How to Import an Google Pub/Sub Topic into Terraform

Import Google Pub/Sub Topic with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Google Cloud Pub/Sub resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live Google Pub/Sub Topic to managed Terraform.

terraback scan all gcp --project my-gcp-project

terraback gcp import --method bulk

The Terraform import block

Terraback emits a Terraform 1.5+ import block like the one below. Because the block lives in your configuration, the import is reviewable in a pull request and repeatable across environments.

import {
  to = google_pubsub_topic.events
  id = "projects/my-project/topics/events"
}

Example google_pubsub_topic configuration

Here is a realistic Google Pub/Sub Topic block. Terraback generates a fuller version from your actual resource attributes; this is a minimal, valid starting point.

resource "google_pubsub_topic" "events" {
  name = "events"

  message_retention_duration = "86400s"
}

Gotchas when importing a Google Pub/Sub Topic

• You can import with the short topic name or the full projects/<project>/topics/<name> path; the full path is unambiguous.
• Subscriptions are separate google_pubsub_subscription resources and are not imported with the topic.
• Schema settings reference a separate google_pubsub_schema resource.
• Durations such as message_retention_duration use a seconds string like 86400s.

Doing it manually with terraform import

The native approach is to write the google_pubsub_topic block by hand, then run terraform import google_pubsub_topic.example <import-id> for every resource, one at a time. That works for a handful of resources, but it does not scale: you author all the HCL yourself and repeat the command for each item. Terraback generates the HCL and the import blocks for your whole account in one pass.

Import other Google Cloud resources