docker: optional Cloudflare tunnel for JupyterLab (UNSLOTH_JUPYTER_CLOUDFLARE)

Mirror the public-link convenience Studio already has for its own UI, for
JupyterLab. Off by default; opt in two ways:

  docker run -e UNSLOTH_JUPYTER_CLOUDFLARE=1 ... unsloth/unsloth
  docker exec <container> unsloth-jupyter-tunnel --force

unsloth-jupyter-tunnel waits for JupyterLab, reuses a cached cloudflared (or
fetches the static binary for the arch, no account needed), and starts a
quick tunnel to the Jupyter port; the https://<name>.trycloudflare.com URL is
printed to docker logs. supervisord runs it as the jupyter-cloudflare program,
autostarted only when UNSLOTH_JUPYTER_CLOUDFLARE=1 (studio_launch.sh exports a
0 default so the autostart gate expands, matching the sshd pattern). JupyterLab
still enforces its password, so the tunnel is not an open door.

Verified: the helper fetches cloudflared and mints a working trycloudflare URL
that reaches JupyterLab (HTTP 200) inside a running container.

docker/.dockerignore

@@ -7,6 +7,7 @@
 !studio_launch.sh
 !unsloth_studio_update.sh
 !unsloth_llama_update.sh
+!unsloth_jupyter_tunnel.sh
 !unsloth_nb_compat.py
 !unsloth_pip_shim.py
 !unsloth_ipython_startup.py

docker/Dockerfile.studio

@@ -167,9 +167,13 @@ COPY unsloth_llama_update.sh /usr/local/bin/unsloth-llama-update
 # API, so it is not rate-limited; deterministic portable bundle that runs on CPU
 # and every supported GPU) rather than the host-probing installer.
 COPY fetch_llama_prebuilt.py /usr/local/lib/unsloth/fetch_llama_prebuilt.py
+# Optional public Cloudflare tunnel for JupyterLab (UNSLOTH_JUPYTER_CLOUDFLARE=1,
+# or `unsloth-jupyter-tunnel --force`); supervisord runs it as jupyter-cloudflare.
+COPY unsloth_jupyter_tunnel.sh /usr/local/bin/unsloth-jupyter-tunnel
 RUN chmod +x /usr/local/bin/unsloth-studio-launch \
              /usr/local/bin/unsloth-studio-update \
-             /usr/local/bin/unsloth-llama-update
+             /usr/local/bin/unsloth-llama-update \
+             /usr/local/bin/unsloth-jupyter-tunnel
 
 # Studio web UI, JupyterLab, sshd. All bind 0.0.0.0 inside the container's
 # network namespace; the operator publishes them explicitly with -p.

docker/studio_launch.sh

@@ -17,6 +17,9 @@ set -euo pipefail
 
 export JUPYTER_PORT="${JUPYTER_PORT:-8888}"
 export UNSLOTH_STUDIO_HOME="${UNSLOTH_STUDIO_HOME:-/opt/unsloth-studio}"
+# Default off so supervisord's %(ENV_UNSLOTH_JUPYTER_CLOUDFLARE)s autostart gate
+# resolves; set to 1 (docker run -e) to expose JupyterLab on a trycloudflare URL.
+export UNSLOTH_JUPYTER_CLOUDFLARE="${UNSLOTH_JUPYTER_CLOUDFLARE:-0}"
 
 # Make the runtime env visible to SSH sessions, which get a fresh login shell
 # without the `docker run -e` vars. Secrets are excluded on purpose: tokens,
@@ -79,6 +82,11 @@ fi
 mkdir -p /workspace
 echo "Unsloth Studio  -> http://localhost:8000   (first-boot password below)"
 echo "JupyterLab      -> http://localhost:${JUPYTER_PORT}   (${JUPYTER_NOTE})"
+if [[ "${UNSLOTH_JUPYTER_CLOUDFLARE}" == "1" ]]; then
+    echo "JupyterLab tunnel-> enabled; public trycloudflare URL appears below once it is up"
+else
+    echo "JupyterLab tunnel-> off (set UNSLOTH_JUPYTER_CLOUDFLARE=1 for a public link)"
+fi
 if [[ "${UNSLOTH_ENABLE_SSHD}" == "true" ]]; then
     echo "sshd            -> port 22 (key-only)"
 fi

docker/supervisord.conf

@@ -53,6 +53,21 @@ stdout_logfile_maxbytes=0
 stderr_logfile=/dev/stderr
 stderr_logfile_maxbytes=0
 
+; Optional public Cloudflare quick-tunnel for JupyterLab. Started only when
+; UNSLOTH_JUPYTER_CLOUDFLARE=1 (studio_launch.sh exports a 0 default so this
+; expands). The trycloudflare URL is printed to docker logs by cloudflared.
+[program:jupyter-cloudflare]
+command=/usr/local/bin/unsloth-jupyter-tunnel
+directory=/workspace
+autostart=%(ENV_UNSLOTH_JUPYTER_CLOUDFLARE)s
+autorestart=true
+startsecs=5
+environment=HOME="/root",USER="root"
+stdout_logfile=/dev/stdout
+stdout_logfile_maxbytes=0
+stderr_logfile=/dev/stderr
+stderr_logfile_maxbytes=0
+
 [program:sshd]
 command=/usr/sbin/sshd -D -e
 autostart=%(ENV_UNSLOTH_ENABLE_SSHD)s

docker/unsloth_jupyter_tunnel.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+# Optional public Cloudflare quick-tunnel for JupyterLab, mirroring the tunnel
+# Studio creates for its own UI. Off by default. Two ways to use it:
+#
+#   * at run time:   docker run -e UNSLOTH_JUPYTER_CLOUDFLARE=1 ... unsloth/unsloth
+#                    -> the https://<name>.trycloudflare.com URL is printed in
+#                       `docker logs` once JupyterLab is up.
+#   * on demand:     docker exec <container> unsloth-jupyter-tunnel --force
+#
+# The tunnel gives a public https URL that works from anywhere with no account
+# or open inbound port. JupyterLab still requires its password, so the notebook
+# is not open to the world; treat the URL as sensitive all the same.
+set -u
+
+FORCE=0
+[ "${1:-}" = "--force" ] && FORCE=1
+if [ "$FORCE" != "1" ] && [ "${UNSLOTH_JUPYTER_CLOUDFLARE:-0}" != "1" ]; then
+    echo "[jupyter-tunnel] disabled (set UNSLOTH_JUPYTER_CLOUDFLARE=1, or run with --force)"
+    exit 0
+fi
+
+PORT="${JUPYTER_PORT:-8888}"
+
+echo "[jupyter-tunnel] waiting for JupyterLab on port ${PORT} ..."
+for _ in $(seq 1 90); do
+    if curl -fsS -o /dev/null "http://localhost:${PORT}/login" 2>/dev/null; then
+        break
+    fi
+    sleep 2
+done
+
+# Reuse a cloudflared already on the host (Studio caches one for its own
+# tunnel); otherwise fetch the static binary for this arch. No account needed.
+CFD=""
+for cand in \
+    "${UNSLOTH_STUDIO_HOME:-/opt/unsloth-studio}/bin/cloudflared" \
+    /usr/local/bin/cloudflared \
+    cloudflared; do
+    if command -v "$cand" >/dev/null 2>&1; then CFD="$(command -v "$cand")"; break; fi
+    [ -x "$cand" ] && { CFD="$cand"; break; }
+done
+if [ -z "$CFD" ]; then
+    case "$(uname -m)" in
+        x86_64|amd64) A=amd64;;
+        aarch64|arm64) A=arm64;;
+        *) A=amd64;;
+    esac
+    CFD=/usr/local/bin/cloudflared
+    echo "[jupyter-tunnel] downloading cloudflared (${A}) ..."
+    if ! curl -fsSL -o "$CFD" \
+        "https://github.com/cloudflare/cloudflared/releases/latest/download/cloudflared-linux-${A}"; then
+        echo "[jupyter-tunnel] could not download cloudflared" >&2
+        exit 1
+    fi
+    chmod +x "$CFD"
+fi
+
+echo "[jupyter-tunnel] starting Cloudflare quick-tunnel to JupyterLab (port ${PORT})."
+echo "[jupyter-tunnel] the https://<name>.trycloudflare.com URL appears below; log in with your Jupyter password."
+exec "$CFD" tunnel --no-autoupdate --url "http://localhost:${PORT}"