question Accessing a role's hostname from SDL or control script in Archives of Support Questions (Read Only)

Accessing a role's hostname from SDL or control script

benbluetalon — Mon, 08 May 2017 23:51:58 GMT

I'm creating a CSD for a custom service with multiple roles. Some of the roles need to have knowledge of which host(s) other roles are running on, similar to how a NameNode needs to know which hosts have DataNodes.

I think this information should be accessible somehow after a user has chosen the role hosts in the CM UI, but I can't figure out how.

So, how can I access a role's hostname from the service.sdl or control.sh files?

Re: Accessing a role's hostname from SDL or control script

csguna — Tue, 09 May 2017 00:49:51 GMT

Dont mistake me I am not savy when it comes to CSD . I have few links in my desktop sleeping.

I believe it might come handy for you. if I understand correctly these links should gear you up.

https://blog.cloudera.com/blog/2014/04/how-to-extend-cloudera-manager-with-custom-service-descriptors/

https://github.com/cloudera/cm_ext/wiki

https://github.com/cloudera/cm_csds

Re: Accessing a role's hostname from SDL or control script

benbluetalon — Tue, 09 May 2017 20:47:57 GMT

Thanks for the reply @csguna. I have seen those links before, and haven't found the answer I'm looking for yet.

Re: Accessing a role's hostname from SDL or control script

csguna — Wed, 10 May 2017 11:06:53 GMT

@benbluetalonMy bad mate.

Re: Accessing a role's hostname from SDL or control script

benbluetalon — Fri, 12 May 2017 00:13:28 GMT

I've figured out a way to do this. I used peerConfigGenerators in the SDL file. Peer configs create a properties file with key/value pairs--the key/value pairs themselves weren't useful to me, but each line of the file is prepended by hostname that the chose role is running on. I then parsed that file for the hostname in the control script.

Re: Accessing a role's hostname from SDL or control script

csguna — Fri, 12 May 2017 01:24:08 GMT

Sounds good .