lookup-srv

DNS lookup utility for SRV records.

Useful for pod initializations in Kubernetes statefulsets.

Usage

It takes -srv option for SRV name:

$ lookup-srv -srv=pg-ha
node-0.pg-ha.default.svc.cluster.local
node-1.pg-ha.default.svc.cluster.local
node-2.pg-ha.default.svc.cluster.local

Or from SRV_NAME environment variable:

$ SRV_NAME=pg-ha lookup-srv
node-0.pg-ha.default.svc.cluster.local
node-1.pg-ha.default.svc.cluster.local
node-2.pg-ha.default.svc.cluster.local

You can pass shell script with -script option:

$ lookup-srv -srv=pg-ha -script="xargs getent hosts | cut -d' ' -f 1"
10.4.9.115      node-0.pg-ha.default.svc.cluster.local node-0
10.5.8.129      node-1.pg-ha.default.svc.cluster.local
10.6.7.137      node-2.pg-ha.default.svc.cluster.local

$ lookup-srv -srv=pg-ha -script="xargs getent hosts | cut -d' ' -f 1 | /opt/config.sh"
Configuring...
Master 10.4.9.115
Slave  10.5.8.129
Slave  10.6.7.137
OK