apiendpoints.py

"""
All the API endpoints for controling processes and tunnels via SSH
"""
import json
from flask import session, redirect, request, Response, make_response
from flask_restful import Resource
import flask_restful
from . import api, islocal

if islocal:
    from .localssh import Ssh
    from .localtunnelstat import Tunnelstat


class GetCert(Resource):
    """
    This class is necessary because I'm not reconfiguring
    SSHAuthZ to support CORS, but the TES does support CORS
    """

    def post(self):
        """
        takes a public key, returns to the SPA a certificate
        """
        print("in GetCert.post")
        data = request.get_json()
        print(data)
        return {'cert':GetCert.get_cert(data['token'], data['pubkey'], data['signing_url'])}

    @staticmethod
    def get_cert(access_token, pub_key, url):
        """
        Sign a pub key into a cert
        """
        import requests
        print("accss_token {}".format(access_token))
        print("pub_key {}".format(pub_key))
        print("url {}".format(url))
        sess = requests.Session()
        headers = {"Authorization":"Bearer %s"%access_token}
        data = {"public_key":pub_key}
        resp = sess.post(url, json=data, headers=headers, verify=False)
        print("get_cert returned from its external call")
        data = resp.json()
        return data['certificate']

class TestAuth(Resource):
    """
    Tests whether the backend can login to the selected compute Resource
    """
    def get(self):
        """
        tell the SPA if the TES is logged in
        """
        return 'token' in session

def get_conn_params():
    """
    Return parameters relating to the backend compute service
    Retrieve them from the session (ideally)
    """
    return get_m3_params()

def get_m3_params():
    """
    Hard code the parameters for M3. This will be removed latter
    factored into a site config file for each compute backend
    parsed and set by the frontend.
    """
    params = {}
    params['host'] = 'm3.massive.org.au'
    params['user'] = 'chines'
    params['cancelcmd'] = 'scancel {jobid}'
    params['statcmd'] = '/home/chines/jsonstat.py'
    params['submitcmd'] = 'sbatch --partition=m3f'
    params['internalfirewall'] = False
    return params

def get_app_params():
    """
    Return the parameters for the application retrieved from the Session
    """
    keys = ['startscript', 'paramscmd', 'client','localbind']
    returnvalue = {}
    for k in keys:
        try:
            returnvalue[k] = session.get(k)
        except: # This should be a key exception, i.e. if the key doesn't exist on the session
            pass
    print("got app params",returnvalue)
    return returnvalue

class TunnelstatEP(Resource):
    """
    Endpoints used by the WS proxy
    """
    def put(self, authtok):
        """
        update the last used time on a tunnel
        """
        Tunnelstat.update(authtok)

    def get(self, authtok):
        """
        given an authtoken, return the port of the tunnels
        """
        port = Tunnelstat.getport(authtok)
        return port

class Stat(Resource):
    """
    endpoints to return info on jobs on the backend compute Resource
    """
    def get(self):
        """
        get info on the job from the backend
        """
        params = get_conn_params()
        res = Ssh.execute(host=params['host'], user=params['user'], cmd=params['statcmd'])
        if not (res['stderr'] == '' or res['stderr'] is None or res['stderr'] == b''):
            print(res['stderr'])
            flask_restful.abort(400, message=res['stderr'].decode())
        return json.loads(res['stdout'].decode())

class JobCancel(Resource):
    """
    Terminate a job on the compute backend
    """
    def delete(self, jobid):
        """
        Terminate a job on the backend
        """
        print("in jobcancle jobid is {}".format(jobid))
        params = get_conn_params()
        res = Ssh.execute(host=params['host'], user=params['user'],
                          cmd=params['cancelcmd'].format(jobid=jobid))
        if not (res['stderr'] == '' or res['stderr'] is None or res['stderr'] == b''):
            flask_restful.abort(400, message=res['stderr'].decode())
        return res['stdout'].decode()

class AppSetup(Resource):
    """
    configure the session for the app the user wants
    """
    def post(self):
        """
        post details of the app to be run or connected to
        """
        data = request.get_json()
        keys = ['startscript', 'paramscmd', 'client','localbind']
        for key in keys:
            session[key] = data[key]
            print(data[key])


class JobSubmit(Resource):
    """
    Class dealing the starting a new job on the compute backend
    """
    def post(self):
        """starting a job is a post, since it changes the state of the backend"""
        params = get_conn_params()
        appparams = get_app_params()
        res = Ssh.execute(host=params['host'], user=params['user'],
                          cmd=params['submitcmd'], stdin=appparams['startscript'])
        if not (res['stderr'] == '' or res['stderr'] is None or res['stderr'] == b''):
            print(res['stderr'])
            flask_restful.abort(400, message=res['stderr'].decode())
        return res['stdout'].decode()

def gen_authtok():
    """
    generate a random string suitable for an auth token stored in a cookie
    """
    import random
    import string
    return ''.join(random.SystemRandom().choice(string.ascii_uppercase +
                                                string.digits) for _ in range(16))

class JobConnect(Resource):
    """
    endpoints for connecting to an existing JobCancel
    """

    def create_tunnel(self, params, appparams, batchhost, data):
        connectparams = {}
        if 'paramscmd' in appparams and appparams['paramscmd'] is not None:
            connectparams['batchhost'] = batchhost
            paramcmd = 'ssh {batchhost} '.format(batchhost=batchhost) + appparams['paramscmd']
            res = Ssh.execute(host=params['host'], user=params['user'], cmd=paramcmd.format(data))
            try:
                connectparams.update(json.loads(res['stdout']))
            except json.decoder.JSONDecodeError as e:
                print(res['stdout'])
                print(res['stderr'])
            if not (res['stderr'] == '' or res['stderr'] is None or res['stderr'] == b''):
                flask_restful.abort(400, message=res['stderr'].decode())

            if 'port' in connectparams and 'batchhost' in connectparams:
                tunnelport, pids = Ssh.tunnel(port=connectparams['port'],
                                              batchhost=connectparams['batchhost'],
                                              user=params['user'], host=params['host'],
                                              internalfirewall=params['internalfirewall'],
                                              localbind=appparams['localbind'])
                authtok = gen_authtok()
                Tunnelstat.newtunnel(authtok, tunnelport, pids)
                connectparams['localtunnelport'] = tunnelport
            connectparams['authtok'] = authtok
        return connectparams

    def get(self, jobid, batchhost):
        """
        Connecting to a job is a get operation (i.e. it does not make modifications)
        """
        params = get_conn_params()
        appparams = get_app_params()
        data = request.get_json()
        connectparams = self.create_tunnel(params, appparams, batchhost, data)
        return self.connect(appparams, connectparams)

    def connect(self, appparams, connectparams):
        """
        perform the connection either by forking a local client or returning a redirect
        """
        import subprocess
        if 'cmd' in appparams['client'] and appparams['client']['cmd'] is not None:
            # We need for fork a local process such as vncviewer or a terminal
            # We may need a wrapper for local processes to find the correct
            # process on all OS
            cmdlist = []
            for cmdarg in appparams['client']['cmd']:
                cmdlist.append(cmdarg.format(**connectparams))
            app_process = subprocess.Popen(cmdlist, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
#            stdout, stderr = app_process.communicate()
#            if stderr is not "":
#                return "connected with cmd {} but got error {}".format(cmdlist,stderr)
        elif 'redir' in appparams['client'] and appparams['client']['redir'] is not None:
            template_response = Response()
            template_response.set_cookie(key='twsproxyauth', value=connectparams['authtok'])
            twsproxy = 'http://localhost:4000/'
            response = make_response(redirect(twsproxy+appparams['client']['redir'].
                                              format(**connectparams)))
            response.set_cookie('twsproxyauth', connectparams['authtok'])
            return response
        return "Connecting with cmd {}".format(cmdlist)


api.add_resource(TunnelstatEP, '/tunnelstat/<string:authtok>')
api.add_resource(GetCert, '/getcert')
api.add_resource(Stat, '/stat')
api.add_resource(JobCancel, '/cancel/<int:jobid>')
api.add_resource(JobSubmit, '/submit')
api.add_resource(JobConnect, '/connect/<int:jobid>/<string:batchhost>')
api.add_resource(AppSetup, '/appsetup')