envoyproxy · htuch · Sep 16, 2020 · Sep 9, 2020 · Sep 9, 2020 · Sep 9, 2020
diff --git a/api/envoy/config/core/v3/substitution_format_string.proto b/api/envoy/config/core/v3/substitution_format_string.proto
@@ -65,4 +65,14 @@ message SubstitutionFormatString {
   //   empty string, so that empty values are omitted entirely.
   // * for ``json_format`` the keys with null values are omitted in the output structure.
   bool omit_empty_values = 3;
+
+  // Specify a *content_type* field.
+  // If this field is not set then ``text/plain`` is used for *text_format* and
+  // ``application/json`` is used for *json_format*.
+  //
+  // .. code-block::
+  //
+  //   content_type: "text/html; charset=UTF-8"
+  //
+  string content_type = 4;
 }
diff --git a/api/envoy/config/core/v4alpha/substitution_format_string.proto b/api/envoy/config/core/v4alpha/substitution_format_string.proto
diff --git a/docs/root/configuration/http/http_conn_man/local_reply.rst b/docs/root/configuration/http/http_conn_man/local_reply.rst
@@ -49,6 +49,8 @@ The response body content type can be customized. If not specified, the content
 
 Local reply format can be specified as :ref:`SubstitutionFormatString <envoy_v3_api_msg_config.core.v3.SubstitutionFormatString>`. It supports :ref:`text_format <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.text_format>` and :ref:`json_format <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.json_format>`.
 
+Optionally, content-type can be modified further via :ref:`content_type <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.content_type>` field. If not specified, default content-type is `text/plain` for :ref:`text_format <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.text_format>` and `application/json` for :ref:`json_format <envoy_v3_api_field_config.core.v3.SubstitutionFormatString.json_format>`.
+
 Example of a LocalReplyConfig with `body_format` field.
 
 .. code-block::
@@ -63,7 +65,8 @@ Example of a LocalReplyConfig with `body_format` field.
             runtime_key: key_b
     status_code: 401
     body_format_override:
-      text_format: "%LOCAL_REPLY_BODY% %REQ(:path)%"
+      text_format: "<h1>%LOCAL_REPLY_BODY% %REQ(:path)%</h1>"
+      content_type: "text/html; charset=UTF-8"
   - filter:
       status_code_filter:
         comparison:

diff --git a/docs/root/version_history/current.rst b/docs/root/version_history/current.rst
@@ -84,6 +84,7 @@ New Features
 * load balancer: added a :ref:`configuration<envoy_v3_api_msg_config.cluster.v3.Cluster.LeastRequestLbConfig>` option to specify the active request bias used by the least request load balancer.
 * load balancer: added an :ref:`option <envoy_v3_api_field_config.cluster.v3.Cluster.LbSubsetConfig.LbSubsetSelector.single_host_per_subset>` to optimize subset load balancing when there is only one host per subset.
 * load balancer: added support for bounded load per host for consistent hash load balancers via :ref:`hash_balance_factor <envoy_api_field_Cluster.CommonLbConfig.consistent_hashing_lb_config>`.
+* local_reply config: added :ref:`content_type<envoy_v3_api_field_config.core.v3.SubstitutionFormatString.content_type>` field to set content-type.
 * lua: added Lua APIs to access :ref:`SSL connection info <config_http_filters_lua_ssl_socket_info>` object.
 * lua: added Lua API for :ref:`base64 escaping a string <config_http_filters_lua_stream_handle_api_base64_escape>`.
 * lua: added new :ref:`source_code <envoy_v3_api_field_extensions.filters.http.lua.v3.LuaPerRoute.source_code>` field to support the dispatching of inline Lua code in per route configuration of Lua filter.

diff --git a/generated_api_shadow/envoy/config/core/v3/substitution_format_string.proto b/generated_api_shadow/envoy/config/core/v3/substitution_format_string.proto
diff --git a/generated_api_shadow/envoy/config/core/v4alpha/substitution_format_string.proto b/generated_api_shadow/envoy/config/core/v4alpha/substitution_format_string.proto
diff --git a/source/common/local_reply/local_reply.cc b/source/common/local_reply/local_reply.cc
@@ -23,10 +23,12 @@ class BodyFormatter {
   BodyFormatter(const envoy::config::core::v3::SubstitutionFormatString& config)
       : formatter_(Formatter::SubstitutionFormatStringUtils::fromProtoConfig(config)),
         content_type_(
-            config.format_case() ==
-                    envoy::config::core::v3::SubstitutionFormatString::FormatCase::kJsonFormat
-                ? Http::Headers::get().ContentTypeValues.Json
-                : Http::Headers::get().ContentTypeValues.Text) {}
+            !config.content_type().empty()
+                ? config.content_type()
+                : config.format_case() ==
+                          envoy::config::core::v3::SubstitutionFormatString::FormatCase::kJsonFormat
+                      ? Http::Headers::get().ContentTypeValues.Json
+                      : Http::Headers::get().ContentTypeValues.Text) {}
 
   void format(const Http::RequestHeaderMap& request_headers,
               const Http::ResponseHeaderMap& response_headers,
@@ -40,7 +42,7 @@ class BodyFormatter {
 
 private:
   const Formatter::FormatterPtr formatter_;
-  const absl::string_view content_type_;
+  const std::string content_type_;
 };
 
 using BodyFormatterPtr = std::unique_ptr<BodyFormatter>;

diff --git a/test/common/local_reply/local_reply_test.cc b/test/common/local_reply/local_reply_test.cc
@@ -336,5 +336,85 @@ TEST_F(LocalReplyTest, TestHeaderAddition) {
   ASSERT_EQ(out[1], "append-bar3");
 }
 
+TEST_F(LocalReplyTest, TestMapperWithContentType) {
+  // Match with response_code, and rewrite the code and body.
+  const std::string yaml = R"(
+    mappers:
+    - filter:
+        status_code_filter:
+          comparison:
+            op: EQ
+            value:
+              default_value: 400
+              runtime_key: key_b
+      status_code: 401
+      body:
+        inline_string: "401 body text"
+      body_format_override:
+        text_format: "<h1>%LOCAL_REPLY_BODY%</h1>"
+        content_type: "text/html; charset=UTF-8"
+    - filter:
+        status_code_filter:
+          comparison:
+            op: EQ
+            value:
+              default_value: 410
+              runtime_key: key_b
+      status_code: 411
+      body:
+        inline_string: "411 body text"
+    - filter:
+        status_code_filter:
+          comparison:
+            op: EQ
+            value:
+              default_value: 420
+              runtime_key: key_b
+      status_code: 421
+      body:
+        inline_string: "421 body text"
+      body_format_override:
+        text_format: "%LOCAL_REPLY_BODY%"
+    body_format:
+      text_format: "<h1>%LOCAL_REPLY_BODY%</h1> %RESPONSE_CODE% default formatter"
+      content_type: "text/html; charset=UTF-8"
+)";
+  TestUtility::loadFromYaml(yaml, config_);
+  auto local = Factory::create(config_, context_);
+
+  // code=400 matches the first filter; rewrite code and body
+  // has its own formatter.
+  // content-type is explicitly set to text/html; charset=UTF-8.
+  resetData(400);
+  local->rewrite(&request_headers_, response_headers_, stream_info_, code_, body_, content_type_);
+  EXPECT_EQ(code_, static_cast<Http::Code>(401));
+  EXPECT_EQ(stream_info_.response_code_, 401U);
+  EXPECT_EQ(response_headers_.Status()->value().getStringView(), "401");
+  EXPECT_EQ(body_, "<h1>401 body text</h1>");
+  EXPECT_EQ(content_type_, "text/html; charset=UTF-8");
+
+  // code=410 matches the second filter; rewrite code and body
+  // but using default formatter.
+  // content-type is explicitly set to text/html; charset=UTF-8.
+  resetData(410);
+  local->rewrite(&request_headers_, response_headers_, stream_info_, code_, body_, content_type_);
+  EXPECT_EQ(code_, static_cast<Http::Code>(411));
+  EXPECT_EQ(stream_info_.response_code_, 411U);
+  EXPECT_EQ(response_headers_.Status()->value().getStringView(), "411");
+  EXPECT_EQ(body_, "<h1>411 body text</h1> 411 default formatter");
+  EXPECT_EQ(content_type_, "text/html; charset=UTF-8");
+
+  // code=420 matches the third filter; rewrite code and body
+  // has its own formatter.
+  // default content-type is set based on reply format type.
+  resetData(420);
+  local->rewrite(&request_headers_, response_headers_, stream_info_, code_, body_, content_type_);
+  EXPECT_EQ(code_, static_cast<Http::Code>(421));
+  EXPECT_EQ(stream_info_.response_code_, 421U);
+  EXPECT_EQ(response_headers_.Status()->value().getStringView(), "421");
+  EXPECT_EQ(body_, "421 body text");
+  EXPECT_EQ(content_type_, "text/plain");
+}
+
 } // namespace LocalReply
 } // namespace Envoy