package prometheus import ( "errors" "strconv" "sync" "github.com/Sirupsen/logrus" "github.com/crosbymichael/cgroups" metrics "github.com/docker/go-metrics" "github.com/prometheus/client_golang/prometheus" ) var ErrAlreadyCollected = errors.New("cgroup is already being collected") // New registers the Collector with the provided namespace and returns it so // that cgroups can be added for collection func New(ns *metrics.Namespace) *Collector { // add machine cpus and memory info c := &Collector{ ns: ns, cgroups: make(map[string]cgroups.Cgroup), } c.metrics = append(c.metrics, pidMetrics...) c.metrics = append(c.metrics, cpuMetrics...) c.metrics = append(c.metrics, memoryMetrics...) c.metrics = append(c.metrics, hugetlbMetrics...) c.metrics = append(c.metrics, blkioMetrics...) ns.Add(c) return c } // Collector provides the ability to collect container stats and export // them in the prometheus format type Collector struct { mu sync.RWMutex cgroups map[string]cgroups.Cgroup ns *metrics.Namespace metrics []*metric } func (c *Collector) Describe(ch chan<- *prometheus.Desc) { for _, m := range c.metrics { ch <- m.desc(c.ns) } } func (c *Collector) Collect(ch chan<- prometheus.Metric) { c.mu.RLock() wg := &sync.WaitGroup{} for id, cg := range c.cgroups { wg.Add(1) go c.collect(id, cg, ch, wg) } c.mu.RUnlock() wg.Wait() } func (c *Collector) collect(id string, cg cgroups.Cgroup, ch chan<- prometheus.Metric, wg *sync.WaitGroup) { defer wg.Done() stats, err := cg.Stat(cgroups.IgnoreNotExist) if err != nil { logrus.WithError(err).Errorf("stat cgroup %s", id) return } for _, m := range c.metrics { m.collect(id, stats, c.ns, ch) } } // Add adds the provided cgroup and id so that metrics are collected and exported func (c *Collector) Add(id string, cg cgroups.Cgroup) error { c.mu.Lock() defer c.mu.Unlock() if _, ok := c.cgroups[id]; ok { return ErrAlreadyCollected } c.cgroups[id] = cg return nil } // Remove removes the provided cgroup by id from the collector func (c *Collector) Remove(id string) { c.mu.Lock() defer c.mu.Unlock() delete(c.cgroups, id) } func blkioValues(l []cgroups.BlkioEntry) []value { var out []value for _, e := range l { out = append(out, value{ v: float64(e.Value), l: []string{e.Op, e.Device, strconv.FormatUint(e.Major, 10), strconv.FormatUint(e.Minor, 10)}, }) } return out }