ci: Initial pass at setting up periodic indexing for Chromium (#335)

Author: varungandhi-src

.buildkite/chromium.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+
+ZONE="us-central-1"
+PROJECT="sourcegraph-ci"
+INSTANCE="scip-clang-runner"
+
+# From https://stackoverflow.com/a/65683139/2682729
+function wait_vm() {
+  local counter=0
+  local maxRetry=20
+  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
+      echo "The machine is up!"
+      exit 0
+    else
+      echo "Maybe later? Retry: $counter/$maxRetry"
+      ((counter++))
+      sleep 5
+    fi
+  done
+}
+
+gcloud compute instances start --zone "$ZONE" --project "$PROJECT" "$INSTANCE"
+wait_vm_start
+
+function run() {
+  gcloud compute ssh --zone "$ZONE" --project "$PROJECT" "$INSTANCE" --tunnel-through-iap --command "cd chromium/src && $*"
+}
+
+run 'git rebase-update && glient sync'
+run 'rm -rf out/X'
+run gn gen out/X --args='symbol_level=0 cc_wrapper="sccache" target_os="android" target_cpu="arm64"'
+# TODO: Remove the jq invocation to index everything.
+run './tools/clang/scripts/generate_compdb.py -p out/X | sed -e "s/sccache //" | jq ".[0:100]" | compile_commands.json'
+run ninja -k 0 -C out/X all
+run 'find out/X -regextype egrep -regex ".*\.(apk|apks|so|jar|zip|o)" -type f -delete'
+run 'wget https://github.com/sourcegraph/scip-clang/releases/latest/download/scip-clang-x86_64-linux -O scip-clang && chmod +x ./scip-clang'
+run scip-clang
+run 'zstd index.scip'
+
+gcloud compute scp --zone "$ZONE" --project "$PROJECT" "$INSTANCE:~/chromium/src/index.scip.zst" .
+run 'rm -rf scip-clang index.scip index.scip.zst'
+
+COMMIT="$(run 'git rev-parse HEAD 2>/dev/null')"
+zstd -d index.scip.zst
+
+wget https://github.com/sourcegraph/src-cli/releases/latest/download/src_linux_amd64 -O src
+
+mv src_linux_amd64 src
+chmod +x src
+src code-intel upload -repo=github.com/chromium/chromium -root="" -commit="$COMMIT" -file=index.scip
+
+rm -rf src index.scip index.scip.zst
+
+gcloud compute instances stop --zone "us-central1-c" --project "sourcegraph-ci" "scip-clang-runner"

.buildkite/chromium.yaml

@@ -0,0 +1,7 @@
+$schema: "http://json.schemastore.org/buildkite"
+steps:
+  - label: "Start VM"
+    agents:
+      queue: bazel
+    command: |
+      ./.buildkite/chromium.sh