From day1, scylla_setup can be run either iteractively or through
command line parameters. Still, one of the requests we are asked the
most from users is whether we can provide them with a version of
scylla_setup that they can call from their scripts.
This probably happens because once you call a script interactively,
it may not be totally obvious that a different mode is available.
Even when we do tell users about that possibility, the request number
two is then "which flags do I pass?"
The solution I am proposing is to just tell users the answers to those
qestions at the end of an interactive session. After this patch, we
print the following message to the console:
ScyllaDB setup finished.
scylla_setup accepts command line arguments as well! For easily provisioning in a similar environmen than this, type:
scylla_setup --no-raid-setup --nic eth0 --no-kernel-check \
--no-verify-package --no-enable-service --no-ntp-setup \
--no-node-exporter --no-fstrim-setup
Also, to avoid the time-consuming I/O tuning you can add --no-io-setup and copy the contents of /etc/scylla.d/io*
Only do that if you are moving the files into machines with the exact same hardware
Notes on the implementation: it is unfortunate for these purposes that
all our options are negated. Most conditionals are branching on true
conditions, so although I could write this:
args.no_option = not interactive_ask_service(...)
if not args.no_option:
...
I opted in this patch to write:
option = interactive_ask_service(...)
args.no_option = not option
if option:
...
There is an extra line and we have to update args separately, but it
makes it less hard to get confused in the conditional with the double
negation. Let me know if there are disagreements here.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20190124153832.21140-1-glauber@scylladb.com>
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