Network Computing Hub

One place to keep your remote connections, launched with whatever client you already use, with credentials in the OS keyring instead of a text file.

The command is rcm.

It is a manager and launcher, not a protocol implementation. Sessions are opened by external programs you configure — Thincast, mstsc, xfreerdp, Remmina, TigerVNC, Radmin Viewer, AnyDesk, anything with a command line — so you keep the clients you like and get grouping, batch import, live session tracking and global shortcuts on top.

Protocols are configurable RDP, VNC and Radmin ship as three sections in protocols.conf; adding a fourth needs no changes to the program. A protocol defines its own button label and colour, its commands, how a live session is recognised, and — if the client does not provide a credentials management, automate the insertion on a password prompt via keystrokes.

• Any protocol you can launch, defined in config: label, colour, commands, session detection, and optional credential typing.
• Connections in one tree, grouped, defined by ordinary .rdp files
• Credentials in the OS keyring (libsecret / GNOME Keyring), never on disk, with a precedence chain from per-connection down to a global default, and per-protocol entries for the same host.
• Any client you have installed, per protocol, configured as command lines with placeholders
• Live session list — see what is connected, focus it, disconnect it
• System-wide shortcuts and an Alt-Tab-style switcher across active sessions
• Batch CSV import/export, .rdp, and an experimental Radmin phonebook export
• Tick connections to queue them up for the Connect buttons; right-click any selection to export it as .rdp files, a CSV, or a Radmin phonebook

Linux/X11 (developed on Cinnamon). A Windows port is planned — see Roadmap.

---

Install

Requirements: Python 3.11+, PyGObject (GTK 3) and xdotool. Plus whichever clients you want it to launch — none are required to install.

sudo apt install python3-gi gir1.2-gtk-3.0 xdotool

git clone https://github.com/thebdr/network-computing-hub.git ~/network-computing-hub
cd ~/network-computing-hub
./bin/rcm init          # writes protocols.conf, creds.conf, shortcuts.conf
./bin/rcm install-icon  # app icon into ~/.local/share/icons
mkdir -p ~/bin && ln -s ~/network-computing-hub/bin/rcm ~/bin/rcm

Open the manager once (rcm gui) and it will create any missing config for you.

Quick start

rcm init                       # create config files
rcm detect radmin --write      # find Radmin, if you use it
rcm import hosts.csv           # or add connections in the GUI
rcm gui                        # the manager

CSV columns are group,name,host,username,port, plus port_<protocol>, protocols, default_protocol and shortcut — only name and host are required. A full export writes all of them, so exporting and re-importing round-trips a connection unchanged. Imported connections are generated from templates/default.rdp, so whatever you set there is inherited by every host.

How connections are stored

RDP/<Group>/<Name>.rdp — ordinary RDP files, which are also the single source of truth for host and username. Groups nest as deeply as you like: put a connection in RDP/Plant/Line2/Cells/ and the tree follows the folders. Ticking or selecting a group takes everything beneath it, at any depth. Two extra keys are ours; clients ignore keys they do not recognise:

rcm-protocols:s:rdp,vnc,radmin
rcm-default-proto:s:rdp
rcm-port-vnc:i:5900

rcm-default-proto is what a double-click and that connection's shortcut use; it is underlined in the Protocols column. Set it in the connection's Edit dialog.

rcm-port-<protocol> overrides that protocol's default port for one host, so a new protocol needs no code change. RDP keeps using the file's own server port.

Rename a group folder with a leading dot (Plant → .Plant) and it disappears from every menu, list and export.

Configuration

Everything is a plain file you can edit by hand; the GUI is a convenience over the same files, never the only way in. Nothing is guessed in code — if a value is missing or wrong, the app says which file and which key, instead of silently falling back to something that happened to work on the author's machine.

File	What
protocols.conf	the protocols: buttons, commands, detection, credential typing
creds.conf	scope → username. No passwords — those are in the keyring
shortcuts.conf	system-wide keys

Protocols

Each [protocol:<id>] section is one way of reaching a machine:

[protocol:rdp]
label = RDP
color = accent                  ; or #rrggbb for the button colour
order = 10
port  = 3389
default = Thincast
launcher.Thincast = flatpak run com.thincast.client {file}
launcher.xfreerdp = xfreerdp3 /v:{host}:{port} /u:{user} +clipboard
detect.process = (^|/)(rdc|xfreerdp3?|mstsc)\b

Placeholders are substituted per argument, so paths with spaces stay one argument: {host} {port} {user} {password} {name} {file} {exe}. The buttons use default; right-click a connection for the others. Edit it all in the GUI under Protocols…, which also writes new protocols for you.

exe is optional and available to commands as {exe}; env.NAME = value sets environment for the launch. Together they cover a program that has to run through a wrapper — Radmin under Wine is just:

[protocol:radmin]
exe = /path/to/Radmin.exe
env.WINEPREFIX = ~/.local/share/wineprefixes/Radmin
launcher.Wine = wine-stable {exe} /connect:{host}:{port}
launcher.Native = {exe} /connect:{host}:{port}

rcm detect radmin ranks the installs it can find; --write records the best one.

Typing credentials into a prompt

Some clients refuse to take a password on the command line — Radmin has no /password: switch because Famatech deliberately prevent saving passwords on the Viewer machine. For those, describe the prompt and the keystrokes:

inject.window_class = [Rr]admin      ; X11 class of the prompt
inject.window_title = security       ; substring of its title
inject.wait   = 20                   ; seconds to wait for it
inject.settle = 0.3                  ; pause after focusing, before typing
inject.delay  = 40                   ; ms between keystrokes
inject.steps  = type:{user} | key:Tab | type:{password} | key:Return

Steps are type:<text>, key:<keysym>, sleep:<seconds>, activate and clear. {password} is read from the keyring at the moment it is typed and never written to disk. rcm calibrate <connection> [protocol] opens the prompt, reports exactly what it is, saves a screenshot of it, and types nothing — use it when writing the steps.

Hooks and via-gateways

Every connection can carry a pre and post command (Edit ▸ Hooks & gateway, stored as rcm-pre / rcm-post in its file). pre runs first and must exit 0 or the launch stops — mount a share, bring up a VPN, check a precondition; post fires after the client starts. Both get the launcher placeholders.

A host that is only reachable through a bastion points at a gateway instead:

[via:plant-gw]         ; in protocols.conf
host = gw.example.local
user = maint
; port = 22            ; the gateway's SSH port
; hold = 30            ; seconds the tunnel waits for the client to attach

Pick it in Edit ▸ Hooks & gateway (stored as rcm-via). Connecting then opens ssh -f -L <free port>:<host>:<port> through the gateway and hands the launcher 127.0.0.1:<free port> in {host}/{port} — any protocol, no client support needed. The tunnel wants key auth to the gateway (it runs BatchMode, so it fails loudly instead of sitting on an invisible prompt) and lives exactly as long as the client's connection. The pre hook still sees the real {host}: it runs before the tunnel opens. A dangling rcm-via shows up in config health.

Credentials

Passwords live in the login keyring. creds.conf holds only key|username|. Lookup is most-specific-first, and within a scope a protocol-specific entry beats the generic one:

Group/Host@radmin → Group/Host → Group@radmin → Group → DEFAULT@radmin → DEFAULT

Nested groups add a rung per level, so a password set on Plant covers everything under it unless something deeper overrides:

Plant/Line2/Cells/Cell A → Plant/Line2/Cells → Plant/Line2 → Plant → DEFAULT

rcm creds list          # where each password lives, never the value
rcm creds set Group     # prompts without echo
rcm creds migrate       # move leftover plaintext into the keyring

Selecting and exporting

Two independent mechanisms, on purpose:

• Tick boxes choose what the Connect buttons act on. Ticking a group ticks all of its members, and the tickbox in the column header ticks every visible row — ✓ when all are ticked, – when only some are — so filtering first and then ticking the header selects a whole group, tag or search result. (With nothing ticked the buttons fall back to the highlighted rows.)
• Ctrl/Shift selection chooses what the right-click menu acts on — connect with a specific program, edit, delete, or Export ▸ the selection as .rdp files, a re-importable CSV, or a Radmin phonebook. A selected group means all of it.

Ctrl+C / Ctrl+V copy connections and whole groups (subtree included) and paste them inside whichever group you are in — the sidebar selection, else the highlighted row's group, else the top level. That one rule holds whatever is on the clipboard and wherever you paste it, including a group pasted into itself (staged through a temporary copy so it cannot walk into what it is writing). A pasted copy is a byte copy of the .rdp, so tags, hooks, gateway and per-protocol ports come along; names never collide, since an existing name becomes <name> (copy), then (copy 2). Passwords are deliberately not copied: the keyring entry belongs to the original's name, so the copy inherits from its group chain until you give it one of its own.

Key	Action
Ctrl+C / Ctrl+V	copy the selection · paste inside the current group
Ctrl+D	duplicate the selection beside itself
Ctrl+E	edit the highlighted connection
Delete	delete the selection (also on a sidebar group)

Right-clicking a group in the Browse sidebar copies, pastes into, renames or deletes that whole group; groups fold away with their expander in the sidebar, the list and the icon view, and stay folded until you open them again (a filter match opens what it matched).

Renaming without a dialog: click a selected row's Connection, Host or User cell a second time and type — the slow double-click every file manager uses. On a group heading row the Connection cell renames the group, which moves the folder with everything in it.

The manager

The window has three layouts (the Layout button, saved as layout = in ui.conf): Browse — the everyday view: a filter-first flat list with match highlighting, a collapsible group sidebar (the ⊞ button), Live and per-protocol filter chips, and live sessions appearing as a strip of one-line cards only while any exist — each with 👁 to focus it and an unplugged-cable button to disconnect. Browse also has an icon view (the grid button, saved as browse_view in ui.conf): every connection as a machine with its protocol chips across its screen — wrapping, spilling past the case when there are many, the default underlined — grouped under the same headings and tickboxes as the list, with a details pane beside the grid carrying the full record of whatever is selected. A single click selects; double-click a chip to connect over that protocol, or the tile for its default; Inspector — a read-only audit showing where every connection's password comes from and whether its protocols are healthy; Classic — the original window. (Earlier builds shipped Browse's variants as separate Rail/Spotlight/Cockpit modes; they were one layout differing in toggles, so now they are toggles — old layout = values migrate.) Pinned filter tabs (Ctrl+T) sit under the headerbar and are shared by every layout. Configuration problems never block the window: they surface in the status bar, on the Setup badge, and per-row.

The hamburger menu is gone — Setup (sidebar footer, or the Layout menu) carries Protocols, Credentials, Keyboard shortcuts and Import/Export as cards over the same plain files. With zero connections the window opens as a first-run checklist.

Pinned filter tabs belong to the connection list, so they appear with it and step aside on Setup, Logs and the first-run checklist.

F1 opens the Help window anywhere: the guide is generated from the source docstrings that implement each behaviour, and every topic ends with an Open-code link to that file and line.

The Net column probes reachability (one TCP connect at a time, visible rows first, paused while hidden — cheap even at hundreds of hosts); offline rows with a learned MAC offer ⚡ Wake (rcm wake <sel>). Right-click also gives Open terminal (embedded VTE tabs when the library is present, each in its own scroller so the prompt never scrolls out of reach — right-click the tab to pop that terminal into its own window, or right-click inside it for Send script — it types a file from scripts/ into the live session with the placeholders substituted, {password} deliberately never), Run script across the selection — SSH when port 22 answers, PowerShell over WinRM otherwise, live per-host verdicts in the dialog, output captured per run — and History. Everything notable — launches, scripts, probes, wakes, tunnels — is one JSONL line under logs/; the Logs page (▤ in the sidebar, or the Layout menu) filters it by kind, text and range back to 90 days, shows each event with its captured output, and exports the filtered view as CSV. History is the same page pre-filtered to one connection. Tags (rcm-tags, edited in the Edit dialog) are free labels orthogonal to groups: they appear as #chips with counts under TAGS in the Browse sidebar — click one to filter — and match in the filter box. Workspaces (workspaces.conf, rcm workspace <name>) open named sets together, focusing members that are already live; they sit under WORKSPACES in the same sidebar (click shows the members, double-click connects them all), a member with a monitor number gets its window moved there once it appears, and workspace:<name> = <combo> under [sessions] in shortcuts.conf binds a key to the whole set. Build them with right-click ▸ Save as workspace… on a selection, then shape members, launch order (drag), monitors and the shortcut under Setup ▸ Workspaces.

Keyboard shortcuts

Set a connection's shortcut in its Edit dialog; the general keys live under Keyboard shortcuts…. Defaults:

Key	Action
Super+R	raise the manager
Super+W / Super+Q	switcher: hold Super, tap to move, release to switch
Super+Alt+1…	jump to a connection — focus if live, connect if not

The switcher grid shows live sessions as solid cards and every shortcut-bound connection that is not running as a dashed one. W and Q cycle live sessions only — switching means switching — while a dashed card is a launcher you click. Clicking any card commits it immediately; clicking the backdrop cancels. With nothing running, nothing is selected, so releasing Super closes the grid instead of connecting something you did not pick.

Escape and Enter work only when the switcher can take the keyboard, which it cannot while Super is held: Cinnamon owns a keyboard grab for its own binding for the whole hold, so the popup gets the pointer instead and says so in its footer. That is also why W and Q keep working — each repeat re-fires the Cinnamon binding, which signals the running switcher.

rcm shortcuts list|install|remove

They are stored as Cinnamon custom keybindings with ids prefixed rcm-; remove touches only those.

Command line

rcm init | list | sessions | gui | focus | next | prev | goto <sel>
rcm connect <sel> [--<protocol>] [--via <launcher>]
rcm connect-all <group>
rcm protocols | detect <protocol> [--write] | creds ... | shortcuts ...
rcm import <csv> [--overwrite] [--dry-run] | export [csv] | phonebook [out.rpb]
rcm calibrate <sel> [protocol] | gen-launcher | install-icon

Notes from building this

Things that cost real time, kept here so they cost you less:

• xdotool type --window does not work with Wine. That flag uses XSendEvent, which Wine ignores outright — the dialog never fills and nothing errors. Always xdotool windowactivate --sync first, then type to the focused window via XTEST.
• An Alt-Tab-style popup cannot grab the keyboard under Cinnamon. While the modifier is held the WM already holds the grab, so Gdk.Seat.grab returns GDK_GRAB_ALREADY_GRABBED and the popup receives no keys at all. The repeat press reaches the WM, which launches the command again — so the second process signals the running popup (SIGUSR1/SIGUSR2) rather than exiting. Modifier release is detected by polling X, which needs no grab.
• On X11 the Super key sets MOD4, and GDK's virtual SUPER_MASK never appears in the raw mask from get_device_position. Watching only SUPER_MASK means you never see Super held.
• Connection names may contain spaces. Unquoted .desktop Exec= arguments split in two — and desktop-file-validate does not flag it — and a (\S+\.rdp) regex over ps output captures only 1.rdp. Quote Exec arguments; match sessions by full-path substring.
• An empty Actions=; in a .desktop file is a validation error, so omit the key entirely when there is nothing to list.
• In bash, ${var:-MASK} prints the value when set. It is a fallback, not a mask. Using it to redact a password prints the password.
• pkill -f <pattern> matches its own shell's command line. When cleaning up test processes that share a pattern with real sessions, discriminate on readlink /proc/<pid>/exe instead.
• Wayland breaks the Radmin injection silently; ydotool is the fallback.

The Radmin phonebook format

rcm phonebook writes a .rpb Radmin Viewer can open, and never touches your real one. The format was reverse-engineered: a 153-byte header (record count at 0x00, record stride at 0x0c), then fixed-size 6138-byte records that are ~99% zero padding, with UTF-16LE strings at fixed offsets — host 4904, name 5104, user 5908. Folder records instead pack a literal folder marker straight after the name's terminator, so it moves with the name length. Verified by rebuilding an existing phonebook from its own records byte-for-byte.

Known limits: folder membership is not reconstructed, so exported hosts may land at the tree root; and since the format has no nested folders, a sub-group becomes a folder named with its full path (Plant/Line2). Names, hosts and usernames are correct.

Roadmap

• Windows support, in phases. Done: the platform seam — every OS call lives in bin/rcm_platform.py (LinuxX11 is the reference behaviour; WindowsNative really implements detached spawn, process listing, ARP lookup, opening files and credentials via the keyring package, and raises a clear PlatformError for window control, monitor placement, credential typing and system shortcuts). Still to come: the tray agent owning RegisterHotKey and window management (Windows has no per-command keybinding registry, and Win+W/Win+Q are shell-reserved), then PyInstaller bundling GTK. Nothing of the Windows class has met a real Windows machine yet — its parsers are tested against fixtures.
• VNC is implemented but has not been exercised against a real server
• The WinRM script transport is exercised against a stub in tests, not yet against a real Windows host; same for via-gateways and a real bastion

Icon

assets/ holds the icon in two variants: the detailed one, and a simplified one for 16–32px where the screen shapes and their highlights turn to mush. rcm install-icon puts the SVG in hicolor/scalable/apps and renders PNGs for each size, picking the right variant per size. rcm gen-launcher installs it automatically if it is missing, since the .desktop it writes references the icon by name.

License

MIT — see LICENSE.