# Accounts and the portal

Fluksio is self-hosted by default. An instance runs offline, keeps its data
on its own disk, and never contacts anything unless you tell it to.

The **portal** is optional, and it exists to solve two specific problems:

1. **Your machine has no inbound route.** A homelab behind CGNAT, a cluster
   node with no open ports, a laptop. Opening one is work, and often not
   allowed.
2. **You want a browser on it anyway.** A `pip install fluksio` instance
   has no web server for the dashboard at all.

An enrolled instance dials *out* to the portal and holds one websocket
open. The portal serves the dashboard from its own side, and only the API calls
travel down the tunnel, so the interface loads at portal speed and your
machine stays unreachable from the internet.

## Enrolling

Two halves: whoever performs the second step decides what the instance's owner
gets.

**On the portal** (`hub.${DOMAIN}`, or [fluksio.com](https://fluksio.com) for
the hosted one): **Instances → Add instance**, give it a name, and copy
the code.

**On the instance**, either from the dashboard:

> **Settings → Remote access**, enter the portal URL and the code, press
> **Connect**.

or from the command line, which is the path for an instance with no web
interface of its own:

```sh
fluksio enroll ABCD-1234 --portal https://hub.fluksio.com
```

The code is single-use and expires in fifteen minutes. A fresh code on an
instance that is already paired replaces the pairing, so moving an instance to
another portal is one command rather than a disconnect and a reconnect.

A portal session then arrives as *that local account*, which the settings screen
states plainly. Use `--as someone@example.com` to enrol as a specific local
account when the instance has several superusers.

Once enrolled, the instance appears under **Instances** with its
status, when it was last seen and its version. **Open** takes you to its
dashboard at `${DOMAIN}/i/{instance-id}`.

## What the portal can and cannot do

The portal holds one credential for your instance and proxies requests down
the tunnel. What those requests may do is decided **on the instance**, by
the same checks a local session passes.

The trust anchor is a signing keypair on the portal. Every instance pins
its public half at enrolment and rejects anything else, which is what stops a
hijacked DNS entry or a mis-issued certificate from impersonating the portal.

## Letting someone else in

Anyone else on the portal reaches your instance only if a superuser there
admits them, and they arrive as a local user of their own rather than as you.

1. **They**: **Instances → Join an instance**, and copy the code. It is
   bound to their portal account and expires in fifteen minutes.
2. **You**, on the instance: **Settings → Remote access → Add remote
   user**, and enter the code.
3. They now see the instance under **Instances**, marked *Shared by*,
   with **Open** and nothing else. Renaming, re-keying and removing stay with
   you.

The instance redeems that code against the portal using its own credential.
A portal session cannot do this, which is what stops somebody you let in from
letting others in.

On the instance they appear under **Admin → Users**, badged *Portal*, never
a superuser and with no password.

## Cutting it off

| From | Action | Effect |
|---|---|---|
| The portal | **New code** | rotates the credential and drops the current link |
| The portal | **Remove** | deletes the registration and cuts the connection |
| The instance | **Disconnect** | unilateral and immediate — the portal's tokens stop verifying here whatever the portal still has on file |
| The instance | delete a user under **Admin → Users** | that one person, immediately, independent of the portal |

**New code** also cuts every credential the portal minted for this instance,
including [wall panels paired through it](dashboards.md#a-screen-somewhere-you-cannot-reach).

The instance's own **Disconnect** is the one to reach for if you are ever
unsure: it does not need the portal's cooperation.

## Running your own portal

The portal is the `index` stack's `hub` service: accounts, the registry of
connected instances, and the websocket each one dials in on. Two things
about it are load-bearing:

- **It runs a single process.** It keeps its attached instances in the
  memory of the process holding their sockets, so a second worker would answer
  for links it does not hold. Scaling out needs a routing layer first.
- **Back up the signing keypair with the database.** Replacing it forces every
  instance to be enrolled again.

Websocket upgrades must be enabled on the `hub` hostname in whatever proxy
fronts it. Without them every instance sits in a reconnect loop and the
portal shows them all offline.

## See also

- [The `fluksio` command](../code/cli.md) — `fluksio enroll`, and what it writes
- [Dashboards and panels](dashboards.md) — pairing a wall screen through the portal
- [Getting started: data science](../getting-started/data-science.md) — the
  shortest path from a pip install to a browser