/.github/{scripts, workflow}: add pod template script and wait loop

.github/scripts/performance-benchmarking/get-pod-spec-json.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+
+set -e
+
+if [ ! -n "$1" ] || [ ! -n "$2" ] || [ ! -n "$3" ]; then
+    echo  "Usage: ./get-pod-spec-json <podname> <fromVersion> <toVersion>"
+    exit 1
+fi
+
+podname="$1"
+fromVersion="$2"
+toVersion="$3"
+
+echo '
+{
+  "apiVersion": "v1",
+  "kind": "Pod",
+  "metadata": {
+    "name": "'$podname'",
+    "namespace": "performance-benchmarking"
+  },
+  "spec": {
+    "serviceAccountName": "performance-benchmarking",
+    "containers": [
+      {
+        "name": "performance-benchmarking",
+        "image": "407903926827.dkr.ecr.us-west-2.amazonaws.com/liquidata/performance-benchmarking:latest",
+        "args": [
+          "--from-version='$fromVersion'",
+          "--to-version='$toVersion'",
+          "select * from from_results;",
+          "select * from to_results;"
+        ]
+      }
+    ],
+    "restartPolicy": "OnFailure"
+  }
+}
+'