Rotonda 0.6.0 'Pollens!' released

Rotonda
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This release of Rotonda incorporates the freshly released Roto 0.11, leveraging the new List[T] and optional types for more natural and ergonomic filters.

It also introduces functionality to call external programs from Roto filters, expanding the possibilities for people to adopt Rotonda in their existing pipelines and measurement infrastructures.

Below is a verbatim copy of the changelog as found on Github release page.

Towards 0.7

As a sneak peek towards 0.7, we plan a series of fundamental changes to support non-unicast address families as well as ADDPATH. And somewhere along that road, development of Rotonda will move to Codeberg.

Changelog

Roto runtime

Roto gained plenty of string related functionality as well as support for optional types, making many formatting helpers obsolete. This means almost all fmt_ Roto methods are removed.

Instead, most types can now be used in formatting strings directly, for example

let s = f"{route.prefix()}";

Many of the removed fmt_ methods papered over the fact that most fields in BGP are optional. There is no guarantee there is an AS_PATH in a BGP PDU for example. And if there is an AS_PATH, it could be empty, in which case there is no originating ASN.

Instead of hiding this from users in Roto scripts, we can now make this explicit with the new Roto Option[T] type.

match route.origin_as() {
    Some(asn) -> f"got an origin AS: {asn}",
    None -> f"no origin AS"
}

Eventually, the Roto language might gain ways to deal with optional values in more ergonomic ways. For now, things can get a bit verbose.

List of removed methods:

Route.fmt_prefix()
Route.fmt_rov_status()
Route.fmt_aspath()
Route.fmt_aspath_origin()
Route.fmt_communities()
Route.fmt_large_communities()

BgpMsg.fmt_aspath()
BgpMsg.fmt_aspath_origin()
BgpMsg.fmt_communities()
BgpMsg.fmt_large_communities()

BmpMsg.fmt_aspath()
BmpMsg.fmt_aspath_origin()
BmpMsg.fmt_communities()
BmpMsg.fmt_large_communities()

The packaged Roto example (etc/examples/filters.roto.example) includes Roto functions showing how one can deal with the printing of optional values (such as route.aspath_origin()), and lists (such as route.communities()).

Similarly to fmt_ methods, several match and contains methods papered over optionals as well. Those too are replaced by Roto native equivalents.

These methods are:

{Route, BgpMsg, BmpMsg}.match_aspath_origin()
{Route, BgpMsg, BmpMsg}.aspath_contains()
{Route, BgpMsg, BmpMsg}.contains_community()
{Route, BgpMsg, BmpMsg}.contains_large_community()
{Route, BgpMsg, BmpMsg}.aspath_contains()

New

  • Rotonda now uses Roto 0.11.
    More details on changes in Roto not affecting Rotonda per se can be found in the changelog.

  • Several format methods are introduced on the various Roto types:

    • The raw, over-the-wire bytes of BgpMsg and BmpMsg can be turned into hexadecimal and base64 strings via .fmt_hex() and .fmt_base64(), respectively.
    • The Route type also has these methods, returning hex/base64 for the wireformat of the path attributes. Additionaly, there is
      Route.fmt_json() that includes the NLRI.

  • In Roto scripts, external commands can be executed using the new command() function, which can be combined with e.g. the fmt_json() method described above to pass a route as an argument to an external script.

  • Experimental HTTP endpoints are added enabling sending BGP PDUs out over established BGP sessions.

Other changes

  • Updated the man page, which included a broken URL for the online documentation, and described command line arguments that are not supported anymore.

Acknowledgements

We would like to very much thank Jannis Imhof (@withjannis) for their (ongoing) input and support.

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