📚 Update cpp-httplib, log error code on failed HTTP requests (#81)

This change updates us to `v0.8.4` of [cpp-httplib](https://github.com/yhirose/cpp-httplib), which includes a decent number of fixes to bugs that I suspect may be causing some of our HTTPS request failures we're seeing in production.

As a result of some of the changes in the httplib update, a few changes were made to the ServiceConnection implementations to avoid copying of `httplib::Client` and `httplib::Result` instances (they are now backed by `unique_ptr`).

Additional logging detail was also added in the Glimesh HTTP request failure case so we can determine root cause if this doesn't resolve the failures.

Verified by testing against local glimesh.tv instance.

src/ServiceConnections/GlimeshServiceConnection.cpp

@@ -12,6 +12,7 @@
 
 #include "../Utilities/FtlTypes.h"
 
+#include <fmt/core.h>
 #include <jansson.h>
 #include <string.h>
 #include <spdlog/spdlog.h>
@@ -23,6 +24,7 @@ GlimeshServiceConnection::GlimeshServiceConnection(
     bool useHttps,
     std::string clientId,
     std::string clientSecret) : 
+    httpClient(fmt::format("{}://{}:{}", (useHttps ? "https" : "http"), hostname, port).c_str()),
     hostname(hostname),
     port(port),
     useHttps(useHttps),
@@ -193,30 +195,11 @@ Result<void> GlimeshServiceConnection::SendJpegPreviewImage(
 #pragma endregion
 
 #pragma region Private methods
-httplib::Client GlimeshServiceConnection::getHttpClient()
-{
-    std::stringstream baseUri;
-    baseUri << (useHttps ? "https" : "http") << "://" << hostname << ":" << port;
-    httplib::Client client = httplib::Client(baseUri.str().c_str());
-
-    if (accessToken.length() > 0)
-    {
-        httplib::Headers headers
-        {
-            {"Authorization", "Bearer " + accessToken}
-        };
-        client.set_default_headers(headers);
-    }
-
-    return client;
-}
-
 void GlimeshServiceConnection::ensureAuth()
 {
     std::lock_guard<std::mutex> lock(authMutex);
 
     // Do we already have an access token that hasn't expired?
-    // TODO: Check expiration
     if (accessToken.length() > 0)
     {
         std::time_t currentTime = std::time(nullptr);
@@ -235,7 +218,6 @@ void GlimeshServiceConnection::ensureAuth()
         { "scope", "streamkey" }
     };
 
-    httplib::Client httpClient = getHttpClient();
     if (httplib::Result res = httpClient.Post("/api/oauth/token", params))
     {
         if (res->status == 200)
@@ -267,6 +249,13 @@ void GlimeshServiceConnection::ensureAuth()
                 std::time_t currentTime = std::time(nullptr);
                 spdlog::info("Received new access token: {}, expires in {} - {} = {} seconds",
                     accessToken, expirationTime, currentTime, (expirationTime - currentTime));
+
+                // Update HTTP client Authorization header
+                httplib::Headers headers
+                {
+                    {"Authorization", "Bearer " + accessToken}
+                };
+                httpClient.set_default_headers(headers);
                 return;
             }
         }
@@ -311,7 +300,6 @@ JsonPtr GlimeshServiceConnection::runGraphQlQuery(
     int numRetries = 0;
     while (true)
     {
-        httplib::Client httpClient = getHttpClient();
         JsonPtr result = nullptr;
 
         // If we're doing files, use a multipart http request
@@ -334,7 +322,7 @@ JsonPtr GlimeshServiceConnection::runGraphQlQuery(
 
         if (numRetries < MAX_RETRIES)
         {
-            spdlog::warn("Attempt {} / {}: Glimesh file upload GraphQL query failed. "
+            spdlog::warn("Attempt {} / {}: Glimesh GraphQL query failed. "
                 "Retrying in {} ms...", (numRetries + 1), MAX_RETRIES, TIME_BETWEEN_RETRIES_MS);
 
             std::this_thread::sleep_for(std::chrono::milliseconds(TIME_BETWEEN_RETRIES_MS));
@@ -347,13 +335,13 @@ JsonPtr GlimeshServiceConnection::runGraphQlQuery(
     }
 
     // We've exceeded our retry limit
-    spdlog::error("Aborting Glimesh file upload GraphQL query after {} failed attempts.",
+    spdlog::error("Aborting Glimesh GraphQL query after {} failed attempts.",
         MAX_RETRIES);
 
     throw ServiceConnectionCommunicationFailedException("Glimesh GraphQL query failed.");
 }
 
-JsonPtr GlimeshServiceConnection::processGraphQlResponse(httplib::Result result)
+JsonPtr GlimeshServiceConnection::processGraphQlResponse(const httplib::Result& result)
 {
     if (result)
     {
@@ -382,7 +370,8 @@ JsonPtr GlimeshServiceConnection::processGraphQlResponse(httplib::Result result)
     }
     else
     {
-        spdlog::warn("Glimesh service connection HTTP request failed.");
+        spdlog::warn("Glimesh service connection HTTP request failed with error {}",
+            result.error());
         return nullptr;
     }
 }

src/ServiceConnections/GlimeshServiceConnection.h

@@ -47,8 +47,9 @@ class GlimeshServiceConnection :
 
 private:
     /* Private members */
-    const int MAX_RETRIES = 5;
+    const int MAX_RETRIES = 10;
     const int TIME_BETWEEN_RETRIES_MS = 3000;
+    httplib::Client httpClient;
     std::string hostname;
     uint16_t port;
     bool useHttps;
@@ -59,9 +60,8 @@ class GlimeshServiceConnection :
     std::mutex authMutex;
 
     /* Private methods */
-    httplib::Client getHttpClient();
     void ensureAuth();
     JsonPtr runGraphQlQuery(std::string query, JsonPtr variables = nullptr, httplib::MultipartFormDataItems fileData = httplib::MultipartFormDataItems());
-    JsonPtr processGraphQlResponse(httplib::Result result);
+    JsonPtr processGraphQlResponse(const httplib::Result& result);
     tm parseIso8601DateTime(std::string dateTimeString);
 };

src/ServiceConnections/RestServiceConnection.cpp

@@ -24,12 +24,22 @@ RestServiceConnection::RestServiceConnection(
     std::string pathBase,
     std::string authToken)
 :
+    httpClient(createBaseUri(false).c_str()),
     hostname(hostname),
     port(port),
     useHttps(useHttps),
     pathBase(pathBase),
     authToken(authToken)
-{ }
+{
+    if (authToken.length() > 0)
+    {
+        httplib::Headers headers
+        {
+            {"Authorization", authToken}
+        };
+        httpClient.set_default_headers(headers);
+    }
+}
 #pragma endregion
 
 #pragma region Public methods
@@ -203,30 +213,12 @@ std::string RestServiceConnection::constructPath(std::string path)
     return ss.str();
 }
 
-httplib::Client RestServiceConnection::getHttpClient()
-{
-    std::string baseUri = createBaseUri(false);
-    httplib::Client client = httplib::Client(baseUri.c_str());
-
-    if (authToken.length() > 0)
-    {
-        httplib::Headers headers
-        {
-            {"Authorization", authToken}
-        };
-        client.set_default_headers(headers);
-    }
-
-    return client;
-}
-
 httplib::Result RestServiceConnection::runGetRequest(std::string url)
 {
     // Make the request, and retry if necessary
     int numRetries = 0;
     while (true)
     {
-        httplib::Client httpClient = getHttpClient();
         std::string fullUrl = constructPath(url);
 
         httplib::Result response = httpClient.Get(fullUrl.c_str());
@@ -277,7 +269,6 @@ httplib::Result RestServiceConnection::runPostRequest(
     int numRetries = 0;
     while (true)
     {
-        httplib::Client httpClient = getHttpClient();
         std::string fullUrl = constructPath(url);
 
         httplib::Result response = (fileData.size() > 0)
@@ -312,7 +303,7 @@ httplib::Result RestServiceConnection::runPostRequest(
     throw ServiceConnectionCommunicationFailedException("REST POST request failed.");
 }
 
-JsonPtr RestServiceConnection::decodeRestResponse(httplib::Result result)
+JsonPtr RestServiceConnection::decodeRestResponse(const httplib::Result& result)
 {
     if (result)
     {

src/ServiceConnections/RestServiceConnection.h

@@ -45,6 +45,7 @@ class RestServiceConnection : public ServiceConnection
     /* Private members */
     const int MAX_RETRIES = 5;
     const int TIME_BETWEEN_RETRIES_MS = 3000;
+    httplib::Client httpClient;
     std::string hostname;
     uint16_t port;
     bool useHttps;
@@ -56,8 +57,8 @@ class RestServiceConnection : public ServiceConnection
     std::string createBaseUri(bool includeBase);
     std::string constructPath(std::string path);
 
-    httplib::Client getHttpClient();
     httplib::Result runGetRequest(std::string url);
-    httplib::Result runPostRequest(std::string url, JsonPtr body = nullptr, httplib::MultipartFormDataItems fileData = httplib::MultipartFormDataItems());
-    JsonPtr decodeRestResponse(httplib::Result result);
+    httplib::Result runPostRequest(std::string url, JsonPtr body = nullptr,
+        httplib::MultipartFormDataItems fileData = httplib::MultipartFormDataItems());
+    JsonPtr decodeRestResponse(const httplib::Result& result);
 };