Remove the now-unused appengine directory.

    - go get -u github.com/dchest/uniuri

    - go get -u github.com/dchest/uniuri

    - go get -u github.com/gorilla/websocket

    - go get -u github.com/gorilla/websocket

    - go get -u git.torproject.org/pluggable-transports/goptlib.git

    - go get -u git.torproject.org/pluggable-transports/goptlib.git

    - go get -u google.golang.org/appengine

    - go get -u golang.org/x/crypto/acme/autocert

    - go get -u golang.org/x/crypto/acme/autocert

    - go get -u golang.org/x/net/http2

    - go get -u golang.org/x/net/http2

    - pushd proxy

    - pushd proxy

# 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

 No newline at end of file

This component runs on Google App Engine. It reflects domain-fronted

requests from a client to the Snowflake broker.

You need the Go App Engine SDK in order to deploy the app.

	https://cloud.google.com/sdk/docs/#linux

After unpacking, install the app-engine-go component:

	google-cloud-sdk/bin/gcloud components install app-engine-go

To test locally, run

	google-cloud-sdk/bin/dev_appserver.py app.yaml

The app will be running at http://127.0.0.1:8080/.

To deploy to App Engine, first create a new project and app. You have to

think of a unique name (marked as "<appname>" in the commands). You only

have to do the "create" step once; subsequent times you can go straight

to the "deploy" step. The "gcloud auth login" command will open a

browser window so you can log in to a Google account.

	google-cloud-sdk/bin/gcloud auth login

	google-cloud-sdk/bin/gcloud projects create <appname>

	google-cloud-sdk/bin/gcloud app create --project=<appname>

Then to deploy the project, run:

	google-cloud-sdk/bin/gcloud app deploy --project=<appname>

To configure the Snowflake client to talk to the App Engine app, provide

"https://<appname>.appspot.com/" as the --url option.

	UseBridges 1

	Bridge snowflake 0.0.2.0:1

	ClientTransportPlugin snowflake exec ./client -url https://<appname>.appspot.com/ -front www.google.com

runtime: go111

handlers:

- url: /.*

  secure: always

  script: auto

// A web app for Google App Engine that proxies HTTP requests and responses to

// the Snowflake broker.

package main

import (

	"context"

	"io"

	"net/http"

	"net/url"

	"time"

	"google.golang.org/appengine"

	"google.golang.org/appengine/log"

	"google.golang.org/appengine/urlfetch"

)

const (

	forwardURL = "https://snowflake-broker.bamsoftware.com/"

	// A timeout of 0 means to use the App Engine default (5 seconds).

	urlFetchTimeout = 20 * time.Second

)

var ctx context.Context

// Join two URL paths.

func pathJoin(a, b string) string {

	if len(a) > 0 && a[len(a)-1] == '/' {

		a = a[:len(a)-1]

	}

	if len(b) == 0 || b[0] != '/' {

		b = "/" + b

	}

	return a + b

}

// We reflect only a whitelisted set of header fields. Otherwise, we may copy

// headers like Transfer-Encoding that interfere with App Engine's own

// hop-by-hop headers.

var reflectedHeaderFields = []string{

	"Content-Type",

	"X-Session-Id",

}

// Make a copy of r, with the URL being changed to be relative to forwardURL,

// and including only the headers in reflectedHeaderFields.

func copyRequest(r *http.Request) (*http.Request, error) {

	u, err := url.Parse(forwardURL)

	if err != nil {

		return nil, err

	}

	// Append the requested path to the path in forwardURL, so that

	// forwardURL can be something like "https://example.com/reflect".

	u.Path = pathJoin(u.Path, r.URL.Path)

	c, err := http.NewRequest(r.Method, u.String(), r.Body)

	if err != nil {

		return nil, err

	}

	for _, key := range reflectedHeaderFields {

		values, ok := r.Header[key]

		if ok {

			for _, value := range values {

				c.Header.Add(key, value)

			}

		}

	}

	return c, nil

}

func handler(w http.ResponseWriter, r *http.Request) {

	ctx = appengine.NewContext(r)

	fr, err := copyRequest(r)

	if err != nil {

		log.Errorf(ctx, "copyRequest: %s", err)

		http.Error(w, err.Error(), http.StatusInternalServerError)

		return

	}

	if urlFetchTimeout != 0 {

		var cancel context.CancelFunc

		ctx, cancel = context.WithTimeout(ctx, urlFetchTimeout)

		defer cancel()

	}

	// Use urlfetch.Transport directly instead of urlfetch.Client because we

	// want only a single HTTP transaction, not following redirects.

	transport := urlfetch.Transport{

		Context: ctx,

	}

	resp, err := transport.RoundTrip(fr)

	if err != nil {

		log.Errorf(ctx, "RoundTrip: %s", err)

		http.Error(w, err.Error(), http.StatusInternalServerError)

		return

	}

	defer resp.Body.Close()

	for _, key := range reflectedHeaderFields {

		values, ok := resp.Header[key]

		if ok {

			for _, value := range values {

				w.Header().Add(key, value)

			}

		}

	}

	w.WriteHeader(resp.StatusCode)

	n, err := io.Copy(w, resp.Body)

	if err != nil {

		log.Errorf(ctx, "io.Copy after %d bytes: %s", n, err)

	}

}

func init() {

	http.HandleFunc("/", handler)

}