ci: Periodic indexing for Chromium (pass 2)

.buildkite/chromium.sh

@@ -1,25 +1,27 @@
 #!/usr/bin/env bash
+set -eux
 
-ZONE="us-central-1"
+ZONE="us-central1-c"
 PROJECT="sourcegraph-ci"
 INSTANCE="scip-clang-runner"
 
 # From https://stackoverflow.com/a/65683139/2682729
-function wait_vm() {
+function wait_vm_start() {
   local counter=0
-  local maxRetry=20
+  local maxRetry=10
   while true ; do
     if (( counter == maxRetry )) ; then
       echo "Reach the retry upper limit $counter"
       exit 1
     fi
 
-    if gcloud compute ssh --quiet --zone "$ZONE" --project "$PROJECT" "$INSTANCE" --tunnel-through-iap --command="true" 2> /dev/null ; then
+    if gcloud compute ssh --quiet --zone "$ZONE" --project "$PROJECT" "$INSTANCE" --tunnel-through-iap --command="true" ; then
       echo "The machine is up!"
       exit 0
     else
       echo "Maybe later? Retry: $counter/$maxRetry"
-      ((counter++))
+      # Don't use post-increment: https://stackoverflow.com/a/22428973/2682729
+      ((++counter))
       sleep 5
     fi
   done

.buildkite/chromium.yaml

@@ -1,7 +1,9 @@
 $schema: "http://json.schemastore.org/buildkite"
 steps:
-  - label: "Start VM"
+  - label: "Index Chromium"
     agents:
       queue: bazel
     command: |
       ./.buildkite/chromium.sh
+notify:
+  - slack: "#code-intel-indexing-alerts"