Spawn and manage Google Compute Engine instances over the REST API.
Why REST?
The Compute Engine API is REST/JSON only — it has no gRPC endpoint.
This library talks to it with Req; there is no
connection pool or supervised process to run. A GcpCompute.Config is the
only handle you pass around.
Quickstart
# 1. Mint tokens with Goth (or any GcpCompute.TokenProvider)
children = [{Goth, name: MyApp.Goth}]
# 2. Build a config (do this once, reuse it)
{:ok, config} =
GcpCompute.Config.production(
project: "my-project",
zone: "us-central1-a",
goth: MyApp.Goth
)
# 3. Spawn a cheap, self-deleting Spot VM and wait for it
{:ok, instance} =
GcpCompute.insert_instance_and_wait(config,
name: "worker-1",
machine_type: "e2-micro",
spot: true,
max_run_duration: 3600,
startup_script: "#!/bin/bash\necho ready > /tmp/ready"
)
GcpCompute.Instance.external_ip(instance)
#=> "34.x.x.x"
# 4. Tear it down
{:ok, _op} = GcpCompute.delete_instance_and_wait(config, "worker-1")The functions here are thin wrappers over GcpCompute.Instances and
GcpCompute.Operations; reach for those modules directly for the full surface.
Summary
Functions
Drop the cached config for {otp_app, key} so the next config/2 re-reads env.
Returns :ok whether or not an entry was cached. See config/2 for the
caching caveat (:persistent_term writes trigger a global GC).
Load (and cache) a config from application env.
# config :my_app, :gcp_compute, project: "p", zone: "...", token_provider: {...}
{:ok, config} = GcpCompute.config(:my_app)The result is memoized in :persistent_term on the first successful load and
reused on every later call. Caching is first-write-wins with no
invalidation: once cached, later changes to the application env are ignored.
Only successful loads are cached — an invalid env returns its {:error, _}
without caching, so it is re-read next call. To force a reload after
reconfiguring at runtime, call clear_config/2 first. (:persistent_term
writes trigger a global GC, so treat clearing as a rare operation, not a
per-request one.)
Spawn an instance and wait until it's running.
Sugar over insert_instance_and_wait/3: the name is lifted out, and spec
options (machine_type, spot, …) are auto-separated from call options
(:zone, :request_id, :timeout).
{:ok, vm} = GcpCompute.launch(config, "worker-1", machine_type: "e2-micro", spot: true)Delete an instance and wait for it to be gone. Returns :ok.