cmd/tipgodoc: simplify Dockerfile and fix deployment

Change-Id: Ib2fd1346255467cb790a9e4c37d25f8e8ca136f5
Reviewed-on: https://go-review.googlesource.com/2534
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

cmd/tipgodoc/Dockerfile

@@ -1,14 +1,9 @@
-FROM google/appengine-go
+FROM golang
 
-RUN apt-get update
-RUN apt-get install --no-install-recommends -y -q curl build-essential git
-RUN mkdir /goroot && curl https://storage.googleapis.com/golang/go1.4.linux-amd64.tar.gz | tar xvzf - -C /goroot --strip-components=1
-RUN mkdir /gopath
+RUN apt-get update && apt-get install --no-install-recommends -y -q build-essential git
 
-ENV GOROOT /goroot
-ENV GOPATH /gopath
-ENV PATH $PATH:$GOROOT/bin:$GOPATH/bin
-
-WORKDIR /app
-ADD . /app
-RUN /bin/bash /app/_ah/build.sh
+# golang sets GOPATH=/go
+ADD . /go/src/tipgodoc
+RUN go install tipgodoc
+ENTRYPOINT ["/go/bin/tipgodoc"]
+EXPOSE 8080 # what kubernetes expects

cmd/tipgodoc/README

@@ -0,0 +1,3 @@
+To deploy as an App Engine Manged VM, use gcloud:
+
+	$ gcloud preview app deploy .

cmd/tipgodoc/app.yaml

@@ -13,4 +13,3 @@ handlers:
 
 health_check:
   enable_health_check: False
-

cmd/tipgodoc/tip.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by the Apache 2.0
 // license that can be found in the LICENSE file.
 
-// +build appenginevm
-
 // Command tipgodoc is the beginning of the new tip.golang.org server,
 // serving the latest HEAD straight from the Git oven.
 package main
@@ -30,10 +28,11 @@ const (
 	metaURL = "https://go.googlesource.com/?b=master&format=JSON"
 )
 
-func init() {
+func main() {
 	p := new(Proxy)
 	go p.run()
 	http.Handle("/", p)
+	log.Fatal(http.ListenAndServe(":8080", nil))
 }
 
 type Proxy struct {