URL Map Host Rule and Path Matcher Resource

[mck-rob-van-kleeck]

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Description

At present, I do not see a way to add a host rule or path matcher to an existing URL Map. All rules have to be added to a URL Map at creation. However, all backend services aren't always known at the time of creation of a given URL Map and my need to have the rules or matchers updated at a later date in a different repo. The API exists (as seen here: https://cloud.google.com/sdk/gcloud/reference/compute/url-maps/add-host-rule), but I do not see a terraform resource to do it.

Use Case:
I want a module that creates every part of a load balancer (IP, Global Forwarding Rule, Certificate Map, URL Map, etc.) that can then be used to attach backend services to it through other modules. The other modules would take care of the host entry and path matcher portions of the URL Map.

New or Affected Resource(s)

• google_compute_url_map

Potential Terraform Configuration

resource "google_compute_url_map" "urlmap" {
  name        = "urlmap"
  description = "a description"
  default_service = google_compute_backend_bucket.static.id
}

resource "google_compute_url_map_host_rule" "mysite" {
    hosts        = ["mysite.com"]
    path_matcher = google_compute_url_map_path_matcher.mysite.name
    url_map_id = google_compute_url_map.urlmap.id
}

resource "google_compute_url_map_host_rule" "myothersite" {
    hosts        = ["myothersite.com"]
    path_matcher = "otherpaths"
    url_map_id = google_compute_url_map.urlmap.id
}

resource "google_compute_url_map_path_matcher" "mysite" {
    name            = "mysite"
    default_service = google_compute_backend_bucket.static.id

    path_rule {
      paths   = ["/home"]
      service = google_compute_backend_bucket.static.id
    }

    path_rule {
      paths   = ["/login"]
      service = google_compute_backend_service.login.id
    }

    path_rule {
      paths   = ["/static"]
      service = google_compute_backend_bucket.static.id
    }
  }
}

References

b/376300141

[sross-tc]

Any news on this?

[dev-whoan]

Any updates?

---

It would be also good to have kind of resources; google_compute_url_map_path_rule or google_compute_url_map_route_rule; which allocate the rule to the url_map_path_matcher

resource "google_compute_url_map_path_matcher" "mysite" {
    name            = "mysite"
    default_service = google_compute_backend_bucket.static.id
}

resource "google_compute_url_map_path_rule" "home" {
  path_matcher = google_compute_url_map_path_matcher.mysite.id

  path = ["/home"]
  service = google_compute_backend_bucket.static.id
}

resource "google_compute_url_map_route_rule" "home" {
  path_matcher = google_compute_url_map_path_matcher.mysite.id
  ...
}

[thetimbecker]

Does anyone have a workaround for this? We are trying to figure out how to do path based routing without having to manually add new services to the central URL map each time.

[melinath]

Looking at this again, it doesn't seem to be a case of needing a new resource necessarily - the API doesn't have a separate endpoint for specifically updating these fields. https://cloud.google.com/compute/docs/reference/rest/v1/urlMaps/patch is available and does seem like it allows patching; the fields also aren't marked as immutable. It ought to be working as-is without needing a separate rule.

That said:

1. I would totally believe that there's a bug here; although we do have tests that update pathMatchers, we don't have tests that update hostRules.
2. It could still make sense to have fine-grained resources that manage these rules separately.
3. Given the number of upvotes, there's definitely something going on here.

[melinath]

Any new resources implemented here should also add regional variants.

[jgangemi]

any update here? i have the exact use case. right now i'm planning to work around it using gcloud and hooks in terragrunt.