get ip of emr master node from yarn cli

Question

In order to get a list of the ip addresses of emr slave nodes, one must run the following code:

yarn node -list 2>/dev/null \
| sed -n "s/^\(ip[^:]*\):.*/\1/p"

yarn node -list happens to print off the ip of the master node to stderr:

19/04/02 18:59:26 INFO client.RMProxy: Connecting to ResourceManager at ip-10-1-0-238.ec2.internal/10.1.0.238:8032

How would I modify the above code to get the private ip of the emr master node instead?

if the ip address is printed to stderr then you should replace `2>/dev/null` with `2>&1` in your command — builder-7000, Apr 02 '19 at 19:09
that's a start, but how would i modify the `sed` pattern matching to get the master IP? — Walrus the Cat, Apr 02 '19 at 19:42

score 3 · Answer 1 · answered Aug 09 '19 at 11:43

3

If you are running on Amazon Elastic Map Reduce, this will read the master IP address from the jobflow JSON object and parse it out with jq:

jq .masterPrivateDnsName /emr/instance-controller/lib/info/job-flow.json

answered Aug 09 '19 at 11:43

vy32

score 2 · Answer 2 · answered Apr 02 '19 at 19:50

2

You could use:

yarn node -list |& sed 's/.*ip-\([^.]*\).*/\1/g'

where |& is a shorthand for 2>&1. This returns:

10-1-0-238

answered Apr 02 '19 at 19:50

builder-7000

lol so... that didn't work... but it turns out you can just type `hostname -f`. thanks though! – Walrus the Cat Apr 02 '19 at 23:26

2 Answers2