ceph_exporter/exporter.go

118 lines
3.5 KiB
Go

// Copyright 2016 DigitalOcean
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Command ceph_exporter provides a Prometheus exporter for a Ceph cluster.
package main
import (
"flag"
"log"
"net/http"
"sync"
"github.com/digitalocean/ceph_exporter/collectors"
"github.com/ceph/go-ceph/rados"
"github.com/prometheus/client_golang/prometheus"
)
// CephExporter wraps all the ceph collectors and provides a single global
// exporter to extracts metrics out of. It also ensures that the collection
// is done in a thread-safe manner, the necessary requirement stated by
// prometheus. It also implements a prometheus.Collector interface in order
// to register it correctly.
type CephExporter struct {
mu sync.Mutex
collectors []prometheus.Collector
}
// Verify that the exporter implements the interface correctly.
var _ prometheus.Collector = &CephExporter{}
// NewCephExporter creates an instance to CephExporter and returns a reference
// to it. We can choose to enable a collector to extract stats out of by adding
// it to the list of collectors.
func NewCephExporter(conn *rados.Conn) *CephExporter {
return &CephExporter{
collectors: []prometheus.Collector{
collectors.NewClusterUsageCollector(conn),
collectors.NewPoolUsageCollector(conn),
collectors.NewClusterHealthCollector(conn),
collectors.NewMonitorCollector(conn),
collectors.NewOSDCollector(conn),
},
}
}
// Describe sends all the descriptors of the collectors included to
// the provided channel.
func (c *CephExporter) Describe(ch chan<- *prometheus.Desc) {
for _, cc := range c.collectors {
cc.Describe(ch)
}
}
// Collect sends the collected metrics from each of the collectors to
// prometheus. Collect could be called several times concurrently
// and thus its run is protected by a single mutex.
func (c *CephExporter) Collect(ch chan<- prometheus.Metric) {
c.mu.Lock()
defer c.mu.Unlock()
for _, cc := range c.collectors {
cc.Collect(ch)
}
}
func main() {
var (
addr = flag.String("telemetry.addr", ":9128", "host:port for ceph exporter")
metricsPath = flag.String("telemetry.path", "/metrics", "URL path for surfacing collected metrics")
cephConfig = flag.String("ceph.config", "", "path to ceph config file")
)
flag.Parse()
conn, err := rados.NewConn()
if err != nil {
log.Fatalf("cannot create new ceph connection: %s", err)
}
if *cephConfig != "" {
err = conn.ReadConfigFile(*cephConfig)
} else {
err = conn.ReadDefaultConfigFile()
}
if err != nil {
log.Fatalf("cannot read ceph config file: %s", err)
}
if err := conn.Connect(); err != nil {
log.Fatalf("cannot connect to ceph cluster: %s", err)
}
defer conn.Shutdown()
prometheus.MustRegister(NewCephExporter(conn))
http.Handle(*metricsPath, prometheus.Handler())
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
http.Redirect(w, r, *metricsPath, http.StatusMovedPermanently)
})
log.Printf("Starting ceph exporter on %q", *addr)
if err := http.ListenAndServe(*addr, nil); err != nil {
log.Fatalf("cannot start ceph exporter: %s", err)
}
}