[Freeipa-devel] Data source-agnostic parameters

[Jan Cholasta]

Dne 6.8.2012 15:20, Simo Sorce napsal(a):
> On Mon, 2012-08-06 at 10:55 +0200, Jan Cholasta wrote:
>> Hi,
>>
>> while thinking about <https://fedorahosted.org/freeipa/ticket/2933>, I
>> had an idea how to make loading data from files available for all
>> parameters:
>>
>> I think we can use URI-like strings in parameter values that the CLI
>> would interpret and extract the wanted information from them (similar to
>> what openssl does in the -pass command line option, see PASS PHRASE
>> ARGUMENTS in openssl(1)).
>>
>> So, instead of adding a new parameter as a file-accepting alternative to
>> any existing parameter (i.e. what is suggested in the ticket), the user
>> would be able to specify the file in a URI-like string:
>>
>> (use new parameter --sshpubkeyfile)
>> $ ipa user-mod --sshpubkey="ssh-rsa AAAA ..."
>> $ ipa user-mod --sshpubkeyfile=.ssh/id_rsa.pub
>>
>> vs.
>>
>> (use file URI-like string)
>> $ ipa user-mod --sshpubkey="ssh-rsa AAAA ..."
>> $ ipa user-mod --sshpubkey=file:.ssh/id_rsa.pub
>>
>> and the CLI would take care of reading the file and using its contents
>> as the parameter value.
>>
>> This could be extended with additional URI(-like) schemes:
>>
>>     - data:<data> - use <data> as the value (useful for escaping values
>> that look like URIs, but you don't want them to be treated as such)
>>     - base64:<data> - use the value of base64 decoded <data> (useful for
>> --delattr on ugly raw binary values)
>>     - fd:<num> - read value from file descriptor <num>
>>     - env:<var> - read value from environment variable <var>
>>     - ask: - always prompt interactively for the value
>>     - default: - use default value, never prompt interactively
>>
>> Thoughts?
>
> How do you handle values that are actually URI strings, how do you tell
> the command to not interpret them ?
>
> Simo.
>

You can escape them like this: --someparam data:actual://uri/string

As for backward compatibility, this change has the potential to break 
things (user scripts which use the CLI, etc.), but AFAIK there is no 
parameter in IPA which expects URI string values specifically, so the 
impact would be miminal IMHO.

Honza

-- 
Jan Cholasta