For example:
```
17:35 ❱ curl -s 127.0.0.1:8080/api/v0/outlet/metrics | promtool check metrics
akvorado_outlet_core_classifier_exporter_cache_size_items counter metrics should have "_total" suffix
akvorado_outlet_core_classifier_interface_cache_size_items counter metrics should have "_total" suffix
akvorado_outlet_flow_decoder_netflow_flowset_records_sum counter metrics should have "_total" suffix
akvorado_outlet_flow_decoder_netflow_flowset_records_sum non-histogram and non-summary metrics should not have "_sum" suffix
akvorado_outlet_flow_decoder_netflow_flowset_sum counter metrics should have "_total" suffix
akvorado_outlet_flow_decoder_netflow_flowset_sum non-histogram and non-summary metrics should not have "_sum" suffix
akvorado_outlet_kafka_buffered_fetch_records_total non-counter metrics should not have "_total" suffix
akvorado_outlet_kafka_buffered_produce_records_total non-counter metrics should not have "_total" suffix
akvorado_outlet_metadata_cache_refreshs counter metrics should have "_total" suffix
akvorado_outlet_routing_provider_bmp_peers_total non-counter metrics should not have "_total" suffix
akvorado_outlet_routing_provider_bmp_routes_total non-counter metrics should not have "_total" suffix
```
Also ensure metrics using errors as label don't have a too great
cardinality by using constants for error messages used.
At first, there was a tentative to use BMP collector implementation
from bio-rd. However, this current implementation is using GoBGP
instead:
- BMP is very simple from a protocol point of view. The hard work is
mostly around decoding. Both bio-rd and GoBGP can decode, but for
testing, GoBGP is able to generate messages as well (this is its
primary purpose, I suppose parsing was done for testing purpose).
Using only one library is always better. An alternative would be
GoBMP, but it also only do parsing.
- Logging and metrics can be customized easily (but the work was done
for bio-rd, so not a real argument).
- bio-rd is an application and there is no API stability (and I did
that too)
- GoBGP supports FlowSpec, which may be useful in the future for the
DDoS part. Again, one library for everything is better (but
honestly, GoBGP as a lib is not the best part of it, maybe
github.com/jwhited/corebgp would be a better fit while keeping GoBGP
for decoding/encoding).
There was a huge effort around having a RIB which is efficient
memory-wise (data are interned to save memory), performant during
reads, while being decent during insertions. We rely on a patched
version of Kentik's Patricia trees to be able to apply mutations to
the tree.
There was several tentatives to implement some kind of graceful
restart, but ultimetaly, the design is kept simple: when a BMP
connection goes down, routes will be removed after a configurable
time. If the connection comes back up, then it is just considered new.
It would have been ideal to rely on EoR markers, but the RFC is
unclear about them, and they are likely to be per peer, making it
difficult to know what to do if one peer is back, but not the other.
Remaining tasks:
- [ ] Confirm support for LocRIB
- [ ] Import data in ClickHouse
- [ ] Make data available in the frontend
Fix#52
