On Fri, 16 Feb 2024 11:23:30 +0100
Paul Holzinger <pholzing@redhat.com> wrote:

Looking at 
the main function I see:

if (c.debug)
         __setlogmask(LOG_UPTO(LOG_DEBUG));
     else if (c.quiet)
         __setlogmask(LOG_UPTO(LOG_ERR));

                                     ^^^

     else
         __setlogmask(LOG_UPTO(LOG_INFO));

So if the default is still log level is info there is no way for podman 
to say show warnings/errors only.

That's because the second clause above is wrong, I think. It should be:

	else if (c.quiet)
		__setlogmask(LOG_UPTO(LOG_WARN));

because we also say in the man page:

       -q, --quiet
              Don't print informational messages.

but nowhere it's written that we'll also hide warnings with it.

We can use --quiet but I think the 
warnings should be displayed to end users as well.
So my next request would be to one of the following:
a) change the default level to warn but then there no way show info 
unless debug is set (or add a new flag for info)

I think LOG_INFO should really be the default, if you use passt or
pasta stand-alone that's very helpful.

b) add a flag to select warning level

...which is however what --quiet is supposed to do.

c) log info to stdout and warn/err to stderr then podman could just show 
stderr and hide stdout

...which doesn't fit the meaning of standard output though: pasta has
no functional terminal output.

I would just fix --quiet if that suits Podman as well.

While at it, make it clear that we're disabling IPv4 or IPv6 if
there's no routable interface for the corresponding IP version.

Reported-by: Paul Holzinger <pholzing@redhat.com>
Link: https://github.com/containers/podman/pull/21563#issuecomment-1937024642
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
v2: Report that we're disabling IPv4 or IPv6 in the message

  conf.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/conf.c b/conf.c
index 5e15b66..3646700 100644
--- a/conf.c
+++ b/conf.c
@@ -579,7 +579,7 @@ static unsigned int conf_ip4(unsigned int ifi,
  		ifi = nl_get_ext_if(nl_sock, AF_INET);
  
  	if (!ifi) {
-		warn("No external routable interface for IPv4");
+		info("No routable interface for IPv4: IPv4 is disabled");
  		return 0;
  	}
  
@@ -651,7 +651,7 @@ static unsigned int conf_ip6(unsigned int ifi,
  		ifi = nl_get_ext_if(nl_sock, AF_INET6);
  
  	if (!ifi) {
-		warn("No external routable interface for IPv6");
+		info("No routable interface for IPv6: IPv6 is disabled");  

The code only looks for a default route, so if one has some custom 
internal routes then saying no routable interface found is confusing. 
What this should really say is:
No interface with a default route for IPv...

Oops, sorry, I just pushed this.

I think it's clear enough in the sense that by design passt and pasta
need a default route, and if you have a specific route on a given
interface, that interface is not "routable" for our purposes.

But sure, we can make it more explicit. Building on your suggestion --
would this be okay:

  "No interface with a default route for IPv[46]: disabling IPv[64]"

? David?