devapp: update Dockerfile and README

Start using the latest stable version of Go and Debian, fix LABEL
syntax, replace brittle docker build speed optimization (see past
CLs like CL 360838, CL 349091 for more detailed motivation).

Update deployment instructions in README.md. We use the 'services'
cluster in the us-central1 region now.

Updates golang/go#48408.

Change-Id: I0901c4f62dfbe37ad78f0ba6928b3eb0eefc4e3a
Reviewed-on: https://go-review.googlesource.com/c/build/+/383814
Trust: Dmitri Shuralyov <[email protected]>
Reviewed-by: Heschi Kreinick <[email protected]>

Author: dmitshur

devapp/Dockerfile

@@ -2,10 +2,8 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-FROM golang:1.13 AS builder
-LABEL maintainer "[email protected]"
-
-ENV GO111MODULE=on
+FROM golang:1.17 AS builder
+LABEL maintainer="[email protected]"
 
 RUN mkdir /gocache
 ENV GOCACHE /gocache
@@ -15,24 +13,16 @@ COPY go.sum /go/src/golang.org/x/build/go.sum
 
 WORKDIR /go/src/golang.org/x/build
 
-# Optimization for iterative docker build speed, not necessary for correctness:
-# TODO: write a tool to make writing Go module-friendly Dockerfiles easier (golang.org/issue/34192)
-RUN go install cloud.google.com/go/storage
-RUN go install golang.org/x/net/http2
-RUN go install golang.org/x/crypto/acme/autocert
-COPY cmd/pubsubhelper/pubsubtypes /go/src/golang.org/x/build/cmd/pubsubhelper/pubsubtypes
-RUN go install golang.org/x/build/cmd/pubsubhelper/pubsubtypes
-COPY autocertcache /go/src/golang.org/x/build/autocertcache
-RUN go install golang.org/x/build/autocertcache
-COPY internal /go/src/golang.org/x/build/internal
-COPY maintner /go/src/golang.org/x/build/maintner
-RUN go install golang.org/x/build/maintner/godata
+# Download module dependencies to improve speed of re-building the
+# Docker image during minor code changes.
+RUN go mod download
 
 COPY . /go/src/golang.org/x/build/
 # Install binary to /go/bin:
 RUN go install golang.org/x/build/devapp
 
-FROM debian:stretch
+FROM debian:bullseye
+LABEL maintainer="[email protected]"
 
 # netbase and ca-certificates are needed for dialing TLS.
 # The rest are useful for debugging if somebody needs to exec into the container.

devapp/README.md

@@ -52,7 +52,7 @@ $ make deploy-staging
 
 ```sh
 $ gcloud config set project symbolic-datum-552
-$ gcloud container clusters get-credentials --zone=us-central1-f go
+$ gcloud container clusters get-credentials --zone=us-central1 services
 $ make push-prod
 ```