More features (#9)

* added config file implementation, refactoring
* add gitignore
* improved test
* preperations for more metrics
* added resource metrics
* added first bgp metrics
* added asn as label for bgp metrics
* added prefix and message counts to bgp metrics
* simplified
* Update README.md
* added yaml dependency
* fixed go routine call
* added timeout
* clean up
* added TLS support
* set default api port for TLS
* added routes metric
* added missing log information
* added type collectorContext to reduce the count of parameters for better readability
* added DHCP and DHCPv6 metrics
* filter for active dhcp leases only
* added pool metrics
* enable/disable feature in config file
* refactoring

* clean up

* comment fix

collector/dhcp_collector.go

@@ -0,0 +1,89 @@
+package collector
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/prometheus/client_golang/prometheus"
+	log "github.com/sirupsen/logrus"
+)
+
+type dhcpCollector struct {
+	leasesActiveCountDesc *prometheus.Desc
+}
+
+func (c *dhcpCollector) init() {
+	const prefix = "dhcp"
+
+	labelNames := []string{"name", "address", "server"}
+	c.leasesActiveCountDesc = description(prefix, "leases_active_count", "number of active leases per DHCP server", labelNames)
+}
+
+func newDHCPCollector() routerOSCollector {
+	c := &dhcpCollector{}
+	c.init()
+	return c
+}
+
+func (c *dhcpCollector) describe(ch chan<- *prometheus.Desc) {
+	ch <- c.leasesActiveCountDesc
+}
+
+func (c *dhcpCollector) collect(ctx *collectorContext) error {
+	names, err := c.fetchDHCPServerNames(ctx)
+	if err != nil {
+		return err
+	}
+
+	for _, n := range names {
+		err := c.colllectForDHCPServer(ctx, n)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *dhcpCollector) fetchDHCPServerNames(ctx *collectorContext) ([]string, error) {
+	reply, err := ctx.client.Run("/ip/dhcp-server/print", "=.proplist=name")
+	if err != nil {
+		log.WithFields(log.Fields{
+			"device": ctx.device.Name,
+			"error":  err,
+		}).Error("error fetching DHCP server names")
+		return nil, err
+	}
+
+	names := []string{}
+	for _, re := range reply.Re {
+		names = append(names, re.Map["name"])
+	}
+
+	return names, nil
+}
+
+func (c *dhcpCollector) colllectForDHCPServer(ctx *collectorContext, dhcpServer string) error {
+	reply, err := ctx.client.Run("/ip/dhcp-server/lease/print", fmt.Sprintf("?server=%s", dhcpServer), "=active=", "=count-only=")
+	if err != nil {
+		log.WithFields(log.Fields{
+			"dhcp_server": dhcpServer,
+			"device":      ctx.device.Name,
+			"error":       err,
+		}).Error("error fetching DHCP lease counts")
+		return err
+	}
+
+	v, err := strconv.ParseFloat(reply.Done.Map["ret"], 32)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"dhcp_server": dhcpServer,
+			"device":      ctx.device.Name,
+			"error":       err,
+		}).Error("error parsing DHCP lease counts")
+		return err
+	}
+
+	ctx.ch <- prometheus.MustNewConstMetric(c.leasesActiveCountDesc, prometheus.GaugeValue, v, ctx.device.Name, ctx.device.Address, dhcpServer)
+	return nil
+}