Sysdig output on Kubernetes Service DNS resolution

k8s-skydns-sysdig.log

15085 15:04:02.227045418 0 client (99a1f06089bb) curl (5451:12) < socket fd=3(<6>) 
15086 15:04:02.227046442 0 client (99a1f06089bb) curl (5451:12) > close fd=3(<6>) 
15087 15:04:02.227047179 0 client (99a1f06089bb) curl (5451:12) < close res=0 
15267 15:04:02.227930016 1 client (99a1f06089bb) curl (5452:13) < socket fd=3(<4>) 
15268 15:04:02.227936726 1 client (99a1f06089bb) curl (5452:13) > connect fd=3(<4>) 
15269 15:04:02.227948559 1 client (99a1f06089bb) curl (5452:13) < connect res=0 tuple=172.17.0.7:33209->10.0.2.15:53 
15277 15:04:02.228136090 1 <NA> (28c677fc8628) skydns (2682:8) > recvmsg fd=6(<3t>:::53) 
15284 15:04:02.228174895 1 <NA> (28c677fc8628) skydns (2682:8) < recvmsg res=56 size=56 data=
(backendcritical-appsvcclusterlocal tuple=::ffff:172.17.0.7:33209->:::53 
15288 15:04:02.228181972 1 <NA> (28c677fc8628) skydns (2682:8) > recvmsg fd=6(<3t>:::53) 
15309 15:04:02.228445142 0 <NA> (28c677fc8628) skydns (2750:10) > write fd=3(<4t>10.0.2.15:46212->10.0.2.15:4001) size=190 
15310 15:04:02.228488171 0 <NA> (28c677fc8628) skydns (2750:10) < write res=190 data=
GET /v2/keys/skydns/local/cluster/svc/critical-app/backend?quorum=false&recursive=true&sorted=false HTTP/1.1
Host: 10.0.2.15:4001
User-Agent: Go 1.1 package http
Accept-Encoding: gzip

 
15362 15:04:02.228828978 0 <NA> (28c677fc8628) skydns (2664:1) > read fd=3(<4t>10.0.2.15:46212->10.0.2.15:4001) size=4096 
15363 15:04:02.228831387 0 <NA> (28c677fc8628) skydns (2664:1) < read res=541 data=
HTTP/1.1 200 OK
Content-Type: application/json
X-Etcd-Cluster-Id: 7e27652122e8b2ae
X-Etcd-Index: 344
X-Raft-Index: 786
X-Raft-Term: 2
Date: Mon, 05 Dec 2016 15:04:02 GMT
Content-Length: 341

{"action":"get","node":{"key":"/skydns/local/cluster/svc/critical-app/backend","dir":true,"nodes":[{"key":"/skydns/local/cluster/svc/critical-app/backend/6ead029a","value":"{\"host\":\"10.3.0.214\",\"priority\":10,\"weight\":10,\"ttl\":30,\"targetstrip\":0}","modifiedIndex":242,"createdIndex":242}],"modifiedIndex":242,"createdIndex":242}}
 
15364 15:04:02.228986136 0 <NA> (28c677fc8628) skydns (2664:1) > sendmsg fd=6(<3t>:::53) size=72 tuple=:::53->::ffff:172.17.0.7:33209 
15365 15:04:02.229044671 0 <NA> (28c677fc8628) skydns (2664:1) < sendmsg res=72 data=
backendcritical-appsvcclusterlocal
 
15366 15:04:02.229055131 0 <NA> (28c677fc8628) skydns (2664:1) > read fd=3(<4t>10.0.2.15:46212->10.0.2.15:4001) size=4096 
15367 15:04:02.229057875 0 <NA> (28c677fc8628) skydns (2664:1) < read res=-11(EAGAIN) data= 
15373 15:04:02.229107647 1 client (99a1f06089bb) curl (5452:13) > ioctl fd=3(<4u>172.17.0.7:33209->10.0.2.15:53) request=541B argument=7F8DB6B28BA0 
15374 15:04:02.229109413 1 client (99a1f06089bb) curl (5452:13) < ioctl res=0 
15375 15:04:02.229111229 1 client (99a1f06089bb) curl (5452:13) > recvfrom fd=3(<4u>172.17.0.7:33209->10.0.2.15:53) size=2048 
15391 15:04:02.229142239 1 client (99a1f06089bb) curl (5452:13) < recvfrom res=72 data=
backendcritical-appsvcclusterlocal
 tuple=10.0.2.15:53->172.17.0.7:33209 
15406 15:04:02.229230597 0 <NA> (28c677fc8628) skydns (2664:1) > sendmsg fd=6(<3t>:::53) size=117 tuple=:::53->::ffff:172.17.0.7:33209 
15407 15:04:02.229270720 0 <NA> (28c677fc8628) skydns (2664:1) < sendmsg res=117 data=
(backendcritical-appsvcclusterlocal%<1nsdns%
hostmasterskydns-XEp :< 
15425 15:04:02.229320962 1 client (99a1f06089bb) curl (5452:13) > ioctl fd=3(<4u>172.17.0.7:33209->10.0.2.15:53) request=541B argument=7F8DB6B2A530 
15426 15:04:02.229322225 1 client (99a1f06089bb) curl (5452:13) < ioctl res=0 
15427 15:04:02.229322683 1 client (99a1f06089bb) curl (5452:13) > recvfrom fd=3(<4u>172.17.0.7:33209->10.0.2.15:53) size=1976 
15430 15:04:02.229326329 1 client (99a1f06089bb) curl (5452:13) < recvfrom res=117 data=
(backendcritical-appsvcclusterlocal%<1nsdns%
hostmasterskydns-XEp :< tuple=10.0.2.15:53->172.17.0.7:33209 
15433 15:04:02.229332884 1 client (99a1f06089bb) curl (5452:13) > close fd=3(<4u>172.17.0.7:33209->10.0.2.15:53) 
15434 15:04:02.229334287 1 client (99a1f06089bb) curl (5452:13) < close res=0 
15571 15:04:02.231444519 0 client (99a1f06089bb) curl (5451:12) < socket fd=3(<4>) 
15578 15:04:02.231459997 0 client (99a1f06089bb) curl (5451:12) > fcntl fd=3(<4>) cmd=4(F_GETFL) 
15579 15:04:02.231461527 0 client (99a1f06089bb) curl (5451:12) < fcntl res=2(<f>/2) 
15580 15:04:02.231461981 0 client (99a1f06089bb) curl (5451:12) > fcntl fd=3(<4>) cmd=5(F_SETFL) 
15581 15:04:02.231462390 0 client (99a1f06089bb) curl (5451:12) < fcntl res=0(<f>/2) 
15582 15:04:02.231463790 0 client (99a1f06089bb) curl (5451:12) > connect fd=3(<4>) 
15587 15:04:02.231769589 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) < accept fd=3(<4t>172.17.0.7:40944->172.17.0.6:80) tuple=172.17.0.7:40944->172.17.0.6:80 queuepct=0 queuelen=0 queuemax=128 
15592 15:04:02.231808354 0 client (99a1f06089bb) curl (5451:12) < connect res=-115(EINPROGRESS) tuple=172.17.0.7:40944->10.3.0.214:80 
15601 15:04:02.231842208 0 client (99a1f06089bb) curl (5451:12) > sendto fd=3(<4t>172.17.0.7:40944->10.3.0.214:80) size=71 tuple=NULL 
15602 15:04:02.231894569 0 client (99a1f06089bb) curl (5451:12) < sendto res=71 data=
GET / HTTP/1.1
User-Agent: curl/7.35.0
Host: backend
Accept: */*

 
15608 15:04:02.231913870 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) > recvfrom fd=3(<4t>172.17.0.7:40944->172.17.0.6:80) size=1024 
15609 15:04:02.231916842 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) < recvfrom res=71 data=
GET / HTTP/1.1
User-Agent: curl/7.35.0
Host: backend
Accept: */*

 tuple=NULL 
15616 15:04:02.232010375 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) > writev fd=3(<4t>172.17.0.7:40944->172.17.0.6:80) size=238 
15617 15:04:02.232040507 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) < writev res=238 data=
HTTP/1.1 200 OK
Server: nginx/1.10.2
Date: Mon, 05 Dec 2016 15:04:02 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 18 Oct 2016 15:03:13 GMT
Connection: keep-alive
ETag: "580639b1-264"
Accept-Ranges: bytes

 
15618 15:04:02.232042842 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) > sendfile out_fd=3(<4t>172.17.0.7:40944->172.17.0.6:80) in_fd=11(<f>/usr/share/nginx/html/index.html) offset=0 size=612 
15619 15:04:02.232067073 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) < sendfile res=612 offset=612 
15626 15:04:02.232130574 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) > recvfrom fd=3(<4t>172.17.0.7:40944->172.17.0.6:80) size=1024 
15627 15:04:02.232131773 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) < recvfrom res=-11(EAGAIN) data= tuple=NULL 
15633 15:04:02.232143892 0 client (99a1f06089bb) curl (5451:12) > recvfrom fd=3(<4t>172.17.0.7:40944->10.3.0.214:80) size=16384 
15634 15:04:02.232145601 0 client (99a1f06089bb) curl (5451:12) < recvfrom res=850 data=
HTTP/1.1 200 OK
Server: nginx/1.10.2
Date: Mon, 05 Dec 2016 15:04:02 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 18 Oct 2016 15:03:13 GMT
Connection: keep-alive
ETag: "580639b1-264"
Accept-Ranges: bytes

<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
 tuple=NULL 
15935 15:04:02.232815933 0 client (99a1f06089bb) curl (5451:12) > close fd=3(<4t>172.17.0.7:40944->10.3.0.214:80) 
15937 15:04:02.232816814 0 client (99a1f06089bb) curl (5451:12) < close res=0 
15967 15:04:02.232894519 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) > recvfrom fd=3(<4t>172.17.0.7:40944->172.17.0.6:80) size=1024 
15968 15:04:02.232896780 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) < recvfrom res=0 data= tuple=NULL 
15969 15:04:02.232898649 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) > close fd=3(<4t>172.17.0.7:40944->172.17.0.6:80) 
15970 15:04:02.232899298 0 backend-1440326531-4n9dy (bc7367e5cea9) nginx (4793:7) < close res=0