I am trying to implement an api endpoint for docker stats --one-shot
but I simply do not understand the difference between --one-shot and --no-stream. The API documentation is located here but doesn't illuminate much. I know this seems like a simple question but I am a newcomer to the docker api and can't seem to find much clarity. Thank you.
If you specify one-shot=true
then the precpu stats will be empty. By default a second check is run on the server side to fill in this value, but it results in an extra 2 second delay:
$ curl -s --unix-socket /var/run/docker.sock 'http://localhost/containers/76c22a363ea8900ddd7ecee74fd6bb19d5dd7c50a26695e6b0dee5c353e2174d/stats?stream=false&one-shot=true' | jq .precpu_stats
{
"cpu_usage": {
"total_usage": 0,
"usage_in_kernelmode": 0,
"usage_in_usermode": 0
},
"throttling_data": {
"periods": 0,
"throttled_periods": 0,
"throttled_time": 0
}
}
$ curl -s --unix-socket /var/run/docker.sock 'http://localhost/containers/76c22a363ea8900ddd7ecee74fd6bb19d5dd7c50a26695e6b0dee5c353e2174d/stats?stream=false&one-shot=false' | jq .precpu_stats
{
"cpu_usage": {
"total_usage": 336500498536,
"percpu_usage": [
42273785950,
42067912050,
42236140288,
42504140826,
42151800123,
41175670348,
41403446188,
42687602763
],
"usage_in_kernelmode": 6110000000,
"usage_in_usermode": 97120000000
},
"system_cpu_usage": 70752558350000000,
"online_cpus": 8,
"throttling_data": {
"periods": 0,
"throttled_periods": 0,
"throttled_time": 0
}
}