In many cases, you don’t have control over the location of the event source. In the example above, the Cloud Storage bucket is in the
europe-west1 region. That’s the location that you need to work with and it has implications for the trigger location (which I’ll get to later).
The location of the event target is the region of the service where you want the events to go. You get to choose this from one of the supported regions when you deploy your Cloud Run service. You typically want this to be in the same region as your event source for latency and data locality reasons (but this is not strictly a requirement). In the example above, the event source (bucket) is in
europe-west1 but the event target (Cloud Run service) is in
us-central1 as specified by the
The location of the trigger is dictated by the event source location, but the trigger type also comes into play. It is specified by the –location flag. Let’s take a look at the trigger location for each trigger type in more detail.
In a Pub/Sub trigger, you connect a Pub/Sub topic to an event target. Pub/Sub topics are global and not tied to a single region. However, when you create a Pub/Sub trigger, you need to specify a region for it (because Eventarc triggers need to live in a region) with the
--location flag as follows: