[SD documentation] Explaination how to run scylla-doctor in case nonroot Scylla installation is missed about scylladb HOT 3 OPEN

@vladzcloudius

from scylladb.

That makes sense. When ScyllaDB is installed without root privileges, the path to python3 is also required.

from scylladb.

When Scylla installed under user, not under root, scylla-doctor cannot be run in with regular command. In this case user have to provide path to scylladb/python3 binary. For example:

/home/scylla-test/scylladb/python3/bin/python3 /home/scylla-test/scylla_doctor.pyz --save-vitals artifacts-centos8-jenkins-db-node-34878130-0-1.vitals.json

Please, add explanation about this in SD documentation

Just providing a path to a Python3 binary is not going to resolve the problem with a non-standard installation.

Scylla Doctor uses more executables provisioned by Scylla packages - the packaged Python3 interpreter used by scylla_doctor.pyz is just one of them. perftune.py and cqlsh are some of examples of other such executables.

When the installation is non-standard one has to alter values in the DefaultPaths configuration section as described here: https://github.com/scylladb/field-engineering/tree/master/scylla-scripts/scylla-doctor#defaultpaths-section

FYI, @annastuchlik @juliayakovlev

from scylladb.