Initial pass on a warm standby start/update tool

This is meant to allow us to start the warm standby and try to keep it up to date with changes published to the image.

Signed-off-by: mward <matt@eclipse.org>

runme.sh

+#!/bin/bash
+#*******************************************************************************
+#* Copyright (c) 2022 onward Eclipse Foundation and others.
+#* All rights reserved. This program and the accompanying materials
+#* are made available under the terms of the Eclipse Public License v2.0
+#* which accompanies this distribution, and is available at
+#* http://www.eclipse.org/legal/epl-v20.html
+#*
+#* Contributors:
+#*   Matt Ward (Eclipse Foundation)
+#*******************************************************************************/
+
+umask 0022
+
+#setup basic definitions
+IMAGE="docker.io/eclipsefdn/www.eclipse.org:latest"
+#podman should be a drop in replacement for docker
+PODMAN="/usr/bin/podman"
+CONTAINER_NAME="www-httpd"
+RUNNING_IMAGE=""
+LATEST_IMAGE=""
+
+function pull_image {
+#  echo "Fetching $IMAGE"
+  $PODMAN pull -q $IMAGE
+}
+
+function get_image_id {
+  local IMAGE_ID=$($PODMAN history --format "{{.ID}}" $IMAGE | head -1)
+  echo $IMAGE_ID
+}
+
+function run_image {
+#  echo "Running Image $LATEST_IMAGE"
+  $PODMAN run --name=$CONTAINER_NAME -d -p 18181:8080 $LATEST_IMAGE
+}
+
+#main loop starts here.
+
+pull_image
+LATEST_IMAGE=$(get_image_id)
+if [[ $RUNNING_IMAGE == "" ]]; then
+#  echo "Init setting RUNNING_IMAGE=LATEST_IMAGE"
+  RUNNING_IMAGE=$LATEST_IMAGE
+fi
+
+run_image
+
+while :
+do
+  sleep 300;
+  #pull and get the image id
+  pull_image
+  LATEST_IMAGE=$(get_image_id)
+  if [[ $RUNNING_IMAGE != $LATEST_IMAGE ]]; then
+    echo "Latest image id is not the running image, restarting"
+    $PODMAN stop $CONTAINER_NAME
+    $PODMAN rm $CONTAINER_NAME
+    run_image
+    RUNNING_IMAGE=$LATEST_IMAGE
+  fi
+
+done
+