fix: remote config polling parsing (#123)

According to the Remote Configuration specification,
`DD_REMOTE_CONFIG_POLL_INTERVAL_SECONDS` support floating point input
and can be set to `0`.

Author: dmehala

src/datadog/datadog_agent_config.cpp

@@ -21,7 +21,7 @@ Expected<DatadogAgentConfig> load_datadog_agent_env_config() {
 
   if (auto raw_rc_poll_interval_value =
           lookup(environment::DD_REMOTE_CONFIG_POLL_INTERVAL_SECONDS)) {
-    auto res = parse_int(*raw_rc_poll_interval_value, 10);
+    auto res = parse_double(*raw_rc_poll_interval_value);
     if (auto error = res.if_error()) {
       return error->with_prefix(
           "DatadogAgent: Remote Configuration poll interval error ");
@@ -114,12 +114,13 @@ Expected<FinalizedDatadogAgentConfig> finalize_config(
                  "milliseconds."};
   }
 
-  if (int rc_poll_interval_seconds =
+  if (double rc_poll_interval_seconds =
           value_or(env_config->remote_configuration_poll_interval_seconds,
-                   user_config.remote_configuration_poll_interval_seconds, 5);
-      rc_poll_interval_seconds > 0) {
+                   user_config.remote_configuration_poll_interval_seconds, 5.0);
+      rc_poll_interval_seconds >= 0.0) {
     result.remote_configuration_poll_interval =
-        std::chrono::seconds(rc_poll_interval_seconds);
+        std::chrono::duration_cast<std::chrono::milliseconds>(
+            std::chrono::duration<double>(rc_poll_interval_seconds));
   } else {
     return Error{Error::DATADOG_AGENT_INVALID_REMOTE_CONFIG_POLL_INTERVAL,
                  "DatadogAgent: Remote Configuration poll interval must be a "

src/datadog/datadog_agent_config.h

@@ -61,7 +61,7 @@ struct DatadogAgentConfig {
   Optional<bool> remote_configuration_enabled;
   // How often, in seconds, to query the Datadog Agent for remote configuration
   // updates.
-  Optional<int> remote_configuration_poll_interval_seconds;
+  Optional<double> remote_configuration_poll_interval_seconds;
 
   static Expected<HTTPClient::URL> parse(StringView);
 };

test/test_tracer_config.cpp

@@ -446,14 +446,6 @@ TEST_CASE("TracerConfig::agent") {
   }
 
   SECTION("remote configuration poll interval") {
-    SECTION("cannot be zero") {
-      config.agent.remote_configuration_poll_interval_seconds = 0;
-      auto finalized = finalize_config(config);
-      REQUIRE(!finalized);
-      REQUIRE(finalized.error().code ==
-              Error::DATADOG_AGENT_INVALID_REMOTE_CONFIG_POLL_INTERVAL);
-    }
-
     SECTION("cannot be negative") {
       config.agent.remote_configuration_poll_interval_seconds = -1337;
       auto finalized = finalize_config(config);
@@ -491,7 +483,7 @@ TEST_CASE("TracerConfig::agent") {
                                  "ddog"};
         auto finalized = finalize_config(config);
         REQUIRE(!finalized);
-        REQUIRE(finalized.error().code == Error::INVALID_INTEGER);
+        REQUIRE(finalized.error().code == Error::INVALID_DOUBLE);
       }
     }
   }