add HTTPS support for flask run command

CHANGES

@@ -118,6 +118,8 @@ Major release, unreleased
 - The dev server now uses threads by default. (`#2529`_)
 - Loading config files with ``silent=True`` will ignore ``ENOTDIR``
   errors. (`#2581`_)
+- Pass ``--cert`` and ``--key`` options to ``flask run`` to run the
+  development server over HTTPS. (`#2606`_)
 
 .. _pallets/meta#24: https://github.com/pallets/meta/issues/24
 .. _#1421: https://github.com/pallets/flask/issues/1421
@@ -154,6 +156,7 @@ Major release, unreleased
 .. _#2450: https://github.com/pallets/flask/pull/2450
 .. _#2529: https://github.com/pallets/flask/pull/2529
 .. _#2581: https://github.com/pallets/flask/pull/2581
+.. _#2606: https://github.com/pallets/flask/pull/2606
 
 
 Version 0.12.3

flask/cli.py

@@ -14,6 +14,7 @@ import ast
 import inspect
 import os
 import re
+import ssl
 import sys
 import traceback
 from functools import update_wrapper
@@ -21,9 +22,10 @@ from operator import attrgetter
 from threading import Lock, Thread
 
 import click
+from werkzeug.utils import import_string
 
 from . import __version__
-from ._compat import getargspec, iteritems, reraise
+from ._compat import getargspec, iteritems, reraise, text_type
 from .globals import current_app
 from .helpers import get_debug_flag, get_env
 
@@ -599,11 +601,96 @@ def show_server_banner(env, debug, app_import_path):
         print(' * Debug mode: {0}'.format('on' if debug else 'off'))
 
 
+class CertParamType(click.ParamType):
+    """Click option type for the ``--cert`` option. Allows either an
+    existing file, the string ``'adhoc'``, or an import for a
+    :class:`~ssl.SSLContext` object.
+    """
+
+    name = 'path'
+
+    def __init__(self):
+        self.path_type = click.Path(
+            exists=True, dir_okay=False, resolve_path=True)
+
+    def convert(self, value, param, ctx):
+        try:
+            return self.path_type(value, param, ctx)
+        except click.BadParameter:
+            value = click.STRING(value, param, ctx).lower()
+
+            if value == 'adhoc':
+                try:
+                    import OpenSSL
+                except ImportError:
+                    raise click.BadParameter(
+                        'Using ad-hoc certificates requires pyOpenSSL.',
+                        ctx, param)
+
+                return value
+
+            obj = import_string(value, silent=True)
+
+            if sys.version_info < (2, 7):
+                if obj:
+                    return obj
+            else:
+                if isinstance(obj, ssl.SSLContext):
+                    return obj
+
+            raise
+
+
+def _validate_key(ctx, param, value):
+    """The ``--key`` option must be specified when ``--cert`` is a file.
+    Modifies the ``cert`` param to be a ``(cert, key)`` pair if needed.
+    """
+    cert = ctx.params.get('cert')
+    is_adhoc = cert == 'adhoc'
+
+    if sys.version_info < (2, 7):
+        is_context = cert and not isinstance(cert, (text_type, bytes))
+    else:
+        is_context = isinstance(cert, ssl.SSLContext)
+
+    if value is not None:
+        if is_adhoc:
+            raise click.BadParameter(
+                'When "--cert" is "adhoc", "--key" is not used.',
+                ctx, param)
+
+        if is_context:
+            raise click.BadParameter(
+                'When "--cert" is an SSLContext object, "--key is not used.',
+                ctx, param)
+
+        if not cert:
+            raise click.BadParameter(
+                '"--cert" must also be specified.',
+                ctx, param)
+
+        ctx.params['cert'] = cert, value
+
+    else:
+        if cert and not (is_adhoc or is_context):
+            raise click.BadParameter(
+                'Required when using "--cert".',
+                ctx, param)
+
+    return value
+
+
 @click.command('run', short_help='Runs a development server.')
 @click.option('--host', '-h', default='127.0.0.1',
               help='The interface to bind to.')
 @click.option('--port', '-p', default=5000,
               help='The port to bind to.')
+@click.option('--cert', type=CertParamType(),
+              help='Specify a certificate file to use HTTPS.')
+@click.option('--key',
+              type=click.Path(exists=True, dir_okay=False, resolve_path=True),
+              callback=_validate_key, expose_value=False,
+              help='The key file to use when specifying a certificate.')
 @click.option('--reload/--no-reload', default=None,
               help='Enable or disable the reloader. By default the reloader '
               'is active if debug is enabled.')
@@ -617,7 +704,7 @@ def show_server_banner(env, debug, app_import_path):
               help='Enable or disable multithreading.')
 @pass_script_info
 def run_command(info, host, port, reload, debugger, eager_loading,
-                with_threads):
+                with_threads, cert):
     """Run a local development server.
 
     This server is for development purposes only. It does not provide
@@ -642,7 +729,7 @@ def run_command(info, host, port, reload, debugger, eager_loading,
 
     from werkzeug.serving import run_simple
     run_simple(host, port, app, use_reloader=reload, use_debugger=debugger,
-               threaded=with_threads)
+               threaded=with_threads, ssl_context=cert)
 
 
 @click.command('shell', short_help='Runs a shell in the app context.')

tests/test_cli.py

@@ -14,7 +14,9 @@
 from __future__ import absolute_import
 
 import os
+import ssl
 import sys
+import types
 from functools import partial
 
 import click
@@ -24,8 +26,8 @@ from click.testing import CliRunner
 
 from flask import Flask, current_app
 from flask.cli import (
-    AppGroup, FlaskGroup, NoAppException, ScriptInfo, dotenv,
+    AppGroup, FlaskGroup, NoAppException, ScriptInfo, dotenv, find_best_app,
-    find_best_app, get_version, load_dotenv, locate_app, prepare_import,
+    get_version, load_dotenv, locate_app, prepare_import, run_command,
     with_appcontext
 )
 
@@ -464,3 +466,62 @@ def test_dotenv_optional(monkeypatch):
     monkeypatch.chdir(test_path)
     load_dotenv()
     assert 'FOO' not in os.environ
+
+
+def test_run_cert_path():
+    # no key
+    with pytest.raises(click.BadParameter):
+        run_command.make_context('run', ['--cert', __file__])
+
+    # no cert
+    with pytest.raises(click.BadParameter):
+        run_command.make_context('run', ['--key', __file__])
+
+    ctx = run_command.make_context(
+        'run', ['--cert', __file__, '--key', __file__])
+    assert ctx.params['cert'] == (__file__, __file__)
+
+
+def test_run_cert_adhoc(monkeypatch):
+    monkeypatch.setitem(sys.modules, 'OpenSSL', None)
+
+    # pyOpenSSL not installed
+    with pytest.raises(click.BadParameter):
+        run_command.make_context('run', ['--cert', 'adhoc'])
+
+    # pyOpenSSL installed
+    monkeypatch.setitem(sys.modules, 'OpenSSL', types.ModuleType('OpenSSL'))
+    ctx = run_command.make_context('run', ['--cert', 'adhoc'])
+    assert ctx.params['cert'] == 'adhoc'
+
+    # no key with adhoc
+    with pytest.raises(click.BadParameter):
+        run_command.make_context('run', ['--cert', 'adhoc', '--key', __file__])
+
+
+def test_run_cert_import(monkeypatch):
+    monkeypatch.setitem(sys.modules, 'not_here', None)
+
+    # ImportError
+    with pytest.raises(click.BadParameter):
+        run_command.make_context('run', ['--cert', 'not_here'])
+
+    # not an SSLContext
+    if sys.version_info >= (2, 7):
+        with pytest.raises(click.BadParameter):
+            run_command.make_context('run', ['--cert', 'flask'])
+
+    # SSLContext
+    if sys.version_info < (2, 7):
+        ssl_context = object()
+    else:
+        ssl_context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
+
+    monkeypatch.setitem(sys.modules, 'ssl_context', ssl_context)
+    ctx = run_command.make_context('run', ['--cert', 'ssl_context'])
+    assert ctx.params['cert'] is ssl_context
+
+    # no --key with SSLContext
+    with pytest.raises(click.BadParameter):
+        run_command.make_context(
+            'run', ['--cert', 'ssl_context', '--key', __file__])