feat(scheduler): make the image fetching policy for slugs and docker images configurable via ENV vars

Closes #563

Author: helgi

rootfs/deis/settings.py

@@ -263,8 +263,11 @@
 random_secret = 'CHANGEME_sapm$s%upvsw5l_zuy_&29rkywd^78ff(qi*#@&*^'
 SECRET_KEY = os.environ.get('DEIS_SECRET_KEY', random_secret)
 BUILDER_KEY = os.environ.get('DEIS_BUILDER_KEY', random_secret)
-defaultImage = "quay.io/deisci/slugrunner:canary"
-SLUGRUNNER_IMAGE = os.environ.get('SLUGRUNNER_IMAGE_NAME', defaultImage)
+
+# k8s image policies
+SLUGRUNNER_IMAGE = os.environ.get('SLUGRUNNER_IMAGE_NAME', 'quay.io/deisci/slugrunner:canary')  # noqa
+SLUG_BUILDER_IMAGE_PULL_POLICY = os.environ.get('SLUG_BUILDER_IMAGE_PULL_POLICY', "Always")  # noqa
+DOCKER_BUILDER_IMAGE_PULL_POLICY = os.environ.get('DOCKER_BUILDER_IMAGE_PULL_POLICY', "Always")  # noqa
 
 # registry settings
 REGISTRY_HOST = os.environ.get('DEIS_REGISTRY_SERVICE_HOST', '127.0.0.1')

rootfs/scheduler/__init__.py

@@ -130,6 +130,7 @@
           {
             "name": "$containername",
             "image": "$image",
+            "imagePullPolicy": "$image_pull_policy",
             "env": [
             {
                 "name":"DEIS_APP",
@@ -184,7 +185,7 @@
           {
             "name": "$containername",
             "image": "$slugimage",
-            "imagePullPolicy": "Always",
+            "imagePullPolicy": "$image_pull_policy",
             "env": [
             {
                 "name":"PORT",
@@ -495,12 +496,14 @@ def run(self, namespace, name, image, entrypoint, command, **kwargs):
             'id': name,
             'version': self.apiversion,
             'image': imgurl,
+            'image_pull_policy': settings.DOCKER_BUILDER_IMAGE_PULL_POLICY,
             'storagetype': os.getenv("APP_STORAGE")
         }
 
         if entrypoint == '/runner/init':
             POD = POD_BTEMPLATE
             l["image"] = image
+            l['image_pull_policy'] = settings.SLUG_BUILDER_IMAGE_PULL_POLICY
             l["slugimage"] = settings.SLUGRUNNER_IMAGE
             l["mHost"] = os.getenv("DEIS_MINIO_SERVICE_HOST")
             l["mPort"] = os.getenv("DEIS_MINIO_SERVICE_PORT")
@@ -876,6 +879,7 @@ def _create_rc(self, namespace, name, image, command, **kwargs):  # noqa
             "appversion": kwargs.get("version"),
             "version": self.apiversion,
             "image": imgurl,
+            'image_pull_policy': settings.DOCKER_BUILDER_IMAGE_PULL_POLICY,
             "replicas": kwargs.get("replicas", 0),
             "containername": container_name,
             "type": app_type,
@@ -887,6 +891,7 @@ def _create_rc(self, namespace, name, image, command, **kwargs):  # noqa
         # Check if it is a slug builder image.
         if kwargs.get('build_type') == "buildpack":
             l["image"] = image
+            l['image_pull_policy'] = settings.SLUG_BUILDER_IMAGE_PULL_POLICY
             l["slugimage"] = settings.SLUGRUNNER_IMAGE
             TEMPLATE = RCB_TEMPLATE