Moby: API returns nothing when I want container's stats
Hello, I have a problem with the Docker API, but first:
$ docker version
Client:
Version: 1.8.2-rc1
API version: 1.20
Go version: go1.4.2
Git commit: 28220ac
Built: Thu Sep 3 19:07:51 UTC 2015
OS/Arch: linux/amd64
Server:
Version: 1.8.2-rc1
API version: 1.20
Go version: go1.4.2
Git commit: 28220ac
Built: Thu Sep 3 19:07:51 UTC 2015
OS/Arch: linux/amd64
$ docker info
Containers: 17
Images: 8
Storage Driver: devicemapper
Pool Name: docker-254:0-1512633-pool
Pool Blocksize: 65.54 kB
Backing Filesystem: extfs
Data file: /dev/loop0
Metadata file: /dev/loop1
Data Space Used: 3.557 GB
Data Space Total: 107.4 GB
Data Space Available: 8.216 GB
Metadata Space Used: 7.848 MB
Metadata Space Total: 2.147 GB
Metadata Space Available: 2.14 GB
Udev Sync Supported: true
Deferred Removal Enabled: false
Data loop file: /var/lib/docker/devicemapper/devicemapper/data
Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
Library Version: 1.02.104 (2015-08-10)
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 4.1.0-1-amd64
Operating System: Debian GNU/Linux stretch/sid
CPUs: 8
Total Memory: 15.65 GiB
Name: n-pc
ID: LWBS:FFUU:5FGD:UXXH:J5FB:G4WL:WUZM:RFS4:3TEC:3IGG:K7GU:YWBV
WARNING: No memory limit support
WARNING: No swap limit support
$ uname -a
Linux n-pc 4.1.0-1-amd64 #1 SMP Debian 4.1.3-1 (2015-08-03) x86_64 GNU/Linux
I am using the API with command line, and when I want to get a container's stats, the API returns nothing:
$ echo -e "GET /containers/57d3/stats?stream=0 HTTP/1.1\r\n" | nc -U /var/run/docker.sock
HTTP/1.1 200 OK
Content-Type: application/json
Server: Docker/1.8.2-rc1 (linux)
Date: Fri, 04 Sep 2015 08:13:10 GMT
Content-Length: 0
With the "docker" command I can get the stats, but I really need to use the API:
docker stats --no-stream 57d3
CONTAINER CPU % MEM USAGE/LIMIT MEM % NET I/O
57d3 1.16% 0 B/16.81 GB 0.00% 8.565 MB/1.499 MB
However the API is working...
echo -e "GET /version HTTP/1.1\r\n" | nc -U /var/run/docker.sock | tail -1 | json
{
"ApiVersion": "1.20",
"Arch": "amd64",
"BuildTime": "Thu Sep 3 19:07:51 UTC 2015",
"GitCommit": "28220ac",
"GoVersion": "go1.4.2",
"KernelVersion": "4.1.0-1-amd64",
"Os": "linux",
"Version": "1.8.2-rc1"
}
What am I doing wrong please? Thank you!
Nurza
All 3 comments
This is likely happening because docker is sending the response header first...
Note that I cannot repro this with curl, only with piping to nc as you have here.
Also the CLI uses the same exact API.
cpuguy83
on 4 Sep 2015
I think this is an 'nc' issue. Try: ... nc -q -1 -U /var/run/docker.sock (note the "-q -1").
I believe 'nc' is closing the http request before the server does its job and as a result we stop the 'stats' processing. If you try other docker cmds that don't check the http request you should see that it works.
Gonna close this because its not really a docker issue as much as an nc issue. Can you use curl instead?
duglin
on 8 Sep 2015
Thank you, it works! but i prefer to set -q to 5 (because -1 is for waiting forever) and 5 will set a timeout to 5 seconds.
I can use curl instead on Debian Stretch but not in Ubuntu 14.04 because: curl: option --unix-socket: is unknown
Nurza
on 9 Sep 2015
Related issues
lvthillo
·
3Comments
dbanck
·
3Comments
kunyan
·
3Comments
cmingxu
·
3Comments
xied75
·
3Comments
Most helpful comment
I think this is an 'nc' issue. Try:
... nc -q -1 -U /var/run/docker.sock(note the "-q -1").I believe 'nc' is closing the http request before the server does its job and as a result we stop the 'stats' processing. If you try other docker cmds that don't check the http request you should see that it works.
Gonna close this because its not really a docker issue as much as an nc issue. Can you use curl instead?