Get container stats based on resource usage

This endpoint returns a live stream of a container’s resource usage statistics.

The precpu_stats is the CPU statistic of the previous read, and is used to calculate the CPU usage percentage. It is not an exact copy of the cpu_stats field.

If either precpu_stats.online_cpus or cpu_stats.online_cpus is nil then for compatibility with older daemons the length of the corresponding cpu_usage.percpu_usage array should be used.

On a cgroup v2 host, the following fields are not set

• blkio_stats: all fields other than io_service_bytes_recursive
• cpu_stats: cpu_usage.percpu_usage
• memory_stats: max_usage and failcnt Also, memory_stats.stats fields are incompatible with cgroup v1.

To calculate the values shown by the stats command of the docker cli tool the following formulas can be used:

• used_memory = memory_stats.usage - memory_stats.stats.cache
• available_memory = memory_stats.limit
• Memory usage % = (used_memory / available_memory) * 100.0
• cpu_delta = cpu_stats.cpu_usage.total_usage - precpu_stats.cpu_usage.total_usage
• system_cpu_delta = cpu_stats.system_cpu_usage - precpu_stats.system_cpu_usage
• number_cpus = length(cpu_stats.cpu_usage.percpu_usage) or cpu_stats.online_cpus
• CPU usage % = (cpu_delta / system_cpu_delta) * number_cpus * 100.0