Merge pull request #11 from exoscale/pushgw_metrics

Prometheus Push Gateway metrics

go.mod

@@ -9,8 +9,6 @@ require (
  github.com/kylelemons/godebug v0.0.0-20170820004349-d65d576e9348
  github.com/mattn/go-colorable v0.0.9 // indirect
  github.com/mattn/go-isatty v0.0.4 // indirect
- github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
- github.com/modern-go/reflect2 v1.0.1 // indirect
  github.com/pkg/errors v0.8.1
  github.com/prometheus/client_golang v1.1.0
  github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a
@@ -20,3 +18,5 @@ require (
 )
 
 replace github.com/rcrowley/go-metrics => github.com/exoscale/go-metrics v0.0.0-20180729161012-6a0b1c6c28ec
+
+go 1.13

metrics.go

@@ -53,6 +53,11 @@ func (r *Reporter) Timer(name string) metrics.Timer {
  return metrics.GetOrRegisterTimer(expandName(name, r.prefix), r.metrics.Registry)
 }
 
+// Push pushes registered metrics to a push gateway.
+func (r *Reporter) Push() error {
+ return r.metrics.Push()
+}
+
 // Healthcheck holds healthcheck state.
 type Healthcheck struct {
  metrics.Healthcheck

metrics/config.go

@@ -67,6 +67,12 @@ func (c *Configuration) UnmarshalYAML(unmarshal func(interface{}) error) error {
  return errors.Wrapf(err, "incorrect collectd configuration for item %d", i+1)
  }
  finalConfiguration[i] = &exporterConfiguration
+ case "prompushgw":
+ var exporterConfiguration PromPushGWConfiguration
+ if err := yaml.Unmarshal(strExporterConfiguration, &exporterConfiguration); err != nil {
+ return errors.Wrapf(err, "incorrect prompushgw configuration for item %d", i+1)
+ }
+ finalConfiguration[i] = &exporterConfiguration
  default:
  return errors.Errorf("unknown metric system %q for item %d",
  exporterName, i+1)

metrics/config_test.go

@@ -81,6 +81,23 @@ func TestUnmarshalConfiguration(t *testing.T) {
  CacertFile: config.FilePath("/tmp/baz"),
  },
  },
+ {
+ in: `
+- prompushgw:
+ url: https://my.pushgateway.net
+ job: bar
+ certfile: /tmp/foo
+ keyfile: /tmp/bar
+ cacertfile: /tmp/baz
+`,
+ want: PromPushGWConfiguration{
+ URL: "https://my.pushgateway.net",
+ Job: "bar",
+ CertFile: config.FilePath("/tmp/foo"),
+ KeyFile: config.FilePath("/tmp/bar"),
+ CacertFile: config.FilePath("/tmp/baz"),
+ },
+ },
  }
  for _, c := range cases {
  var got Configuration
@@ -117,6 +134,13 @@ func TestUnmarshalIncompleteConfiguration(t *testing.T) {
  namespace: foo
  subsystem: bar
  certfile: /tmp/foo
+`,
+ `
+- prompushgw:
+ url: https://my.pushgateway.net
+ certfile: /tmp/foo
+ keyfile: /tmp/bar
+ cacertfile: /tmp/baz
 `,
  }
  for _, c := range cases {

metrics/prompushgw.go

@@ -0,0 +1,82 @@
+package metrics
+
+import (
+ "crypto/tls"
+ "crypto/x509"
+ "io/ioutil"
+ "net/http"
+
+ "github.com/exoscale/go-reporter/config"
+ "github.com/pkg/errors"
+ "github.com/prometheus/client_golang/prometheus/push"
+)
+
+type PromPushGWConfiguration struct {
+ URL string
+ Job string
+ CertFile config.FilePath
+ KeyFile config.FilePath
+ CacertFile config.FilePath
+
+ pusher *push.Pusher
+}
+
+func (c *PromPushGWConfiguration) UnmarshalYAML(unmarshal func(interface{}) error) error {
+ type rawPromPushGWConfiguration PromPushGWConfiguration
+ raw := rawPromPushGWConfiguration{}
+ if err := unmarshal(&raw); err != nil {
+ return errors.Wrap(err, "unable to decode prompushgw configuration")
+ }
+ if raw.URL == "" {
+ return errors.Errorf("missing URL value")
+ }
+ if raw.Job == "" {
+ return errors.Errorf("missing job value")
+ }
+ if (raw.CertFile != "" || raw.KeyFile != "" || raw.CacertFile != "") &&
+ (raw.CertFile == "" || raw.KeyFile == "" || raw.CacertFile == "") {
+ return errors.Errorf("certfile, keyfile and cacertfile should be configured")
+ }
+ *c = PromPushGWConfiguration(raw)
+ return nil
+}
+
+func (c *PromPushGWConfiguration) initExporter(m *Metrics) error {
+ httpClient, err := NewHTTPClient(*c)
+ if err != nil {
+ return errors.Wrap(err, "can't create http client with given prompushgw config")
+ }
+
+ c.pusher = push.New(c.URL, c.Job).Client(httpClient)
+ return nil
+}
+
+// NewHTTPClient creates an HTTP client for a given config.
+func NewHTTPClient(config PromPushGWConfiguration) (*http.Client, error) {
+ var transport = &http.Transport{}
+ var tlsConfig *tls.Config
+
+ if config.CacertFile != "" {
+ cert, err := tls.LoadX509KeyPair(string(config.CertFile), string(config.KeyFile))
+ if err != nil {
+ return nil, errors.Wrap(err, "can't load certificate pair")
+ }
+
+ caCert, err := ioutil.ReadFile(string(config.CertFile))
+ if err != nil {
+ return nil, errors.Wrap(err, "can't load certificate")
+ }
+
+ caCertPool := x509.NewCertPool()
+ caCertPool.AppendCertsFromPEM(caCert)
+
+ tlsConfig = &tls.Config{
+ Certificates: []tls.Certificate{cert},
+ RootCAs: caCertPool,
+ }
+ tlsConfig.BuildNameToCertificate()
+ transport = &http.Transport{TLSClientConfig: tlsConfig}
+ }
+
+ return &http.Client{Transport: transport}, nil
+}

metrics/root.go

@@ -5,8 +5,11 @@
 package metrics
 
 import (
+ "errors"
+ "strings"
  "time"
 
+ "github.com/prometheus/client_golang/prometheus"
  "github.com/rcrowley/go-metrics"
  "gopkg.in/tomb.v2"
 )
@@ -71,6 +74,39 @@ func (m *Metrics) MustStart() {
  }
 }
 
+// Push pushes registered metrics to a Prometheus push gateway.
+func (m *Metrics) Push() error {
+ registry := prometheus.NewRegistry()
+ m.Registry.Each(func(name string, metric interface{}) {
+ name = strings.Replace(strings.ToLower(name), ".", "_", -1)
+
+ switch metric := metric.(type) {
+ case *metrics.StandardGauge:
+ g := prometheus.NewGauge(prometheus.GaugeOpts{Name: name})
+ g.Set(float64(metric.Value()))
+ registry.Register(g)
+
+ case *metrics.StandardGaugeFloat64:
+ g := prometheus.NewGauge(prometheus.GaugeOpts{Name: name})
+ g.Set(float64(metric.Value()))
+ registry.Register(g)
+
+ case *metrics.StandardCounter:
+ c := prometheus.NewCounter(prometheus.CounterOpts{Name: name})
+ c.Add(float64(metric.Count()))
+ registry.Register(c)
+ }
+ })
+
+ for _, c := range m.config {
+ if p, ok := c.(*PromPushGWConfiguration); ok {
+ return p.pusher.Gatherer(registry).Push()
+ }
+ }
+
+ return errors.New("no prompushgw exporter configured")
+}
+
 // Stop stops all exporters and wait for them to terminate.
 func (m *Metrics) Stop() error {
  m.t.Kill(nil)