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kuberneteskubernetes-ingress

unable to access service from inside another pod in k8s


I am trying to ping and access a k8s service from two different pods. However, I am able to access from one pod while from other pod it is inaccessible. What could be the reason for that ? And how can I fix?

--- service accessible from the pod

/home/ravi>sudo docker exec -it bc1104f73042  /bin/bash
root@kpimon-go:/opt# ps -eaf
UID          PID    PPID  C STIME TTY          TIME CMD
root           1       0  0 15:01 ?        00:00:00 ./kpimon
root          21       0  0 15:27 pts/0    00:00:00 /bin/bash
root          36      21  0 15:27 pts/0    00:00:00 ps -eaf

root@kpimon-go:/opt# cat /etc/resolv.conf 
nameserver 10.96.0.10
search ricxapp.svc.cluster.local svc.cluster.local cluster.local
options ndots:5
   
root@kpimon-go:/opt# cat /etc/hosts 
# Kubernetes-managed hosts file.
127.0.0.1   localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
fe00::0 ip6-mcastprefix
fe00::1 ip6-allnodes
fe00::2 ip6-allrouters
10.244.0.253    kpimon-go
root@kpimon-go:/opt# ping service-ricplt-e2mgr-http
ping: service-ricplt-e2mgr-http: Name or service not known   ----------> unable to ping on k8s service
root@kpimon-go:/opt# 

--- service inaccessible from the pod

/home/ravi>sudo docker exec -it 1df20eaae850  /bin/bash
root@rtmgr:/# cat /etc/hosts
# Kubernetes-managed hosts file.
127.0.0.1   localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
fe00::0 ip6-mcastprefix
fe00::1 ip6-allnodes
fe00::2 ip6-allrouters
10.244.0.250    rtmgr
root@rtmgr:/# 
root@rtmgr:/# cat /etc/resolv.conf 
nameserver 10.96.0.10
search ricplt.svc.cluster.local svc.cluster.local cluster.local
options ndots:5
root@rtmgr:/#
root@rtmgr:/# 
root@rtmgr:/# ping service-ricplt-e2mgr-http                    ----------> unable to ping on k8s service
PING service-ricplt-e2mgr-http.ricplt.svc.cluster.local (10.101.210.88) 56(84) bytes of data.
64 bytes from service-ricplt-e2mgr-http.ricplt.svc.cluster.local (10.101.210.88): icmp_seq=1 ttl=64 time=0.059 ms
64 bytes from service-ricplt-e2mgr-http.ricplt.svc.cluster.local (10.101.210.88): icmp_seq=2 ttl=64 time=0.107 ms
^C
--- service-ricplt-e2mgr-http.ricplt.svc.cluster.local ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1025ms
rtt min/avg/max/mdev = 0.059/0.083/0.107/0.024 ms
root@rtmgr:/# 
root@rtmgr:/# 

-- info about k8s pods and services

/home/ravi>kubeclt get pods -A
NAMESPACE     NAME                                                         READY   STATUS      RESTARTS   AGE
kube-system   coredns-5644d7b6d9-ngpd6                                     1/1     Running     13         9d
kube-system   coredns-5644d7b6d9-pvzvz                                     1/1     Running     13         9d
kube-system   etcd-ubuntu-20                                               1/1     Running     13         9d
kube-system   kube-apiserver-ubuntu-20                                     1/1     Running     13         9d
kube-system   kube-controller-manager-ubuntu-20                            1/1     Running     13         9d
kube-system   kube-flannel-ds-hrrml                                        1/1     Running     13         9d
kube-system   kube-proxy-7hbwm                                             1/1     Running     13         9d
kube-system   kube-scheduler-ubuntu-20                                     1/1     Running     13         9d
ricinfra      deployment-tiller-ricxapp-68f777c4d4-lcmff                   1/1     Running     1          4h22m
ricinfra      tiller-secret-generator-vgkr9                                0/1     Completed   0          4h22m
ricplt        deployment-ricplt-a1mediator-669cc74647-mw7bb                1/1     Running     1          4h21m
ricplt        deployment-ricplt-alarmmanager-57785458dd-ks5t2              1/1     Running     1          4h20m
ricplt        deployment-ricplt-appmgr-77986c9cbb-h2mq8                    1/1     Running     1          4h21m
ricplt        deployment-ricplt-e2mgr-5dd878f58b-bhvss                     1/1     Running     5          4h21m
ricplt        deployment-ricplt-e2term-alpha-5d58997d8f-8kcrz              1/1     Running     1          4h21m
ricplt        deployment-ricplt-o1mediator-5ddd66b4d6-h8nt8                1/1     Running     1          4h20m
ricplt        deployment-ricplt-rtmgr-788975975b-kgxfj                     1/1     Running     3          4h21m
ricplt        deployment-ricplt-submgr-68fc656488-hcccs                    1/1     Running     1          4h21m
ricplt        deployment-ricplt-vespamgr-84f7d87dfb-mp76j                  1/1     Running     1          4h20m
ricplt        r4-influxdb-influxdb2-0                                      1/1     Running     1          4h12m
ricplt        r4-infrastructure-kong-7995f4679b-brhdq                      2/2     Running     6          4h22m
ricplt        r4-infrastructure-prometheus-alertmanager-5798b78f48-hbn8k   2/2     Running     2          4h22m
ricplt        r4-infrastructure-prometheus-server-c8ddcfdf5-vr8dk          1/1     Running     1          4h22m
ricplt        statefulset-ricplt-dbaas-server-0                            1/1     Running     1          4h21m
ricxapp       ricxapp-kpimon-go-7b8bb97ffb-5x76c                           1/1     Running     1          3h51m
/home/ravi>
/home/ravi>
/home/ravi>kubeclt get svc -A
NAMESPACE     NAME                                        TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                           AGE
default       kubernetes                                  ClusterIP   10.96.0.1        <none>        443/TCP                           9d
kube-system   kube-dns                                    ClusterIP   10.96.0.10       <none>        53/UDP,53/TCP,9153/TCP            9d
ricinfra      service-tiller-ricxapp                      ClusterIP   10.98.94.194     <none>        44134/TCP                         4h22m
ricplt        aux-entry                                   ClusterIP   10.105.149.143   <none>        80/TCP,443/TCP                    4h22m
ricplt        r4-influxdb-influxdb2                       ClusterIP   10.110.14.243    <none>        80/TCP                            4h13m
ricplt        r4-infrastructure-kong-proxy                NodePort    10.107.12.178    <none>        32080:32080/TCP,32443:32443/TCP   4h22m
ricplt        r4-infrastructure-prometheus-alertmanager   ClusterIP   10.104.86.76     <none>        80/TCP                            4h22m
ricplt        r4-infrastructure-prometheus-server         ClusterIP   10.102.224.176   <none>        80/TCP                            4h22m
ricplt        service-ricplt-a1mediator-http              ClusterIP   10.105.45.1      <none>        10000/TCP                         4h21m
ricplt        service-ricplt-a1mediator-rmr               ClusterIP   10.108.188.147   <none>        4561/TCP,4562/TCP                 4h21m
ricplt        service-ricplt-alarmmanager-http            ClusterIP   10.111.239.130   <none>        8080/TCP                          4h20m
ricplt        service-ricplt-alarmmanager-rmr             ClusterIP   10.106.30.195    <none>        4560/TCP,4561/TCP                 4h20m
ricplt        service-ricplt-appmgr-http                  ClusterIP   10.110.110.91    <none>        8080/TCP                          4h21m
ricplt        service-ricplt-appmgr-rmr                   ClusterIP   10.110.96.28     <none>        4561/TCP,4560/TCP                 4h21m
ricplt        service-ricplt-dbaas-tcp                    ClusterIP   None             <none>        6379/TCP                          4h22m
ricplt        service-ricplt-e2mgr-http                   ClusterIP   10.101.210.88    <none>        3800/TCP                          4h21m
ricplt        service-ricplt-e2mgr-rmr                    ClusterIP   10.101.245.34    <none>        4561/TCP,3801/TCP                 4h21m
ricplt        service-ricplt-e2term-prometheus-alpha      ClusterIP   10.97.95.213     <none>        8088/TCP                          4h21m
ricplt        service-ricplt-e2term-rmr-alpha             ClusterIP   10.100.36.142    <none>        4561/TCP,38000/TCP                4h21m
ricplt        service-ricplt-e2term-sctp-alpha            NodePort    10.108.215.136   <none>        36422:32222/SCTP                  4h21m
ricplt        service-ricplt-o1mediator-http              ClusterIP   10.96.196.67     <none>        9001/TCP,8080/TCP,3000/TCP        4h20m
ricplt        service-ricplt-o1mediator-tcp-netconf       NodePort    10.104.237.252   <none>        830:30830/TCP                     4h20m
ricplt        service-ricplt-rtmgr-http                   ClusterIP   10.105.27.42     <none>        3800/TCP                          4h21m
ricplt        service-ricplt-rtmgr-rmr                    ClusterIP   10.110.0.158     <none>        4561/TCP,4560/TCP                 4h21m
ricplt        service-ricplt-submgr-http                  ClusterIP   None             <none>        3800/TCP                          4h21m
ricplt        service-ricplt-submgr-rmr                   ClusterIP   None             <none>        4560/TCP,4561/TCP                 4h21m
ricplt        service-ricplt-vespamgr-http                ClusterIP   10.98.139.191    <none>        8080/TCP,9095/TCP                 4h21m
ricxapp       aux-entry                                   ClusterIP   10.99.152.66     <none>        80/TCP,443/TCP                    4h22m
ricxapp       service-ricxapp-kpimon-go-http              ClusterIP   10.109.170.194   <none>        8080/TCP                          3h51m
ricxapp       service-ricxapp-kpimon-go-rmr               ClusterIP   10.111.137.11    <none>        4560/TCP,4561/TCP                 3h51m
/home/ravi>

Solution

  • Does the inaccessible pod's namespace same with service? If not, try to

    ping service-ricplt-e2mgr-http.<namespace>