Home Manager separates an installation from a daemon. This module put
both under `services.hermes-agent`, and `installPackage` added a program
to the PATH from a service module.
`programs.hermes-agent` now installs the command line application and
the desktop application. `services.hermes-agent` keeps the state, the
configuration and the daemons, and stays the authority: the new module
reads `hermesHome` and the backend address from it. A person can enable
one without the other, which is a machine with an application and no
gateway, or a headless gateway with no display.
The desktop application needs this split to work correctly. A launcher
that starts from the desktop menu reads no shell profile, thus the
HERMES_HOME that `home.sessionVariables` exports reaches an interactive
shell only. Home Manager writes `systemd.user.sessionVariables` to
environment.d, and this module puts no HERMES_HOME there, because that
file applies to each user unit. The application then opens ~/.hermes
while the services use `hermesHome`, and the person sees no sessions and
no keys. Thus the launcher carries the value itself, through a new
`extraEnv` argument on the desktop package.
The application also gets the Nix agent package, with
HERMES_DESKTOP_HERMES. The usual distribution of the Electron
application carries its own Hermes runtime and downloads more at the
first start. `hermesDesktop` is a passthru of the agent and pins
`finalAttrs.finalPackage`, so an override of `extraPythonPackages` or
`extraDependencyGroups` reaches both. One machine thus has one runtime.
`backend.sessionTokenFile` connects the application to the backend of
the service. Without it the module runs `hermes serve` and the
application starts a backend of its own, which gives two backends on one
HERMES_HOME. The backend reads the file into
HERMES_DASHBOARD_SESSION_TOKEN. The launcher reads the same file into
HERMES_DESKTOP_REMOTE_TOKEN, beside a HERMES_DESKTOP_REMOTE_URL that
names the address of the service.
Measurements against a live `hermes serve` on loopback show why that
shape is the correct one:
- `_resolve_session_token()` reads HERMES_DASHBOARD_SESSION_TOKEN, and
`_has_valid_session_token` accepts that value as a Bearer credential.
A request without it gets 401, and a request with the wrong value
gets 401.
- The /api/ws socket accepts a query parameter only. A header gets 403,
and `?token=` connects. Hermes Desktop builds exactly that URL, in
`apps/desktop/electron/connection-config.ts`. Thus a test of the HTTP
leg alone is a false positive.
- `resolveDesktopRemoteRoute` throws when the URL is set and the token
is not. Thus the two variables travel together or not at all.
The token enters no Nix store path. `makeWrapper --set` and a systemd
`Environment=` value both write a literal into the store, which all
users can read. Thus each side reads the file at start time. The
launcher does it through a new `extraRun` argument on the desktop
package, and the backend through the launcher script that
`backend.waitFor` already uses. launchd has no EnvironmentFile, so a
script is the one shape that works on Linux and on Darwin.
`backendArgv` gives the plain argv only when nothing must run before
the backend.
`services.hermes-agent.installPackage` is removed. It defaulted to true,
so a person who never named it still got the command line. A silent
removal thus gives them a machine with no `hermes` and no message. The
module refuses a configuration that sets it, and the text names the
exact replacement for the value they gave.
Checks:
- the launcher carries HERMES_HOME
- the launcher reports HERMES_MANAGED only when the services own the
configuration, because no activation writes a marker without them
- the launcher pins the agent package that `programs.enable` installs
- the launcher names the backend of the service, and gives a token
beside the URL
- the backend reads the session token
- each side reads the file at start time, and the token is no `--set`
value
- `programs.enable` alone starts no service
- `installPackage` is refused, with a message that names the
replacement, and its absence evaluates
Each check reads the wrapper of the real package, and not an option
value. Each one was tested with a mutation that breaks the behavior it
asserts.
76f6ba3706