add feature to advertise anycast addresses via BGP

add gobgp dependency

ensure that we ignore advertisements from bgp peers

add option to pass gobgpd config file, which helped figure out how
to actually configure gobgpd to block peers from publishing routes
into our routing table.

install gobgpd and gobgp during github action tests

update Makefile github target for use with bgp tests

adding bgp documentation

updating fabio.properties to show off bgp options

.github/workflows/build.yml

@@ -19,5 +19,5 @@ jobs:
         uses: actions/checkout@v3
       - name: Test
         run: |
-          export PATH=$PATH:$HOME/bin
+          export PATH=$PATH:$HOME/bin:$HOME/go/bin
           make github

.gitignore

@@ -20,3 +20,4 @@ fabio.sublime-*
 demo/cert/
 /pkg/
 dist/
+*~

Makefile

@@ -23,6 +23,7 @@ GORELEASER ?= $(shell which goreleaser)
 CI_CONSUL_VERSION ?= 1.12.3
 CI_VAULT_VERSION ?= 1.11.0
 CI_HUGO_VERSION ?= 0.101.0
+CI_GOBGP_VERSION ?= 3.8.0
 
 BETA_OSES = linux darwin
 
@@ -161,8 +162,11 @@ travis-pages:
 github:
 	wget -q -O ~/consul.zip https://releases.hashicorp.com/consul/$(CI_CONSUL_VERSION)/consul_$(CI_CONSUL_VERSION)_linux_amd64.zip
 	wget -q -O ~/vault.zip https://releases.hashicorp.com/vault/$(CI_VAULT_VERSION)/vault_$(CI_VAULT_VERSION)_linux_amd64.zip
+	wget -q -O ~/vault.zip https://releases.hashicorp.com/vault/$(CI_VAULT_VERSION)/vault_$(CI_VAULT_VERSION)_linux_amd64.zip
+	wget -q -O ~/gobgp.tar.gz https://github.com/osrg/gobgp/releases/download/v$(CI_GOBGP_VERSION)/gobgp_$(CI_GOBGP_VERSION)_linux_amd64.tar.gz
 	unzip -o -d ~/bin ~/consul.zip
 	unzip -o -d ~/bin ~/vault.zip
+	tar xzf ~/gobgp.tar.gz -C ~/bin
 	vault --version
 	consul --version
 	make test