add VRRP

README.md

@@ -4,11 +4,11 @@
 [![License](https://img.shields.io/github/license/natesales/bcg?style=for-the-badge)](https://choosealicense.com/licenses/gpl-3.0/)
 [![Release](https://img.shields.io/github/v/release/natesales/bcg?style=for-the-badge)](https://github.com/natesales/bcg/releases)
 
-The automatic BIRD configuration generator with bogon, IRR, RPKI, and max prefix filtering support.
+The automatic router configuration generator for BGP with bogon, IRR, RPKI, and max prefix filtering support.
 
 ### Installation
 
-bcg depends on [bird2](https://gitlab.nic.cz/labs/bird/), [GoRTR](https://github.com/cloudflare/gortr), and [bgpq4](https://github.com/bgp/bgpq4). Make sure the `bird` and `gortr` daemons are running and `bgpq4` is in path before running bcg. Releases can be downloaded from Github and from my public code repositories - see https://github.com/natesales/repo for more info. You can also build from source by cloning the repo and running `go build`. It's recommended to run bcg every 12 hours to update IRR prefix lists and PeeringDB prefix limits. Adding `0 */12 * * * /usr/bin/bcg` to your crontab will update the filters at 12 AM and PM. If you're using ZSH you might also be interested in my [birdc completion](https://github.com/natesales/zsh-bird-completions).
+bcg depends on [bird2](https://gitlab.nic.cz/labs/bird/), [GoRTR](https://github.com/cloudflare/gortr), [bgpq4](https://github.com/bgp/bgpq4), and optionally [keepalived](https://github.com/acassen/keepalived). Make sure the `bird` and `gortr` daemons are running and `bgpq4` is in path before running bcg. Releases can be downloaded from Github and from my public code repositories - see https://github.com/natesales/repo for more info. You can also build from source by cloning the repo and running `go build`. It's recommended to run bcg every 12 hours to update IRR prefix lists and PeeringDB prefix limits. Adding `0 */12 * * * /usr/bin/bcg` to your crontab will update the filters at 12 AM and PM. If you're using ZSH you might also be interested in my [birdc completion](https://github.com/natesales/zsh-bird-completions).
 
 #### Configuration
 
@@ -101,6 +101,10 @@ bcg uses RFC 8092 BGP Large Communities
 
 Peers with type `peer` or `downstream` reject any route with a Tier 1 ASN in path ([Peerlock Lite](https://github.com/job/peerlock)).
 
+#### VRRP
+
+bcg can build [keepalived](https://github.com/acassen/keepalived) configs for VRRP. To enable VRRP, add a `vrrp` config key containing a list of VRRP instances to your bcg config file.
+
 #### Communities
 
 | Large     | Meaning                   |
@@ -132,7 +136,7 @@ Peers with type `peer` or `downstream` reject any route with a Tier 1 ASN in pat
 | filter-default | Should default routes be denied?                                                                         |
 | enable-default | Add static default routes                                                                                |
 
-#### Peer Configuration Options
+#### BGP Peer Configuration Options
 
 | Option         | Usage                                                                                                     |
 | -------------- | --------------------------------------------------------------------------------------------------------- |
@@ -157,10 +161,19 @@ Peers with type `peer` or `downstream` reject any route with a Tier 1 ASN in pat
 | bfd            | Enable BFD                                                                                                |
 | session-global | String to add to session global config                                                                    |
 | enforce-first-as | Reject routes that don't have the peer ASN as the first ASN in path                                     |
-| enforce-peer-nexthop | Reject routes where the next hop doesn't match the neighbor address                                     |
-| export-default | Should a default route be sent over the session? (default false)                                            |
+| enforce-peer-nexthop | Reject routes where the next hop doesn't match the neighbor address                                 |
+| export-default | Should a default route be sent over the session? (default false)                                          |
 | no-specifics | Don't send specific routes (default false, make sure to enable export-default or else no routes will be exported) |
 | allow-blackholes | Accept community (ASN,1,666) to blackhole /32 and /128 prefixes |
 | communities | List of BGP communities to add on export (two comma-separated values per list element; example `0,0`) |
 | large-communities | List of BGP large communities to add on export (three comma-separated values per list element; example `0,0,0`) |
 | description | Description string (just for human reference) |
+
+#### VRRP instance config options
+| Option      | Usage                                                                          |
+| ----------- | ------------------------------------------------------------------------------ |
+| state       | VRRP state (`primary` or `backup`)                                             |
+| interface   | Interface to run VRRP on                                                       |
+| vrrid       | VRRP Router ID (must be the same for multiple routers in the same VRRP domain  |
+| priority    | VRRP router selection priority                                                 |
+| vips        | List of Virtual IPs                                                            |

internal/config/main.go

@@ -60,12 +60,25 @@ type Peer struct {
 	PrefixSet6 []string `yaml:"-" toml:"-" json:"-"`
 }
 
+// VRRPInstance stores a VRRP instance
+type VRRPInstance struct {
+	State     string   `yaml:"state" json:"state" toml:"State"`
+	Interface string   `yaml:"interface" json:"interface" toml:"Interface"`
+	VRRID     uint     `yaml:"vrrid" json:"vrrid" toml:"VRRID"`
+	Priority  uint8    `yaml:"priority" json:"priority" toml:"Priority"`
+	VIPs      []string `yaml:"vips" json:"vips" toml:"VIPs"`
+
+	VIPs4 []string `yaml:"-" json:"-" toml:"-"`
+	VIPs6 []string `yaml:"-" json:"-" toml:"-"`
+}
+
 // Config contains global configuration about this router and BCG instance
 type Config struct {
 	Asn            uint             `yaml:"asn" toml:"ASN" json:"asn"`
 	RouterId       string           `yaml:"router-id" toml:"Router-ID" json:"router-id"`
 	Prefixes       []string         `yaml:"prefixes" toml:"Prefixes" json:"prefixes"`
 	Peers          map[string]*Peer `yaml:"peers" toml:"Peers" json:"peers"`
+	VRRPInstances  []*VRRPInstance  `yaml:"vrrp" toml:"VRRP" json:"vrrp"`
 	IrrDb          string           `yaml:"irrdb" toml:"IRRDB" json:"irrdb"`
 	RtrServer      string           `yaml:"rtr-server" toml:"RTR-Server" json:"rtr-server"`
 	RtrPort        int              `yaml:"rtr-port" toml:"RTR-Port" json:"rtr-port"`
@@ -182,5 +195,39 @@ func Load(filename string) (*Config, error) {
 		setPeerDefaults(name, peer)
 	}
 
+	// Parse VRRP configs
+	for _, vrrpInstance := range config.VRRPInstances {
+		// Sort VIPs by address family
+		for _, vip := range vrrpInstance.VIPs {
+			ip, _, err := net.ParseCIDR(vip)
+			if err != nil {
+				return nil, errorx.Decorate(err, "Invalid VIP")
+			}
+
+			if ip.To4() == nil { // If IPv6
+				vrrpInstance.VIPs6 = append(vrrpInstance.VIPs6, vip)
+			} else { // If IPv4
+				vrrpInstance.VIPs4 = append(vrrpInstance.VIPs4, vip)
+			}
+		}
+
+		// Validate vrrpInstance
+		if vrrpInstance.State == "primary" {
+			vrrpInstance.State = "MASTER"
+		} else if vrrpInstance.State == "backup" {
+			vrrpInstance.State = "BACKUP"
+		} else {
+			return nil, errors.New("VRRP state must be 'primary' or 'backup', unexpected " + vrrpInstance.State)
+		}
+
+		if vrrpInstance.Interface == "" {
+			return nil, errors.New("VRRP interface is not defined")
+		}
+
+		if len(vrrpInstance.VIPs) < 1 {
+			return nil, errors.New("VRRP instance must have at least one VIP defined")
+		}
+	}
+
 	return &config, nil // nil error
 }

internal/templating/main.go

@@ -72,6 +72,7 @@ var funcMap = template.FuncMap{
 var PeerTemplate *template.Template
 var GlobalTemplate *template.Template
 var UiTemplate *template.Template
+var VRRPTemplate *template.Template
 
 // Load loads the templates from the embedded filesystem
 func Load(fs embed.FS) error {
@@ -95,5 +96,11 @@ func Load(fs embed.FS) error {
 		return errorx.Decorate(err, "Reading ui template")
 	}
 
+	// Generate VRRP template
+	VRRPTemplate, err = template.New("").Funcs(funcMap).ParseFS(fs, "templates/vrrp.tmpl")
+	if err != nil {
+		return errorx.Decorate(err, "Reading VRRP template")
+	}
+
 	return nil // nil error
 }

main.go

@@ -46,15 +46,16 @@ const (
 
 // Flags
 var opts struct {
-	ConfigFile  string `short:"c" long:"config" description:"Configuration file in YAML, TOML, or JSON format" default:"/etc/bcg/config.yml"`
-	Output      string `short:"o" long:"output" description:"Directory to write output files to" default:"/etc/bird/"`
-	Socket      string `short:"s" long:"socket" description:"BIRD control socket" default:"/run/bird/bird.ctl"`
-	UiFile      string `short:"u" long:"ui-file" description:"File to store web UI" default:"/tmp/bcg-ui.html"`
-	NoUi        bool   `short:"n" long:"no-ui" description:"Don't generate web UI"`
-	Verbose     bool   `short:"v" long:"verbose" description:"Show verbose log messages"`
-	DryRun      bool   `short:"d" long:"dry-run" description:"Don't modify BIRD config"`
-	NoConfigure bool   `long:"no-configure" description:"Don't configure BIRD"`
-	ShowVersion bool   `long:"version" description:"Show version and exit"`
+	ConfigFile       string `short:"c" long:"config" description:"Configuration file in YAML, TOML, or JSON format" default:"/etc/bcg/config.yml"`
+	Output           string `short:"o" long:"output" description:"Directory to write output files to" default:"/etc/bird/"`
+	Socket           string `short:"s" long:"socket" description:"BIRD control socket" default:"/run/bird/bird.ctl"`
+	KeepalivedConfig string `short:"k" long:"keepalived-config" description:"Configuration file for keepalived" default:"/etc/keepalived/keepalived.conf"`
+	UiFile           string `short:"u" long:"ui-file" description:"File to store web UI" default:"/tmp/bcg-ui.html"`
+	NoUi             bool   `short:"n" long:"no-ui" description:"Don't generate web UI"`
+	Verbose          bool   `short:"v" long:"verbose" description:"Show verbose log messages"`
+	DryRun           bool   `short:"d" long:"dry-run" description:"Don't modify BIRD config"`
+	NoConfigure      bool   `long:"no-configure" description:"Don't configure BIRD"`
+	ShowVersion      bool   `long:"version" description:"Show version and exit"`
 }
 
 // Embedded filesystem
@@ -392,6 +393,23 @@ func main() {
 		}
 	}
 
+	// Write VRRP config
+	if !opts.DryRun && len(globalConfig.VRRPInstances) > 0 {
+		// Create the peer specific file
+		peerSpecificFile, err := os.Create(path.Join(opts.KeepalivedConfig))
+		if err != nil {
+			log.Fatalf("Create peer specific output file: %v", err)
+		}
+
+		// Render the template and write to disk
+		err = templating.VRRPTemplate.ExecuteTemplate(peerSpecificFile, "vrrp.tmpl", globalConfig.VRRPInstances)
+		if err != nil {
+			log.Fatalf("Execute template: %v", err)
+		}
+	} else {
+		log.Infof("Dry run is enabled, not writing VRRP config")
+	}
+
 	if !opts.DryRun {
 		if !opts.NoUi {
 			// Create the ui output file

templates/vrrp.tmpl

@@ -1,12 +1,23 @@
-vrrp_instance {{ .Name }} {
-        state {{ .State }}
-        interface {{ .Interface }}
-        virtual_router_id {{ .VRRID }}
-        priority {{ .Priority }}
-        advert_int 1
-        virtual_ipaddress {
-              {{- range $i, $vip := .VIPs4 }}
-              {{ $vip }}
-              {{- end }}
-        }
+{{- range $instanceId, $instance := . -}}
+vrrp_instance VRRP{{ $instanceId }} {
+    state {{ .State }}
+    interface {{ .Interface }}
+    virtual_router_id {{ .VRRID }}
+    priority {{ .Priority }}
+    advert_int 1
+    {{- if .VIPs4 }}
+    virtual_ipaddress {
+        {{- range $i, $vip := .VIPs4 }}
+        {{ $vip }}
+        {{- end }}
+    }
+    {{- end }}
+    {{- if .VIPs6 }}
+    virtual_ipaddress_excluded {
+        {{- range $i, $vip := .VIPs6 }}
+        {{ $vip }}
+        {{- end }}
+    }
+    {{- end }}
 }
+{{- end }}