[SMAGENT-1855] Docker engine support for cpuset usage (#1473)

Parses the CpusetCpus value from the docker socket, parses it to count the number of cpus and stores the value with the other container data.

Author: bryanseay

userspace/libsinsp/cgroup_list_counter.h

@@ -0,0 +1,136 @@
+#pragma once
+
+#include <stdexcept>
+#include "logger.h"
+
+namespace libsinsp
+{
+
+/**
+ * Simple helper to read a comma-separated list that includes ranges and
+ * determine the total count of the values within.
+ * Examples: 1,4-5 = 3; 0-15 = 16; 3,7,11 = 3
+ *
+ * See the "List Format" section of
+ * http://man7.org/linux/man-pages/man7/cpuset.7.html
+ *
+ * Returns -1 if string is invalid.
+ */
+class cgroup_list_counter
+{
+public:
+	const int INVALID_CPU_COUNT = -1;
+
+	/**
+	 * Return the number of elements given by the buffer. If needed, log at the
+	 * given log-level.
+	 */
+	int operator ()(const char *buffer, sinsp_logger::severity log_level)
+	{
+		reset();
+
+		int cpu_count = 0;
+
+		try
+		{
+			const char *position = buffer;
+			for(; '\0' != *position; ++position)
+			{
+				if ('-' == *position)
+				{
+					if (nullptr == m_section_start)
+					{
+						throw std::runtime_error("duplicate range indicator before start");
+					}
+					if (nullptr != m_range_indicator)
+					{
+						throw std::runtime_error("duplicate range indicators");
+					}
+
+					m_range_indicator = position;
+				}
+				else if (',' == *position)
+				{
+					cpu_count += process_section(m_section_start, position, m_range_indicator);
+					reset();
+				}
+				else if (nullptr == m_section_start)
+				{
+					m_section_start = position;
+				}
+
+			}
+
+			// There is never a trailing comma so always process the
+			// final section
+			cpu_count += process_section(m_section_start, position, m_range_indicator);
+
+		}
+		catch (const std::exception& ex)
+		{
+			g_logger.format(log_level,
+					"Invalid List Format: %s. Detail: %s",
+					buffer,
+					ex.what());
+			return INVALID_CPU_COUNT;
+		}
+
+		return cpu_count;
+	}
+
+private:
+
+	static int process_number(const char *section_start, const char *section_end)
+	{
+		std::string section(section_start, section_end - section_start);
+		return std::stoi(section.c_str());
+
+	}
+
+	static int process_section(const char *section_start, const char *section_end, const char *range_indicator)
+	{
+		if (nullptr == section_start)
+		{
+			throw std::runtime_error("invalid end of section before start of section");
+		}
+
+		if (nullptr == section_end)
+		{
+			throw std::runtime_error("invalid end of section");
+		}
+
+		if (section_end <= section_start)
+		{
+			throw std::runtime_error("invalid section");
+		}
+
+		if (range_indicator)
+		{
+			// Split into two sections
+			int first = process_number(section_start, range_indicator);
+			int second = process_number(range_indicator + 1, section_end);
+
+			if (second <= first)
+			{
+				throw std::runtime_error("invalid range");
+			}
+
+			return second - first + 1;
+		}
+
+		// We don't care what the value is, we just want to know that it is a number
+		(void)process_number(section_start, section_end);
+		return 1;
+	}
+
+	void reset()
+	{
+		m_section_start = nullptr;
+		m_range_indicator = nullptr;
+	}
+
+	const char *m_section_start = nullptr;
+	const char *m_range_indicator = nullptr;
+};
+
+}

userspace/libsinsp/container.cpp

@@ -219,6 +219,7 @@ string sinsp_container_manager::container_to_json(const sinsp_container_info& co
 	container["cpu_shares"] = (Json::Value::Int64) container_info.m_cpu_shares;
 	container["cpu_quota"] = (Json::Value::Int64) container_info.m_cpu_quota;
 	container["cpu_period"] = (Json::Value::Int64) container_info.m_cpu_period;
+	container["cpuset_cpu_count"] = (Json::Value::Int) container_info.m_cpuset_cpu_count;
 
 	if(!container_info.m_mesos_task_id.empty())
 	{

userspace/libsinsp/container_engine/docker_common.cpp

@@ -18,6 +18,7 @@ limitations under the License.
 */
 
 #include "container_engine/docker.h"
+#include "cgroup_list_counter.h"
 #include "sinsp.h"
 #include "sinsp_int.h"
 #include "container.h"
@@ -739,7 +740,13 @@ bool docker_async_source::parse_docker(std::string &container_id, sinsp_containe
 	{
 		container->m_cpu_period = cpu_period;
 	}
-	const Json::Value &privileged = host_config_obj["Privileged"];
+	const auto cpuset_cpus = host_config_obj["CpusetCpus"].asString();
+	if (!cpuset_cpus.empty())
+	{
+		libsinsp::cgroup_list_counter counter;
+		container->m_cpuset_cpu_count = counter(cpuset_cpus.c_str(), sinsp_logger::SEV_DEBUG);
+	}
+	const Json::Value& privileged = host_config_obj["Privileged"];
 	if(!privileged.isNull() && privileged.isBool())
 	{
 		container->m_privileged = privileged.asBool();

userspace/libsinsp/container_info.h

@@ -182,6 +182,7 @@ class sinsp_container_info
 		m_cpu_shares(1024),
 		m_cpu_quota(0),
 		m_cpu_period(100000),
+		m_cpuset_cpu_count(0),
 		m_is_pod_sandbox(false),
 		m_metadata_complete(true),
 		m_metadata_deadline(0)
@@ -223,6 +224,7 @@ class sinsp_container_info
 	int64_t m_cpu_shares;
 	int64_t m_cpu_quota;
 	int64_t m_cpu_period;
+	int32_t m_cpuset_cpu_count;
 	std::list<container_health_probe> m_health_probes;
 
 	bool m_is_pod_sandbox;

userspace/libsinsp/parsers.cpp

@@ -4708,6 +4708,12 @@ void sinsp_parser::parse_container_json_evt(sinsp_evt *evt)
 			container_info.m_cpu_period = cpu_period.asInt64();
 		}
 
+		const Json::Value& cpuset_cpu_count = container["cpuset_cpu_count"];
+		if(check_json_val_is_convertible(cpuset_cpu_count, Json::intValue, "cpuset_cpu_count"))
+		{
+			container_info.m_cpuset_cpu_count = cpuset_cpu_count.asInt();
+		}
+
 		const Json::Value& mesos_task_id = container["mesos_task_id"];
 		if(check_json_val_is_convertible(mesos_task_id, Json::stringValue, "mesos_task_id"))
 		{