Examples: only terminate vtadmin if it was started (#13433)

* Do not error stopping vtadmin web and api if pidd files do not exist.

For fixing below.
#13432

Signed-off-by: Jean-François Gagné <jfg956@users.noreply.github.com>

* Get rid of code duplication in vtadmin-down.sh.

Signed-off-by: Jean-François Gagné <jfg956@users.noreply.github.com>

* Use bash test

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Use SIGTERM and wait for process to end

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Validate function parameters

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Add license header

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Move vtadmin stop function to utils

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Generalize simple process shutdown with timeout

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Correct output

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Remove now redundant log message

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Corrections

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Add missing license header to modified file

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Only check PID if we killed it

Signed-off-by: Matt Lord <mattalord@gmail.com>

* Remove mix of spaces and tabs

Signed-off-by: Matt Lord <mattalord@gmail.com>

---------

Signed-off-by: Jean-François Gagné <jfg956@users.noreply.github.com>
Signed-off-by: Matt Lord <mattalord@gmail.com>
Co-authored-by: Matt Lord <mattalord@gmail.com>

examples/common/lib/utils.sh

@@ -139,6 +139,39 @@ function wait_for_healthy_shard() {
 	wait_for_shard_vreplication_engine "${keyspace}" "${shard}"
 }
 
+# Stop the specified binary name using the provided PID file.
+# Example:
+#  stop_process "vtadmin-web" "$VTDATAROOT/tmp/vtadmin-web.pid"
+function stop_process() {
+	if [[ -z ${1} || -z ${2} ]]; then
+		fail "A binary name and PID file must be specified when attempting to shutdown a process"
+	fi
+
+	local binary_name="${1}"
+	local pidfile="${2}"
+	local pid=""
+	local wait_secs=90
+
+	if [[ -e "${pidfile}" ]]; then
+		pid=$(cat "${pidfile}")
+		echo "Stopping ${binary_name}..."
+		kill "${pid}"
+
+		# Wait for the process to terminate
+		for _ in $(seq 1 ${wait_secs}); do
+			if ! ps -p "${pid}" > /dev/null; then
+				break
+			fi
+			sleep 1
+		done
+		if ps -p "${pid}" > /dev/null; then
+			fail "Timed out after ${wait_secs} seconds waiting for the ${binary_name} using PID file ${pidfile} to terminate"
+		fi
+	else
+		echo "Skipping stopping ${binary_name} because the specified PID file (${pidfile}) does not exist."
+	fi
+}
+
 # Print error message and exit with error code.
 function fail() {
 	echo "ERROR: ${1}"

examples/common/scripts/consul-down.sh

@@ -18,5 +18,5 @@
 
 source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 
-echo "Stopping consul..."
-kill -9 `cat $VTDATAROOT/tmp/consul.pid` 
+stop_process "consul" "$VTDATAROOT/tmp/consul.pid"
+

examples/common/scripts/etcd-down.sh

@@ -18,5 +18,5 @@
 
 source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 
-echo "Stopping etcd..."
-kill -9 `cat $VTDATAROOT/tmp/etcd.pid` 
+stop_process "etcd" "$VTDATAROOT/tmp/etcd.pid"
+

examples/common/scripts/vtadmin-down.sh

@@ -1,9 +1,20 @@
 #!/bin/bash
 
-source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
+# Copyright 2023 The Vitess Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
-echo "Stopping vtadmin-web..."
-kill -9 "$(cat "$VTDATAROOT/tmp/vtadmin-web.pid")"
+source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 
-echo "Stopping vtadmin-api..."
-kill -9 "$(cat "$VTDATAROOT/tmp/vtadmin-api.pid")"
+stop_process "vtadmin-web" "$VTDATAROOT/tmp/vtadmin-web.pid"
+stop_process "vtadmin-api" "$VTDATAROOT/tmp/vtadmin-api.pid"

examples/common/scripts/vtctld-down.sh

@@ -18,5 +18,5 @@
 
 source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 
-echo "Stopping vtctld..."
-kill -9 `cat $VTDATAROOT/tmp/vtctld.pid`
+stop_process "vtctld" "$VTDATAROOT/tmp/vtctld.pid"
+

examples/common/scripts/vtgate-down.sh

@@ -18,6 +18,5 @@
 
 source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 
-# Stop vtgate.
-echo "Stopping vtgate..."
-kill `cat $VTDATAROOT/tmp/vtgate.pid`
+stop_process "vtgate" "$VTDATAROOT/tmp/vtgate.pid"
+

examples/common/scripts/vtorc-down.sh

@@ -1,7 +1,20 @@
 #!/bin/bash
 
+# Copyright 2023 The Vitess Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 
-echo "Stopping vtorc."
-kill -9 "$(cat "$VTDATAROOT/tmp/vtorc.pid")"
+stop_process "vtorc" "$VTDATAROOT/tmp/vtorc.pid"
 

examples/common/scripts/vttablet-down.sh

@@ -19,12 +19,7 @@
 
 source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 
-printf -v tablet_dir 'vt_%010d' $TABLET_UID
-pid=`cat $VTDATAROOT/$tablet_dir/vttablet.pid`
-
-kill $pid
-
-# Wait for vttablet to die.
-while ps -p $pid > /dev/null; do sleep 1; done
+printf -v tablet_dir 'vt_%010d' "$TABLET_UID"
 
+stop_process "vttablet" "$VTDATAROOT/$tablet_dir/vttablet.pid"