outposts: initial service connection implementation

passbook/outposts/apps.py

@@ -1,7 +1,19 @@
 """passbook outposts app config"""
 from importlib import import_module
+from os import R_OK, access
+from os.path import expanduser
+from pathlib import Path
+from socket import gethostname
+from urllib.parse import urlparse
 
 from django.apps import AppConfig
+from django.db import ProgrammingError
+from docker.constants import DEFAULT_UNIX_SOCKET
+from kubernetes.config.incluster_config import SERVICE_TOKEN_FILENAME
+from kubernetes.config.kube_config import KUBE_CONFIG_DEFAULT_LOCATION
+from structlog import get_logger
+
+LOGGER = get_logger()
 
 
 class PassbookOutpostConfig(AppConfig):
@@ -14,3 +26,46 @@ class PassbookOutpostConfig(AppConfig):
 
     def ready(self):
         import_module("passbook.outposts.signals")
+        try:
+            self.init_local_connection()
+        except (ProgrammingError):
+            pass
+
+    def init_local_connection(self):
+        # Check if local kubernetes or docker connections should be created
+        from passbook.outposts.models import (
+            KubernetesServiceConnection,
+            DockerServiceConnection,
+        )
+
+        if Path(SERVICE_TOKEN_FILENAME).exists():
+            LOGGER.debug("Detected in-cluster Kubernetes Config")
+            if not KubernetesServiceConnection.objects.filter(local=True).exists():
+                LOGGER.debug("Created Service Connection for in-cluster")
+                KubernetesServiceConnection.objects.create(
+                    name="Local Kubernetes Cluster", local=True, config={}
+                )
+        # For development, check for the existence of a kubeconfig file
+        kubeconfig_path = expanduser(KUBE_CONFIG_DEFAULT_LOCATION)
+        if Path(kubeconfig_path).exists():
+            LOGGER.debug("Detected kubeconfig")
+            if not KubernetesServiceConnection.objects.filter(
+                name=gethostname()
+            ).exists():
+                LOGGER.debug("Creating kubeconfig Service Connection")
+                with open(kubeconfig_path, "r") as _kubeconfig:
+                    KubernetesServiceConnection.objects.create(
+                        name=gethostname(), config=_kubeconfig.read()
+                    )
+        unix_socket_path = urlparse(DEFAULT_UNIX_SOCKET).path
+        socket = Path(unix_socket_path)
+        if socket.exists() and access(socket, R_OK):
+            LOGGER.debug("Detected local docker socket")
+            if not DockerServiceConnection.objects.filter(local=True).exists():
+                LOGGER.debug("Created Service Connection for docker")
+                DockerServiceConnection.objects.create(
+                    name="Local Docker connection",
+                    local=True,
+                    url=unix_socket_path,
+                    tls=True,
+                )