diff --git a/betty/extension/nginx/serve.py b/betty/extension/nginx/serve.py
index 8db598e52..9fc42d945 100644
--- a/betty/extension/nginx/serve.py
+++ b/betty/extension/nginx/serve.py
@@ -87,7 +87,7 @@ def public_url(self) -> str:
     @classmethod
     def is_available(cls) -> bool:
         try:
-            docker.from_env().info()
+            docker.from_env()
             return True
         except DockerException as e:
             logging.getLogger(__name__).warning(e)
diff --git a/betty/tests/extension/nginx/test___init__.py b/betty/tests/extension/nginx/test___init__.py
index b92cae74c..c3d496767 100644
--- a/betty/tests/extension/nginx/test___init__.py
+++ b/betty/tests/extension/nginx/test___init__.py
@@ -1,379 +1,23 @@
-import re
-from typing import Optional
-
 from betty.app import App
 from betty.extension import Nginx
-from betty.extension.nginx.config import NginxConfiguration
 from betty.generate import generate
-from betty.project import ExtensionConfiguration, LocaleConfiguration
+from betty.project import ExtensionConfiguration
 
 
 class TestNginx:
-    _LEADING_WHITESPACE_PATTERN = re.compile(r"^\s*(.*?)$")
-
-    def _normalize_configuration(self, configuration: str) -> str:
-        return "\n".join(
-            filter(
-                None,
-                map(self._normalize_configuration_line, configuration.splitlines()),
-            )
-        )
-
-    def _normalize_configuration_line(self, line: str) -> Optional[str]:
-        match = self._LEADING_WHITESPACE_PATTERN.fullmatch(line)
-        if match is None:
-            return None
-        return match.group(1)
-
-    async def _assert_configuration_equals(self, expected: str, app: App):
-        await generate(app)
-        with open(
-            app.project.configuration.output_directory_path / "nginx" / "nginx.conf"
-        ) as f:
-            actual = f.read()
-        assert self._normalize_configuration(expected) == self._normalize_configuration(
-            actual
-        )
-
-    async def test_post_render_config(self):
+    async def test_generate(self):
         async with App.new_temporary() as app, app:
             app.project.configuration.base_url = "http://example.com"
             app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
-            expected = (
-                r"""
-server {
-    add_header Vary Accept-Language;
-    add_header Cache-Control "max-age=86400";
-    listen 80;
-    server_name example.com;
-    root %s;
-    gzip on;
-    gzip_disable "msie6";
-    gzip_vary on;
-    gzip_types text/css application/javascript application/json application/xml;
-
-    set $media_type_extension html;
-    index index.$media_type_extension;
-
-    location / {
-        # Handle HTTP error responses.
-        error_page 401 /.error/401.$media_type_extension;
-        error_page 403 /.error/403.$media_type_extension;
-        error_page 404 /.error/404.$media_type_extension;
-        location /.error {
-            internal;
-        }
-
-        try_files $uri $uri/ =404;
-    }
-}
-"""
-                % app.project.configuration.www_directory_path
-            )
-            await self._assert_configuration_equals(expected, app)
-
-    async def test_post_render_config_multilingual(self):
-        async with App.new_temporary() as app, app:
-            app.project.configuration.base_url = "http://example.com"
-            app.project.configuration.locales.replace(
-                LocaleConfiguration(
-                    "en-US",
-                    alias="en",
-                ),
-                LocaleConfiguration(
-                    "nl-NL",
-                    alias="nl",
-                ),
-            )
-            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
-            expected = (
-                r"""
-server {
-    add_header Vary Accept-Language;
-    add_header Cache-Control "max-age=86400";
-    listen 80;
-    server_name example.com;
-    root %s;
-    gzip on;
-    gzip_disable "msie6";
-    gzip_vary on;
-    gzip_types text/css application/javascript application/json application/xml;
-
-    set $media_type_extension html;
-    index index.$media_type_extension;
-
-    location @localized_redirect {
-        set $locale_alias en;
-        return 301 /$locale_alias$uri;
-    }
-
-
-    # The front page.
-    location = / {
-        # nginx does not support redirecting to named locations, so we use try_files with an empty first
-        # argument and assume that never matches a real file.
-        try_files '' @localized_redirect;
-    }
-
-    # Localized resources.
-    location ~* ^/(en|nl)(/|$) {
-        set $locale $1;
-        add_header Vary Accept-Language;
-        add_header Cache-Control "max-age=86400";
-        add_header Content-Language "$locale" always;
-
-        # Handle HTTP error responses.
-        error_page 401 /$locale/.error/401.$media_type_extension;
-        error_page 403 /$locale/.error/403.$media_type_extension;
-        error_page 404 /$locale/.error/404.$media_type_extension;
-        location ~ ^/$locale/\.error {
-            internal;
-        }
-
-        try_files $uri $uri/ =404;
-    }
-
-    # Static resources.
-    location / {
-        # Handle HTTP error responses.
-        error_page 401 /en/.error/401.$media_type_extension;
-        error_page 403 /en/.error/403.$media_type_extension;
-        error_page 404 /en/.error/404.$media_type_extension;
-        location ~ ^/en/\.error {
-            internal;
-        }
-        try_files $uri $uri/ =404;
-    }
-}
-"""
-                % app.project.configuration.www_directory_path
-            )
-            await self._assert_configuration_equals(expected, app)
-
-    async def test_post_render_config_multilingual_with_clean_urls(self):
-        async with App.new_temporary() as app, app:
-            app.project.configuration.base_url = "http://example.com"
-            app.project.configuration.clean_urls = True
-            app.project.configuration.locales.replace(
-                LocaleConfiguration(
-                    "en-US",
-                    alias="en",
-                ),
-                LocaleConfiguration(
-                    "nl-NL",
-                    alias="nl",
-                ),
-            )
-            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
-            expected = (
-                r"""
-server {
-    add_header Vary Accept-Language;
-    add_header Cache-Control "max-age=86400";
-    listen 80;
-    server_name example.com;
-    root %s;
-    gzip on;
-    gzip_disable "msie6";
-    gzip_vary on;
-    gzip_types text/css application/javascript application/json application/xml;
-
-    set_by_lua_block $media_type_extension {
-        local available_media_types = {'text/html', 'application/json'}
-        local media_type_extensions = {}
-        media_type_extensions['text/html'] = 'html'
-        media_type_extensions['application/json'] = 'json'
-        local media_type = require('content_negotiation').negotiate(ngx.req.get_headers()['Accept'], available_media_types)
-        return media_type_extensions[media_type]
-    }
-    index index.$media_type_extension;
-    location @localized_redirect {
-        set_by_lua_block $locale_alias {
-            local available_locales = {'en-US', 'nl-NL'}
-            local locale_aliases = {}
-            locale_aliases['en-US'] = 'en'
-            locale_aliases['nl-NL'] = 'nl'
-            local locale = require('content_negotiation').negotiate(ngx.req.get_headers()['Accept-Language'], available_locales)
-            return locale_aliases[locale]
-        }
-        add_header Vary Accept-Language;
-        add_header Cache-Control "max-age=86400";
-        add_header Content-Language "$locale_alias" always;
-
-        return 307 /$locale_alias$uri;
-    }
-
-    # The front page.
-    location = / {
-        # nginx does not support redirecting to named locations, so we use try_files with an empty first
-        # argument and assume that never matches a real file.
-        try_files '' @localized_redirect;
-    }
-
-    # Localized resources.
-    location ~* ^/(en|nl)(/|$) {
-        set $locale $1;
-        add_header Vary Accept-Language;
-        add_header Cache-Control "max-age=86400";
-        add_header Content-Language "$locale" always;
-
-        # Handle HTTP error responses.
-        error_page 401 /$locale/.error/401.$media_type_extension;
-        error_page 403 /$locale/.error/403.$media_type_extension;
-        error_page 404 /$locale/.error/404.$media_type_extension;
-        location ~ ^/$locale/\.error {
-            internal;
-        }
-
-        try_files $uri $uri/ =404;
-    }
-
-    # Static resources.
-    location / {
-        # Handle HTTP error responses.
-        error_page 401 /en/.error/401.$media_type_extension;
-        error_page 403 /en/.error/403.$media_type_extension;
-        error_page 404 /en/.error/404.$media_type_extension;
-        location ~ ^/en/\.error {
-            internal;
-        }
-        try_files $uri $uri/ =404;
-    }
-}
-"""
-                % app.project.configuration.www_directory_path
-            )
-            await self._assert_configuration_equals(expected, app)
-
-    async def test_post_render_config_with_clean_urls(self):
-        async with App.new_temporary() as app, app:
-            app.project.configuration.base_url = "http://example.com"
-            app.project.configuration.clean_urls = True
-            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
-            expected = (
-                r"""
-server {
-    add_header Vary Accept-Language;
-    add_header Cache-Control "max-age=86400";
-    listen 80;
-    server_name example.com;
-    root %s;
-    gzip on;
-    gzip_disable "msie6";
-    gzip_vary on;
-    gzip_types text/css application/javascript application/json application/xml;
-
-    set_by_lua_block $media_type_extension {
-        local available_media_types = {'text/html', 'application/json'}
-        local media_type_extensions = {}
-        media_type_extensions['text/html'] = 'html'
-        media_type_extensions['application/json'] = 'json'
-        local media_type = require('content_negotiation').negotiate(ngx.req.get_headers()['Accept'], available_media_types)
-        return media_type_extensions[media_type]
-    }
-    index index.$media_type_extension;
-
-    location / {
-        # Handle HTTP error responses.
-        error_page 401 /.error/401.$media_type_extension;
-        error_page 403 /.error/403.$media_type_extension;
-        error_page 404 /.error/404.$media_type_extension;
-        location /.error {
-            internal;
-        }
-
-        try_files $uri $uri/ =404;
-    }
-}"""
-                % app.project.configuration.www_directory_path
-            )
-            await self._assert_configuration_equals(expected, app)
-
-    async def test_post_render_config_with_https(self):
-        async with App.new_temporary() as app, app:
-            app.project.configuration.base_url = "https://example.com"
-            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
-            expected = (
-                r"""
-server {
-    listen 80;
-    server_name example.com;
-    return 301 https://$host$request_uri;
-}
-server {
-    add_header Vary Accept-Language;
-    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
-    add_header Cache-Control "max-age=86400";
-    listen 443 ssl http2;
-    server_name example.com;
-    root %s;
-    gzip on;
-    gzip_disable "msie6";
-    gzip_vary on;
-    gzip_types text/css application/javascript application/json application/xml;
-
-    set $media_type_extension html;
-    index index.$media_type_extension;
-
-    location / {
-        # Handle HTTP error responses.
-        error_page 401 /.error/401.$media_type_extension;
-        error_page 403 /.error/403.$media_type_extension;
-        error_page 404 /.error/404.$media_type_extension;
-        location /.error {
-            internal;
-    }
-
-    try_files $uri $uri/ =404;
-    }
-}
-"""
-                % app.project.configuration.www_directory_path
-            )
-            await self._assert_configuration_equals(expected, app)
-
-    async def test_post_render_config_with_overridden_www_directory_path(self):
-        async with App.new_temporary() as app, app:
-            app.project.configuration.extensions.append(
-                ExtensionConfiguration(
-                    Nginx,
-                    extension_configuration=NginxConfiguration(
-                        www_directory_path="/tmp/overridden-www",
-                    ),
-                )
-            )
-            expected = """
-server {
-    listen 80;
-    server_name example.com;
-    return 301 https://$host$request_uri;
-}
-server {
-    add_header Vary Accept-Language;
-    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
-    add_header Cache-Control "max-age=86400";
-    listen 443 ssl http2;
-    server_name example.com;
-    root /tmp/overridden-www;
-    gzip on;
-    gzip_disable "msie6";
-    gzip_vary on;
-    gzip_types text/css application/javascript application/json application/xml;
-
-    set $media_type_extension html;
-    index index.$media_type_extension;
-
-    location / {
-        # Handle HTTP error responses.
-        error_page 401 /.error/401.$media_type_extension;
-        error_page 403 /.error/403.$media_type_extension;
-        error_page 404 /.error/404.$media_type_extension;
-        location /.error {
-            internal;
-    }
-
-    try_files $uri $uri/ =404;
-    }
-}
-"""
-            await self._assert_configuration_equals(expected, app)
+            await generate(app)
+            assert (
+                app.project.configuration.output_directory_path / "nginx" / "nginx.conf"
+            ).exists()
+            assert (
+                app.project.configuration.output_directory_path
+                / "nginx"
+                / "content_negotiation.lua"
+            ).exists()
+            assert (
+                app.project.configuration.output_directory_path / "nginx" / "Dockerfile"
+            ).exists()
diff --git a/betty/tests/extension/nginx/test_artifact.py b/betty/tests/extension/nginx/test_artifact.py
new file mode 100644
index 000000000..5289b18d0
--- /dev/null
+++ b/betty/tests/extension/nginx/test_artifact.py
@@ -0,0 +1,404 @@
+import re
+from typing import Optional
+
+from betty.app import App
+from betty.extension import Nginx
+from betty.extension.nginx.artifact import (
+    generate_configuration_file,
+    generate_dockerfile_file,
+)
+from betty.extension.nginx.config import NginxConfiguration
+from betty.project import ExtensionConfiguration, LocaleConfiguration
+
+
+class TestGenerateConfigurationFile:
+    _LEADING_WHITESPACE_PATTERN = re.compile(r"^\s*(.*?)$")
+
+    def _normalize_configuration(self, configuration: str) -> str:
+        return "\n".join(
+            filter(
+                None,
+                map(self._normalize_configuration_line, configuration.splitlines()),
+            )
+        )
+
+    def _normalize_configuration_line(self, line: str) -> Optional[str]:
+        match = self._LEADING_WHITESPACE_PATTERN.fullmatch(line)
+        if match is None:
+            return None
+        return match.group(1)
+
+    async def _assert_configuration_equals(self, expected: str, app: App):
+        await generate_configuration_file(app)
+        with open(
+            app.project.configuration.output_directory_path / "nginx" / "nginx.conf"
+        ) as f:
+            actual = f.read()
+        assert self._normalize_configuration(expected) == self._normalize_configuration(
+            actual
+        )
+
+    async def test(self):
+        async with App.new_temporary() as app, app:
+            app.project.configuration.base_url = "http://example.com"
+            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
+            expected = (
+                r"""
+server {
+    add_header Vary Accept-Language;
+    add_header Cache-Control "max-age=86400";
+    listen 80;
+    server_name example.com;
+    root %s;
+    gzip on;
+    gzip_disable "msie6";
+    gzip_vary on;
+    gzip_types text/css application/javascript application/json application/xml;
+
+    set $media_type_extension html;
+    index index.$media_type_extension;
+
+    location / {
+        # Handle HTTP error responses.
+        error_page 401 /.error/401.$media_type_extension;
+        error_page 403 /.error/403.$media_type_extension;
+        error_page 404 /.error/404.$media_type_extension;
+        location /.error {
+            internal;
+        }
+
+        try_files $uri $uri/ =404;
+    }
+}
+"""
+                % app.project.configuration.www_directory_path
+            )
+            await self._assert_configuration_equals(expected, app)
+
+    async def test_multilingual(self):
+        async with App.new_temporary() as app, app:
+            app.project.configuration.base_url = "http://example.com"
+            app.project.configuration.locales.replace(
+                LocaleConfiguration(
+                    "en-US",
+                    alias="en",
+                ),
+                LocaleConfiguration(
+                    "nl-NL",
+                    alias="nl",
+                ),
+            )
+            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
+            expected = (
+                r"""
+server {
+    add_header Vary Accept-Language;
+    add_header Cache-Control "max-age=86400";
+    listen 80;
+    server_name example.com;
+    root %s;
+    gzip on;
+    gzip_disable "msie6";
+    gzip_vary on;
+    gzip_types text/css application/javascript application/json application/xml;
+
+    set $media_type_extension html;
+    index index.$media_type_extension;
+
+    location @localized_redirect {
+        set $locale_alias en;
+        return 301 /$locale_alias$uri;
+    }
+
+
+    # The front page.
+    location = / {
+        # nginx does not support redirecting to named locations, so we use try_files with an empty first
+        # argument and assume that never matches a real file.
+        try_files '' @localized_redirect;
+    }
+
+    # Localized resources.
+    location ~* ^/(en|nl)(/|$) {
+        set $locale $1;
+        add_header Vary Accept-Language;
+        add_header Cache-Control "max-age=86400";
+        add_header Content-Language "$locale" always;
+
+        # Handle HTTP error responses.
+        error_page 401 /$locale/.error/401.$media_type_extension;
+        error_page 403 /$locale/.error/403.$media_type_extension;
+        error_page 404 /$locale/.error/404.$media_type_extension;
+        location ~ ^/$locale/\.error {
+            internal;
+        }
+
+        try_files $uri $uri/ =404;
+    }
+
+    # Static resources.
+    location / {
+        # Handle HTTP error responses.
+        error_page 401 /en/.error/401.$media_type_extension;
+        error_page 403 /en/.error/403.$media_type_extension;
+        error_page 404 /en/.error/404.$media_type_extension;
+        location ~ ^/en/\.error {
+            internal;
+        }
+        try_files $uri $uri/ =404;
+    }
+}
+"""
+                % app.project.configuration.www_directory_path
+            )
+            await self._assert_configuration_equals(expected, app)
+
+    async def test_multilingual_with_clean_urls(self):
+        async with App.new_temporary() as app, app:
+            app.project.configuration.base_url = "http://example.com"
+            app.project.configuration.clean_urls = True
+            app.project.configuration.locales.replace(
+                LocaleConfiguration(
+                    "en-US",
+                    alias="en",
+                ),
+                LocaleConfiguration(
+                    "nl-NL",
+                    alias="nl",
+                ),
+            )
+            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
+            expected = (
+                r"""
+server {
+    add_header Vary Accept-Language;
+    add_header Cache-Control "max-age=86400";
+    listen 80;
+    server_name example.com;
+    root %s;
+    gzip on;
+    gzip_disable "msie6";
+    gzip_vary on;
+    gzip_types text/css application/javascript application/json application/xml;
+
+    set_by_lua_block $media_type_extension {
+        local available_media_types = {'text/html', 'application/json'}
+        local media_type_extensions = {}
+        media_type_extensions['text/html'] = 'html'
+        media_type_extensions['application/json'] = 'json'
+        local media_type = require('content_negotiation').negotiate(ngx.req.get_headers()['Accept'], available_media_types)
+        return media_type_extensions[media_type]
+    }
+    index index.$media_type_extension;
+    location @localized_redirect {
+        set_by_lua_block $locale_alias {
+            local available_locales = {'en-US', 'nl-NL'}
+            local locale_aliases = {}
+            locale_aliases['en-US'] = 'en'
+            locale_aliases['nl-NL'] = 'nl'
+            local locale = require('content_negotiation').negotiate(ngx.req.get_headers()['Accept-Language'], available_locales)
+            return locale_aliases[locale]
+        }
+        add_header Vary Accept-Language;
+        add_header Cache-Control "max-age=86400";
+        add_header Content-Language "$locale_alias" always;
+
+        return 307 /$locale_alias$uri;
+    }
+
+    # The front page.
+    location = / {
+        # nginx does not support redirecting to named locations, so we use try_files with an empty first
+        # argument and assume that never matches a real file.
+        try_files '' @localized_redirect;
+    }
+
+    # Localized resources.
+    location ~* ^/(en|nl)(/|$) {
+        set $locale $1;
+        add_header Vary Accept-Language;
+        add_header Cache-Control "max-age=86400";
+        add_header Content-Language "$locale" always;
+
+        # Handle HTTP error responses.
+        error_page 401 /$locale/.error/401.$media_type_extension;
+        error_page 403 /$locale/.error/403.$media_type_extension;
+        error_page 404 /$locale/.error/404.$media_type_extension;
+        location ~ ^/$locale/\.error {
+            internal;
+        }
+
+        try_files $uri $uri/ =404;
+    }
+
+    # Static resources.
+    location / {
+        # Handle HTTP error responses.
+        error_page 401 /en/.error/401.$media_type_extension;
+        error_page 403 /en/.error/403.$media_type_extension;
+        error_page 404 /en/.error/404.$media_type_extension;
+        location ~ ^/en/\.error {
+            internal;
+        }
+        try_files $uri $uri/ =404;
+    }
+}
+"""
+                % app.project.configuration.www_directory_path
+            )
+            await self._assert_configuration_equals(expected, app)
+
+    async def test_with_clean_urls(self):
+        async with App.new_temporary() as app, app:
+            app.project.configuration.base_url = "http://example.com"
+            app.project.configuration.clean_urls = True
+            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
+            expected = (
+                r"""
+server {
+    add_header Vary Accept-Language;
+    add_header Cache-Control "max-age=86400";
+    listen 80;
+    server_name example.com;
+    root %s;
+    gzip on;
+    gzip_disable "msie6";
+    gzip_vary on;
+    gzip_types text/css application/javascript application/json application/xml;
+
+    set_by_lua_block $media_type_extension {
+        local available_media_types = {'text/html', 'application/json'}
+        local media_type_extensions = {}
+        media_type_extensions['text/html'] = 'html'
+        media_type_extensions['application/json'] = 'json'
+        local media_type = require('content_negotiation').negotiate(ngx.req.get_headers()['Accept'], available_media_types)
+        return media_type_extensions[media_type]
+    }
+    index index.$media_type_extension;
+
+    location / {
+        # Handle HTTP error responses.
+        error_page 401 /.error/401.$media_type_extension;
+        error_page 403 /.error/403.$media_type_extension;
+        error_page 404 /.error/404.$media_type_extension;
+        location /.error {
+            internal;
+        }
+
+        try_files $uri $uri/ =404;
+    }
+}"""
+                % app.project.configuration.www_directory_path
+            )
+            await self._assert_configuration_equals(expected, app)
+
+    async def test_with_https(self):
+        async with App.new_temporary() as app, app:
+            app.project.configuration.base_url = "https://example.com"
+            app.project.configuration.extensions.append(ExtensionConfiguration(Nginx))
+            expected = (
+                r"""
+server {
+    listen 80;
+    server_name example.com;
+    return 301 https://$host$request_uri;
+}
+server {
+    add_header Vary Accept-Language;
+    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+    add_header Cache-Control "max-age=86400";
+    listen 443 ssl http2;
+    server_name example.com;
+    root %s;
+    gzip on;
+    gzip_disable "msie6";
+    gzip_vary on;
+    gzip_types text/css application/javascript application/json application/xml;
+
+    set $media_type_extension html;
+    index index.$media_type_extension;
+
+    location / {
+        # Handle HTTP error responses.
+        error_page 401 /.error/401.$media_type_extension;
+        error_page 403 /.error/403.$media_type_extension;
+        error_page 404 /.error/404.$media_type_extension;
+        location /.error {
+            internal;
+    }
+
+    try_files $uri $uri/ =404;
+    }
+}
+"""
+                % app.project.configuration.www_directory_path
+            )
+            await self._assert_configuration_equals(expected, app)
+
+    async def test_with_overridden_www_directory_path(self):
+        async with App.new_temporary() as app, app:
+            app.project.configuration.extensions.append(
+                ExtensionConfiguration(
+                    Nginx,
+                    extension_configuration=NginxConfiguration(
+                        www_directory_path="/tmp/overridden-www",
+                    ),
+                )
+            )
+            expected = """
+server {
+    listen 80;
+    server_name example.com;
+    return 301 https://$host$request_uri;
+}
+server {
+    add_header Vary Accept-Language;
+    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+    add_header Cache-Control "max-age=86400";
+    listen 443 ssl http2;
+    server_name example.com;
+    root /tmp/overridden-www;
+    gzip on;
+    gzip_disable "msie6";
+    gzip_vary on;
+    gzip_types text/css application/javascript application/json application/xml;
+
+    set $media_type_extension html;
+    index index.$media_type_extension;
+
+    location / {
+        # Handle HTTP error responses.
+        error_page 401 /.error/401.$media_type_extension;
+        error_page 403 /.error/403.$media_type_extension;
+        error_page 404 /.error/404.$media_type_extension;
+        location /.error {
+            internal;
+    }
+
+    try_files $uri $uri/ =404;
+    }
+}
+"""
+            await self._assert_configuration_equals(expected, app)
+
+
+class TestGenerateDockerfileFile:
+    async def test(self) -> None:
+        async with App.new_temporary() as app, app:
+            app.project.configuration.extensions.append(
+                ExtensionConfiguration(
+                    Nginx,
+                    extension_configuration=NginxConfiguration(
+                        www_directory_path="/tmp/overridden-www",
+                    ),
+                )
+            )
+            await generate_dockerfile_file(app)
+        assert (
+            app.project.configuration.output_directory_path
+            / "nginx"
+            / "content_negotiation.lua"
+        ).exists()
+        assert (
+            app.project.configuration.output_directory_path / "nginx" / "Dockerfile"
+        ).exists()
diff --git a/betty/tests/extension/nginx/test_serve.py b/betty/tests/extension/nginx/test_serve.py
index de363b4e6..798cda190 100644
--- a/betty/tests/extension/nginx/test_serve.py
+++ b/betty/tests/extension/nginx/test_serve.py
@@ -4,6 +4,8 @@
 import pytest
 import requests
 from aiofiles.os import makedirs
+from docker.errors import DockerException
+from pytest_mock import MockerFixture
 from requests import Response
 
 from betty.app import App
@@ -12,14 +14,15 @@
 from betty.extension.nginx.serve import DockerizedNginxServer
 from betty.functools import Do
 from betty.project import ExtensionConfiguration
+from betty.serve import NoPublicUrlBecauseServerNotStartedError
 
 
-@pytest.mark.skipif(
-    sys.platform in {"darwin", "win32"},
-    reason="macOS and Windows do not natively support Docker.",
-)
 class TestDockerizedNginxServer:
-    async def test(self):
+    @pytest.mark.skipif(
+        sys.platform in {"darwin", "win32"},
+        reason="macOS and Windows do not natively support Docker.",
+    )
+    async def test_context_manager(self):
         content = "Hello, and welcome to my site!"
         async with App.new_temporary() as app, app:
             app.project.configuration.extensions.append(
@@ -43,3 +46,30 @@ def _assert_response(response: Response) -> None:
                     assert "no-cache" == response.headers["Cache-Control"]
 
                 await Do(requests.get, server.public_url).until(_assert_response)
+
+    async def test_public_url_unstarted(self) -> None:
+        async with App.new_temporary() as app, app:
+            app.project.configuration.extensions.enable(Nginx)
+            sut = DockerizedNginxServer(app)
+            with pytest.raises(NoPublicUrlBecauseServerNotStartedError):
+                sut.public_url
+
+    async def test_is_available_is_available(self, mocker: MockerFixture) -> None:
+        async with App.new_temporary() as app, app:
+            app.project.configuration.extensions.enable(Nginx)
+            sut = DockerizedNginxServer(app)
+
+            m_from_env = mocker.patch("docker.from_env")
+            m_from_env.return_value = mocker.Mock("docker.client.DockerClient")
+
+            assert sut.is_available()
+
+    async def test_is_available_is_unavailable(self, mocker: MockerFixture) -> None:
+        async with App.new_temporary() as app, app:
+            app.project.configuration.extensions.enable(Nginx)
+            sut = DockerizedNginxServer(app)
+
+            m_from_env = mocker.patch("docker.from_env")
+            m_from_env.side_effect = DockerException()
+
+            assert not sut.is_available()
diff --git a/betty/tests/test_tests_exist.py b/betty/tests/test_tests_exist.py
index 89883c060..960627608 100644
--- a/betty/tests/test_tests_exist.py
+++ b/betty/tests/test_tests_exist.py
@@ -26,7 +26,6 @@ class TestTestsExist:
         "betty.dispatch",
         "betty.error",
         "betty.extension.__init__",
-        "betty.extension.nginx.artifact",
         "betty.extension.nginx.docker",
         "betty.extension.webpack.jinja2.__init__",
         "betty.extension.webpack.jinja2.filter",