cmd/getgo/server: update to go112 GAE runtime

Change-Id: Ib8a301da7ce32ece3fe15d7cbecddeaf380ec43a
Reviewed-on: https://go-review.googlesource.com/c/tools/+/191377
Reviewed-by: Katie Hockman <katie@golang.org>

cmd/getgo/server/.gcloudignore

@@ -0,0 +1,25 @@
+# This file specifies files that are *not* uploaded to Google Cloud Platform
+# using gcloud. It follows the same syntax as .gitignore, with the addition of
+# "#!include" directives (which insert the entries of the given .gitignore-style
+# file at that point).
+#
+# For more information, run:
+#   $ gcloud topic gcloudignore
+#
+.gcloudignore
+# If you would like to upload your .git directory, .gitignore file or files
+# from your .gitignore file, remove the corresponding line
+# below:
+.git
+.gitignore
+
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+# Test binary, build with `go test -c`
+*.test
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out

cmd/getgo/server/app.yaml

@@ -1,7 +1,2 @@
-runtime: go
+runtime: go112
 service: get
-api_version: go1
-
-handlers:
-- url: /.*
-  script: _go_app

cmd/getgo/server/main.go

@@ -4,11 +4,12 @@
 
 // Command server serves get.golang.org, redirecting users to the appropriate
 // getgo installer based on the request path.
-package server
+package main
 
 import (
 	"fmt"
 	"net/http"
+	"os"
 	"strings"
 	"time"
 )
@@ -28,8 +29,19 @@ var stringMatch = map[string]string{
 	"Darwin": macInstaller,
 }
 
-func init() {
+func main() {
 	http.HandleFunc("/", handler)
+
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+		fmt.Printf("Defaulting to port %s", port)
+	}
+
+	fmt.Printf("Listening on port %s", port)
+	if err := http.ListenAndServe(fmt.Sprintf(":%s", port), nil); err != nil {
+		fmt.Fprintf(os.Stderr, "http.ListenAndServe: %v", err)
+	}
 }
 
 func handler(w http.ResponseWriter, r *http.Request) {