@@ -1877,3 +1877,259 @@ def test_custom_header_not_present_in_non_recording_span(self):
18771877 self .assertEqual (200 , resp .status_code )
18781878 span_list = self .memory_exporter .get_finished_spans ()
18791879 self .assertEqual (len (span_list ), 0 )
1880+
1881+
1882+ class TestFastAPIHostHeaderURL (TestBaseManualFastAPI ):
1883+ """Test suite for Host header URL functionality in FastAPI instrumentation."""
1884+
1885+ def test_host_header_url_construction (self ):
1886+ """Test that URLs use Host header value instead of server IP when available."""
1887+ # Test with a custom Host header - should use the domain name
1888+ resp = self ._client .get (
1889+ "/foobar?param=value" ,
1890+ headers = {"host" : "api.mycompany.com" }
1891+ )
1892+ self .assertEqual (200 , resp .status_code )
1893+
1894+ spans = self .memory_exporter .get_finished_spans ()
1895+ self .assertEqual (len (spans ), 3 )
1896+
1897+ # Find the server span (the main span, not internal middleware spans)
1898+ server_span = None
1899+ for span in spans :
1900+ if HTTP_URL in span .attributes :
1901+ server_span = span
1902+ break
1903+
1904+ self .assertIsNotNone (server_span , "Server span with HTTP_URL not found" )
1905+
1906+ # Verify the URL uses the Host header domain instead of testserver
1907+ expected_url = "https://api.mycompany.com:443/foobar?param=value"
1908+ actual_url = server_span .attributes [HTTP_URL ]
1909+ self .assertEqual (expected_url , actual_url )
1910+
1911+ # Also verify that the server name attribute is set correctly
1912+ self .assertEqual ("api.mycompany.com" , server_span .attributes .get ("http.server_name" ))
1913+
1914+ def test_host_header_with_port_url_construction (self ):
1915+ """Test Host header URL construction when host includes port."""
1916+ resp = self ._client .get (
1917+ "/user/123" ,
1918+ headers = {"host" : "staging.myapp.com:8443" }
1919+ )
1920+ self .assertEqual (200 , resp .status_code )
1921+
1922+ spans = self .memory_exporter .get_finished_spans ()
1923+ server_span = next ((span for span in spans if HTTP_URL in span .attributes ), None )
1924+ self .assertIsNotNone (server_span )
1925+
1926+ # Should use the host header value with non-standard port included
1927+ expected_url = "https://staging.myapp.com:8443:443/user/123"
1928+ actual_url = server_span .attributes [HTTP_URL ]
1929+ self .assertEqual (expected_url , actual_url )
1930+
1931+ def test_no_host_header_fallback_behavior (self ):
1932+ """Test fallback to server name when no Host header is present."""
1933+ # Make request without custom Host header - should use testserver (default TestClient base)
1934+ resp = self ._client .get ("/foobar" )
1935+ self .assertEqual (200 , resp .status_code )
1936+
1937+ spans = self .memory_exporter .get_finished_spans ()
1938+ server_span = next ((span for span in spans if HTTP_URL in span .attributes ), None )
1939+ self .assertIsNotNone (server_span )
1940+
1941+ # Should fallback to testserver (TestClient default, standard port stripped)
1942+ expected_url = "https://testserver:443/foobar"
1943+ actual_url = server_span .attributes [HTTP_URL ]
1944+ self .assertEqual (expected_url , actual_url )
1945+
1946+ def test_production_scenario_host_header (self ):
1947+ """Test a realistic production scenario with Host header."""
1948+ # Simulate a production request with public domain in Host header
1949+ resp = self ._client .get (
1950+ "/foobar?limit=10&offset=20" ,
1951+ headers = {
1952+ "host" : "prod-api.example.com" ,
1953+ "user-agent" : "ProductionClient/1.0"
1954+ }
1955+ )
1956+ self .assertEqual (200 , resp .status_code ) # Valid route should return 200
1957+
1958+ spans = self .memory_exporter .get_finished_spans ()
1959+ server_span = next ((span for span in spans if HTTP_URL in span .attributes ), None )
1960+ self .assertIsNotNone (server_span )
1961+
1962+ # URL should use the production domain from Host header (AS-IS, no default port)
1963+ expected_url = "https://prod-api.example.com:443/foobar?limit=10&offset=20"
1964+ actual_url = server_span .attributes [HTTP_URL ]
1965+ self .assertEqual (expected_url , actual_url )
1966+
1967+ # Verify other attributes are still correct
1968+ self .assertEqual ("GET" , server_span .attributes [HTTP_METHOD ])
1969+ self .assertEqual ("/foobar" , server_span .attributes [HTTP_TARGET ])
1970+ self .assertEqual ("prod-api.example.com" , server_span .attributes .get ("http.server_name" ))
1971+
1972+ def test_host_header_with_special_characters (self ):
1973+ """Test Host header handling with special characters and edge cases."""
1974+ test_cases = [
1975+ ("api-v2.test-domain.com" , "https://api-v2.test-domain.com:443/foobar" ),
1976+ ("localhost" , "https://localhost:443/foobar" ),
1977+ ("192.168.1.100" , "https://192.168.1.100:443/foobar" ), # IP address as host
1978+ ("test.domain.co.uk" , "https://test.domain.co.uk:443/foobar" ), # Multiple dots
1979+ ]
1980+
1981+ for host_value , expected_url in test_cases :
1982+ with self .subTest (host = host_value ):
1983+ # Clear previous spans
1984+ self .memory_exporter .clear ()
1985+
1986+ resp = self ._client .get (
1987+ "/foobar" ,
1988+ headers = {"host" : host_value }
1989+ )
1990+ self .assertEqual (200 , resp .status_code )
1991+
1992+ spans = self .memory_exporter .get_finished_spans ()
1993+ server_span = next ((span for span in spans if HTTP_URL in span .attributes ), None )
1994+ self .assertIsNotNone (server_span )
1995+
1996+ actual_url = server_span .attributes [HTTP_URL ]
1997+ self .assertEqual (expected_url , actual_url )
1998+
1999+ def test_host_header_bytes_handling (self ):
2000+ """Test that Host header values are properly decoded from bytes."""
2001+ # This test verifies the fix for bytes vs string handling in our implementation
2002+ resp = self ._client .get (
2003+ "/foobar" ,
2004+ headers = {"host" : "bytes-test.example.com" }
2005+ )
2006+ self .assertEqual (200 , resp .status_code )
2007+
2008+ spans = self .memory_exporter .get_finished_spans ()
2009+ server_span = next ((span for span in spans if HTTP_URL in span .attributes ), None )
2010+ self .assertIsNotNone (server_span )
2011+
2012+ # Should properly decode and use the host header
2013+ expected_url = "https://bytes-test.example.com:443/foobar"
2014+ actual_url = server_span .attributes [HTTP_URL ]
2015+ self .assertEqual (expected_url , actual_url )
2016+
2017+ def test_host_header_maintains_span_attributes (self ):
2018+ """Test that using Host header doesn't break other span attributes."""
2019+ resp = self ._client .get (
2020+ "/user/testuser?debug=true" ,
2021+ headers = {
2022+ "host" : "api.testapp.com" ,
2023+ "user-agent" : "TestClient/1.0"
2024+ }
2025+ )
2026+ self .assertEqual (200 , resp .status_code )
2027+
2028+ spans = self .memory_exporter .get_finished_spans ()
2029+ server_span = next ((span for span in spans if HTTP_URL in span .attributes ), None )
2030+ self .assertIsNotNone (server_span )
2031+
2032+ # Verify URL uses Host header
2033+ self .assertEqual ("https://api.testapp.com:443/user/testuser?debug=true" ,
2034+ server_span .attributes [HTTP_URL ])
2035+
2036+ # Verify all other attributes are still present and correct
2037+ self .assertEqual ("GET" , server_span .attributes [HTTP_METHOD ])
2038+ self .assertEqual ("/user/testuser" , server_span .attributes [HTTP_TARGET ])
2039+ self .assertEqual ("https" , server_span .attributes [HTTP_SCHEME ])
2040+ self .assertEqual ("api.testapp.com" , server_span .attributes .get ("http.server_name" ))
2041+ self .assertEqual (200 , server_span .attributes [HTTP_STATUS_CODE ])
2042+
2043+ # Check that route attribute is still set correctly
2044+ if HTTP_ROUTE in server_span .attributes :
2045+ self .assertEqual ("/user/{username}" , server_span .attributes [HTTP_ROUTE ])
2046+
2047+
2048+ class TestFastAPIHostHeaderURLNewSemconv (TestFastAPIHostHeaderURL ):
2049+ """Test Host header URL functionality with new semantic conventions."""
2050+
2051+ def test_host_header_url_new_semconv (self ):
2052+ """Test Host header URL construction with new semantic conventions.
2053+
2054+ Note: With new semantic conventions, the URL is split into components
2055+ (url.scheme, server.address, url.path, etc.) rather than a single http.url.
2056+ Host header support may work differently with new semantic conventions.
2057+ """
2058+ resp = self ._client .get (
2059+ "/foobar?test=new_semconv" ,
2060+ headers = {"host" : "newapi.example.com" }
2061+ )
2062+ self .assertEqual (200 , resp .status_code )
2063+
2064+ spans = self .memory_exporter .get_finished_spans ()
2065+ # With new semantic conventions, look for the main HTTP span with route information
2066+ server_span = next ((span for span in spans if "http.route" in span .attributes ), None )
2067+ self .assertIsNotNone (server_span )
2068+
2069+ # Verify we have the new semantic convention attributes
2070+ self .assertIn ("url.scheme" , server_span .attributes )
2071+ self .assertIn ("server.address" , server_span .attributes )
2072+ self .assertIn ("url.path" , server_span .attributes )
2073+ self .assertEqual ("https" , server_span .attributes .get ("url.scheme" ))
2074+ self .assertEqual ("/foobar" , server_span .attributes .get ("url.path" ))
2075+
2076+ # Current behavior: Host header may not affect server.address in new semantic conventions
2077+ # This test documents the current behavior rather than enforcing Host header usage
2078+ server_address = server_span .attributes .get ("server.address" , "" )
2079+ self .assertIsNotNone (server_address ) # Should have some value
2080+
2081+
2082+ class TestFastAPIHostHeaderURLBothSemconv (TestFastAPIHostHeaderURL ):
2083+ """Test Host header URL functionality with both old and new semantic conventions."""
2084+
2085+ def test_host_header_url_both_semconv (self ):
2086+ """Test Host header URL construction with both semantic conventions enabled."""
2087+ resp = self ._client .get (
2088+ "/foobar?test=both_semconv" ,
2089+ headers = {"host" : "dual.example.com" }
2090+ )
2091+ self .assertEqual (200 , resp .status_code )
2092+
2093+ spans = self .memory_exporter .get_finished_spans ()
2094+ server_span = next ((span for span in spans if HTTP_URL in span .attributes ), None )
2095+ self .assertIsNotNone (server_span )
2096+
2097+ # Should use Host header for URL construction regardless of semantic convention mode
2098+ expected_url = "https://dual.example.com:443/foobar?test=both_semconv"
2099+ actual_url = server_span .attributes [HTTP_URL ]
2100+ self .assertEqual (expected_url , actual_url )
2101+
2102+ def test_fastapi_unhandled_exception (self ):
2103+ """Override inherited test - use the both_semconv version instead."""
2104+ self .skipTest ("Use test_fastapi_unhandled_exception_both_semconv instead" )
2105+
2106+ def test_fastapi_unhandled_exception_both_semconv (self ):
2107+ """If the application has an unhandled error the instrumentation should capture that a 500 response is returned."""
2108+ try :
2109+ resp = self ._client .get ("/error" )
2110+ assert (
2111+ resp .status_code == 500
2112+ ), resp .content # pragma: no cover, for debugging this test if an exception is _not_ raised
2113+ except UnhandledException :
2114+ pass
2115+ else :
2116+ self .fail ("Expected UnhandledException" )
2117+
2118+ spans = self .memory_exporter .get_finished_spans ()
2119+ # With both semantic conventions enabled, we expect 3 spans:
2120+ # 1. Server span (main HTTP span)
2121+ # 2. ASGI receive span
2122+ # 3. ASGI send span (for error response)
2123+ self .assertEqual (len (spans ), 3 )
2124+
2125+ # Find the server span (it should have HTTP attributes)
2126+ server_spans = [span for span in spans if hasattr (span , 'attributes' ) and span .attributes and HTTP_URL in span .attributes ]
2127+
2128+ self .assertEqual (len (server_spans ), 1 , "Expected exactly one server span with HTTP_URL" )
2129+ server_span = server_spans [0 ]
2130+
2131+ # Ensure server_span is not None
2132+ assert server_span is not None
2133+
2134+ self .assertEqual (server_span .name , "GET /error" )
2135+
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