fix(userspace/falco): fix outputs_http timeout

libcurl timeout prevent to send alert through http
keep trying to send the alert

Signed-off-by: Clément Bénier <clement.benier@iot.bzh>

Author: benierc

falco.yaml

@@ -746,6 +746,8 @@ http_output:
   echo: false
   compress_uploads: false
   keep_alive: false
+  # Maximum consecutive timeouts of libcurl to ignore
+  max_consecutive_timeouts: 5
 
 # [Stable] `program_output`
 #

userspace/falco/configuration.cpp

@@ -447,6 +447,11 @@ void falco_configuration::load_yaml(const std::string &config_name) {
 		keep_alive = m_config.get_scalar<bool>("http_output.keep_alive", false);
 		http_output.options["keep_alive"] = keep_alive ? std::string("true") : std::string("false");
 
+		uint32_t max_consecutive_timeouts;
+		max_consecutive_timeouts =
+		        m_config.get_scalar<uint32_t>("http_output.max_consecutive_timeouts", 5);
+		http_output.options["max_consecutive_timeouts"] = std::to_string(max_consecutive_timeouts);
+
 		m_outputs.push_back(http_output);
 	}
 

userspace/falco/outputs_http.cpp

@@ -36,6 +36,8 @@ bool falco::outputs::output_http::init(const config &oc,
 
 	m_curl = nullptr;
 	m_http_headers = nullptr;
+	m_max_consecutive_timeouts =
+	        static_cast<uint32_t>(std::stoi(m_oc.options["max_consecutive_timeouts"]));
 	CURLcode res = CURLE_FAILED_INIT;
 
 	m_curl = curl_easy_init();
@@ -103,7 +105,16 @@ bool falco::outputs::output_http::init(const config &oc,
 
 void falco::outputs::output_http::output(const message *msg) {
 	CURLcode res = curl_easy_setopt(m_curl, CURLOPT_POSTFIELDS, msg->msg.c_str());
-	CHECK_RES(curl_easy_perform(m_curl));
+	uint32_t curl_easy_platform_calls = 0;
+
+	if(res == CURLE_OK) {
+		do {
+			res = curl_easy_perform(m_curl);
+			curl_easy_platform_calls++;
+		} while(res == CURLE_OPERATION_TIMEDOUT &&
+		        curl_easy_platform_calls <= m_max_consecutive_timeouts);
+	}
+
 	if(res != CURLE_OK) {
 		falco_logger::log(
 		        falco_logger::level::ERR,

userspace/falco/outputs_http.h

@@ -36,6 +36,7 @@ class output_http : public abstract_output {
 private:
 	CURL *m_curl;
 	struct curl_slist *m_http_headers;
+	uint32_t m_max_consecutive_timeouts;
 };
 
 }  // namespace outputs