Google Cloud Functions

This document will walk you through setting up a Google Cloud Function for serverless backend search. For more guidance on configuration options for full backend search check here.

1. Build the code package:

   cd ./cmd/tempo-serverless && make build-gcf-zip
   

   This will create a ZIP file containing all the code required for the function. The file name will be of the form: ./cloud-functions/tempo-<branch name>-<commit hash>.zip. Here is an example of that name:

   ls cloud-functions/*.zip
   cloud-functions/tempo-serverless-backend-search-297172a.zip
   

2. Provision a GCS bucket.

3. Copy the ZIP file into your bucket.

   gsutil cp cloud-functions/tempo-serverless-backend-search-297172a.zip gs://<newly provisioned gcs bucket>
   

4. Provision the Google Cloud Function. This example uses Terraform:

   locals {
     // this can be increased if you would like to use multiple functions
     count = 1
   }
   
   resource "google_cloudfunctions_function" "function" {
     count = local.count
   
     name        = "<function name>-${count.index}"
     description = "Tempo Search Function"
     runtime     = "go116"
   
     available_memory_mb   = 1024
     source_archive_bucket = <GCS bucket created above>
     source_archive_object = "tempo-serverless-backend-search-297172a.zip"
     trigger_http          = true
     entry_point           = "Handler"
     ingress_settings      = "ALLOW_INTERNAL_ONLY"
     min_instances         = 1
   
     // Tempo serverless functions are configured via environment variables
     environment_variables = {
       "TEMPO_GCS_BUCKET_NAME"          = "<GCS bucket name backing your Tempo instance>"
       "TEMPO_BACKEND"                  = "gcs"
       "TEMPO_GCS_HEDGE_REQUESTS_AT"    = "400ms"
       "TEMPO_GCS_HEDGE_REQUESTS_UP_TO" = "2"
     }
   }
   

5. Add the newly-created functions as external endpoints in your querier configuration. The endpoint can be retrieved from the trigger tab in Google Cloud Functions:

   

   querier:
     search:
       external_endpoints:
       - <trigger url from console>