Let me take those questions in order
Q) How should I set PATH
For environment files used in systemd you’ll need to set the path explicitly, instead of adding on to the existing PATH. systemd doesn’t allow environment variables to references other variables. Remember systemd isn’t shell based, so shell-like features you are use to working with at the commandline prompt aren’t available. Trying setting a path like this in /etc/sysconfig/sensu-backend
You’ll want to tailor that for your systems obviously, maybe you’ll want to add /usr/loca/bin as well
Also note you can use the full path to the command you want to run instead of trying to edit the PATH, if that’s easier for you.
Q) Why did I not get embedded ruby in my default installation?
This is due to an architectual shift between Sensu Classic and Sensu Go. Sensu Go is a completely new codebase written in GO. Sensu Classic was ruby based, and as such included an embedded ruby environment to help make it easier to use the sensu services of the box. Sensu Go backend doesn’t explicitly need a Ruby environment to operate so its not included. You’ll only need a Ruby environment for plugins that require it…its no longer needed for the Sensu services themselves.
Q) Is there any diff procedure to follow for embedded ruby to be installed?
I included a link to the documentation on how to install a ruby environment packages by Sensu that best matches the Sensu classic environment. Its probably best to stop referring to it as embedded…since the Sensu Go backend nor agent processes does not use ruby…technicaly its not “embedded”… its just a pre-packaged ruby environment now. I think part of your difficulty is trying to map Sensu Classic concepts directly over into Sensu Go, and that’s causing a little bit of confusion.
Here’s the link to the Sensu Go documentation again for how to install the pre-packaged Ruby environment that includes sensu-install:
You may want to also read up on the new Sensu Go concept of assets. Assets are a new way to distribute plugins which we think will be much easier for people.