[Freeipa-users] CSV support in IPA administration tools - to be, or not to be?

[Petr Viktorin]

On 01/11/2013 09:57 PM, John Dennis wrote:
> On 01/11/2013 03:52 PM, Dmitri Pal wrote:
>> On 01/11/2013 03:27 PM, John Dennis wrote:
>>> On 01/11/2013 03:10 PM, Dmitri Pal wrote:
>>>> On 01/10/2013 11:00 AM, John Dennis wrote:
>>>>> On 01/10/2013 08:15 AM, Petr Spacek wrote:
>>>>>> Hello,
>>>>>>
>>>>>> is there any user of CSV support built-in to IPA administration tools
>>>>>> ("ipa"
>>>>>> command)? Do you consider it sane or even useful? Please reply.
>>>>>
>>>>> I've always disliked our use of CSV values on both the command line
>>>>> and internally. They're just weird, nothing else in Unix works like
>>>>> this and as you point out below there are easier better alternatives.
>>>>> Plus with the use of CSV's there is a lot of awkward quoting in a
>>>>> variety of places.
>>>>>
>>>>> On the command line I always thought multiple values should be
>>>>> specified multiple times and internally they should be encapsulated in
>>>>> lists rather than parsing a CSV string (if it's logically a list then
>>>>> why isn't it a list?)
>>>>>
>>>>> However at this juncture I'm not sure we can make such a change, we
>>>>> have a published API that we would be violating. But perhaps we're not
>>>>> so far down the road we can't make such a change and we're better off
>>>>> doing it now while there is even a chance. It's not clear to me how
>>>>> much the command line is being used and specifically with CSV values.
>>>>>
>>>>> Do I think CSV's are sane and useful? No. Can we change that? That's a
>>>>> whole other story.
>>>>>
>>>>>
>>>>>> I wanted to add single TXT record with double quotation marks (")
>>>>>> inside the
>>>>>> TXT data.
>>>>>>
>>>>>> I spent some time figuring out how it is supposed to work ... and
>>>>>> with help of
>>>>>> Petr^3 I managed to write the command.
>>>>>>
>>>>>> The resulting command (for BASH) is absolutely crazy:
>>>>>> ipa dnsrecord-add example.test. newrec --txt-rec='"""created on
>>>>>> 13:01:23"""'
>>>>>>
>>>>>> Do we really need support for this piece of insanity? Shells can do
>>>>>> the same
>>>>>> thing with much less pain :-)
>>>>>>
>>>>>> IPA with CSV support can add multiple attributes at once, e.g.
>>>>>> ipa dnsrecord-add example.test. newrec --txt-rec=1,2,3,4,5,6,7,8,9
>>>>>> will add TXT records with value 1, 2, 3 etc.
>>>>>>
>>>>>> BASH can do the same thing (without the escaping hell):
>>>>>> ipa dnsrecord-add example.test. newrec --txt-rec={1,2,3,4,5,6,7,8,9}
>>>>>> and
>>>>>> ipa dnsrecord-add example.test. newrec --txt-rec={1..9}
>>>>>> BASH would expand to
>>>>>> ipa dnsrecord-add example.test. newrec --txt-rec=1 --txt-rec=2
>>>>>> --txt-rec=3
>>>>>> --txt-rec=4 --txt-rec=5 --txt-rec=6 --txt-rec=7 --txt-rec=8
>>>>>> --txt-rec=9
>>>>>>
>>>>>
>>>>>
>>>> Do we already have CSV support?
>>>> Where is it used?
>>>> It is not clear to me if BASH example above requires the CSV support or
>>>> it does expansion on its own. Please explain.
>>>>
>>>
>>> We already have CSV support. It's a mechanism that allows multiple
>>> values to be passed for one command line argument. The alternate
>>> approach is rather than having one command line arg that takes
>>> multiple values is to allow multiple command line args, each one
>>> taking a single value. This is the UNIX methodology. I believe the
>>> original thinking was who would want to type out multiple command line
>>> args, it's too verbose. However the shell expansion illustrated above
>>> shows how with simple shell syntax one can have succicent args and
>>> allow the shell to expand them into the preferred verbose form.
>>>
>>
>> So both are already supported and we want to stop using CSV and
>> deprecate it over time?
>> This makes sense if there are good examples of how to use bash expansion.
>> I suggest we create a page and describe preferred method of dealing with
>> the lists and document it.
>> Also do the same with the manual, i.e. review it to make sure we do not
>> show CSV syntax in the docs, same with the man pages.
>> On the project page we will say that CSV will not be added to the new
>> and existing commands and will be deprecated over time (probably by IPA
>> version 4).
>> Do I get it right?
>>
>
> I'm not sure both are currently supported. I'm not sure we permit
> multiple args with the same name and aggregate them, I thought that was
> part of the proposal.
>

We do support multiple arguments.

The trouble with CSV is that to put commas (or in some cases double 
quotes) in the data, they need to be escaped in a way that's not 
intuitive. The proposal is to change this, so that instead of
     --txt-rec='"""created on 13:01:23"""'
you can use just
     --txt-rec='"created on 13:01:23"'
and instead of
     --txt-rec='Record one, record two'
you need to say
     --txt-rec={'Record one','record two'}
The assumption is that this makes more sense to a sysadmin, who is much 
more likely to know bash scripting than our flavor of CSV escaping.


-- 
Petr³