Add graceful shutdown via sigterm (#42)

* Add graceful shutdown via sigterm

* Add documentation

* minor fixes; search port number

* Add documentation and fix CI

* fix test

Co-authored-by: Cody Lin <clin@ibm.com>

Author: codyjlin

Dockerfile

@@ -32,3 +32,5 @@ USER root
 USER presto:presto
 # Add Db2 connector
 COPY --from=builder --chown=presto:presto presto-db2-* /usr/lib/presto/plugin/db2
+
+CMD ["./run-presto.sh"]

README.md

@@ -40,3 +40,9 @@ Then:
 ```SHELL
 docker run -d -p 8080:8080 -v /foo/bar/db2.properties:/usr/lib/presto/default/etc/catalog/db2.properties:ro shawnzhu/prestodb:latest
 ```
+
+## Features
+
+### Graceful Shutdown
+
+It adds the [graceful shutdown](https://trino.io/docs/current/admin/graceful-shutdown.html) feature from Trino such that on a SIGTERM signal to the container, the worker will have a grace period before interrupting active queries.

run-presto.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+set -xeuo pipefail
+
+graceful_shutdown() {
+    echo "calling graceful shutdown"
+    PORT=$(grep "^http-server.http.port=" /etc/presto/config.properties | cut -d '=' -f2)
+    curl -v -X PUT -d '"SHUTTING_DOWN"' -H "Content-type: application/json" http://localhost:$PORT\/v1/info/state -H X-Presto-User:name
+}
+trap graceful_shutdown TERM
+
+set +e
+grep -s -q 'node.id' /etc/presto/node.properties
+NODE_ID_EXISTS=$?
+set -e
+
+NODE_ID=""
+if [[ ${NODE_ID_EXISTS} != 0 ]] ; then
+    NODE_ID="-Dnode.id=${HOSTNAME}"
+fi
+
+exec /usr/lib/presto/bin/launcher run --etc-dir /etc/presto ${NODE_ID} "$@"
+

test_config.yaml

@@ -19,4 +19,4 @@ metadataTest:
     value: /usr/lib/jvm/zulu11
   exposedPorts: ["8080"]
   cmd:
-  - /usr/lib/presto/bin/run-presto
+  - ./run-presto.sh