Google App Engine Go SDK: Request to '/' failed - google-app-engine

Question

i'm just getting started using GAE, i have following guide in here https://developers.google.com/appengine/docs/go/gettingstarted/devenvironment and some hello word tutorial here https://developers.google.com/appengine/docs/go/gettingstarted/helloworld .
my problem is when i'm typing goapp serve it works. and show log like this:
INFO 2014-05-18 08:44:57,130 devappserver2.py:765] Skipping SDK update check.
WARNING 2014-05-18 08:44:57,135 api_server.py:374] Could not initialize images API; you are likely missing the Python "PIL" module.
INFO 2014-05-18 08:44:57,140 api_server.py:171] Starting API server at: http://localhost:59559
INFO 2014-05-18 08:44:57,154 dispatcher.py:182] Starting module "default" running at: http://localhost:8080
INFO 2014-05-18 08:44:57,156 admin_server.py:117] Starting admin server at: http://localhost:8000
but, when i'm trying to access http://localhost:8080 , it not show me "hello, world!" in the browser. and error log show me like this:
ERROR 2014-05-18 08:48:05,002 module.py:714] Request to '/' failed
Traceback (most recent call last):
File "/home/bayu/.go_appengine/google/appengine/tools/devappserver2/module.py", line 708, in _handle_request
environ, wrapped_start_response)
File "/home/bayu/.go_appengine/google/appengine/tools/devappserver2/request_rewriter.py", line 311, in _rewriter_middleware
response_body = iter(application(environ, wrapped_start_response))
File "/home/bayu/.go_appengine/google/appengine/tools/devappserver2/module.py", line 1228, in _handle_script_request
request_type)
File "/home/bayu/.go_appengine/google/appengine/tools/devappserver2/instance.py", line 382, in handle
request_type))
File "/home/bayu/.go_appengine/google/appengine/tools/devappserver2/http_proxy.py", line 148, in handle
connection.connect()
File "/home/bayu/.pyenv/versions/2.7.6/lib/python2.7/httplib.py", line 772, in connect
self.timeout, self.source_address)
File "/home/bayu/.pyenv/versions/2.7.6/lib/python2.7/socket.py", line 571, in create_connection
raise err
error: [Errno 111] Connection refused
INFO 2014-05-18 08:48:05,007 module.py:639] default: "GET / HTTP/1.1" 500 -
i have google it and trying another get started tutorial in here http://blog.joshsoftware.com/2014/03/12/learn-to-build-and-deploy-simple-go-web-apps-part-one/
but it's not work also.
what should i do?
i'm on ubuntu 12.04 , Python 2.7.3, go version go1.2.1 linux/386
using go_appengine_sdk_linux_386-1.9.4.zip
this is my hello.go and app.yaml
hello.go
package hello
import (
"fmt"
"net/http"
)
func init() {
http.HandleFunc("/", handler)
}
func handler(w http.ResponseWriter, r *http.Request) {
fmt.Fprint(w, "Hello,")
}
app.yaml
application: helloworld
version: 1
runtime: go
api_version: go1
handlers:
- url: /.*
script: _go_app
thank you,

Answer 1

Not sure if this will help anyone or not but I came across the exact same issues and finally tracked it down to my hosts file. Basically what is happening is the app engine server is running on 0.0.0.0:8080 yet the interface / output is displaying localhost:8080. In my hosts file 0.0.0.0:8080 wasn't mapped to localhost so:
edit your /private/etc/hosts file with vim or whatever
add 0.0.0.0 localhost to your hosts file
save, start a new terminal and try and run you appengine server again
After that simple edit everything worked for me.