feat: Add support for redirection requests. (#31)

Author: kinyoklion

apps/hello-cpp/main.cpp

@@ -3,7 +3,6 @@
 
 #include <boost/asio/io_context.hpp>
 
-#include "config/detail/builders/data_source_builder.hpp"
 #include "console_backend.hpp"
 #include "context_builder.hpp"
 #include "launchdarkly/client_side/data_sources/detail/streaming_data_source.hpp"
@@ -35,6 +34,12 @@ int main() {
 
     Client client(
         ConfigBuilder(key)
+            .ServiceEndpoints(
+                launchdarkly::client_side::EndpointsBuilder()
+                    // Set to http to demonstrate redirect to https.
+                    .PollingBaseUrl("http://sdk.launchdarkly.com")
+                    .StreamingBaseUrl("https://stream.launchdarkly.com")
+                    .EventsBaseUrl("https://events.launchdarkly.com"))
             .DataSource(DataSourceBuilder()
                             .Method(DataSourceBuilder::Polling().PollInterval(
                                 std::chrono::seconds{30}))

libs/client-sdk/src/api.cpp

@@ -23,11 +23,10 @@ static std::unique_ptr<IDataSource> MakeDataSource(
         return std::make_unique<launchdarkly::client_side::data_sources::
                                     detail::StreamingDataSource>(
             config, executor, context, &flag_updater, status_manager, logger);
-    } else {
-        return std::make_unique<
-            launchdarkly::client_side::data_sources::detail::PollingDataSource>(
-            config, executor, context, &flag_updater, status_manager, logger);
     }
+    return std::make_unique<
+        launchdarkly::client_side::data_sources::detail::PollingDataSource>(
+        config, executor, context, &flag_updater, status_manager, logger);
 }
 
 Client::Client(Config config, Context context)
@@ -48,8 +47,6 @@ Client::Client(Config config, Context context)
                                   status_manager_,
                                   logger_)),
       initialized_(false) {
-    data_source_->Start();
-
     status_manager_.OnDataSourceStatusChange([this](auto status) {
         if (status.State() == DataSourceStatus::DataSourceState::kValid ||
             status.State() == DataSourceStatus::DataSourceState::kShutdown ||
@@ -62,6 +59,9 @@ Client::Client(Config config, Context context)
         }
     });
 
+    // Should listen to status before attempting to start.
+    data_source_->Start();
+
     run_thread_ = std::move(std::thread([&]() { ioc_.run(); }));
 }
 

libs/client-sdk/src/data_sources/polling_data_source.cpp

@@ -9,13 +9,16 @@
 
 namespace launchdarkly::client_side::data_sources::detail {
 
+static char const* const kCouldNotParseEndpoint =
+    "Could not parse polling endpoint URL.";
+
 static network::detail::HttpRequest MakeRequest(Config const& config,
                                                 Context const& context) {
-    std::string url = config.ServiceEndpoints().PollingBaseUrl();
+    auto url = std::make_optional(config.ServiceEndpoints().PollingBaseUrl());
 
-    auto& data_source_config = config.DataSourceConfig();
+    auto const& data_source_config = config.DataSourceConfig();
 
-    auto& polling_config = boost::get<
+    auto const& polling_config = boost::get<
         config::detail::built::PollingConfig<config::detail::ClientSDK>>(
         config.DataSourceConfig().method);
 
@@ -28,27 +31,32 @@ static network::detail::HttpRequest MakeRequest(Config const& config,
     network::detail::HttpMethod method = network::detail::HttpMethod::kGet;
 
     if (data_source_config.use_report) {
-        url.append(polling_config.polling_report_path);
+        url =
+            network::detail::AppendUrl(url, polling_config.polling_report_path);
         method = network::detail::HttpMethod::kReport;
         body = string_context;
     } else {
-        url.append(polling_config.polling_get_path);
+        url = network::detail::AppendUrl(url, polling_config.polling_get_path);
         // When not using 'REPORT' we need to base64
         // encode the context so that we can safely
         // put it in a url.
-        url.append("/" + Base64UrlEncode(string_context));
+        url = network::detail::AppendUrl(url, Base64UrlEncode(string_context));
     }
 
     if (data_source_config.with_reasons) {
-        url.append("?withReasons=true");
+        // TODO: Handle better.
+        if (url) {
+            url->append("?withReasons=true");
+        }
     }
 
     config::detail::builders::HttpPropertiesBuilder<config::detail::ClientSDK>
         builder(config.HttpProperties());
 
     builder.Header("authorization", config.SdkKey());
 
-    return {url, method, builder.Build(), body};
+    // If no URL is set, then we will fail the request.
+    return {url.value_or(""), method, builder.Build(), body};
 }
 
 PollingDataSource::PollingDataSource(Config const& config,
@@ -70,7 +78,7 @@ PollingDataSource::PollingDataSource(Config const& config,
               config.DataSourceConfig().method)
               .poll_interval),
       request_(MakeRequest(config, context)) {
-    auto& polling_config = boost::get<
+    auto const& polling_config = boost::get<
         config::detail::built::PollingConfig<config::detail::ClientSDK>>(
         config.DataSourceConfig().method);
     if (polling_interval_ < polling_config.min_polling_interval) {
@@ -147,7 +155,6 @@ void PollingDataSource::DoPoll() {
 }
 
 void PollingDataSource::StartPollingTimer() {
-    // TODO: Calculate interval based on request time.
     auto time_since_poll_seconds =
         std::chrono::duration_cast<std::chrono::seconds>(
             std::chrono::system_clock::now() - last_poll_start_);
@@ -181,6 +188,17 @@ void PollingDataSource::StartPollingTimer() {
 }
 
 void PollingDataSource::Start() {
+    if (!request_.Valid()) {
+        LD_LOG(logger_, LogLevel::kError) << kCouldNotParseEndpoint;
+        status_manager_.SetState(
+            DataSourceStatus::DataSourceState::kShutdown,
+            DataSourceStatus::ErrorInfo::ErrorKind::kNetworkError,
+            kCouldNotParseEndpoint);
+
+        // No need to attempt to poll if the URL is not valid.
+        return;
+    }
+
     DoPoll();
 }
 

libs/client-sdk/src/data_sources/streaming_data_source.cpp

@@ -10,10 +10,14 @@
 #include "context_builder.hpp"
 #include "launchdarkly/client_side/data_sources/detail/base_64.hpp"
 #include "launchdarkly/client_side/data_sources/detail/streaming_data_source.hpp"
+#include "network/detail/http_requester.hpp"
 #include "serialization/json_context.hpp"
 
 namespace launchdarkly::client_side::data_sources::detail {
 
+static char const* const kCouldNotParseEndpoint =
+    "Could not parse streaming endpoint URL.";
+
 StreamingDataSource::StreamingDataSource(
     Config const& config,
     boost::asio::any_io_executor ioc,
@@ -25,13 +29,6 @@ StreamingDataSource::StreamingDataSource(
       status_manager_(status_manager),
       data_source_handler_(
           DataSourceEventHandler(handler, logger, status_manager_)) {
-    auto uri_components =
-        boost::urls::parse_uri(config.ServiceEndpoints().StreamingBaseUrl());
-
-    // TODO: Handle parsing error?
-    // TODO: Initial reconnect delay.
-    boost::urls::url url = uri_components.value();
-
     auto string_context =
         boost::json::serialize(boost::json::value_from(context));
 
@@ -41,15 +38,32 @@ StreamingDataSource::StreamingDataSource(
         config::detail::built::StreamingConfig<config::detail::ClientSDK>>(
         data_source_config.method);
 
-    // Add the eval endpoint.
-    url.set_path(url.path().append(streaming_config.streaming_path));
+    auto updated_url =
+        network::detail::AppendUrl(config.ServiceEndpoints().StreamingBaseUrl(),
+                                   streaming_config.streaming_path);
 
     if (!data_source_config.use_report) {
         // When not using 'REPORT' we need to base64
         // encode the context so that we can safely
         // put it in a url.
-        url.set_path(url.path().append("/" + Base64UrlEncode(string_context)));
+        updated_url = network::detail::AppendUrl(
+            updated_url, Base64UrlEncode(string_context));
+    }
+    // Bad URL, don't set the client. Start will then report the bad status.
+    if (!updated_url) {
+        return;
     }
+
+    auto uri_components = boost::urls::parse_uri(*updated_url);
+
+    // Unlikely that it could be parsed earlier and it cannot be parsed now.
+    if (!uri_components) {
+        return;
+    }
+
+    // TODO: Initial reconnect delay.
+    boost::urls::url url = uri_components.value();
+
     if (data_source_config.with_reasons) {
         url.params().set("withReasons", "true");
     }
@@ -86,12 +100,22 @@ StreamingDataSource::StreamingDataSource(
 }
 
 void StreamingDataSource::Start() {
+    if (!client_) {
+        LD_LOG(logger_, LogLevel::kError) << kCouldNotParseEndpoint;
+        status_manager_.SetState(
+            DataSourceStatus::DataSourceState::kShutdown,
+            DataSourceStatus::ErrorInfo::ErrorKind::kNetworkError,
+            kCouldNotParseEndpoint);
+        return;
+    }
     client_->run();
 }
 
 void StreamingDataSource::Close() {
     status_manager_.SetState(DataSourceStatus::DataSourceState::kShutdown);
-    client_->close();
+    if (client_) {
+        client_->close();
+    }
 }
 
 }  // namespace launchdarkly::client_side::data_sources::detail

libs/common/include/config/detail/built/data_source_config.hpp

@@ -14,8 +14,7 @@ struct StreamingConfig;
 template <>
 struct StreamingConfig<ClientSDK> {
     std::chrono::milliseconds initial_reconnect_delay;
-
-    inline static const std::string streaming_path = "/meval";
+    std::string streaming_path;
 };
 
 template <>
@@ -29,13 +28,9 @@ struct PollingConfig;
 template <>
 struct PollingConfig<ClientSDK> {
     std::chrono::seconds poll_interval;
-
-    inline const static std::string polling_get_path = "/msdk/evalx/contexts";
-
-    inline const static std::string polling_report_path = "/msdk/evalx/context";
-
-    inline const static std::chrono::seconds min_polling_interval =
-        std::chrono::seconds{30};
+    std::string polling_get_path;
+    std::string polling_report_path;
+    std::chrono::seconds min_polling_interval;
 };
 
 template <>

libs/common/include/config/detail/defaults.hpp

@@ -47,7 +47,7 @@ struct Defaults<ClientSDK> {
     }
 
     static auto StreamingConfig() -> built::StreamingConfig<ClientSDK> {
-        return {std::chrono::milliseconds{1000}};
+        return {std::chrono::milliseconds{1000}, "/meval"};
     }
 
     static auto DataSourceConfig() -> built::DataSourceConfig<ClientSDK> {
@@ -56,7 +56,8 @@ struct Defaults<ClientSDK> {
 
     static auto PollingConfig() -> built::PollingConfig<ClientSDK> {
         // Default to 5 minutes;
-        return {std::chrono::seconds{5 * 60}};
+        return {std::chrono::seconds{5 * 60}, "/msdk/evalx/contexts",
+                "/msdk/evalx/context", std::chrono::seconds{30}};
     }
 };