How to get mesos master URL through APIs dynamically?

Question

is there a way to get the mesos master end point using a POST/GET call dynamically? Are there any APIs to call zookeeper which in turn returns the mesos master URL?

Answer 1

You should be able to query for the master in zookeeper by querying your zookeeper DNS endpoint (eg zookeeper.example.com) with:

zookeeper.example.com:2181/mesos .

You may also query any of your masters in mesos, and the request will automatically get forwarded to the leading master.

Lastly, there's a project called Mesos-DNS that has a DNS endpoint for any of your mesos masters (with master.mesos ).

However, the most important point is that you shouldn't be storing that information . There's no reason to assume that the current leading master (or any master for that matter) won't change.

Answer 2

Use zookeeper command-line.

https://github.com/apache/zookeeper/blob/trunk/bin/zkCli.sh

./bin/zkCli.sh

help
# see how to connect to other zookeeper
# default is: localhost:2181

ls /
# [mesos, zookeeper]

ls /mesos
# [json.info_0000000001]

get /mesos/json.info_0000000001
# It will return the Mesos Master's hostname & IP

The result is like this:

{"address":{"hostname":"ced7f7fb79fc","ip":"172.17.0.3","port":5050},"hostname":"ced7f7fb79fc","id":"c8055c4c-3ae0-40e6-a710-5184bcb957a9","ip":50336172,"pid":"master@172.17.0.3:5050","port":5050,"version":"0.26.0"}

Answer 3

With mesos-dns you can simplye use leader.mesos to get the current master.

dig leader.mesos

; <<>> DiG 9.9.5-3ubuntu0.6-Ubuntu <<>> leader.mesos
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8386
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;leader.mesos.                  IN      A

;; ANSWER SECTION:
leader.mesos.           60      IN      A       10.100.12.40

;; Query time: 1 msec
;; SERVER: 10.100.14.206#53(10.100.14.206)
;; WHEN: Wed Sep 14 15:31:55 UTC 2016
;; MSG SIZE  rcvd: 46