Re: [gentoo-user] Re: Lowest common denominator compile

[Alan McKinnon]

On 04/09/2017 22:55, Grant wrote:
>> This is exactly the use-case ansible was designed for: declarative,
>> idempotent, predictable management of a fleet of machines that may or
>> may not be around when you feel like updating something (so it catches
>> up later), and needs only sshd and python to do it's magic :-)
>
> ansible does sound pretty cool.  I'll check it out if I outgrow my
> script but as long as I can keep using Dell XPS 13 laptops I don't
> think it will have any trouble scaling.


Allow me a few moments to convince you more :-)

Maybe you don't need it right this minute, but your current method will
become less and less workable with time, and when you feel that maybe
you ought to do it differently, you might remember this conversation.

ansible works like you do - ssh's into a host, and does what needs
doing. It figures out what to do the same way you do, by having a clear
picture of what should be and making the host that way. It's very much
like a proxy for you.

The difference comes in when you observe that with ansible you don't
have to deal with the details of HOW to do something (the shipped
modules already deal with all of that), you only concern yourself with
WHAT you want to accomplish.

If you only use ansible to basically run ssh in a for loop, then it's a
waste of the setup effort. But let's say Dell retire or change those
XPS13s dramatically. 4 of yours wear out, and you buy 8 Precisions.
Bugger, they have different hardware and the chipset running the SSDs
has a different drive. The GPU, the wifi NIC, these things all drift
with time. Then you figure you want 2 management Precisions, plus
your's, the wife's and the workshop manager's laptops need extra stuff;
and the plebs can stay the same on the XPS.

And your script gets out of hand real quick (we've all been there). How
do you detect that some is a Precision and do appropriate actions in a
nasty script? It's not easy.
Ansible does all that for you upfront out the box. It always knows what
it's working on (thanks to a module called setup) and catering for
inevitable differences is trivial to handle. With none of the downsides
to copying entire tree structures around (like copying way too many
files you didn't intend to. Like /var/run...)

-- 
Alan McKinnon
alan.mckinnon@×××××.com