Add support to set large_client_header_buffers directive

gateway/http.d/core.conf

@@ -1 +1,3 @@
-client_max_body_size 0;
+client_max_body_size 0;
+
+large_client_header_buffers {{env.APICAST_LARGE_CLIENT_HEADER_BUFFERS | default:  "4 8k"}};

t/large-client-header-buffers.t

@@ -0,0 +1,198 @@
+use lib 't';
+use Test::APIcast::Blackbox 'no_plan';
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: large header (the header exceed exceed the size of one buffer)
+Default configuration for large_client_header_buffers: 4 8k
+--- configuration env
+{
+  "services": [
+    {
+      "id": 42,
+      "backend_version":  1,
+      "backend_authentication_type": "service_token",
+      "backend_authentication_value": "token-value",
+      "proxy": {
+        "api_backend": "http://test:$TEST_NGINX_SERVER_PORT/",
+        "proxy_rules": [
+          { "pattern": "/", "http_method": "GET", "metric_system_name": "hits", "delta": 2 }
+        ]
+      }
+    }
+  ]
+}
+--- backend
+  location /transactions/authrep.xml {
+    content_by_lua_block {
+      ngx.exit(ngx.OK)
+    }
+  }
+--- upstream
+
+  client_header_buffer_size 10;
+  location / {
+    content_by_lua_block {
+        ngx.print(ngx.req.raw_header())
+    }
+  }
+--- more_headers eval
+my $s = "User-Agent: curl\nBah: bah\n";
+$s .= "Accept: */*\n";
+$s .= "Large-Header: " . "ABCDEFGH" x 1024 . "\n";
+$s
+--- request
+GET /?user_key=value
+--- error_code: 400
+--- no_error_log
+
+
+
+=== TEST 2: large header with APICAST_LARGE_CLIENT_HEADER_BUFFERS set to 4 12k
+--- env eval
+(
+  'APICAST_LARGE_CLIENT_HEADER_BUFFERS' => '4 12k',
+)
+--- configuration
+{
+  "services": [
+    {
+      "id": 42,
+      "backend_version":  1,
+      "backend_authentication_type": "service_token",
+      "backend_authentication_value": "token-value",
+      "proxy": {
+        "api_backend": "http://test:$TEST_NGINX_SERVER_PORT/",
+        "proxy_rules": [
+          { "pattern": "/", "http_method": "GET", "metric_system_name": "hits", "delta": 2 }
+        ]
+      }
+    }
+  ]
+}
+--- backend
+  location /transactions/authrep.xml {
+    content_by_lua_block {
+      ngx.exit(ngx.OK)
+    }
+  }
+--- upstream
+
+  client_header_buffer_size 10;
+  location / {
+    content_by_lua_block {
+        ngx.print(ngx.req.raw_header())
+    }
+  }
+--- more_headers eval
+my $s = "User-Agent: curl\nBah: bah\n";
+$s .= "Accept: */*\n";
+$s .= "Large-Header: " . "ABCDEFGH" x 1024 . "\n";
+$s
+--- request
+GET /?user_key=value
+--- response_body eval
+"GET /?user_key=value HTTP/1.1\r
+X-Real-IP: 127.0.0.1\r
+Host: test:$ENV{TEST_NGINX_SERVER_PORT}\r
+User-Agent: curl\r
+Bah: bah\r
+Accept: */*\r
+Large-Header: " . ("ABCDEFGH" x 1024) . "\r\n\r\n"
+--- error_code: 200
+--- no_error_log
+
+
+
+=== TEST 3: large request line that exceed default header buffer
+--- configuration env
+{
+  "services": [
+    {
+      "id": 42,
+      "backend_version":  1,
+      "backend_authentication_type": "service_token",
+      "backend_authentication_value": "token-value",
+      "proxy": {
+        "api_backend": "http://test:$TEST_NGINX_SERVER_PORT/",
+        "proxy_rules": [
+          { "pattern": "/", "http_method": "GET", "metric_system_name": "hits", "delta": 2 }
+        ]
+      }
+    }
+  ]
+}
+--- backend
+  location /transactions/authrep.xml {
+    content_by_lua_block {
+      ngx.exit(ngx.OK)
+    }
+  }
+--- upstream
+
+  client_header_buffer_size 10;
+  location / {
+    content_by_lua_block {
+        ngx.print(ngx.req.raw_header())
+    }
+  }
+--- more_headers eval
+my $s = "User-Agent: curl\nBah: bah\n";
+$s .= "Accept: */*\n";
+$s .= "Large-Header: " . "ABCDEFGH" x 1024 . "\n";
+$s
+--- request eval
+"GET /?user_key=value&foo=" . ("ABCDEFGH" x 1024)
+--- error_code: 414
+--- error_log
+client sent too long URI while reading client request line
+
+
+
+=== TEST 4: large request line with APICAST_LARGE_CLIENT_HEADER_BUFFERS set to "4 12k"
+--- env eval
+(
+  'APICAST_LARGE_CLIENT_HEADER_BUFFERS' => '4 12k',
+)
+--- configuration
+{
+  "services": [
+    {
+      "id": 42,
+      "backend_version":  1,
+      "backend_authentication_type": "service_token",
+      "backend_authentication_value": "token-value",
+      "proxy": {
+        "api_backend": "http://test:$TEST_NGINX_SERVER_PORT/",
+        "proxy_rules": [
+          { "pattern": "/", "http_method": "GET", "metric_system_name": "hits", "delta": 2 }
+        ]
+      }
+    }
+  ]
+}
+--- backend
+  location /transactions/authrep.xml {
+    content_by_lua_block {
+      ngx.exit(ngx.OK)
+    }
+  }
+--- upstream
+
+  client_header_buffer_size 10;
+  location / {
+    content_by_lua_block {
+        ngx.print(ngx.req.raw_header())
+    }
+  }
+--- more_headers eval
+my $s = "User-Agent: curl\nBah: bah\n";
+$s .= "Accept: */*\n";
+$s .= "Large-Header: " . "ABCDEFGH" x 1024 . "\n";
+$s
+--- request eval
+"GET /?user_key=value&foo=" . ("ABCDEFGH" x 1024)
+--- error_code: 200
+--- no_error_log