cmd/coordinator: stop using gitlock, use go modules

Also, along for the ride:

* update from jessie to stretch
* update from Go 1.10 to Go 1.12
* move to multi-stage Dockerfile, including drawterm, reducing image size
* remove the static linking which was resulting in build warnings
* clean up Makefile

Updates golang/go#26872
Updates golang/go#27719

Change-Id: Ic4dc9b8539fb8662c9621c113fa94b70bc7de061
Reviewed-on: https://go-review.googlesource.com/c/build/+/175985
Reviewed-by: Dmitri Shuralyov <[email protected]>

Author: bradfitz

cmd/coordinator/.gitignore

@@ -1,4 +1,3 @@
 buildongce/client-*.dat
 buildongce/token.dat
 coordinator
-ca-certificates.crt

cmd/coordinator/Dockerfile

@@ -1,20 +1,68 @@
 # Copyright 2017 The Go Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
-FROM debian:jessie
+
+FROM golang:1.12 AS build
 LABEL maintainer "[email protected]"
 
-# openssh client is for the gomote ssh proxy client.
-# telnet is for the gomote ssh proxy to windows. (no ssh server there)
-# git-core, make, gcc, libc6-dev, and libx11-dev are to build 0intro/conterm,
-# used to connect to plan9 instances.
-RUN apt-get update && apt-get install -y \
-	--no-install-recommends \
-	ca-certificates \
-	openssh-client \
-	telnet \
-	git-core make gcc libc6-dev libx11-dev \
-	&& rm -rf /var/lib/apt/lists/*
+ENV GO111MODULE=on
+ENV GOPROXY=https://proxy.golang.org
+
+RUN mkdir /gocache
+ENV GOCACHE /gocache
+
+COPY go.mod /go/src/golang.org/x/build/go.mod
+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.
+RUN go install \
+    cloud.google.com/go/compute/metadata \
+    cloud.google.com/go/datastore \
+    cloud.google.com/go/errorreporting \
+    cloud.google.com/go/monitoring/apiv3 \
+    cloud.google.com/go/storage \
+    github.com/gliderlabs/ssh \
+    github.com/golang/protobuf/ptypes \
+    github.com/kr/pty \
+    go4.org/syncutil \
+    golang.org/x/crypto/acme/autocert \
+    golang.org/x/crypto/ssh \
+    golang.org/x/oauth2 \
+    golang.org/x/oauth2/google \
+    golang.org/x/perf/storage \
+    golang.org/x/time/rate \
+    google.golang.org/api/compute/v1 \
+    google.golang.org/api/container/v1 \
+    google.golang.org/api/googleapi \
+    google.golang.org/genproto/googleapis/api/metric \
+    google.golang.org/genproto/googleapis/monitoring/v3 \
+    gopkg.in/inf.v0 \
+    grpc.go4.org \
+    && true
+
+# Makefile passes a string with --build-arg version
+# This becomes part of the cache key for all subsequent instructions,
+# so it must not be placed above the "go install" commands above.
+ARG version=unknown
+
+# TODO: ideally we'd first copy all of x/build here EXCEPT
+# cmd/coordinator, then build x/build/..., and *then* COPY in the
+# cmd/coordinator files and then build the final binary. Currently we
+# do too much building of x/build/foo stuff when just modifying
+# cmd/coordinator/*.go files.
+
+COPY . /go/src/golang.org/x/build/
+
+RUN go install -ldflags "-X 'main.Version=$version'" golang.org/x/build/cmd/coordinator
+
+
+FROM debian:stretch AS build_drawterm
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    git-core ca-certificates make gcc libc6-dev libx11-dev
 
 # drawterm connects to plan9 instances like:
 #    echo glenda123 | ./drawterm -a <addr> -c <addr> -u glenda -k user=glenda
@@ -25,5 +73,20 @@ RUN git clone https://github.com/0intro/conterm /tmp/conterm && \
     CONF=unix make && mv /tmp/conterm/drawterm /usr/local/bin && \
     rm -rf /tmp/conterm
 
-COPY coordinator /
+
+FROM debian:stretch
+
+# openssh client is for the gomote ssh proxy client.
+# telnet is for the gomote ssh proxy to windows. (no ssh server there)
+RUN apt-get update && apt-get install -y \
+	--no-install-recommends \
+	ca-certificates \
+	openssh-client \
+	telnet \
+	&& rm -rf /var/lib/apt/lists/*
+
+
+COPY --from=build /go/bin/coordinator /
+COPY --from=build_drawterm /usr/local/bin/drawterm /usr/local/bin/
+
 ENTRYPOINT ["/coordinator"]