driver.go

// Copyright 2015 Google Inc. All Rights Reserved.
//
// 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.

package hawkular

import (
	"crypto/tls"
	"crypto/x509"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"strconv"
	"sync"

	"github.com/golang/glog"
	"github.com/hawkular/hawkular-client-go/metrics"

	"k8s.io/heapster/metrics/core"
	kube_client "k8s.io/kubernetes/pkg/client/unversioned"
	kubeClientCmd "k8s.io/kubernetes/pkg/client/unversioned/clientcmd"
)

const (
	unitsTag           = "units"
	descriptionTag     = "_description"
	descriptorTag      = "descriptor_name"
	groupTag           = "group_id"
	separator          = "/"
	batchSizeDefault   = 1000
	concurrencyDefault = 5

	defaultServiceAccountFile = "/var/run/secrets/kubernetes.io/serviceaccount/token"
)

// START: ExternalSink interface implementations

func (self *hawkularSink) Register(mds []core.MetricDescriptor) error {
	// Create model definitions based on the MetricDescriptors
	for _, md := range mds {
		hmd := self.descriptorToDefinition(&md)
		self.models[md.Name] = &hmd
	}

	// Fetch currently known metrics from Hawkular-Metrics and cache them
	types := []metrics.MetricType{metrics.Gauge, metrics.Counter}
	for _, t := range types {
		err := self.updateDefinitions(t)
		if err != nil {
			return err
		}
	}

	return nil
}

func (self *hawkularSink) Stop() {
	self.regLock.Lock()
	defer self.regLock.Unlock()
	self.init()
}

func (self *hawkularSink) ExportData(db *core.DataBatch) {
	totalCount := 0
	for _, ms := range db.MetricSets {
		totalCount += len(ms.MetricValues)
	}

	if len(db.MetricSets) > 0 {
		tmhs := make(map[string][]metrics.MetricHeader)

		if &self.labelTenant == nil {
			tmhs[self.client.Tenant] = make([]metrics.MetricHeader, 0, totalCount)
		}

		wg := &sync.WaitGroup{}

		for _, ms := range db.MetricSets {
		Store:
			for metricName := range ms.MetricValues {

				for _, filter := range self.filters {
					if !filter(ms, metricName) {
						continue Store
					}
				}

				tenant := self.client.Tenant

				if &self.labelTenant != nil {
					if v, found := ms.Labels[self.labelTenant]; found {
						tenant = v
					}
				}

				// Registering should not block the processing
				// This isn't concurrency limited (and is mostly network limited on HWKMETRICS end)
				wg.Add(1)
				go func(ms *core.MetricSet, metricName string, tenant string) {
					defer wg.Done()
					self.registerIfNecessary(ms, metricName, metrics.Tenant(tenant))
				}(ms, metricName, tenant)

				mH, err := self.pointToMetricHeader(ms, metricName, db.Timestamp)
				if err != nil {
					// One transformation error should not prevent the whole process
					glog.Errorf(err.Error())
					continue
				}

				if _, found := tmhs[tenant]; !found {
					tmhs[tenant] = make([]metrics.MetricHeader, 0)
				}

				tmhs[tenant] = append(tmhs[tenant], *mH)
			}
		}
		self.sendData(tmhs, wg) // Send to a limited channel? Only batches.. egg.
		wg.Wait()
	}
}

func (self *hawkularSink) DebugInfo() string {
	info := fmt.Sprintf("%s\n", self.Name())

	self.regLock.Lock()
	defer self.regLock.Unlock()
	info += fmt.Sprintf("Known metrics: %d\n", len(self.reg))
	if &self.labelTenant != nil {
		info += fmt.Sprintf("Using label '%s' as tenant information\n", self.labelTenant)
	}

	// TODO Add here statistics from the Hawkular-Metrics client instance
	return info
}

func (self *hawkularSink) Name() string {
	return "Hawkular-Metrics Sink"
}

func NewHawkularSink(u *url.URL) (core.DataSink, error) {
	sink := &hawkularSink{
		uri:       u,
		batchSize: 1000,
	}
	if err := sink.init(); err != nil {
		return nil, err
	}
	metrics := make([]core.MetricDescriptor, 0, len(core.StandardMetrics))
	for _, metric := range core.StandardMetrics {
		metrics = append(metrics, metric.MetricDescriptor)
	}
	sink.Register(metrics)
	return sink, nil
}

func (self *hawkularSink) init() error {
	self.reg = make(map[string]*metrics.MetricDefinition)
	self.models = make(map[string]*metrics.MetricDefinition)
	self.modifiers = make([]metrics.Modifier, 0)
	self.filters = make([]Filter, 0)
	self.batchSize = batchSizeDefault
	self.concurrencyLimit = concurrencyDefault

	p := metrics.Parameters{
		Tenant: "heapster",
		Url:    self.uri.String(),
	}

	opts := self.uri.Query()

	if v, found := opts["tenant"]; found {
		p.Tenant = v[0]
	}

	if v, found := opts["labelToTenant"]; found {
		self.labelTenant = v[0]
	}

	if v, found := opts["useServiceAccount"]; found {
		if b, _ := strconv.ParseBool(v[0]); b {
			// If a readable service account token exists, then use it
			if contents, err := ioutil.ReadFile(defaultServiceAccountFile); err == nil {
				p.Token = string(contents)
			}
		}
	}

	// Authentication / Authorization parameters
	tC := &tls.Config{}

	if v, found := opts["auth"]; found {
		if _, f := opts["caCert"]; f {
			return fmt.Errorf("Both auth and caCert files provided, combination is not supported")
		}
		if len(v[0]) > 0 {
			// Authfile
			kubeConfig, err := kubeClientCmd.NewNonInteractiveDeferredLoadingClientConfig(&kubeClientCmd.ClientConfigLoadingRules{
				ExplicitPath: v[0]},
				&kubeClientCmd.ConfigOverrides{}).ClientConfig()
			if err != nil {
				return err
			}
			tC, err = kube_client.TLSConfigFor(kubeConfig)
			if err != nil {
				return err
			}
		}
	}

	if u, found := opts["user"]; found {
		if _, wrong := opts["useServiceAccount"]; wrong {
			return fmt.Errorf("If user and password are used, serviceAccount cannot be used")
		}
		if p, f := opts["pass"]; f {
			self.modifiers = append(self.modifiers, func(req *http.Request) error {
				req.SetBasicAuth(u[0], p[0])
				return nil
			})
		}
	}

	if v, found := opts["caCert"]; found {
		caCert, err := ioutil.ReadFile(v[0])
		if err != nil {
			return err
		}

		caCertPool := x509.NewCertPool()
		caCertPool.AppendCertsFromPEM(caCert)

		tC.RootCAs = caCertPool
	}

	if v, found := opts["insecure"]; found {
		_, f := opts["caCert"]
		_, f2 := opts["auth"]
		if f || f2 {
			return fmt.Errorf("Insecure can't be defined with auth or caCert")
		}
		insecure, err := strconv.ParseBool(v[0])
		if err != nil {
			return err
		}
		tC.InsecureSkipVerify = insecure
	}

	p.TLSConfig = tC

	// Filters
	if v, found := opts["filter"]; found {
		filters, err := parseFilters(v)
		if err != nil {
			return err
		}
		self.filters = filters
	}

	// Concurrency limitations
	if v, found := opts["concurrencyLimit"]; found {
		cs, err := strconv.Atoi(v[0])
		if err != nil || cs < 0 {
			return fmt.Errorf("Supplied concurrency value of %s is invalid", v[0])
		}
		self.concurrencyLimit = cs
	}

	if v, found := opts["batchSize"]; found {
		bs, err := strconv.Atoi(v[0])
		if err != nil || bs < 0 {
			return fmt.Errorf("Supplied batchSize value of %s is invalid", v[0])
		}
		self.batchSize = bs
	}

	c, err := metrics.NewHawkularClient(p)
	if err != nil {
		return err
	}

	self.client = c

	glog.Infof("Initialised Hawkular Sink with parameters %v", p)
	return nil
}