fix(jupyter): bind notebook services to loopback by default

registry/coder/modules/jupyter-notebook/README.md

@@ -12,11 +12,31 @@ A module that adds Jupyter Notebook in your Coder template.
 
 ![Jupyter Notebook](../../.images/jupyter-notebook.png)
 
+Jupyter Notebook listens on `127.0.0.1` by default so that unauthenticated
+traffic must pass through Coder's application proxy.
+
+```tf
+module "jupyter-notebook" {
+  count    = data.coder_workspace.me.start_count
+  source   = "registry.coder.com/coder/jupyter-notebook/coder"
+  version  = "1.3.0"
+  agent_id = coder_agent.main.id
+}
+```
+
+## External network access
+
+> [!WARNING]
+> For advanced environments that require direct network access, set `host`
+> explicitly. Binding to `0.0.0.0` exposes the unauthenticated service to every
+> reachable network interface and is less secure.
+
 ```tf
 module "jupyter-notebook" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/jupyter-notebook/coder"
-  version  = "1.2.1"
+  version  = "1.3.0"
   agent_id = coder_agent.main.id
+  host     = "0.0.0.0"
 }
 ```

registry/coder/modules/jupyter-notebook/main.test.ts

@@ -0,0 +1,97 @@
+import { describe, expect, it, setDefaultTimeout } from "bun:test";
+import {
+  execContainer,
+  findResourceInstance,
+  readFileContainer,
+  removeContainer,
+  runContainer,
+  runTerraformApply,
+  runTerraformInit,
+  testRequiredVariables,
+  writeFileContainer,
+} from "~test";
+
+setDefaultTimeout(30_000);
+
+describe("jupyter-notebook", async () => {
+  await runTerraformInit(import.meta.dir);
+
+  testRequiredVariables(import.meta.dir, {
+    agent_id: "foo",
+  });
+
+  it("binds to loopback by default", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+    });
+    const script = findResourceInstance(state, "coder_script").script;
+
+    expect(script).toContain("--ServerApp.ip='127.0.0.1'");
+    expect(script).not.toContain("0.0.0.0");
+    expect(script).not.toContain("--ServerApp.ip='*'");
+    expect(script).toContain("--ServerApp.allow_remote_access=True");
+
+    const id = await runContainer("alpine");
+    try {
+      await execContainer(id, ["mkdir", "-p", "/root/.local/bin"]);
+      await writeFileContainer(
+        id,
+        "/root/.local/bin/jupyter-notebook",
+        "#!/bin/sh\nprintf '%s\\n' \"$@\" > /tmp/jupyter-args\n",
+      );
+      await execContainer(id, [
+        "chmod",
+        "755",
+        "/root/.local/bin/jupyter-notebook",
+      ]);
+      const result = await execContainer(
+        id,
+        ["sh", "-c", script],
+        [
+          "--env",
+          "PATH=/root/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+        ],
+      );
+      expect(result.exitCode).toBe(0);
+      const args = await readFileContainer(id, "/tmp/jupyter-args");
+      expect(args).toContain("--ServerApp.ip=127.0.0.1");
+      expect(args).toContain("--ServerApp.allow_remote_access=True");
+    } finally {
+      await removeContainer(id);
+    }
+  });
+
+  it("renders an explicit external host", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+      host: "0.0.0.0",
+    });
+    const script = findResourceInstance(state, "coder_script").script;
+    expect(script).toContain("--ServerApp.ip='0.0.0.0'");
+    expect(script).toContain("--ServerApp.allow_remote_access=True");
+  });
+
+  it("renders an IPv6 loopback host", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+      host: "::1",
+    });
+    const script = findResourceInstance(state, "coder_script").script;
+    expect(script).toContain("--ServerApp.ip='::1'");
+  });
+
+  for (const unsafeHost of [
+    "127.0.0.1; touch /tmp/injected",
+    "127.0.0.1 $(id)",
+    "127.0.0.1`id`",
+    "127.0.0.1'quoted",
+  ]) {
+    it(`rejects unsafe host ${JSON.stringify(unsafeHost)}`, async () => {
+      const apply = runTerraformApply(import.meta.dir, {
+        agent_id: "foo",
+        host: unsafeHost,
+      });
+      await expect(apply).rejects.toThrow("host must contain only");
+    });
+  }
+});

registry/coder/modules/jupyter-notebook/main.tf

@@ -21,6 +21,17 @@ variable "log_path" {
   default     = "/tmp/jupyter-notebook.log"
 }
 
+variable "host" {
+  description = "The host address that Jupyter Notebook listens on."
+  type        = string
+  default     = "127.0.0.1"
+
+  validation {
+    condition     = can(regex("^[A-Za-z0-9:][A-Za-z0-9.:%_-]*$", var.host))
+    error_message = "host must contain only letters, numbers, colons, dots, percent signs, underscores, and hyphens."
+  }
+}
+
 variable "port" {
   type        = number
   description = "The port to run jupyter-notebook on."
@@ -66,6 +77,7 @@ resource "coder_script" "jupyter-notebook" {
   icon         = "/icon/jupyter.svg"
   script = templatefile("${path.module}/run.sh", {
     LOG_PATH : var.log_path,
+    HOST : var.host,
     PORT : var.port,
     REQUIREMENTS_PATH : var.requirements_path,
     PIP_INSTALL_EXTRA_PACKAGES : var.pip_install_extra_packages

registry/coder/modules/jupyter-notebook/main.tftest.hcl

@@ -0,0 +1,73 @@
+run "secure_defaults" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+  }
+
+  assert {
+    condition     = var.host == "127.0.0.1"
+    error_message = "host must default to 127.0.0.1"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='127.0.0.1'")
+    error_message = "the default script must bind Jupyter Notebook to 127.0.0.1"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--ServerApp.allow_remote_access=True")
+    error_message = "the script must allow requests forwarded by the Coder application proxy"
+  }
+
+  assert {
+    condition     = !strcontains(coder_script.jupyter-notebook.script, "0.0.0.0") && !strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='*'")
+    error_message = "the default script must not bind Jupyter Notebook to all interfaces"
+  }
+
+  assert {
+    condition     = coder_app.jupyter-notebook.url == "http://localhost:19999"
+    error_message = "the default Coder application URL must remain unchanged"
+  }
+}
+
+run "explicit_external_host" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+    host     = "0.0.0.0"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='0.0.0.0'")
+    error_message = "the script must render an explicitly configured host"
+  }
+}
+
+run "ipv6_loopback_host" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+    host     = "::1"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='::1'")
+    error_message = "the script must render an IPv6 loopback host"
+  }
+}
+
+run "unsafe_host_rejected" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+    host     = "127.0.0.1; touch /tmp/injected"
+  }
+
+  expect_failures = [
+    var.host,
+  ]
+}

registry/coder/modules/jupyter-notebook/run.sh

@@ -40,4 +40,11 @@ fi
 
 echo "👷 Starting jupyter-notebook in background..."
 echo "check logs at ${LOG_PATH}"
-$HOME/.local/bin/jupyter-notebook --NotebookApp.ip='0.0.0.0' --ServerApp.port=${PORT} --no-browser --ServerApp.token='' --ServerApp.password='' > ${LOG_PATH} 2>&1 &
+"$HOME/.local/bin/jupyter-notebook" \
+  --ServerApp.ip='${HOST}' \
+  --ServerApp.port='${PORT}' \
+  --ServerApp.allow_remote_access=True \
+  --no-browser \
+  --ServerApp.token='' \
+  --ServerApp.password='' \
+  > "${LOG_PATH}" 2>&1 &

registry/coder/modules/jupyterlab/README.md

@@ -12,12 +12,32 @@ A module that adds JupyterLab in your Coder template.
 
 ![JupyterLab](../../.images/jupyterlab.png)
 
+JupyterLab listens on `127.0.0.1` by default so that unauthenticated traffic
+must pass through Coder's application proxy.
+
+```tf
+module "jupyterlab" {
+  count    = data.coder_workspace.me.start_count
+  source   = "registry.coder.com/coder/jupyterlab/coder"
+  version  = "1.3.0"
+  agent_id = coder_agent.main.id
+}
+```
+
+## External network access
+
+> [!WARNING]
+> For advanced environments that require direct network access, set `host`
+> explicitly. Binding to `0.0.0.0` exposes the unauthenticated service to every
+> reachable network interface and is less secure.
+
 ```tf
 module "jupyterlab" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/jupyterlab/coder"
-  version  = "1.2.2"
+  version  = "1.3.0"
   agent_id = coder_agent.main.id
+  host     = "0.0.0.0"
 }
 ```
 
@@ -29,7 +49,7 @@ JupyterLab is automatically configured to work with Coder's iframe embedding. Fo
 module "jupyterlab" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/jupyterlab/coder"
-  version  = "1.2.2"
+  version  = "1.3.0"
   agent_id = coder_agent.main.id
   config = {
     ServerApp = {

registry/coder/modules/jupyterlab/main.test.ts

@@ -1,4 +1,4 @@
-import { describe, expect, it } from "bun:test";
+import { describe, expect, it, setDefaultTimeout } from "bun:test";
 import {
   execContainer,
   executeScriptInContainer,
@@ -10,8 +10,11 @@ import {
   runTerraformInit,
   testRequiredVariables,
   type TerraformState,
+  writeFileContainer,
 } from "~test";
 
+setDefaultTimeout(30_000);
+
 // executes the coder script after installing pip
 const executeScriptInContainerWithPip = async (
   state: TerraformState,
@@ -166,4 +169,72 @@ describe("jupyterlab", async () => {
     );
     expect(configScripts.length).toBe(1);
   });
+
+  it("binds to loopback by default without changing Coder URLs", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+    });
+    const script = findResourceInstance(
+      state,
+      "coder_script",
+      "jupyterlab",
+    ).script;
+    const app = findResourceInstance(state, "coder_app", "jupyterlab");
+
+    expect(script).toContain("--ServerApp.ip='127.0.0.1'");
+    expect(script).not.toContain("0.0.0.0");
+    expect(script).not.toContain("--ServerApp.ip='*'");
+    expect(script).toContain("--ServerApp.allow_remote_access=True");
+    expect(app.url).toBe("http://localhost:19999");
+
+    const id = await runContainer("alpine");
+    try {
+      await writeFileContainer(
+        id,
+        "/usr/local/bin/jupyter-lab",
+        "#!/bin/sh\nprintf '%s\\n' \"$@\" > /tmp/jupyter-args\n",
+      );
+      await execContainer(id, ["chmod", "755", "/usr/local/bin/jupyter-lab"]);
+      const result = await execContainer(id, ["sh", "-c", script]);
+      expect(result.exitCode).toBe(0);
+      const args = await readFileContainer(id, "/tmp/jupyter-args");
+      expect(args).toContain("--ServerApp.ip=127.0.0.1");
+      expect(args).toContain("--ServerApp.allow_remote_access=True");
+    } finally {
+      await removeContainer(id);
+    }
+  });
+
+  it("preserves path mode and renders an explicit external host", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+      host: "0.0.0.0",
+      subdomain: false,
+    });
+    const script = findResourceInstance(
+      state,
+      "coder_script",
+      "jupyterlab",
+    ).script;
+
+    expect(script).toContain("--ServerApp.ip='0.0.0.0'");
+    expect(script).toContain("--ServerApp.allow_remote_access=True");
+    expect(script).toContain("--ServerApp.base_url=/@");
+    expect(script).toContain("/apps/jupyterlab");
+  });
+
+  for (const unsafeHost of [
+    "127.0.0.1; touch /tmp/injected",
+    "127.0.0.1 $(id)",
+    "127.0.0.1`id`",
+    "127.0.0.1'quoted",
+  ]) {
+    it(`rejects unsafe host ${JSON.stringify(unsafeHost)}`, async () => {
+      const apply = runTerraformApply(import.meta.dir, {
+        agent_id: "foo",
+        host: unsafeHost,
+      });
+      await expect(apply).rejects.toThrow("host must contain only");
+    });
+  }
 });