peer-finder

kubernetes peer-finder

usage

Dockerfile

...

# script
ADD bootstrap.sh /bootstrap.sh
ADD on-change.sh /on-change.sh
RUN chmod +x /bootstrap.sh
RUN chmod +x /on-change.sh

ENTRYPOINT ["/bootstrap.sh"]

bootstrap.sh

/peer-finder -on-change=/on-change.sh -on-start=/on-change.sh -service=sfs -ns=default -dns-suffix=svc.cluster.local

while true; do sleep 1000; done

on-change.sh

#! /bin/bash

> /etc/peer_config
while read -ra LINE; do
    IP=${LINE#*,}
    DNS=${LINE%%,*}
    HOST=${LINE%%.*}

    PEERS=("${PEERS[@]}" ${DNS})

    echo "${DNS}" >> /etc/peer_config
done

echo ${PEERS}

kubectl logs sfs-1

2017/04/17 14:03:14 Peer list updated
iam sfs-1.sfs.default.svc.cluster.local,172.1.56.2
was []
now [sfs-0.sfs.default.svc.cluster.local,172.1.65.7 sfs-1.sfs.default.svc.cluster.local,172.1.56.2]
2017/04/17 14:03:14 execing: /on-change.sh with stdin: sfs-0.sfs.default.svc.cluster.local,172.1.65.7
sfs-1.sfs.default.svc.cluster.local,172.1.56.2
2017/04/17 14:03:14 sfs-0.sfs.default.svc.cluster.local
[dev_dean@VM_61_2_centos statefulset]$ kubectl logs sfs-0
2017/04/17 14:03:08 lookup sfs on 182.1.0.100:53: server misbehaving
2017/04/17 14:03:09 Peer list updated
iam sfs-0.sfs.default.svc.cluster.local,172.1.65.7
was []
now [sfs-0.sfs.default.svc.cluster.local,172.1.65.7]
2017/04/17 14:03:09 execing: /on-change.sh with stdin: sfs-0.sfs.default.svc.cluster.local,172.1.65.7
2017/04/17 14:03:09 sfs-0.sfs.default.svc.cluster.local
2017/04/17 14:03:15 Peer list updated
iam sfs-0.sfs.default.svc.cluster.local,172.1.65.7
was [sfs-0.sfs.default.svc.cluster.local,172.1.65.7]
now [sfs-0.sfs.default.svc.cluster.local,172.1.65.7 sfs-1.sfs.default.svc.cluster.local,172.1.56.2]
2017/04/17 14:03:15 execing: /on-change.sh with stdin: sfs-0.sfs.default.svc.cluster.local,172.1.65.7
sfs-1.sfs.default.svc.cluster.local,172.1.56.2
2017/04/17 14:03:15 sfs-0.sfs.default.svc.cluster.local

kubectl exec sfs-1 -- cat /etc/peer_config

sfs-0.sfs.default.svc.cluster.local
sfs-1.sfs.default.svc.cluster.local