# This holds all the tasks. They are pulled from this directory
# with a FIFO execution style. The tasks are identified by the pid of
# the requesting process. Unless the tasks really jam up and the server
# is rebooted, there's no chance of collision.
local_queue_dir = '/tmp/jsonrpc_queue'
# This holds all the temporary files for the tasks. It is only used
# here as the root of the cleanup process. Each task identifies its own
# tmpdir whish is the home directory for the task. This will almost always
# be the same as queue filename. But there # is still the option for the
# user to identify a specific tmpdir to run from.
jsonrpc_tmpdir = '/tmp/jsonrpc'
rpc_service = rpc_service_setup()
class JSONRPCDaemon(Daemon):
"Daemon class for processing JSON RPC requests"
def run_an_item(self,qfile_list):
"Pulls an item from the queue, and sends it to the rpc_service."
# Get the contents of the oldest file.
oldest = qfile_list[0]
oldest_time = os.stat(local_queue_dir + '/' + oldest).st_mtime
for qf in qfile_list[1:]:
qf_time = os.stat(local_queue_dir + '/' + qf).st_mtime
if qf_time < oldest_time:
oldest = qf
oldest_time = qf_time
def main():
# This sets up all the json_procs to accessuble for the rpc_service.
rpc_service = rpc_service_setup()
# QUERY_STRING could have these options
# signature Required for any service access. This is an hmak/sha1
# hash againt the request string.
# diag ..... Run "run_diagnostics" This allows the user to get a lot
# of info on what might be happening on the server.
# async .... Send the request to the asynchronous queue.
# tmpdir ... User explicitly sets the tmpdir for the task execution.
# log ...... Logs the request, response, and environment in
# tmpdir/jsonrpc.log
option_dict = cgi.parse_qs(os.environ['QUERY_STRING'])
# Check that there is a signature.
if not 'signature' in option_dict:
print json.dumps({
"jsonrpc": "2.0",
"error": {"code": -32098, "message": "No signature."},
"id": None});
return
pass
# Read the request data.
form = cgi.FieldStorage()
request_str = ''
multipart_keys = []
if form.type == 'multipart/form-data':
## Read the "jsonrpc" part, and collect all the names of the file parts.
for part_key in form.keys():
if part_key == 'jsonrpc':
request_str = form['jsonrpc'].value
else:
multipart_keys.append(part_key);
else:
if not form.file:
print json.dumps({
"jsonrpc": "2.0",
"error": {"code": -32099, "message": "No post data."},
"id": None});
return
request_str = form.file.read()
# The default hashkey is the local DNS name. This can be changed to grab
# the user-data string by uncommenting the code below.
#
# The main idea is that we want a hashkey that is easily accessible, but
# hard to guess. The local DNS fits the bill because an intruder needs to
# know both the the public and private DNS names to get access to the
# JSONRPC service. Instance tags were considered but they require
# the AWS_SECRET_ACCESS_KEY to get. My feeling is that the extra
# security provided to this instance by using the AWS secret key, isn't
# worth the risk of exposing the key.
#
ud = None
ud = urllib2.urlopen('http://169.254.169.254/latest/meta-data/local-hostname')
#try:
# ud = urllib2.urlopen('http://169.254.169.254/latest/user-data')
#except Exception:
# ud = urllib2.urlopen('http://169.254.169.254/latest/meta-data/local-hostname')
hashkey = ud.read()
h = hmac.new(hashkey,request_str,sha)
target_sig = base64.b64encode(h.digest())
if target_sig != option_dict['signature'][0]:
data = ''
# data += '~'+hashkey+'~'+request_str+'~'+target_sig+'~'+str(option_dict['signature'][0])+'~'
print json.dumps({
"jsonrpc": "2.0",
"error": {
"code": -32097,
"message": "Invalid Signature.",
"data": data
},
"id": None});
return
# output all diagnostic data
if 'diag' in option_dict and option_dict['diag'][0]:
diag_info = diagnostic_data(option_dict)
print json.dumps(diag_info, indent=4)
return;
# Establish a tmpdir location.
# A user specified a tmpdir then is relative to tht tmpdir_root.
# All diretories are created as needed.
global tmpdir_root
if 'tmpdir' in option_dict:
tmpdir = tmpdir_root + '/' + option_dict['tmpdir'][0]
else:
tmpdir = tmpdir_root + '/' + str(os.getpid())
if not os.access(tmpdir,os.F_OK):
os.makedirs(tmpdir)
os.chdir(tmpdir)
# Now handle file uploads if necessary
for part in multipart_keys:
outfd = open(form[part].filename,'w')
inbytes = form[part].file.read(1000000)
while inbytes:
outfd.write(inbytes)
inbytes = form[part].file.read(1000000)
outfd.close()
result = ''
if 'async' in option_dict and option_dict['async'][0]:
## Item to be put in the async queue. Currently just need a tmpdir
## and the request.
async_item = {
'tmpdir': tmpdir,
'request': json.loads(request_str)
}
rpc_queue_dir = '/tmp/jsonrpc_queue'
queue_path = rpc_queue_dir + '/' + str(os.getpid())
f = open(queue_path,'w')
f.write(json.dumps(async_item))
result = json.dumps({'queue_path': queue_path })
print json.dumps({
"jsonrpc": "2.0",
"result": json.loads(result),
"id": None
});
else:
# synchronous execution.
result = rpc_service.call(request_str)
print result
if 'log' in option_dict and option_dict['log'][0]:
# Logs request, response, and environment to "tmpdir/jsonrpc.log"
log_fd = open('jsonrpc.log','w')
log_fd.write('{"Request":' + request_str + ', ')
log_fd.write('"Result":' + json.dumps(result) + ', ')
log_fd.write('"Environment": [')
env_keys = sorted(os.environ.keys())
env_out = ''
for k in env_keys:
env_out += '["'+k+'"' + ', '+ json.dumps(os.environ[k]) + '], '
log_fd.write(env_out[:-2]+']}')
log_fd.close()
