[VOL-2282] Split out ofagent-py into it's own repo

Brought over from voltha-go commit: 006dc84ee1977cc47990439823c539ac258c34a1

Change-Id: I4355d33ddd8996d0be1a50263f270268c8b11533
diff --git a/ofagent/main.py b/ofagent/main.py
new file mode 100755
index 0000000..ec2ad0f
--- /dev/null
+++ b/ofagent/main.py
@@ -0,0 +1,307 @@
+#!/usr/bin/env python
+#
+# Copyright 2017 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+import argparse
+import os
+
+import yaml
+import SocketServer
+
+from probe import Probe
+from twisted.internet import reactor
+from twisted.internet.defer import inlineCallbacks
+
+from pyvoltha.common.structlog_setup import setup_logging
+from pyvoltha.common.utils.dockerhelpers import get_my_containers_name
+from pyvoltha.common.utils.nethelpers import get_my_primary_local_ipv4
+from connection_mgr import ConnectionManager
+
+defs = dict(
+    config=os.environ.get('CONFIG', './ofagent.yml'),
+    consul=os.environ.get('CONSUL', 'localhost:8500'),
+    controller=os.environ.get('CONTROLLER', 'localhost:6653'),
+    probe=os.environ.get('PROBE', ':8080'),
+    external_host_address=os.environ.get('EXTERNAL_HOST_ADDRESS',
+                                         get_my_primary_local_ipv4()),
+    grpc_endpoint=os.environ.get('GRPC_ENDPOINT', 'localhost:50055'),
+    grpc_timeout=os.environ.get('GRPC_TIMEOUT', '10'),
+    core_binding_key=os.environ.get('CORE_BINDING_KEY', 'voltha_backend_name'),
+    core_transaction_key=os.environ.get('CORE_TRANSACTION_KEY', 'voltha_serial_number'),
+    instance_id=os.environ.get('INSTANCE_ID', os.environ.get('HOSTNAME', '1')),
+    internal_host_address=os.environ.get('INTERNAL_HOST_ADDRESS',
+                                         get_my_primary_local_ipv4()),
+    work_dir=os.environ.get('WORK_DIR', '/tmp/ofagent'),
+    key_file=os.environ.get('KEY_FILE', '/ofagent/pki/voltha.key'),
+    cert_file=os.environ.get('CERT_FILE', '/ofagent/pki/voltha.crt')
+)
+
+
+def parse_args():
+
+    parser = argparse.ArgumentParser()
+
+    _help = ('Path to ofagent.yml config file (default: %s). '
+             'If relative, it is relative to main.py of ofagent.'
+             % defs['config'])
+    parser.add_argument('-c', '--config',
+                        dest='config',
+                        action='store',
+                        default=defs['config'],
+                        help=_help)
+
+    _help = '<hostname>:<port> to consul agent (default: %s)' % defs['consul']
+    parser.add_argument(
+        '-C', '--consul', dest='consul', action='store',
+        default=defs['consul'],
+        help=_help)
+
+    _help = '<hostname1>:<port1> <hostname2>:<port2> <hostname3>:<port3> ... <hostnamen>:<portn>   to openflow controller (default: %s)' % \
+            defs['controller']
+    parser.add_argument(
+        '-O', '--controller',nargs = '*', dest='controller', action='store',
+        default=defs['controller'],
+        help=_help)
+
+    _help = '<hostname>:<port> for liveness and readiness probes (default: %s)' % defs['probe']
+    parser.add_argument(
+        '-P', '--probe', dest='probe', action='store',
+        default=defs['probe'],
+        help=_help)
+
+    _help = ('<hostname> or <ip> at which ofagent is reachable from outside '
+             'the cluster (default: %s)' % defs['external_host_address'])
+    parser.add_argument('-E', '--external-host-address',
+                        dest='external_host_address',
+                        action='store',
+                        default=defs['external_host_address'],
+                        help=_help)
+
+    _help = ('gRPC end-point to connect to. It can either be a direct '
+             'definition in the form of <hostname>:<port>, or it can be an '
+             'indirect definition in the form of @<service-name> where '
+             '<service-name> is the name of the grpc service as registered '
+             'in consul (example: @voltha-grpc). (default: %s)'
+             % defs['grpc_endpoint'])
+    parser.add_argument('-G', '--grpc-endpoint',
+                        dest='grpc_endpoint',
+                        action='store',
+                        default=defs['grpc_endpoint'],
+                        help=_help)
+
+    _help = 'gRPC timeout in seconds (default: %s)' % defs['grpc_timeout']
+    parser.add_argument('-T', '--grpc-timeout',
+                        dest='grpc_timeout',
+                        action='store',
+                        default=defs['grpc_timeout'],
+                        help=_help)
+
+    _help = ('The name of the meta-key whose value is the rw-core group '
+             'to which the ofagent\'s gRPC client is bound. '
+             '(default: %s)' % defs['core_binding_key'])
+    parser.add_argument('-B', '--core-binding-key',
+                        dest='core_binding_key',
+                        action='store',
+                        default=defs['core_binding_key'],
+                        help=_help)
+
+    _help = ('The name of the meta-key whose value is the transaction ID '
+             'used by the OFAgent to send requests to the Voltha RW Core. '
+             '(default: %s)' % defs['core_transaction_key'])
+    parser.add_argument('-ctk', '--core_transaction_key',
+                        dest='core_transaction_key',
+                        action='store',
+                        default=defs['core_transaction_key'],
+                        help=_help)
+
+    _help = ('<hostname> or <ip> at which ofagent is reachable from inside '
+             'the cluster (default: %s)' % defs['internal_host_address'])
+    parser.add_argument('-H', '--internal-host-address',
+                        dest='internal_host_address',
+                        action='store',
+                        default=defs['internal_host_address'],
+                        help=_help)
+
+    _help = ('unique string id of this ofagent instance (default: %s)'
+             % defs['instance_id'])
+    parser.add_argument('-i', '--instance-id',
+                        dest='instance_id',
+                        action='store',
+                        default=defs['instance_id'],
+                        help=_help)
+
+    _help = 'omit startup banner log lines'
+    parser.add_argument('-n', '--no-banner',
+                        dest='no_banner',
+                        action='store_true',
+                        default=False,
+                        help=_help)
+
+    _help = "suppress debug and info logs"
+    parser.add_argument('-q', '--quiet',
+                        dest='quiet',
+                        action='count',
+                        help=_help)
+
+    _help = 'enable verbose logging'
+    parser.add_argument('-v', '--verbose',
+                        dest='verbose',
+                        action='count',
+                        help=_help)
+
+    _help = ('work dir to compile and assemble generated files (default=%s)'
+             % defs['work_dir'])
+    parser.add_argument('-w', '--work-dir',
+                        dest='work_dir',
+                        action='store',
+                        default=defs['work_dir'],
+                        help=_help)
+
+    _help = ('use docker container name as ofagent instance id'
+             ' (overrides -i/--instance-id option)')
+    parser.add_argument('--instance-id-is-container-name',
+                        dest='instance_id_is_container_name',
+                        action='store_true',
+                        default=False,
+                        help=_help)
+
+    _help = ('Specify this option to enable TLS security between ofagent \
+              and onos.')
+    parser.add_argument('-t', '--enable-tls',
+                        dest='enable_tls',
+                        action='store_true',
+                        help=_help)
+
+    _help = ('key file to be used for tls security (default=%s)'
+             % defs['key_file'])
+    parser.add_argument('-k', '--key-file',
+                        dest='key_file',
+                        action='store',
+                        default=defs['key_file'],
+                        help=_help)
+
+    _help = ('certificate file to be used for tls security (default=%s)'
+             % defs['cert_file'])
+    parser.add_argument('-r', '--cert-file',
+                        dest='cert_file',
+                        action='store',
+                        default=defs['cert_file'],
+                        help=_help)
+
+    args = parser.parse_args()
+
+    # post-processing
+
+    if args.instance_id_is_container_name:
+        args.instance_id = get_my_containers_name()
+
+    return args
+
+
+def load_config(args):
+    path = args.config
+    if path.startswith('.'):
+        dir = os.path.dirname(os.path.abspath(__file__))
+        path = os.path.join(dir, path)
+    path = os.path.abspath(path)
+    with open(path) as fd:
+        config = yaml.load(fd)
+    return config
+
+banner = r'''
+  ___  _____ _                    _
+ / _ \|  ___/ \   __ _  ___ _ __ | |_
+| | | | |_ / _ \ / _` |/ _ \ '_ \| __|
+| |_| |  _/ ___ \ (_| |  __/ | | | |_
+ \___/|_|/_/   \_\__, |\___|_| |_|\__|
+                 |___/
+'''
+
+def print_banner(log):
+    for line in banner.strip('\n').splitlines():
+        log.info(line)
+    log.info('(to stop: press Ctrl-C)')
+
+
+class Main(object):
+
+    def __init__(self):
+
+        self.args = args = parse_args()
+        self.config = load_config(args)
+        self.grpc_timeout = int(self.args.grpc_timeout)
+
+        verbosity_adjust = (args.verbose or 0) - (args.quiet or 0)
+        self.log = setup_logging(self.config.get('logging', {}),
+                                 args.instance_id,
+                                 verbosity_adjust=verbosity_adjust)
+
+        # components
+        self.connection_manager = None
+
+        self.exiting = False
+
+        if not args.no_banner:
+            print_banner(self.log)
+
+        self.startup_components()
+
+    def start(self):
+        self.start_reactor()  # will not return except Keyboard interrupt
+
+    @inlineCallbacks
+    def startup_components(self):
+        self.log.info('starting-internal-components')
+        args = self.args
+        self.connection_manager = yield ConnectionManager(
+            args.consul,
+            args.grpc_endpoint,
+            self.grpc_timeout,
+            args.core_binding_key,
+            args.core_transaction_key,
+            args.controller,
+            args.instance_id,
+            args.enable_tls,
+            args.key_file,
+            args.cert_file).start()
+        Probe.connection_manager = self.connection_manager
+        self.log.info('started-internal-services')
+
+    @inlineCallbacks
+    def shutdown_components(self):
+        """Execute before the reactor is shut down"""
+        self.log.info('exiting-on-keyboard-interrupt')
+        self.exiting = True
+        if self.connection_manager is not None:
+            yield self.connection_manager.stop()
+
+    def start_reactor(self):
+        reactor.callWhenRunning(
+            lambda: self.log.info('twisted-reactor-started'))
+
+        reactor.addSystemEventTrigger('before', 'shutdown',
+                                      self.shutdown_components)
+        reactor.callInThread(self.start_probe)
+        reactor.run()
+
+    def start_probe(self):
+        args = self.args
+        host = args.probe.split(':')[0]
+        port = args.probe.split(':')[1]
+        server = SocketServer.TCPServer((host, int(port)), Probe)
+        server.serve_forever()
+
+if __name__ == '__main__':
+    Main().start()