Make flasgger an optional dependency

httpbin/core.py

@@ -33,7 +33,10 @@
 except ImportError:  # werkzeug < 2.1
     from werkzeug.wrappers import BaseResponse as Response
 
-from flasgger import Swagger, NO_SANITIZER
+try:
+    from flasgger import Swagger, NO_SANITIZER
+except ImportError:
+    Swagger = False
 
 from . import filters
 from .helpers import (
@@ -95,77 +98,83 @@ def jsonify(*args, **kwargs):
 
 app.config["SWAGGER"] = {"title": "httpbin.org", "uiversion": 3}
 
-template = {
-    "swagger": "2.0",
-    "info": {
-        "title": "httpbin.org",
-        "description": (
-            "A simple HTTP Request & Response Service."
-            "<br/> A <a href='http://kennethreitz.com/'>Kenneth Reitz</a> project."
-            "<br/> <br/> <b>Run locally: </b> <br/> "
-            "<code>$ docker pull ghcr.io/psf/httpbin</code> <br/>"
-            "<code>$ docker run -p 80:8080 ghcr.io/psf/httpbin</code>"
-        ),
-        "contact": {
-            "responsibleOrganization": "Python Software Foundation",
-            "responsibleDeveloper": "Kenneth Reitz",
-            "url": "https://github.com/psf/httpbin/",
-        },
-        # "termsOfService": "http://me.com/terms",
-        "version": version,
-    },
-    "host": "httpbin.org",  # overrides localhost:5000
-    "basePath": "/",  # base bash for blueprint registration
-    "schemes": ["https"],
-    "protocol": "https",
-    "tags": [
-        {
-            "name": "HTTP Methods",
-            "description": "Testing different HTTP verbs",
-            # 'externalDocs': {'description': 'Learn more', 'url': 'https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html'}
-        },
-        {"name": "Auth", "description": "Auth methods"},
-        {
-            "name": "Status codes",
-            "description": "Generates responses with given status code",
-        },
-        {"name": "Request inspection", "description": "Inspect the request data"},
-        {
-            "name": "Response inspection",
-            "description": "Inspect the response data like caching and headers",
-        },
-        {
-            "name": "Response formats",
-            "description": "Returns responses in different data formats",
-        },
-        {"name": "Dynamic data", "description": "Generates random and dynamic data"},
-        {"name": "Cookies", "description": "Creates, reads and deletes Cookies"},
-        {"name": "Images", "description": "Returns different image formats"},
-        {"name": "Redirects", "description": "Returns different redirect responses"},
-        {
-            "name": "Anything",
-            "description": "Returns anything that is passed to request",
+if Swagger:
+    template = {
+        "swagger": "2.0",
+        "info": {
+            "title": "httpbin.org",
+            "description": (
+                "A simple HTTP Request & Response Service."
+                "<br/> A <a href='http://kennethreitz.com/'>Kenneth Reitz</a> project."
+                "<br/> <br/> <b>Run locally: </b> <br/> "
+                "<code>$ docker pull ghcr.io/psf/httpbin</code> <br/>"
+                "<code>$ docker run -p 80:8080 ghcr.io/psf/httpbin</code>"
+            ),
+            "contact": {
+                "responsibleOrganization": "Python Software Foundation",
+                "responsibleDeveloper": "Kenneth Reitz",
+                "url": "https://github.com/psf/httpbin/",
+            },
+            # "termsOfService": "http://me.com/terms",
+            "version": version,
         },
-    ],
-}
-
-swagger_config = {
-    "headers": [],
-    "specs": [
-        {
-            "endpoint": "spec",
-            "route": "/spec.json",
-            "rule_filter": lambda rule: True,  # all in
-            "model_filter": lambda tag: True,  # all in
-        }
-    ],
-    "static_url_path": "/flasgger_static",
-    # "static_folder": "static",  # must be set by user
-    "swagger_ui": True,
-    "specs_route": "/",
-}
+        "host": "httpbin.org",  # overrides localhost:5000
+        "basePath": "/",  # base bash for blueprint registration
+        "schemes": ["https"],
+        "protocol": "https",
+        "tags": [
+            {
+                "name": "HTTP Methods",
+                "description": "Testing different HTTP verbs",
+                # 'externalDocs': {'description': 'Learn more', 'url': 'https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html'}
+            },
+            {"name": "Auth", "description": "Auth methods"},
+            {
+                "name": "Status codes",
+                "description": "Generates responses with given status code",
+            },
+            {"name": "Request inspection", "description": "Inspect the request data"},
+            {
+                "name": "Response inspection",
+                "description": "Inspect the response data like caching and headers",
+            },
+            {
+                "name": "Response formats",
+                "description": "Returns responses in different data formats",
+            },
+            {"name": "Dynamic data", "description": "Generates random and dynamic data"},
+            {"name": "Cookies", "description": "Creates, reads and deletes Cookies"},
+            {"name": "Images", "description": "Returns different image formats"},
+            {"name": "Redirects", "description": "Returns different redirect responses"},
+            {
+                "name": "Anything",
+                "description": "Returns anything that is passed to request",
+            },
+        ],
+    }
+
+    swagger_config = {
+        "headers": [],
+        "specs": [
+            {
+                "endpoint": "spec",
+                "route": "/spec.json",
+                "rule_filter": lambda rule: True,  # all in
+                "model_filter": lambda tag: True,  # all in
+            }
+        ],
+        "static_url_path": "/flasgger_static",
+        # "static_folder": "static",  # must be set by user
+        "swagger_ui": True,
+        "specs_route": "/",
+    }
 
-swagger = Swagger(app, sanitizer=NO_SANITIZER, template=template, config=swagger_config)
+    swagger = Swagger(app, sanitizer=NO_SANITIZER, template=template, config=swagger_config)
+else:
+    app.logger.warning(
+        "flasgger is not installed; serving the static landing page at / "
+        "and skipping the Swagger UI and /spec.json."
+    )
 
 # Set up Bugsnag exception tracking, if desired. To use Bugsnag, install the
 # Bugsnag Python client with the command "pip install bugsnag", and set the
@@ -243,8 +252,12 @@ def set_cors_headers(response):
 # Routes
 # ------
 
+if Swagger:
+    staticroute = "/legacy"
+else:
+    staticroute = "/"
 
-@app.route("/legacy")
+@app.route(staticroute)
 def view_landing_page():
     """Generates Landing Page in legacy layout."""
     return render_template("index.html")

pyproject.toml

@@ -34,7 +34,6 @@ classifiers = [
 dependencies = [
     "brotlicffi",
     "decorator",
-    "flasgger",
     "flask >= 2.2.4",
     'greenlet < 3.0; python_version<"3.12"',
     'greenlet >= 3.0.0a1; python_version>="3.12.0rc0"',
@@ -46,6 +45,7 @@ dependencies = [
 [project.optional-dependencies]
 test = ["pytest", "tox"]
 mainapp = [
+    "flasgger",
     "gunicorn",
     "gevent",
 ]

tests/test_httpbin.py

@@ -1,7 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 import os
+import sys
 import base64
+import subprocess
 import unittest
 import contextlib
 import json
@@ -796,6 +798,31 @@ def test_etag_with_no_headers(self):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.headers.get('ETag'), 'abc')
 
+    def test_index_falls_back_to_static_page_without_flasgger(self):
+        """When flasgger isn't installed, / serves the static legacy landing
+        page (HTTP 200) instead of the Swagger UI, rather than 500ing.
+
+        flasgger is imported at module load, so this runs in a subprocess that
+        poisons sys.modules['flasgger'] before httpbin is imported.
+        """
+        code = (
+            "import sys\n"
+            "sys.modules['flasgger'] = None\n"  # makes `import flasgger` raise ImportError
+            "import httpbin\n"
+            "assert httpbin.core.Swagger is False, repr(httpbin.core.Swagger)\n"
+            "r = httpbin.app.test_client().get('/')\n"
+            "assert r.status_code == 200, r.status_code\n"
+            "body = r.get_data(as_text=True)\n"
+            "assert 'httpbin(1): HTTP Client Testing Service' in body, 'legacy page not served'\n"
+            "assert 'swagger-ui' not in body, 'swagger UI unexpectedly rendered'\n"
+            "print('OK')\n"
+        )
+        result = subprocess.run(
+            [sys.executable, "-c", code], capture_output=True, text=True
+        )
+        self.assertEqual(result.returncode, 0, result.stderr)
+        self.assertIn("OK", result.stdout)
+
     def test_parse_multi_value_header(self):
         self.assertEqual(parse_multi_value_header('xyzzy'), [ "xyzzy" ])
         self.assertEqual(parse_multi_value_header('"xyzzy"'), [ "xyzzy" ])