Simplify linkerd admin shutdown pattern

timescale · Dec 7, 2023 · 2e96eac · 2e96eac
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commit 2e96eac
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Showing 4 changed files with 14 additions and 13 deletions.
diff --git a/charts/timescaledb-single/docs/admin-guide.md b/charts/timescaledb-single/docs/admin-guide.md
@@ -36,8 +36,7 @@ The following table lists the configurable parameters of the TimescaleDB Helm ch
 | `image.pullPolicy`                | The pull policy                             | `IfNotPresent`                                      |
 | `image.repository`                | The image to pull                           | `timescale/timescaledb-ha`                       |
 | `image.tag`                       | The version of the image to pull            | `pg13-ts2.1-latest`
-| `linkerd.enabled`                 | Enabled limited linkerd support.            | `false`
-| `linkerd.shutdownAfterCheckpoint` | When `true`, configures the StatefulSet Pod's `lifecycle.preStop` to issue a shutdown call to the local linkerd-proxy sidecar after checkpointing is complete. | `false`
+| `linkerd.adminShutdownOnExit`     | If `true`, then the main TimescaleDB container will be configured to call the local linkerd-proxy sidecar container's `/shutdown` endpoint as soon as Patroni exits. | `false` |
 | `service.primary.type`        | The service type to use for the primary service | `ClusterIP`                          |
 | `service.primary.port`        | The service port to use for the primary service | `5432`                               |
 | `service.primary.nodePort`    | The service nodePort to use for the primary service when `type` is `NodePort` | `null` |

diff --git a/charts/timescaledb-single/scripts/prestop.sql b/charts/timescaledb-single/scripts/prestop.sql
@@ -60,7 +60,3 @@ CHECKPOINT;
     SELECT 'We are a primary: Successfully invoked checkpoints, now issuing a switchover.';
     \! curl -s http://localhost:8008/switchover -XPOST -d '{"leader": "$(hostname)"}'
 \endif
-
-\if :linkerdShutdown
-    \! curl -s -m 5 -X POST http://localhost:4191/shutdown
-\endif
diff --git a/charts/timescaledb-single/templates/statefulset-timescaledb.yaml b/charts/timescaledb-single/templates/statefulset-timescaledb.yaml
@@ -113,7 +113,6 @@ spec:
               command:
               - psql
               - -X
-              - --set=linkerdShutdown="{{ if and .Values.linkerd.enabled .Values.linkerd.terminateAfterCheckpoint }}1{{else}}0{{end}}"
               - --file
               - "{{ template "scripts_dir" . }}/lifecycle_preStop.sql"
         # When reusing an already existing volume it sometimes happens that the permissions
@@ -168,7 +167,16 @@ spec:
 
             export PATRONI_POSTGRESQL_PGPASS="${HOME}/.pgpass.patroni"
 
-            exec patroni /etc/timescaledb/patroni.yaml
+            patroni /etc/timescaledb/patroni.yaml
+            rcode=$?
+
+            {{- if .Values.linkerd.adminShutdownOnExit }}
+            # Once Patroni exits, when running with a linkerd-proxy sidecar, we call linkerd-proxy shutdown.
+            curl -s -m 5 -X POST http://localhost:4191/shutdown
+            {{- end }}
+
+            # Ensure we exit with the code which was returned by Patroni.
+            exit $rcode
         env:
         # We use mixed case environment variables for Patroni User management,
         # as the variable themselves are documented to be PATRONI_<username>_OPTIONS.

diff --git a/charts/timescaledb-single/values.yaml b/charts/timescaledb-single/values.yaml
@@ -600,8 +600,6 @@ debug:
 
 # Support for specific use cases when deploying with the linkerd service mesh.
 linkerd:
-  enabled: false
-  # As part of the statefulset pod's `lifecycle.preStop`, call the local linkerd sidecar
-  # to cleanly terminate the proxy. If this is not performed, then the proxy will remain
-  # alive unnecessarily, blocking pod termination for a period of time.
-  terminateAfterCheckpoint: true
+  # If true, then the main TimescaleDB container will be configured to call the local
+  # linkerd-proxy sidecar container's /shutdown endpoint as soon as Patroni exits.
+  adminShutdownOnExit: false