fix(libsinsp): Don't loop forever on container api

Add an escape clause on the container lookup path to make sure we're not just constantly getting timeouts. /kind bug /area libsinsp ```release-note NONE ``` Signed-off-by: Nathan Baker <[email protected]>
falcosecurity · Sep 15, 2023 · e2cdf1e · e2cdf1e
1 parent 7c0b0b2
commit e2cdf1e
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Showing 3 changed files with 20 additions and 1 deletion.
diff --git a/userspace/libsinsp/container_engine/docker/async_source.cpp b/userspace/libsinsp/container_engine/docker/async_source.cpp
@@ -672,6 +672,7 @@ bool docker_async_source::parse(const docker_lookup_request& request, sinsp_cont
 		}
 		/* FALLTHRU */
 	case docker_connection::docker_response::RESP_ERROR:
+	case docker_connection::docker_response::RESP_TIMEOUT:
 		g_logger.format(sinsp_logger::SEV_DEBUG,
 				"docker_async (%s): Url fetch failed, returning false",
 				request.container_id.c_str());

diff --git a/userspace/libsinsp/container_engine/docker/connection.h b/userspace/libsinsp/container_engine/docker/connection.h
@@ -18,7 +18,8 @@ class docker_connection {
 	enum docker_response {
 		RESP_OK = 0,
 		RESP_BAD_REQUEST = 1,
-		RESP_ERROR = 2
+		RESP_ERROR = 2,
+		RESP_TIMEOUT = 3
 	};
 
 	docker_connection();

diff --git a/userspace/libsinsp/container_engine/docker/connection_linux.cpp b/userspace/libsinsp/container_engine/docker/connection_linux.cpp
@@ -20,6 +20,7 @@ limitations under the License.
 #include "sinsp_int.h"
 
 namespace {
+const uint32_t max_allowed_timeouts = 5;
 
 size_t docker_curl_write_callback(const char *ptr, size_t size, size_t nmemb, std::string *json)
 {
@@ -107,6 +108,7 @@ docker_connection::docker_response docker_connection::get_docker(const docker_lo
 		return docker_response::RESP_ERROR;
 	}
 
+	uint32_t num_timeouts = 0;
 	while(true)
 	{
 		int still_running;
@@ -141,6 +143,21 @@ docker_connection::docker_response docker_connection::get_docker(const docker_lo
 			ASSERT(false);
 			return docker_response::RESP_ERROR;
 		}
+		if(numfds == 0)
+		{
+			// Operation timed out
+			if(++num_timeouts >= max_allowed_timeouts)
+			{
+				g_logger.format(sinsp_logger::SEV_WARNING,
+				                "docker_async (%s): Max timeouts exceeded",
+				                url.c_str());
+				return docker_response::RESP_TIMEOUT;
+			}
+			g_logger.format(sinsp_logger::SEV_DEBUG,
+			                "docker_async (%s): Operation timed out %d times",
+			                url.c_str(),
+			                num_timeouts);
+		}
 	}
 
 	if(curl_multi_remove_handle(m_curlm, curl) != CURLM_OK)