lib: add bootstrap command

passbook/lib/management/commands/bootstrap.py

@@ -0,0 +1,66 @@
+"""passbook management command to bootstrap"""
+from argparse import REMAINDER
+from subprocess import Popen  # nosec
+
+# pylint: disable=redefined-builtin
+from sys import exit, stderr, stdin, stdout
+from time import sleep
+
+from django.core.management.base import BaseCommand
+from django.db import connection
+from django.db.utils import OperationalError
+from django_redis import get_redis_connection
+from redis.exceptions import ConnectionError as RedisConnectionError
+from structlog import get_logger
+
+LOGGER = get_logger()
+
+
+class Command(BaseCommand):
+    """Bootstrap passbook, ensure Database and Cache are
+    reachable, and directories are writeable"""
+
+    help = """Bootstrap passbook, ensure Database and Cache are
+    reachable, and directories are writeable"""
+
+    def add_arguments(self, parser):
+        parser.add_argument("command", nargs=REMAINDER)
+
+    def check_database(self) -> bool:
+        """Return true if database is reachable, false otherwise"""
+        try:
+            connection.cursor()
+            LOGGER.info("Database reachable")
+            return True
+        except OperationalError:
+            LOGGER.info("Database unreachable")
+            return False
+
+    def check_cache(self) -> bool:
+        """Return true if cache is reachable, false otherwise"""
+        try:
+            con = get_redis_connection("default")
+            con.ping()
+            LOGGER.info("Cache reachable")
+            return True
+        except RedisConnectionError:
+            LOGGER.info("Cache unreachable")
+            return False
+
+    def handle(self, *args, **options):
+        LOGGER.info("passbook bootstrapping...")
+        should_check = True
+        while should_check:
+            should_check = not (self.check_database() and self.check_cache())
+            sleep(1)
+        LOGGER.info("Dependencies are up, starting command...")
+        proc = Popen(
+            args=options.get("command"), stdout=stdout, stderr=stderr, stdin=stdin
+        )  # nosec
+        try:
+            proc.wait()
+            exit(proc.returncode)
+        except KeyboardInterrupt:
+            LOGGER.info("Killing process")
+            proc.kill()
+            exit(254)