LogDog: Add collector service implementation.

server/cmd/logdog_collector/run.sh

+#!/bin/bash

[dnj (Google), 2016/01/21 04:36:24]

This is invoked at startup by the Dockerfile to pull configuration metadata from
GCE metadata service and pass it as command-line arguments to the Collector
invocation. It's basically environmental glue. The remainder of the config is
then picked up from luci-config.

+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+METADATA_URL="http://metadata.google.internal"
+
+_help() {
+  echo -e "Usage: $0 <logdog-coordinator-path>"
+  echo -e ""
+  echo -e "  logdog-coordinator-path\tThe path to the application binary."
+}
+
+APP=$1; shift
+if [ -z "${APP}" ]; then
+  echo "ERROR: Missing argument <logdog-coordiantor-path>"
+  _help
+  exit 1
+fi
+APP=$(readlink -f "${APP}")
+if [ ! -x "${APP}" ]; then
+  echo "ERROR: Application path is not an executable file [${APP}]"
+  exit 1
+fi
+
+_load_metadata_domain() {
+  local __resultvar=$1; shift
+  local domain=$1; shift
+  local resource=$1; shift
+
+  OUTPUT=$(curl \
+    -s \
+    --fail \
+    "${METADATA_URL}/computeMetadata/v1/${domain}/attributes/${resource}" \
+    -H "Metadata-Flavor: Google")
+  RV=$?
+  if [ ${RV} != 0 ]; then
+    return ${RV}
+  fi
+  if [ -z "${OUTPUT}" ]; then
+    return 1
+  fi
+
+  eval $__resultvar="'${OUTPUT}'"
+}
+
+# Loads metadata from the GCE metadata server.
+_load_metadata() {
+  local __resultvar=$1; shift
+  local resource=$1; shift
+
+  # Try loading from 'instance' domain.
+  _load_metadata_domain "$__resultvar" "instance" "$resource"
+  if [ $? == 0 ]; then
+    return 0
+  fi
+
+  # Try loading from 'project' domain.
+  _load_metadata_domain "$__resultvar" "project" "$resource"
+  if [ $? == 0 ]; then
+    return 0
+  fi
+
+  echo "WARN: Failed to load metadata [${resource}]."
+  return 1
+}
+
+_load_metadata_check() {
+  local __resultvar=$1; shift
+  local resource=$1; shift
+
+  _load_metadata "$__resultvar" "$resource"
+  if [ $? != 0 ]; then
+    echo "ERROR: Metadata resource [${resource}] is required."
+    exit 1
+  fi
+
+  return 0
+}
+
+_write_credentials() {
+  local path=$1; shift
+  local data=$1; shift
+  echo "${data}" > "${path}"
+}
+
+# Test if we're running on a GCE instance.
+curl \
+  -s \
+  --fail \
+  "${METADATA_URL}" \
+  1>/dev/null
+if [ $? != 0 ]; then
+  echo "ERROR: Not running on GCE instance."
+  exit 1
+fi
+
+# Load metadata.
+_load_metadata_check COORDINATOR_URL "logdog_coordinator_url"
+
+_load_metadata LOG_LEVEL "logdog_collector_log_level"
+_load_metadata STORAGE_CREDENTIALS "logdog_collector_storage_auth_json"
+
+# Runtime temporary directory.
+TEMPDIR=$(mktemp -d)
+trap "rm -rf ${TEMPDIR}" EXIT
+
+# Compose command line.
+ARGS=(
+  "-coordinator-url" "${COORDINATOR_URL}"
+  )
+
+if [ ! -z "${LOG_LEVEL}" ]; then
+  ARGS+=("-log_level" "${LOG_LEVEL}")
+fi
+if [ ! -z "${STORAGE_CREDENTIALS}" ]; then
+  STORAGE_CREDENTIALS_JSON_PATH="${TEMPDIR}/storage_service_account_json.json"
+        _write_credentials "${STORAGE_CREDENTIALS_JSON_PATH}" "${STORAGE_CREDENTIALS}"
+  ARGS+=("-storage-credential-json-path" "${STORAGE_CREDENTIALS_JSON_PATH}")
+fi
+
+echo "INFO: Running command line args: ${APP} ${ARGS[*]}"
+"${APP}" ${ARGS[*]}