jls(8) inconsistent output

[James Gritton]

On 2016-11-27 13:00, Christian Schwarz wrote:
> Hi all,
> 
> jls(8) is generating inconsistent output regarding IPv4 & IPv6 
> addresses.
> 
> Below are some examples documenting the behavior.
> 
>   - For readability, I use `--libxo json` and pipe the output through 
> jq.
>     However, the information is the same as without `--libxo`
>   - These are all jails spawned by ezjail(8), hence spawned using the
> old rc.conf syntax.
> 
> Can anyone reproduce these inconsistencies on their system?
>   Possibly with the native jail.conf / other jail managers.
> 
> Furthermore: I would be willing to try fixing the behavior.
>   However, do you think changing/correcting the output at this point 
> will
>   break existing software?

Most of the output doesn't need fixing, just understanding why it is the 
way it is.  The no-option jls is the original format used when jails had 
much less information in them, and has been kept in that format for just 
the reason you mentioned (not breaking existing software).  Later on, 
jails got a little more complex, and the "-v" was added to show the 
(then) complete jail information.  I consider both of these options 
(well, the one option and the one lack of options) to be back-compatible 
behavior at this point.

For the modern jails with the more dynamic parameters you should either 
specify the parameters you want on the command line, or use "all".  The 
"-n" doesn't matter if you're using libxo which needs to print names 
anyway.  This explains the difference in your examples, except the 
weirdness of the -v output having both IPv4 and IPv6 addresses listed as 
"ipv4_addrs".  I guess that follows the non-libxo -v convention of 
printing both kinds of addresses together, though the label "ipv4_addrs" 
is incorrect and probably should be "ip_addrs" or the like.  That may be 
worth fixing, or may have the existing software problem at this point; I 
don't know what software uses the libxo output, but I imagine something 
does.

I can only give a similar "maybe" for your comment of the multiple 
addresses being better presented as JSON arrays.  That does seem 
cleaner, as long as it doesn't break much.

On the point ip ip4 and ip6 being inconsistent: yes they are.  I'm going 
to have to look in to why they're showing as "disabled" when then should 
be "new".  This is a problem independent of whether the output is from 
libxo.

- Jamie


> jls --libxo json
>   IPv6 addresses are not printed at all
>   ...
>       {
>         ...
>         "ipv4": "10.123.234.6",
>         ...
>       }
>   ...
> 
> jls --libxo json -n all
>   Both address types are printed, but not particularly nicely (should
> use JSON arrays)
>   Additionally, the ip(4|6) variables seem inconsistent.
>   ...
>         {
>         "ip4": "disable",
>         "ip6": "disable",
>         ...
>         "ip4.addr": "10.123.234.6",
>         "ip4.saddrsel": true,
>         "ip6.addr": "2001:ffff:ffff::b,2001:ffff:ffff::d",
>         "ip6.saddrsel": true
>       }
>   ...
> 
> jls --libxo json -v
>   Attention: no -n specified
>   Prints IPv6-Addresses as IPv4 addresses.
>   ...
>       {
>         ...
>         "ipv4_addrs": [
>           "10.123.234.6",
>           "2001:ffff:ffff::b",
>           "2001:ffff:ffff::d"
>         ]
>       }
>   ...