AS build
+# syntax=docker/dockerfile:1.4
+FROM --platform=$BUILDPLATFORM golang:1.18-alpine AS builder
 
-WORKDIR /compose/hello-docker
-COPY main.go main.go
-RUN CGO_ENABLED=0 go build -o backend main.go
+WORKDIR /code
+
+ENV CGO_ENABLED 0
+ENV GOPATH /go
+ENV GOCACHE /go-build
+
+COPY go.mod go.sum ./
+RUN --mount=type=cache,target=/go/pkg/mod/cache \
+    go mod download
+
+COPY . .
+
+RUN --mount=type=cache,target=/go/pkg/mod/cache \
+    --mount=type=cache,target=/go-build \
+    go build -o bin/backend main.go
+
+CMD ["/code/bin/backend"]
+
+FROM builder as dev-envs
+
+RUN <<EOF
+apk update
+apk add git
+EOF
+
+RUN <<EOF
+addgroup -S docker
+adduser -S --shell /bin/bash --ingroup docker vscode
+EOF
+
+# install Docker tools (cli, buildx, compose)
+COPY --from=gloursdocker/docker / /
+
+CMD ["go", "run", "main.go"]
 
 FROM scratch
-COPY --from=build /compose/hello-docker/backend /usr/local/bin/backend
+COPY --from=builder /code/bin/backend /usr/local/bin/backend
 CMD ["/usr/local/bin/backend"]
-
-

nginx-golang/backend/go.mod

@@ -0,0 +1,5 @@
+module github.com/docker/awesome-compose/nginx-golang/backend
+
+go 1.18
+
+require github.com/go-chi/chi/v5 v5.0.7

nginx-golang/backend/go.sum

@@ -0,0 +1,2 @@
+github.com/go-chi/chi/v5 v5.0.7 h1:rDTPXLDHGATaeHvVlLcR4Qe0zftYethFucbjVQ1PxU8=
+github.com/go-chi/chi/v5 v5.0.7/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=

nginx-golang/backend/main.go

@@ -4,11 +4,14 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
 )
 
 func handler(w http.ResponseWriter, r *http.Request) {
-	fmt.Println(r.URL.RawQuery)
-	fmt.Fprintf(w, `
+	fmt.Fprintf(
+		w, `
           ##         .
     ## ## ##        ==
  ## ## ## ## ##    ===
@@ -21,10 +24,15 @@ func handler(w http.ResponseWriter, r *http.Request) {
 	
 Hello from Docker!
 
-`)
+`,
+	)
 }
 
 func main() {
-	http.HandleFunc("/", handler)
-	log.Fatal(http.ListenAndServe(":80", nil))
+	r := chi.NewRouter()
+	r.Use(middleware.Logger)
+	r.Get("/", handler)
+
+	fmt.Println("Go backend started!")
+	log.Fatal(http.ListenAndServe(":80", r))
 }