gcp_compute

# Changelog

All notable changes to this project are documented here. The format is based on
[Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and this project
adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [Unreleased]

### Added

- **Compute REST client layer.**
  - `GcpCompute` facade: `insert_instance/3`, `insert_instance_and_wait/3`,
    `get_instance/3`, `list_instances/2`, `list_instances_page/2`,
    `delete_instance/3`, `delete_instance_and_wait/3`, `start_instance/3`,
    `stop_instance/3`, `wait_for_operation/3`, `config/2`, `clear_config/2`.
  - `GcpCompute.Config` — NimbleOptions-validated config / client handle with
    `new/1`, `new!/1`, `production/1`, `local/1`, `local!/1`, `from_env/2`.
  - `GcpCompute.TokenProvider` behaviour with `Goth` (optional dep) and `Static`
    adapters.
  - `GcpCompute.Instance` — `spec/1` insert-body builder (Spot VM defaults) plus
    parsing and `external_ip/1` / `internal_ip/1` accessors.
  - `GcpCompute.Instances` (`list_page/2` surfaces `nextPageToken`) and
    `GcpCompute.Operations` modules.
  - `GcpCompute.Operation` and `GcpCompute.Error` data types.
  - `GcpCompute.Telemetry` — `[:gcp_compute, :request, :start | :stop | :exception]`
    spans on every API call.

### Security

- **Cleartext bearer tokens rejected.** `GcpCompute.Config.new/1` now requires an `https://`
  `base_url` unless you explicitly pass `allow_insecure: true` (for a local emulator/proxy on
  a trusted network). Gating on that flag rather than the token provider means even a `Static`
  provider holding a real out-of-band token stays TLS-only by default. `local/1` sets
  `allow_insecure: true` for you. The scheme check is case-insensitive. Applies to `from_env/2`
  and any direct `new/1` use, not just `production/1`.
- **`req_options` can no longer override auth or URL.** The request `:method`,
  `:url`, and `:auth` are always computed by the library and layered on top of the
  app-supplied `req_options`, which is treated as trusted transport config.
- **Fail closed on a missing token.** A `nil`/empty token now returns
  `{:error, %GcpCompute.Error{reason: :missing_token}}` before any request goes
  out, instead of sending an unauthenticated call.
- **No secrets in error messages.** Token-fetch failures use a fixed
  `"token fetch failed"` message; the raw reason is kept only in `:body`, which
  `GcpCompute.Error`'s `Inspect` implementation redacts.

### Changed

- `GcpCompute.Instances.insert_and_wait/3` returns
  `{:error, %GcpCompute.Error{reason: :missing_instance_name}}` for a name-less
  spec instead of raising `ArgumentError`.

### Notes

- The Compute Engine API is REST/JSON only (no gRPC); transport is `Req`.
- A higher-level sandbox orchestration layer (gen_statem, DynamicSupervisor,
  reaper, profiles) is planned on top of this client.

[Unreleased]: https://github.com/nyo16/gcp_compute/commits/master