diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index fa608055..b7d99c1c 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -31,7 +31,10 @@ jobs:
         pip install -e '.[test]'
     - name: Run tests
       run: |
-        pytest
+        pytest -n auto -m "not serial"
+        pytest -m "serial"
+        # And the test that exceeds a localhost HTTPS server
+        tests/test_datasette_https_server.sh
 
   deploy:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 886f649a..39aa8b13 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -35,6 +35,8 @@ jobs:
       run: |
         pytest -n auto -m "not serial"
         pytest -m "serial"
+        # And the test that exceeds a localhost HTTPS server
+        tests/test_datasette_https_server.sh
     - name: Check if cog needs to be run
       run: |
         cog --check docs/*.rst
diff --git a/datasette/app.py b/datasette/app.py
index 246269f3..ea9bb6d2 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -64,16 +64,14 @@ from .utils import (
 )
 from .utils.asgi import (
     AsgiLifespan,
-    Base400,
     Forbidden,
     NotFound,
     Request,
     Response,
+    AsgiRunOnFirstRequest,
     asgi_static,
     asgi_send,
     asgi_send_file,
-    asgi_send_html,
-    asgi_send_json,
     asgi_send_redirect,
 )
 from .utils.internal_db import init_internal_db, populate_schema_tables
@@ -1260,7 +1258,7 @@ class Datasette:
 
         async def setup_db():
             # First time server starts up, calculate table counts for immutable databases
-            for dbname, database in self.databases.items():
+            for database in self.databases.values():
                 if not database.is_mutable:
                     await database.table_counts(limit=60 * 60 * 1000)
 
@@ -1274,10 +1272,8 @@ class Datasette:
         )
         if self.setting("trace_debug"):
             asgi = AsgiTracer(asgi)
-        asgi = AsgiLifespan(
-            asgi,
-            on_startup=setup_db,
-        )
+        asgi = AsgiLifespan(asgi)
+        asgi = AsgiRunOnFirstRequest(asgi, on_startup=[setup_db, self.invoke_startup])
         for wrapper in pm.hook.asgi_wrapper(datasette=self):
             asgi = wrapper(asgi)
         return asgi
@@ -1566,42 +1562,34 @@ class DatasetteClient:
         return path
 
     async def get(self, path, **kwargs):
-        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.get(self._fix(path), **kwargs)
 
     async def options(self, path, **kwargs):
-        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.options(self._fix(path), **kwargs)
 
     async def head(self, path, **kwargs):
-        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.head(self._fix(path), **kwargs)
 
     async def post(self, path, **kwargs):
-        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.post(self._fix(path), **kwargs)
 
     async def put(self, path, **kwargs):
-        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.put(self._fix(path), **kwargs)
 
     async def patch(self, path, **kwargs):
-        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.patch(self._fix(path), **kwargs)
 
     async def delete(self, path, **kwargs):
-        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.delete(self._fix(path), **kwargs)
 
     async def request(self, method, path, **kwargs):
-        await self.ds.invoke_startup()
         avoid_path_rewrites = kwargs.pop("avoid_path_rewrites", None)
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.request(
diff --git a/datasette/cli.py b/datasette/cli.py
index 6eb42712..2b61292b 100644
--- a/datasette/cli.py
+++ b/datasette/cli.py
@@ -607,7 +607,7 @@ def serve(
         url = "http://{}:{}{}?token={}".format(
             host, port, ds.urls.path("-/auth-token"), ds._root_token
         )
-        print(url)
+        click.echo(url)
     if open_browser:
         if url is None:
             # Figure out most convenient URL - to table, database or homepage
diff --git a/datasette/publish/heroku.py b/datasette/publish/heroku.py
index 171252ce..f576a346 100644
--- a/datasette/publish/heroku.py
+++ b/datasette/publish/heroku.py
@@ -3,7 +3,9 @@ from datasette import hookimpl
 import click
 import json
 import os
+import pathlib
 import shlex
+import shutil
 from subprocess import call, check_output
 import tempfile
 
@@ -28,6 +30,11 @@ def publish_subcommand(publish):
         "--tar",
         help="--tar option to pass to Heroku, e.g. --tar=/usr/local/bin/gtar",
     )
+    @click.option(
+        "--generate-dir",
+        type=click.Path(dir_okay=True, file_okay=False),
+        help="Output generated application files and stop without deploying",
+    )
     def heroku(
         files,
         metadata,
@@ -49,6 +56,7 @@ def publish_subcommand(publish):
         about_url,
         name,
         tar,
+        generate_dir,
     ):
         "Publish databases to Datasette running on Heroku"
         fail_if_publish_binary_not_installed(
@@ -105,6 +113,16 @@ def publish_subcommand(publish):
             secret,
             extra_metadata,
         ):
+            if generate_dir:
+                # Recursively copy files from current working directory to it
+                if pathlib.Path(generate_dir).exists():
+                    raise click.ClickException("Directory already exists")
+                shutil.copytree(".", generate_dir)
+                click.echo(
+                    f"Generated files written to {generate_dir}, stopping without deploying",
+                    err=True,
+                )
+                return
             app_name = None
             if name:
                 # Check to see if this app already exists
@@ -176,7 +194,7 @@ def temporary_heroku_directory(
                 fp.write(json.dumps(metadata_content, indent=2))
 
         with open("runtime.txt", "w") as fp:
-            fp.write("python-3.8.10")
+            fp.write("python-3.11.0")
 
         if branch:
             install = [
diff --git a/datasette/utils/asgi.py b/datasette/utils/asgi.py
index 8a2fa060..16f90077 100644
--- a/datasette/utils/asgi.py
+++ b/datasette/utils/asgi.py
@@ -428,3 +428,18 @@ class AsgiFileDownload:
             content_type=self.content_type,
             headers=self.headers,
         )
+
+
+class AsgiRunOnFirstRequest:
+    def __init__(self, asgi, on_startup):
+        assert isinstance(on_startup, list)
+        self.asgi = asgi
+        self.on_startup = on_startup
+        self._started = False
+
+    async def __call__(self, scope, receive, send):
+        if not self._started:
+            self._started = True
+            for hook in self.on_startup:
+                await hook()
+        return await self.asgi(scope, receive, send)
diff --git a/datasette/version.py b/datasette/version.py
index 3a4f06dc..8aaf793d 100644
--- a/datasette/version.py
+++ b/datasette/version.py
@@ -1,2 +1,2 @@
-__version__ = "0.63.1"
+__version__ = "0.63.3"
 __version_info__ = tuple(__version__.split("."))
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 0e0393ef..270765c8 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -4,6 +4,22 @@
 Changelog
 =========
 
+.. _v0_63_3:
+
+0.63.3 (2022-12-17)
+-------------------
+
+- Fixed a bug where ``datasette --root``, when running in Docker, would only output the URL to sign in as root when the server shut down, not when it started up. (:issue:`1958`)
+- You no longer need to ensure ``await datasette.invoke_startup()`` has been called in order for Datasette to start correctly serving requests - this is now handled automatically the first time the server receives a request. This fixes a bug experienced when Datasette is served directly by an ASGI application server such as Uvicorn or Gunicorn. It also fixes a bug with the `datasette-gunicorn <https://datasette.io/plugins/datasette-gunicorn>`__ plugin. (:issue:`1955`)
+
+.. _v0_63_2:
+
+0.63.2 (2022-11-18)
+-------------------
+
+- Fixed a bug in ``datasette publish heroku`` where deployments failed due to an older version of Python being requested. (:issue:`1905`)
+- New ``datasette publish heroku --generate-dir <dir>`` option for generating a Heroku deployment directory without deploying it.
+
 .. _v0_63_1:
 
 0.63.1 (2022-11-10)
diff --git a/docs/cli-reference.rst b/docs/cli-reference.rst
index 4a8465cb..a6885fc8 100644
--- a/docs/cli-reference.rst
+++ b/docs/cli-reference.rst
@@ -501,6 +501,8 @@ See :ref:`publish_heroku`.
       -n, --name TEXT                 Application name to use when deploying
       --tar TEXT                      --tar option to pass to Heroku, e.g.
                                       --tar=/usr/local/bin/gtar
+      --generate-dir DIRECTORY        Output generated application files and stop
+                                      without deploying
       --help                          Show this message and exit.
 
 
diff --git a/docs/plugin_hooks.rst b/docs/plugin_hooks.rst
index b61f953a..101911cc 100644
--- a/docs/plugin_hooks.rst
+++ b/docs/plugin_hooks.rst
@@ -855,13 +855,14 @@ Potential use-cases:
 
 .. note::
 
-   If you are writing :ref:`unit tests <testing_plugins>` for a plugin that uses this hook you will need to explicitly call ``await ds.invoke_startup()`` in your tests. An example:
+   If you are writing :ref:`unit tests <testing_plugins>` for a plugin that uses this hook and doesn't exercise Datasette by sending
+   any simulated requests through it you will need to explicitly call ``await ds.invoke_startup()`` in your tests. An example:
 
    .. code-block:: python
 
         @pytest.mark.asyncio
         async def test_my_plugin():
-            ds = Datasette([], metadata={})
+            ds = Datasette()
             await ds.invoke_startup()
             # Rest of test goes here
 
diff --git a/docs/publish.rst b/docs/publish.rst
index 4ba94792..7ae0399e 100644
--- a/docs/publish.rst
+++ b/docs/publish.rst
@@ -73,6 +73,10 @@ This will output some details about the new deployment, including a URL like thi
 
 You can specify a custom app name by passing ``-n my-app-name`` to the publish command. This will also allow you to overwrite an existing app.
 
+Rather than deploying directly you can use the ``--generate-dir`` option to output the files that would be deployed to a directory::
+
+    datasette publish heroku mydatabase.db --generate-dir=/tmp/deploy-this-to-heroku
+
 See :ref:`cli_help_publish_heroku___help` for the full list of options for this command.
 
 .. _publish_vercel:
diff --git a/docs/testing_plugins.rst b/docs/testing_plugins.rst
index 41f50e56..6d2097ad 100644
--- a/docs/testing_plugins.rst
+++ b/docs/testing_plugins.rst
@@ -80,7 +80,7 @@ Creating a ``Datasette()`` instance like this as useful shortcut in tests, but t
 
 This method registers any :ref:`plugin_hook_startup` or :ref:`plugin_hook_prepare_jinja2_environment` plugins that might themselves need to make async calls.
 
-If you are using ``await datasette.client.get()`` and similar methods then you don't need to worry about this - those method calls ensure that ``.invoke_startup()`` has been called for you.
+If you are using ``await datasette.client.get()`` and similar methods then you don't need to worry about this - Datasette automatically calls ``invoke_startup()`` the first time it handles a request.
 
 .. _testing_plugins_pdb:
 
diff --git a/test-in-pyodide-with-shot-scraper.sh b/test-in-pyodide-with-shot-scraper.sh
index e5df7398..0c140818 100755
--- a/test-in-pyodide-with-shot-scraper.sh
+++ b/test-in-pyodide-with-shot-scraper.sh
@@ -25,6 +25,7 @@ async () => {
   let output = await pyodide.runPythonAsync(\`
     import micropip
     await micropip.install('h11==0.12.0')
+    await micropip.install('httpx==0.23')
     await micropip.install('http://localhost:8529/$wheel')
     import ssl
     import setuptools
diff --git a/tests/conftest.py b/tests/conftest.py
index f4638a14..ee13df11 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -23,6 +23,17 @@ UNDOCUMENTED_PERMISSIONS = {
 }
 
 
+def wait_until_responds(url, timeout=5.0, client=httpx, **kwargs):
+    start = time.time()
+    while time.time() - start < timeout:
+        try:
+            client.get(url, **kwargs)
+            return
+        except httpx.ConnectError:
+            time.sleep(0.1)
+    raise AssertionError("Timed out waiting for {} to respond".format(url))
+
+
 def pytest_report_header(config):
     return "SQLite: {}".format(
         sqlite3.connect(":memory:").execute("select sqlite_version()").fetchone()[0]
@@ -111,13 +122,7 @@ def ds_localhost_http_server():
         # Avoid FileNotFoundError: [Errno 2] No such file or directory:
         cwd=tempfile.gettempdir(),
     )
-    # Loop until port 8041 serves traffic
-    while True:
-        try:
-            httpx.get("http://localhost:8041/")
-            break
-        except httpx.ConnectError:
-            time.sleep(0.1)
+    wait_until_responds("http://localhost:8041/")
     # Check it started successfully
     assert not ds_proc.poll(), ds_proc.stdout.read().decode("utf-8")
     yield ds_proc
@@ -125,46 +130,6 @@ def ds_localhost_http_server():
     ds_proc.terminate()
 
 
-@pytest.fixture(scope="session")
-def ds_localhost_https_server(tmp_path_factory):
-    cert_directory = tmp_path_factory.mktemp("certs")
-    ca = trustme.CA()
-    server_cert = ca.issue_cert("localhost")
-    keyfile = str(cert_directory / "server.key")
-    certfile = str(cert_directory / "server.pem")
-    client_cert = str(cert_directory / "client.pem")
-    server_cert.private_key_pem.write_to_path(path=keyfile)
-    for blob in server_cert.cert_chain_pems:
-        blob.write_to_path(path=certfile, append=True)
-    ca.cert_pem.write_to_path(path=client_cert)
-    ds_proc = subprocess.Popen(
-        [
-            "datasette",
-            "--memory",
-            "-p",
-            "8042",
-            "--ssl-keyfile",
-            keyfile,
-            "--ssl-certfile",
-            certfile,
-        ],
-        stdout=subprocess.PIPE,
-        stderr=subprocess.STDOUT,
-        cwd=tempfile.gettempdir(),
-    )
-    while True:
-        try:
-            httpx.get("https://localhost:8042/", verify=client_cert)
-            break
-        except httpx.ConnectError:
-            time.sleep(0.1)
-    # Check it started successfully
-    assert not ds_proc.poll(), ds_proc.stdout.read().decode("utf-8")
-    yield ds_proc, client_cert
-    # Shut it down at the end of the pytest session
-    ds_proc.terminate()
-
-
 @pytest.fixture(scope="session")
 def ds_unix_domain_socket_server(tmp_path_factory):
     # This used to use tmp_path_factory.mktemp("uds") but that turned out to
@@ -181,12 +146,7 @@ def ds_unix_domain_socket_server(tmp_path_factory):
     # Poll until available
     transport = httpx.HTTPTransport(uds=uds)
     client = httpx.Client(transport=transport)
-    while True:
-        try:
-            client.get("http://localhost/_memory.json")
-            break
-        except httpx.ConnectError:
-            time.sleep(0.1)
+    wait_until_responds("http://localhost/_memory.json", client=client)
     # Check it started successfully
     assert not ds_proc.poll(), ds_proc.stdout.read().decode("utf-8")
     yield ds_proc, uds
diff --git a/tests/test_cli_serve_server.py b/tests/test_cli_serve_server.py
index 1c31e2a3..47f23c08 100644
--- a/tests/test_cli_serve_server.py
+++ b/tests/test_cli_serve_server.py
@@ -13,17 +13,6 @@ def test_serve_localhost_http(ds_localhost_http_server):
     }.items() <= response.json().items()
 
 
-@pytest.mark.serial
-def test_serve_localhost_https(ds_localhost_https_server):
-    _, client_cert = ds_localhost_https_server
-    response = httpx.get("https://localhost:8042/_memory.json", verify=client_cert)
-    assert {
-        "database": "_memory",
-        "path": "/_memory",
-        "tables": [],
-    }.items() <= response.json().items()
-
-
 @pytest.mark.serial
 @pytest.mark.skipif(
     not hasattr(socket, "AF_UNIX"), reason="Requires socket.AF_UNIX support"
diff --git a/tests/test_datasette_https_server.sh b/tests/test_datasette_https_server.sh
new file mode 100755
index 00000000..a701ad4c
--- /dev/null
+++ b/tests/test_datasette_https_server.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+# Generate certificates
+python -m trustme
+# This creates server.pem, server.key, client.pem
+
+# Start the server in the background
+datasette --memory \
+    --ssl-keyfile=server.key \
+    --ssl-certfile=server.pem \
+    -p 8152 &
+
+# Store the background process ID in a variable
+server_pid=$!
+
+# Wait for the server to start
+sleep 2
+
+# Make a test request using curl
+curl -f --cacert client.pem 'https://localhost:8152/_memory.json'
+
+# Save curl's exit code (-f option causes it to return one on HTTP errors)
+curl_exit_code=$?
+
+# Shut down the server
+kill $server_pid
+sleep 1
+
+# Clean up the certificates
+rm server.pem server.key client.pem
+
+echo $curl_exit_code
+exit $curl_exit_code
diff --git a/tests/test_publish_heroku.py b/tests/test_publish_heroku.py
index b5a8af73..cab83654 100644
--- a/tests/test_publish_heroku.py
+++ b/tests/test_publish_heroku.py
@@ -2,6 +2,7 @@ from click.testing import CliRunner
 from datasette import cli
 from unittest import mock
 import os
+import pathlib
 import pytest
 
 
@@ -128,3 +129,55 @@ def test_publish_heroku_plugin_secrets(
             mock.call(["heroku", "builds:create", "-a", "f", "--include-vcs-ignore"]),
         ]
     )
+
+
+@pytest.mark.serial
+@mock.patch("shutil.which")
+@mock.patch("datasette.publish.heroku.check_output")
+@mock.patch("datasette.publish.heroku.call")
+def test_publish_heroku_generate_dir(
+    mock_call, mock_check_output, mock_which, tmp_path_factory
+):
+    mock_which.return_value = True
+    mock_check_output.side_effect = lambda s: {
+        "['heroku', 'plugins']": b"heroku-builds",
+    }[repr(s)]
+    runner = CliRunner()
+    os.chdir(tmp_path_factory.mktemp("runner"))
+    with open("test.db", "w") as fp:
+        fp.write("data")
+    output = str(tmp_path_factory.mktemp("generate_dir") / "output")
+    result = runner.invoke(
+        cli.cli,
+        [
+            "publish",
+            "heroku",
+            "test.db",
+            "--generate-dir",
+            output,
+        ],
+    )
+    assert result.exit_code == 0
+    path = pathlib.Path(output)
+    assert path.exists()
+    file_names = {str(r.relative_to(path)) for r in path.glob("*")}
+    assert file_names == {
+        "requirements.txt",
+        "bin",
+        "runtime.txt",
+        "Procfile",
+        "test.db",
+    }
+    for name, expected in (
+        ("requirements.txt", "datasette"),
+        ("runtime.txt", "python-3.11.0"),
+        (
+            "Procfile",
+            (
+                "web: datasette serve --host 0.0.0.0 -i test.db "
+                "--cors --port $PORT --inspect-file inspect-data.json"
+            ),
+        ),
+    ):
+        with open(path / name) as fp:
+            assert fp.read().strip() == expected