From 11d399468ae1c8a4fc68473b51a053b7ce6cf974 Mon Sep 17 00:00:00 2001
From: Chris Veilleux <veilleux.chris@gmail.com>
Date: Mon, 3 Jun 2019 23:28:52 -0500
Subject: [PATCH] new base class for batch jobs

---
 batch/base/__init__.py |   1 +
 batch/base/base.py     | 101 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+)
 create mode 100644 batch/base/__init__.py
 create mode 100644 batch/base/base.py

diff --git a/batch/base/__init__.py b/batch/base/__init__.py
new file mode 100644
index 00000000..ad72b3b1
--- /dev/null
+++ b/batch/base/__init__.py
@@ -0,0 +1 @@
+from .base import SeleneScript
diff --git a/batch/base/base.py b/batch/base/base.py
new file mode 100644
index 00000000..ba39cb36
--- /dev/null
+++ b/batch/base/base.py
@@ -0,0 +1,101 @@
+from argparse import ArgumentParser
+from datetime import date, datetime
+from logging import getLogger
+from os import environ, path
+import sys
+
+from selene.data.metrics import JobMetric, JobRepository
+from selene.util.db import DatabaseConnectionConfig, connect_to_db
+from selene.util.log import configure_logger
+
+
+class SeleneScript(object):
+    _db = None
+    _job_name = None
+
+    def __init__(self, job_file_path):
+        self._job_file_path = job_file_path
+        configure_logger(self.job_name)
+        self.log = getLogger(self.job_name)
+        self._arg_parser = ArgumentParser()
+        self.args = None
+        self.start_ts = datetime.now()
+        self.end_ts = None
+        self.success = False
+
+    @property
+    def job_name(self):
+        if self._job_name is None:
+            job_file_name = path.basename(self._job_file_path)
+            self._job_name = job_file_name[:-3]
+
+        return self._job_name
+
+    @property
+    def db(self):
+        if self._db is None:
+            db_connection_config = DatabaseConnectionConfig(
+                host=environ['DB_HOST'],
+                db_name=environ['DB_NAME'],
+                password=environ['DB_PASSWORD'],
+                port=environ.get('DB_PORT', 5432),
+                user=environ['DB_USER'],
+                sslmode=environ.get('DB_SSLMODE'),
+                use_namedtuple_cursor=True
+            )
+            self._db = connect_to_db(db_connection_config)
+
+        return self._db
+
+    def run(self):
+        try:
+            self._start_job()
+            self._run()
+            self.success = True
+        except:
+            self.log.exception('An exception occurred - aborting script')
+            raise
+        finally:
+            self._finish_job()
+
+    def _start_job(self):
+        # Logger builds daily files, delineate start in case of multiple runs
+        self.log.info('* * * * *  START OF JOB  * * * * *')
+        self._define_args()
+        self.args = self._arg_parser.parse_args()
+
+    def _define_args(self):
+        self._arg_parser.add_argument(
+            "--date",
+            default=date.today(),
+            help='Processing date in YYYY-MM-DD format',
+            type=lambda dt: datetime.strptime(dt, '%Y-%m-%d').date()
+        )
+
+    def _run(self):
+        """Subclass must override this to perform job-specific logic"""
+        raise NotImplementedError
+
+    def _finish_job(self):
+        self.end_ts = datetime.now()
+        self._insert_metrics()
+        self.db.close()
+        self.log.info(
+            'script run time: ' + str(self.end_ts - self.start_ts)
+        )
+        # Logger builds daily files, delineate end in case of multiple runs
+        self.log.info('* * * * *  END OF JOB  * * * * *')
+
+    def _insert_metrics(self):
+        if self.args is not None:
+            job_repository = JobRepository(self.db)
+            job_metric = JobMetric(
+                job_name=self.job_name,
+                batch_date=self.args.date,
+                start_ts=self.start_ts,
+                end_ts=self.end_ts,
+                command=' '.join(sys.argv),
+                success=self.success
+            )
+            job_id = job_repository.add(job_metric)
+            self.log.info('Job ID: ' + job_id)