Improve kube deploy process. (#13397)

* switch bootloader to job and add recreate strategy to db

* add comment about recreate strategy

* Add comment about ttl on bootloader

* add comment about Pod vs Job

Author: lmossman

kube/resources/bootloader.yaml

@@ -1,40 +1,51 @@
-apiVersion: v1
-kind: Pod
+# We would prefer to use Pod instead of Job here for exactly-once execution guarantee, however
+# Pods have a problem of sticking around after completion, causing errors upon upgrade if they
+# are not manually deleted first.
+# Using generateName would solve this by giving each bootloader pod a unique name, but Kustomize
+# does not currently support generateName.
+# Therefore, using Job here with a ttl is required in order to have a smooth upgrade process for kube.
+# See discussion about this on the PR: https://github.com/airbytehq/airbyte/pull/13397#discussion_r887600449
+apiVersion: batch/v1
+kind: Job
 metadata:
   name: airbyte-bootloader
 spec:
-  restartPolicy: Never
-  containers:
-    - name: airbyte-bootloader-container
-      image: airbyte/bootloader
-      env:
-        - name: AIRBYTE_VERSION
-          valueFrom:
-            configMapKeyRef:
-              name: airbyte-env
-              key: AIRBYTE_VERSION
-        - name: DATABASE_HOST
-          valueFrom:
-            configMapKeyRef:
-              name: airbyte-env
-              key: DATABASE_HOST
-        - name: DATABASE_PORT
-          valueFrom:
-            configMapKeyRef:
-              name: airbyte-env
-              key: DATABASE_PORT
-        - name: DATABASE_PASSWORD
-          valueFrom:
-            secretKeyRef:
-              name: airbyte-secrets
-              key: DATABASE_PASSWORD
-        - name: DATABASE_URL
-          valueFrom:
-            configMapKeyRef:
-              name: airbyte-env
-              key: DATABASE_URL
-        - name: DATABASE_USER
-          valueFrom:
-            secretKeyRef:
-              name: airbyte-secrets
-              key: DATABASE_USER
+  # This ttl is necessary to prevent errors when upgrading airbyte
+  ttlSecondsAfterFinished: 5
+  template:
+    spec:
+      restartPolicy: Never
+      containers:
+        - name: airbyte-bootloader-container
+          image: airbyte/bootloader
+          env:
+            - name: AIRBYTE_VERSION
+              valueFrom:
+                configMapKeyRef:
+                  name: airbyte-env
+                  key: AIRBYTE_VERSION
+            - name: DATABASE_HOST
+              valueFrom:
+                configMapKeyRef:
+                  name: airbyte-env
+                  key: DATABASE_HOST
+            - name: DATABASE_PORT
+              valueFrom:
+                configMapKeyRef:
+                  name: airbyte-env
+                  key: DATABASE_PORT
+            - name: DATABASE_PASSWORD
+              valueFrom:
+                secretKeyRef:
+                  name: airbyte-secrets
+                  key: DATABASE_PASSWORD
+            - name: DATABASE_URL
+              valueFrom:
+                configMapKeyRef:
+                  name: airbyte-env
+                  key: DATABASE_URL
+            - name: DATABASE_USER
+              valueFrom:
+                secretKeyRef:
+                  name: airbyte-secrets
+                  key: DATABASE_USER

kube/resources/db.yaml

@@ -16,6 +16,9 @@ metadata:
   name: airbyte-db
 spec:
   replicas: 1
+  # Recreate strategy is necessary to avoid multiple simultaneous db pods running and corrupting the db state
+  strategy:
+    type: Recreate
   selector:
     matchLabels:
       airbyte: db