From e34270c51e6cdcd9306f2d3f71e0d05d24eb8108 Mon Sep 17 00:00:00 2001
From: Michael Beaver <michaelbeaver64@gmail.com>
Date: Tue, 8 Jan 2019 13:32:11 -0600
Subject: [PATCH] Basic support for BGP communities in calico

This creates a new section in calico/values.yaml that enables
BGP communities to be applied to a cidr by using the bird_ipam
templates.

Change-Id: I4dbbc8d8e761e0484eeb7c8bf0fefa28d29493e5
---
 .../bird/_bird6_ipam.cfg.template.tpl         | 16 ++++++++++
 .../bird/_bird_ipam.cfg.template.tpl          | 16 ++++++++++
 calico/values.yaml                            | 30 +++++++++++++++++++
 3 files changed, 62 insertions(+)

diff --git a/calico/templates/bird/_bird6_ipam.cfg.template.tpl b/calico/templates/bird/_bird6_ipam.cfg.template.tpl
index fadf1eb5a5..a73a16acc6 100644
--- a/calico/templates/bird/_bird6_ipam.cfg.template.tpl
+++ b/calico/templates/bird/_bird6_ipam.cfg.template.tpl
@@ -8,7 +8,23 @@ function osh_filters ()
 {{- end }}
 }
 
+function apply_communities ()
+{
+  # Set community value based on dictionary of cidrs
+{{- $asnum := .Values.networking.bgp.asnumber }}
+{{- range .Values.networking.bgp.ipv6.community_cidr_ref }}
+  {{- $community := .community }}
+  {{- $cidr := .cidr }}
+  {{- with .prefix }}
+  if ( net ~ {{ $cidr }} ) then { bgp_community.add(({{ . }}, {{ $community }})); }
+  {{- else }}
+  if ( net ~ {{ $cidr }} ) then { bgp_community.add(({{ $asnum }}, {{ $community }})); }
+  {{- end }}
+{{- end }}
+}
+
 filter calico_pools {
+  apply_communities();
   calico_aggr();
   osh_filters();
 {{`{{range ls "/pool"}}{{$data := json (getv (printf "/pool/%s" .))}}`}}
diff --git a/calico/templates/bird/_bird_ipam.cfg.template.tpl b/calico/templates/bird/_bird_ipam.cfg.template.tpl
index da74389090..2900856950 100644
--- a/calico/templates/bird/_bird_ipam.cfg.template.tpl
+++ b/calico/templates/bird/_bird_ipam.cfg.template.tpl
@@ -8,7 +8,23 @@ function osh_filters ()
 {{- end }}
 }
 
+function apply_communities ()
+{
+  # Set community value based on dictionary of cidrs
+{{- $asnum := .Values.networking.bgp.asnumber }}
+{{- range .Values.networking.bgp.ipv4.community_cidr_ref }}
+  {{- $community := .community }}
+  {{- $cidr := .cidr }}
+  {{- with .prefix }}
+  if ( net ~ {{ $cidr }} ) then { bgp_community.add(({{ . }}, {{ $community }})); }
+  {{- else }}
+  if ( net ~ {{ $cidr }} ) then { bgp_community.add(({{ $asnum }}, {{ $community }})); }
+  {{- end }}
+{{- end }}
+}
+
 filter calico_pools {
+  apply_communities();
   calico_aggr();
   osh_filters();
 {{`{{range ls "/v1/ipam/v4/pool"}}{{$data := json (getv (printf "/v1/ipam/v4/pool/%s" .))}}`}}
diff --git a/calico/values.yaml b/calico/values.yaml
index b73e58820d..a46f751034 100644
--- a/calico/values.yaml
+++ b/calico/values.yaml
@@ -224,6 +224,21 @@ networking:
       # IPs within them on a host, we will announce the address in
       # addition to traditional pod workloads
       additional_cidrs: []
+      # community_cidr_ref contains embedded objects that describe a
+      # BGP community that is to be associated with the supplied CIDR.
+      # The top-level key names are not important.
+      #
+      # The resulting BGP community will take the form of
+      #    <prefix>:<community>
+      # If no prefix is specified then the asnumber is used
+      community_cidr_ref:
+#        cidr_community_description:
+#          cidr: 192.168.0.0/16
+#          community: 54321
+#          prefix: 55555
+#        alpha:
+#          cidr: 10.0.0.0/16
+#          community: 54322
       port:
         neighbor: 179
         listen: 179
@@ -247,6 +262,21 @@ networking:
       # IPs within them on a host, we will announce them in addition
       # to traditional pod workloads
       additional_cidrs: []
+      # community_cidr_ref contains embedded objects that describe a
+      # BGP community that is to be associated with the supplied CIDR.
+      # The top-level key names are not important.
+      #
+      # The resulting BGP community will take the form of
+      #    <prefix>:<community>
+      # If no prefix is specified then the asnumber is used
+      community_cidr_ref:
+#        cidr_community_description:
+#          cidr: 2600:1:2:3::abcd/28
+#          community: 54321
+#          prefix: 55555
+#        alpha:
+#          cidr: 1400:a:2:3::abcd/26
+#          community: 54322
       port:
         neighbor: 179
         listen: 179