# Native host management

Electric Cherry controls Docker/Plutainer through an outbound host agent. A native
instance never uses Komodo or a filesystem mounted into the controller. The
controller owns desired state, campaigns, collections, safety queues and history;
the agent owns local execution and its durable operation journal.

## Install and launch

1. Run the controller with persistent `/data` storage. Set `EC_PUBLIC_URL` to its
   HTTPS origin and proxy TLS to port 3000. Set a random `EC_SETUP_TOKEN` and create
   the first administrator at `/setup`. Management pages/APIs require user login
   and roles; agent endpoints authenticate their own host credentials. See
   [Users and access](authentication.md) for setup and password recovery.
2. Open **Hosts → Add Host**, choose a name, local game-port range and bind address,
   and generate an enrollment. Run the displayed command on Debian 12/13 amd64.
3. The installer validates the platform, installs Python 3 and an absent Docker
   installation, verifies the downloaded agent SHA-256 over HTTPS, enrolls it and
   enables `electric-cherry-agent.service`. It needs no Git, Node.js or local build.
4. In **Hosts**, prepare a Plutainer runtime image. In **Game Files**, select T5 or
   T6 and upload your local game folder. Name the library and version and publish
   it after the upload finishes. Include the DLC files in that folder; there is
   no separate DLC declaration. Uploading also works before enrolling any host.
5. Cache the published version on each destination host. Wait for verification.
   Hosts report connection and readiness separately; deployment also checks the
   particular library, image, capacity and ports you selected.
6. Launch a server or collection. Select the host, immutable game-file version(s)
   and runtime image. EC selects lobby IDs and reserves UDP/TCP ports atomically.
   Saved Plutonium server keys remain associated with their exact server names.

A fresh destination host downloads centrally stored game files without manual
copying or per-container setup. EC does not supply the game content itself.

The default host root is `/var/lib/electric-cherry`; installer `--data-dir` changes
it. Data is separated into `libraries/<game>/<version>/content`,
`instances/<UUID>/<generation>/app`, and `agent/operations.sqlite3`. Base libraries
are mounted read-only and instance deletion removes only that instance's files.
The controller stores large files under `GAME_FILES_ROOT` (default beside the
SQLite database), with manifests/checksums and operation metadata in SQLite.

The agent uses Plutainer's documented [game-file and app mounts](https://github.com/Ayymoss/Plutainer/blob/main/docs/volumes-and-configs.md).
Its log reader supports relative log links that resolve inside the instance app
directory, while file writes reject symlinks and paths outside that directory.

## Identity, transport and credentials

Enrollment tokens are random, hashed at rest, single-use and expire after 15
minutes. Consumption and credential issuance are transactional. Enrollment only
works at the enrollment endpoint. Each host receives a distinct bearer credential
and the controller only stores its hash. Host and enrollment bearer credentials
are rejected outside `/api/agent/`.

The agent uses HTTPS, operating-system certificate validation, outbound heartbeats
and polling; Docker has no exposed remote API. Agent endpoints reject HTTP unless
`EC_AGENT_ALLOW_HTTP=true` is explicitly enabled for development. The agent's
insecure development option is limited to loopback. Public release assets contain
no credentials. The release checksum is authenticated by the controller's HTTPS
origin; there is no separate offline release-signing infrastructure.

Browser sessions do not authorize agents. Similarly, host credentials never grant
access to operator pages. Game telemetry uses a separate `EC_TELEMETRY_TOKEN`,
configured in each reporter's authorization header; see the
[telemetry contract](beta-test-plans.md#game-reporter-protocol).

Hosts offers credential rotation and revocation. Rotation persists the new secret
on the agent before switching controller credentials, so a lost response can be
retried using the same proposed secret. Revocation affects one host only and does
not stop its running game containers. Re-enrollment requires a fresh token and an
explicit installer `--reenroll` when local credentials already exist.

API outline:

- `GET /api/hosts/:id`: host details, operation history and deletion blockers.
- `DELETE /api/hosts/:id`: administrator removes an unused host and revokes access;
  returns `409` if servers, reservations or unresolved delivered operations remain.
- `POST /api/agent/enroll`: consume enrollment token and return host credentials.
- `POST /api/agent/heartbeat`: authenticated inventory, current operation and caches.
- `GET /api/agent/operations`: deliver/reconcile durable operation IDs.
- `POST /api/agent/operations/:id`: authenticated acceptance, progress or result.
- `POST /api/game-files`: administrator creates a folder upload with game, name,
  version, optional description and `files: [{path, size, lastModified}]`.
- `GET /api/game-files/:id/upload`: durable per-file offsets and publication status.
- `PUT /api/game-files/:id/upload/files/:path`: administrator uploads a raw chunk
  with `X-Upload-Offset`, `X-Upload-Length` and `X-Content-SHA256` headers.
- `POST /api/game-files/:id/upload/complete`: administrator starts asynchronous
  verification/publication; poll the upload endpoint for completion.
- `/api/agent/libraries/...`: authenticated game-file downloads. Legacy
  `/api/agent/imports/...` endpoints remain compatible with already queued imports.

The operation envelope is independent of polling and can be carried over a
persistent transport later. No unrestricted shell operation is available.

## Safety and durable operations

Each remote request has an immutable ID and payload, plus an instance UUID and
generation where applicable. Reusing a key with a different request is rejected.
The controller records remote IDs before dispatch. The agent persists accepted,
running, completed, failed and unknown states in SQLite. Lost acknowledgments
return the recorded result; restarting the controller never creates a new
mutation simply because the previous reply was lost.

The agent reconciles ambiguous results using owned Docker labels, generations and
persisted execution checkpoints when those observations prove the outcome.
Otherwise the result remains **Unknown** and holds dependent work. Running alone
is insufficient evidence that a particular restart happened. EC neither assumes
an unreachable server stopped nor launches a duplicate replacement elsewhere.

Campaign bytes are staged and verified while players remain connected. Only
Provisioning can dispatch activation. It checks source eligibility and shared
capacity, and the agent repeats a fresh local RCON occupancy check immediately
before activation/restart, stop, removal or rebuild. Busy or unverifiable lobbies
wait indefinitely, including multi-hour Zombies sessions. Before images returned
by the agent populate existing campaign/beta rollback history. A beta cannot be
closed while its remote activation receipt is still unresolved.

Rebuild uses a new generation, fresh instance storage and the latest promoted
configuration/scripts/plugins. It retains the selected game-file version and
runtime image. Old generation commands cannot target the replacement. Start,
restart and create complete only after post-operation health evidence; creation
and rebuild also verify the selected map and running Plutonium revision. The
base-game library and runtime revision are independent records.

**Drain** blocks new deployments and queues safe retirement of existing lobbies.
Active beta ownership and other operations continue to gate retirement. Players
may still join until an eligible empty moment; draining does not kick them.
**Disable** holds agent dispatch. Neither mode, controller downtime nor agent
communication loss stops unrelated running containers.

Administrators can choose **Delete host** on a host card or at the top of its
detail page. The confirmation lists anything that must be resolved first:
registered servers, reserved ports, or operations already sent to the agent.
Drain the host or remove its servers, then let outstanding operations reconcile.
An unused host can be deleted before enrollment or while offline.

Deleting a host removes it from the controller's host list and deployment
choices, revokes its credentials, and invalidates unused installer links.
Queued commands that have never been sent to the agent are cancelled. Operation
history and published libraries are retained; the agent and game files remain on
the machine. Adding the machine again requires a new host enrollment.

## Libraries and ports

Choose the actual game folder, not its parent, a ZIP archive or the Plutonium
launcher data folder. The selected folder's name is removed once; nested paths
such as `zone/english/...` and `main/...` stay intact. Plutonium's
[T5 server guide](https://plutonium.pw/docs/server/t5/setting-up-a-server/) and
[T6 server guide](https://plutonium.pw/docs/server/t6/setting-up-a-server/) use a
copy of the game directory, separately from the launcher/runtime. The uploader
preserves the supplied files rather than attempting to infer installed maps from
a manually maintained DLC list.

Folder uploads use chunks of at most 8 MiB, each checked against its SHA-256 before
being appended to temporary controller storage. Memory usage does not grow with
the size of an individual game file. Pause/retry uses the controller's saved file
offsets. After a page reload, choose **Resume upload** and reselect the original,
unchanged folder; relative paths, sizes and modification times must match. Keep
the page open while transferring. Once publication starts, the controller hashes
every complete file and publishes the directory atomically; closing the browser
does not stop that verification. An interrupted controller can retry publication.
Published versions cannot be updated;
changing files requires a new version. Hosts download with HTTP Range resumption,
report progress, verify all checksums and atomically promote the complete cache.
Corrupt or incomplete content never becomes Ready. Cache inventory is reconciled
on heartbeats, including vanished caches. Older immutable versions remain usable
when their exact manifest is verified.

The controller and reverse proxy must accept 8 MiB upload requests and folder
manifests up to 32 MiB. Compose sets `BODY_SIZE_LIMIT=Infinity`; application routes
still enforce these limits, declared file sizes and checksums. Set a proxy body
limit of at least 32 MiB (for example `client_max_body_size 32m` in nginx).
Existing published versions and cached host libraries remain usable after the
upload workflow replaces source-host imports.

Reservations include host ID, local bind address, protocol and port. Wildcard
binds conflict with concrete addresses on the same host. UDP and TCP reservations
for one launch commit together; the same number can be used independently on
another host. Optional public/NAT address and port are recorded separately and do
not change local Docker bindings. EC does not configure external NAT/firewalls.

## Development and validation

```sh
npm run agent:package
npm run check
npm test
npm run test:agent
npm run build
```

The build packages `agent/ec_agent.py` and `agent/install.sh` into the static
release, generates its checksum manifest and serves those same assets in the
Node-adapter image. The Python agent uses only its standard library.

Automated tests cover enrollment/authentication, rotation/revocation, host
readiness, scoped ports, immutable library publication, streaming/ranges,
checksums, interrupted downloads, instance generation ownership, local occupancy
holds, controller restart/reconnect, ambiguous results, occupied campaign staging,
activation before images, collections and draining. Docker/UDP and host
observations are simulated in these tests.

A real Debian/Docker/Plutonium acceptance run is still required before production
rollout. This workspace has no Docker engine or Debian game host, so automated
coverage is not evidence that a real T5/T6 server has been deployed here. Run:

- Installer on Debian 12 and 13 amd64, then rerun without changing identity/data.
- T5 and T6 deployments and a mixed collection from a fresh destination host.
- Start, stop, restart, rebuild, destroy; verify RCON, map and runtime revision.
- Read console and game logs, including Plutainer's relative game-log links.
- File campaign and rollback, with a player joining between controller check and
  agent activation, and during file activation before restart; verify that the
  agent holds disruption.
- Drain occupied lobbies and verify shared libraries survive their retirement.
- Corrupt/interrupted library downloads, resumed transfer and verified promotion.
- Controller restart, agent restart and network loss before execution, during
  execution and after execution but before acknowledgement. Verify the same
  operation IDs and absence of duplicate containers/restarts.

Legacy backend code remains for existing database registrations. New native
launches do not require its configuration, API, network or mounted directories.