Ship binaries, systemd units, and install docs

- Allow committing compiled server/client binaries; add systemd units
  (tunnel-client.service, tunnel-server.service) and env examples.
- README: install from git.nixc.us HTTPS raw (curl binary + unit from
  raw/branch/main); document multiple tunnels (one unit/env per tunnel).
- Keys: do not recycle host or shared keys; use a dedicated ed25519 per
  tunnel/host; central server must have that public key in authorized_keys.

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitignore

@@ -1,9 +1,3 @@
-# Binaries (root level only)
-/tunnel-server
-/tunnel-client
-/server
-/client
-
 # Keys (never commit secrets)
 keys/
 

README.md

@@ -151,7 +151,7 @@ http:
 ## Building
 
 ```bash
-# Build both binaries locally
+# Build both binaries locally (commit and push these for remote deployment)
 go build -o tunnel-server ./cmd/server/
 go build -o tunnel-client ./cmd/client/
 
@@ -160,6 +160,74 @@ docker compose build                                # server image
 docker build --target client -t tunnel-client .     # client image
 ```
 
+## Binaries and systemd (bare metal)
+
+The repo ships compiled `tunnel-server` and `tunnel-client` for remote hosts that run without Docker. Use the included systemd units under `systemd/`.
+
+**Keys:** Do not reuse the host’s SSH keys or share one key between hosts or tunnels. Generate a dedicated ed25519 key per tunnel (or per host). The **central tunnel server** must have that key’s **public** half in its `authorized_keys` so the client can connect.
+
+**Multiple tunnels:** Run one systemd instance per tunnel (different env file and optional unit name), e.g. `tunnel-client@app1.service` and `tunnel-client@app2.service` each with their own env and key.
+
+### Install from git.nixc.us (HTTPS raw)
+
+From a host with curl, install the binary and systemd unit directly from the repo (replace `main` with your branch if needed):
+
+```bash
+REPO=https://git.nixc.us/colin/better-argo-tunnels/raw/branch/main
+sudo curl -o /usr/local/bin/tunnel-client -L "$REPO/client"
+sudo chmod +x /usr/local/bin/tunnel-client
+sudo curl -o /etc/systemd/system/tunnel-client.service -L "$REPO/systemd/tunnel-client.service"
+```
+
+Then add a dedicated key for this tunnel, env file, and authorize on the server:
+
+```bash
+sudo mkdir -p /etc/tunnel-client
+sudo ssh-keygen -t ed25519 -f /etc/tunnel-client/id_ed25519 -N ""
+# Add the public key to the central server's authorized_keys:
+sudo cat /etc/tunnel-client/id_ed25519.pub
+# (On the central server: append that line to authorized_keys)
+sudo cp systemd/tunnel-client.env.example /etc/tunnel-client.env   # or curl from $REPO/systemd/tunnel-client.env.example
+sudo edit /etc/tunnel-client.env   # set TUNNEL_SERVER, TUNNEL_DOMAIN, TUNNEL_KEY=/etc/tunnel-client/id_ed25519
+sudo systemctl daemon-reload && sudo systemctl enable --now tunnel-client
+```
+
+### Client on a remote host (clone or copy)
+
+1. Install the binary (from repo clone or raw URL above; repo has `client`/`server`):
+
+   ```bash
+   sudo cp client /usr/local/bin/tunnel-client && sudo chmod +x /usr/local/bin/tunnel-client
+   ```
+
+2. Copy the systemd unit and create env file:
+
+   ```bash
+   sudo cp systemd/tunnel-client.service /etc/systemd/system/
+   sudo cp systemd/tunnel-client.env.example /etc/tunnel-client.env
+   sudo edit /etc/tunnel-client.env   # set TUNNEL_SERVER, TUNNEL_DOMAIN, TUNNEL_KEY
+   ```
+
+3. Use a **dedicated** ed25519 key for this tunnel (not the host’s keys). Put the private key on the host (e.g. `/etc/tunnel-client/id_ed25519`) and set `TUNNEL_KEY` in env. Ensure the **central server** has the matching **public** key in its `authorized_keys`.
+
+4. Enable and start:
+
+   ```bash
+   sudo systemctl daemon-reload
+   sudo systemctl enable --now tunnel-client
+   sudo journalctl -u tunnel-client -f
+   ```
+
+For a second tunnel on the same host, use a separate env and key (e.g. `/etc/tunnel-client-app2.env`, `/etc/tunnel-client/app2_id_ed25519`) and a second unit (e.g. copy to `tunnel-client-app2.service` with `EnvironmentFile=/etc/tunnel-client-app2.env`).
+
+### Server (optional, bare metal)
+
+If you run the tunnel server without Docker:
+
+1. Install binary and keys under e.g. `/etc/tunnel-server/` (host_key, authorized_keys, traefik_deploy_key).
+2. Copy `systemd/tunnel-server.service` to `/etc/systemd/system/` and `systemd/tunnel-server.env.example` to `/etc/tunnel-server.env`. Set `TRAEFIK_SSH_HOST`, `TRAEFIK_SSH_KEY`, and paths to keys.
+3. `systemctl enable --now tunnel-server`.
+
 ## Security Notes
 
 - Only clients whose public keys are in `authorized_keys` can connect

systemd/tunnel-client.env.example

@@ -0,0 +1,10 @@
+# Copy to /etc/tunnel-client.env and set values.
+# Required:
+TUNNEL_SERVER=ingress.example.com:2222
+TUNNEL_DOMAIN=myapp.example.com
+TUNNEL_KEY=/etc/tunnel-client/id_ed25519
+
+# Optional (defaults shown):
+# TUNNEL_PORT=8080
+# TUNNEL_AUTH_USER=
+# TUNNEL_AUTH_PASS=

systemd/tunnel-client.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=Reverse SSH tunnel client for Traefik
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+# Load env from same directory as this unit, or override with drop-in
+EnvironmentFile=-/etc/tunnel-client.env
+ExecStart=/usr/local/bin/tunnel-client
+Restart=always
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target

systemd/tunnel-server.env.example

@@ -0,0 +1,15 @@
+# Copy to /etc/tunnel-server.env and set values.
+# Required:
+TRAEFIK_SSH_HOST=ingress.example.com
+TRAEFIK_SSH_KEY=/etc/tunnel-server/traefik_deploy_key
+
+# Optional (defaults shown):
+# SSH_PORT=2222
+# SSH_HOST_KEY=/etc/tunnel-server/host_key
+# AUTHORIZED_KEYS=/etc/tunnel-server/authorized_keys
+# PORT_RANGE_START=10000
+# PORT_RANGE_END=10100
+# TRAEFIK_SSH_USER=root
+# SWARM_SERVICE_NAME=better-argo-tunnels_tunnel-server
+# TRAEFIK_ENTRYPOINT=websecure
+# TRAEFIK_CERT_RESOLVER=letsencryptresolver

systemd/tunnel-server.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=Reverse SSH tunnel server for Traefik
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+EnvironmentFile=-/etc/tunnel-server.env
+ExecStart=/usr/local/bin/tunnel-server
+Restart=always
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target