Add OTI event-handler project

OTI event handler application in DCAEGEN2 platform

Change-Id: Ie64f26f851e2045f00043f90279d503c2dc62948
Issue-ID: DCAEGEN2-1910
Signed-off-by: Kotagiri, Ramprasad (rp5662) <rp5662@att.com>

1 files changed, 175 insertions, 0 deletions

diff --git a/oti/event-handler/otihandler/docker_client.py b/oti/event-handler/otihandler/docker_client.py
new file mode 100644
index 0000000..621a1ec
--- /dev/null
+++ b/oti/event-handler/otihandler/docker_client.py
@@ -0,0 +1,175 @@
+# ================================================================================
+# Copyright (c) 2019-2020 AT&T Intellectual Property. All rights reserved.
+# ================================================================================
+# 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.
+# ============LICENSE_END=========================================================
+
+"""client interface to docker"""
+
+import docker
+import json
+import logging
+import time
+
+from otihandler.config import Config
+from otihandler.consul_client import ConsulClient
+from otihandler.utils import decrypt
+
+
+# class DockerClientError(RuntimeError):
+#     pass
+
+class DockerClientConnectionError(RuntimeError):
+    pass
+
+
+class DockerClient(object):
+    """
+    All Docker logins are in Consul's key-value store under
+    "docker_plugin/docker_logins" as a list of json objects where
+    each object is a single login:
+
+        [{ "username": "XXXX", "password": "yyyy",
+           "registry": "hostname.domain:18443" }]
+    """
+
+    _logger = logging.getLogger("oti_handler.docker_client")
+
+    def __init__(self, docker_host, reauth=False):
+        """Create Docker client
+
+        Args:
+        -----
+        reauth: (boolean) Forces reauthentication, e.g., Docker login
+        """
+
+        (fqdn, port) = ConsulClient.get_service_fqdn_port(docker_host, node_meta=True)
+        base_url = "https://{}:{}".format(fqdn, port)
+
+        try:
+            tls_config = docker.tls.TLSConfig(
+                client_cert=(
+                    Config.tls_server_ca_chain_file,
+                    Config.tls_private_key_file
+                )
+            )
+            self._client = docker.APIClient(base_url=base_url, tls=tls_config, version='auto', timeout=60)
+
+            for dcl in ConsulClient.get_value("docker_plugin/docker_logins"):
+                dcl['password'] = decrypt(dcl['password'])
+                dcl["reauth"] = reauth
+                self._client.login(**dcl)
+
+        # except requests.exceptions.RequestException as e:
+        except Exception as e:
+            msg = "DockerClient.__init__({}) attempt to {} with TLS got exception {}: {!s}".format(
+                      docker_host, base_url, type(e).__name__, e)
+
+            # Then try connecting to dockerhost without TLS
+            try:
+                base_url = "tcp://{}:{}".format(fqdn, port)
+                self._client = docker.APIClient(base_url=base_url, tls=False, version='auto', timeout=60)
+
+                for dcl in ConsulClient.get_value("docker_plugin/docker_logins"):
+                    dcl['password'] = decrypt(dcl['password'])
+                    dcl["reauth"] = reauth
+                    self._client.login(**dcl)
+
+            # except requests.exceptions.RequestException as e:
+            except Exception as e:
+                msg = "{}\nDockerClient.__init__({}) attempt to {} without TLS got exception {}: {!s}".format(
+                          msg, docker_host, base_url, type(e).__name__, e)
+                DockerClient._logger.error(msg)
+                raise DockerClientConnectionError(msg)
+
+    @staticmethod
+    def build_cmd(script_path, use_sh=True, msg_type="dti", **kwargs):
+        """Build command to execute"""
+
+        data = json.dumps(kwargs or {})
+
+        if use_sh:
+            return ['/bin/sh', script_path, msg_type, data]
+        else:
+            return [script_path, msg_type, data]
+
+    def notify_for_reconfiguration(self, container_id, cmd):
+        """Notify Docker container that reconfiguration occurred
+
+        Notify the Docker container by doing Docker exec of passed-in command
+
+        Args:
+        -----
+        container_id: (string)
+        cmd: (list) of strings each entry being part of the command
+        """
+
+        for attempts_remaining in range(11,-1,-1):
+            try:
+                result = self._client.exec_create(container=container_id, cmd=cmd)
+            except docker.errors.APIError as e:
+                # e  #  500 Server Error: Internal Server Error ("{"message":"Container 624108d1ab96f24b568662ca0e5ffc39b59c1c57431aec0bef231fb62b04e166 is not running"}")
+                DockerClient._logger.debug("exec_create() returned APIError: {!s}".format(e))
+
+                # e.message               # 500 Server Error: Internal Server Error
+                # DockerClient._logger.debug("e.message: {}".format(e.message))
+                # e.response.status_code  # 500
+                # DockerClient._logger.debug("e.response.status_code: {}".format(e.response.status_code))
+                # e.response.reason       # Internal Server Error
+                # DockerClient._logger.debug("e.response.reason: {}".format(e.response.reason))
+                # e.explanation           # {"message":"Container 624108d1ab96f24b568662ca0e5ffc39b59c1c57431aec0bef231fb62b04e166 is not running"}
+                # DockerClient._logger.debug("e.explanation: {}".format(e.explanation))
+
+                # docker container restarting can wait
+                if e.explanation and 'is restarting' in e.explanation.lower():
+                    DockerClient._logger.debug("notification exec_create() experienced: {!s}".format(e))
+                    if attempts_remaining == 0:
+                        result = None
+                        break
+                    time.sleep(10)
+                # elif e.explanation and 'no such container' in e.explanation.lower():
+                # elif e.explanation and 'is not running' in e.explanation.lower():
+                else:
+                    DockerClient._logger.warn("aborting notification exec_create() because exception {}: {!s}".format(type(e).__name__, e))
+                    return str(e)  # don't raise or CM will retry usually forever
+                    # raise DockerClientError(e)
+            except Exception as e:
+                DockerClient._logger.warn("aborting notification exec_create() because exception {}: {!s}".format(
+                    type(e).__name__, e))
+                return str(e)  # don't raise or CM will retry usually forever
+                # raise DockerClientError(e)
+            else:
+                break
+        if not result:
+            DockerClient._logger.warn("aborting notification exec_create() because docker exec failed")
+            return "notification unsuccessful"  # failed to get an exec_id, perhaps trying multiple times, so don't raise or CM will retry usually forever
+        DockerClient._logger.debug("notification exec_create() succeeded")
+
+        for attempts_remaining in range(11,-1,-1):
+            try:
+                result = self._client.exec_start(exec_id=result['Id'])
+            except Exception as e:
+                DockerClient._logger.debug("notification exec_start() got exception {}: {!s}".format(type(e).__name__, e))
+                if attempts_remaining == 0:
+                    DockerClient._logger.warn("aborting notification exec_start() because exception {}: {!s}".format(type(e).__name__, e))
+                    return str(e)  # don't raise or CM will retry usually forever
+                    # raise DockerClientError(e)
+                time.sleep(10)
+            else:
+                break
+        DockerClient._logger.debug("notification exec_start() succeeded")
+
+        DockerClient._logger.info("Pass to docker exec {} {} {}".format(
+            container_id, cmd, result))
+
+        return result