Implement the interface with the AlertManager

Implement a class with the functionalities to call AlertManager.
This is a first implementation with methods to:
* Schedule a Silence
* Removed a previously scheduled Silence

The code has been written using the existing one for
icinga as guidance.

lib/alertmanager_api/silence.py

@@ -0,0 +1,148 @@
+import logging
+import requests
+from exceptions.missing_mandatory_param_error import MissingMandatoryParamError
+from requests.auth import HTTPBasicAuth
+from requests.exceptions import RequestException
+
+
+class AlertManagerAPI:
+    """
+    class implementing an interface to the Kayobe's alertmanager
+    functionalities:
+        * create a silence
+        * remove an existing silence
+    """
+
+    def __init__(self, alertmanager_account):
+        """
+        :param alertmanager_account: object with credentials
+        :type alertmanager_account: AlertManagerAccount
+        """
+        self.log = logging.getLogger("AlertManagerAPI")
+        self.alertmanager_account = alertmanager_account
+        self.auth = HTTPBasicAuth(
+            alertmanager_account.username, alertmanager_account.password
+        )
+        self.api_url = f"{alertmanager_account.alertmanager_endpoint}/api/v2/silences"
+
+    def schedule_silence(self, silence):
+        """
+        Schedules a silence in alertmanager
+
+        :param silence: object with the specs to create a silence
+        :type silence: SilenceDetails
+        :return: a new silence object, including the silence_id
+        :rtype: SilenceDetails
+        :raises MissingMandatoryParamError:
+            if any of the required attributes are missing
+            in the silence object:
+            instance_name
+            start time
+            end time
+            author
+            comment
+        :raises requests.exceptions.RequestException:
+            when the request to the AlertManager failed
+        """
+        if not silence.instance_name:
+            msg = "Missing silence instance name"
+            self.log.critical(msg)
+            raise MissingMandatoryParamError(msg)
+        if not silence.start_time:
+            msg = "Missing silence start time"
+            self.log.critical(msg)
+            raise MissingMandatoryParamError(msg)
+        if not silence.end_time:
+            msg = "Missing silence end time"
+            self.log.critical(msg)
+            raise MissingMandatoryParamError(msg)
+        if not silence.author:
+            msg = "Missing silence author"
+            self.log.critical(msg)
+            raise MissingMandatoryParamError(msg)
+        if not silence.comment:
+            msg = "Missing silence comment"
+            self.log.critical(msg)
+            raise MissingMandatoryParamError(msg)
+
+        payload = {
+            "matchers": [
+                {
+                    "name": "instance_name",
+                    "value": silence.instance_name,
+                    "isRegex": False,
+                }
+            ],
+            "startsAt": silence.start_time,
+            "endsAt": silence.end_time,
+            "createdBy": silence.author,
+            "comment": silence.comment,
+        }
+        try:
+            response = requests.post(
+                self.api_url,
+                auth=self.auth,
+                headers={"Accept": "application/json"},
+                json=payload,
+                timeout=10,
+            )
+            if response.status_code != 200:
+                msg = (
+                    "Failed to create silence. "
+                    f"Response status code: {response.status_code} "
+                    f"Response text: {response.text}"
+                )
+                self.log.error(msg)
+                raise RequestException(msg, response=response)
+            silence_id = response.json()["silenceID"]
+            silence.silence_id = silence_id
+            return silence
+
+        except RequestException as req_ex:
+            msg = f"Failed to create silence in Alertmanager: {req_ex} "
+            if req_ex.response is not None:
+                msg += (
+                    f"Response status code: {req_ex.response.status_code} "
+                    f"Response text: {req_ex.response.text}"
+                )
+            self.log.critical(msg)
+            raise req_ex
+
+    def remove_silence(self, silence):
+        """
+        Removes a previously scheduled silence in alertmanager
+
+        :param silence: object including the silence_id to be removed
+        :type silence: SilenceDetails
+        :raises MissingMandatoryParamError: when the silence_id is missing
+        :raises requests.exceptions.RequestException:
+            when the request to the AlertManager failed
+        """
+        if not silence.silence_id:
+            msg = "Missing silence silence_id"
+            self.log.critical(msg)
+            raise MissingMandatoryParamError(msg)
+
+        try:
+            response = requests.delete(
+                self.api_url,
+                auth=self.auth,
+                timeout=10,
+            )
+            if response.status_code != 200:
+                msg = (
+                    f"Failed to delete silence with ID {silence.silence_id}. "
+                    f"Response status code: {response.status_code} "
+                    f"Response text: {response.text}"
+                )
+                self.log.critical(msg)
+                raise RequestException(msg, response=response)
+        except RequestException as req_ex:
+            msg = f"Failed to delete silence in Alertmanager: {req_ex} "
+            if req_ex.response is not None:
+                msg += (
+                    f"Response status code: {req_ex.response.status_code} "
+                    f"Response text: {req_ex.response.text}"
+                )
+            self.log.critical(msg)
+            raise req_ex

lib/structs/alertmanager/alertmanager_account.py

@@ -34,15 +34,20 @@ def from_pack_config(pack_config: dict, alertmanager_account_name: str):
         :param alertmanager_account_name: The account name to get from the config
         :raises ValueError: When the pack config does not have alertmanager_accounts defined
         :raises KeyError: When the account does not appear in the given config
-        :return: (Dictionary) alertmanager account names and properties
+        :return: alertmanager account names and properties
+        :rtype: dictionary
         """
         alertmanager_accounts_config = pack_config.get("alertmanager_accounts", None)
 
         if alertmanager_accounts_config is None:
-            raise ValueError("Pack config must contain the 'alertmanager_accounts' field")
+            raise ValueError(
+                "Pack config must contain the 'alertmanager_accounts' field"
+            )
 
         try:
-            key_value = {config["name"]: config for config in alertmanager_accounts_config}
+            key_value = {
+                config["name"]: config for config in alertmanager_accounts_config
+            }
             account_data = key_value[alertmanager_account_name]
         except KeyError as exc:
             raise KeyError(