Re: [RFC ndctl PATCH 0/3] Rename monitor.conf to ndctl.conf as a ndctl global config file

From: "Verma, Vishal L" <vishal.l.verma@intel.com>
To: "Williams, Dan J" <dan.j.williams@intel.com>
Cc: "fukuri.sai@gmail.com" <fukuri.sai@gmail.com>,
	"nvdimm@lists.linux.dev" <nvdimm@lists.linux.dev>,
	"qi.fuli@fujitsu.com" <qi.fuli@fujitsu.com>
Subject: Re: [RFC ndctl PATCH 0/3] Rename monitor.conf to ndctl.conf as a ndctl global config file
Date: Wed, 2 Jun 2021 17:15:44 +0000	[thread overview]
Message-ID: <98516fb56623180b78bce2a6a15103023a59b884.camel@intel.com> (raw)
In-Reply-To: <CAPcyv4inknvApE1xZOiK8u2xPLejuqixf_XKbS05fPKvno+Yyg@mail.gmail.com>

On Wed, 2021-06-02 at 09:47 -0700, Dan Williams wrote:
> On Tue, Jun 1, 2021 at 10:31 PM Verma, Vishal L
> <vishal.l.verma@intel.com> wrote:
> > 
> > [switching to the new mailing list]
> > 
> > On Mon, 2021-05-17 at 08:14 +0900, QI Fuli wrote:
> > > From: QI Fuli <qi.fuli@fujitsu.com>
> > > 
> > > This patch set is to rename monitor.conf to ndctl.conf, and make it a
> > > global ndctl configuration file that all ndctl commands can refer to.
> > > 
> > > As this patch set has been pending until now, I would like to know if
> > > current idea works or not. If yes, I will finish the documents and test.
> > > 
> > > Signed-off-by: QI Fuli <qi.fuli@fujitsu.com>
> > 
> > Hi Qi,
> > 
> > Thanks for picking up on this! The approach generally looks good to me,
> > I think we can definitely move forward with this direction.
> > 
> > One thing that stands out is - I don't think we can simply rename the
> > existing monitor.conf. We have to keep supporting the 'legacy'
> > monitor.conf so that we don't break any deployments. I'd suggest
> > keeping the old monitor.conf as is, and continuing to parse it as is,
> > but also adding a new ndctl.conf as you have done.
> > 
> > We can indicate that 'monitor.conf' is legacy, and any new features
> > will only get added to the new global config to encourage migration to
> > the new config. Perhaps we can even provide a helper script to migrate
> > the old config to new - but I think it needs to be a user triggered
> > action.
> > 
> > This is timely as I also need to go add some config related
> > functionality to daxctl, and basing it on this would be perfect, so I'd
> > love to get this series merged in soon.
> 
> I wonder if ndctl should treat /etc/ndctl like a conf.d directory of
> which all files with the .conf suffix are concatenated into one
> combined configuration file. I.e. something that maintains legacy, but
> also allows for config fragments to be deployed individually.

Agreed, this would be the most flexible. ciniparser doesn't seem to
support multiple files directly, but perhaps ndctl can, early on, load
up multiple files/dictionaries, and stash them in ndctl_ctx. Then there
can be accessor functions to retrieve specific conf strings from that
as needed by different commands.