mirror of
https://github.com/kubernetes-sigs/external-dns.git
synced 2025-10-30 18:20:59 +01:00
132 lines
3.3 KiB
Go
132 lines
3.3 KiB
Go
/*
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Copyright 2017 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package controller
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import (
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"time"
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"github.com/prometheus/client_golang/prometheus"
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log "github.com/sirupsen/logrus"
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"github.com/kubernetes-incubator/external-dns/plan"
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"github.com/kubernetes-incubator/external-dns/registry"
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"github.com/kubernetes-incubator/external-dns/source"
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)
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var (
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registryErrors = prometheus.NewCounter(
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prometheus.CounterOpts{
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Name: "registry_errors_total",
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Help: "Number of Registry errors.",
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},
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)
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sourceErrors = prometheus.NewCounter(
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prometheus.CounterOpts{
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Name: "source_errors_total",
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Help: "Number of Source errors.",
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},
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)
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sourceEndpointsTotal = prometheus.NewGauge(
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prometheus.GaugeOpts{
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Namespace: "external_dns",
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Subsystem: "source",
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Name: "endpoints_total",
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Help: "Number of Endpoints in all sources",
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},
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)
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registryEndpointsTotal = prometheus.NewGauge(
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prometheus.GaugeOpts{
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Namespace: "external_dns",
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Subsystem: "registry",
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Name: "endpoints_total",
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Help: "Number of Endpoints in the registry",
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},
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)
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)
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func init() {
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prometheus.MustRegister(registryErrors)
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prometheus.MustRegister(sourceErrors)
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prometheus.MustRegister(sourceEndpointsTotal)
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prometheus.MustRegister(registryEndpointsTotal)
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}
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// Controller is responsible for orchestrating the different components.
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// It works in the following way:
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// * Ask the DNS provider for current list of endpoints.
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// * Ask the Source for the desired list of endpoints.
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// * Take both lists and calculate a Plan to move current towards desired state.
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// * Tell the DNS provider to apply the changes calucated by the Plan.
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type Controller struct {
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Source source.Source
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Registry registry.Registry
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// The policy that defines which changes to DNS records are allowed
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Policy plan.Policy
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// The interval between individual synchronizations
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Interval time.Duration
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}
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// RunOnce runs a single iteration of a reconciliation loop.
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func (c *Controller) RunOnce() error {
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records, err := c.Registry.Records()
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if err != nil {
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registryErrors.Inc()
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return err
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}
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registryEndpointsTotal.Set(float64(len(records)))
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endpoints, err := c.Source.Endpoints()
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if err != nil {
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sourceErrors.Inc()
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return err
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}
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sourceEndpointsTotal.Set(float64(len(endpoints)))
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plan := &plan.Plan{
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Policies: []plan.Policy{c.Policy},
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Current: records,
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Desired: endpoints,
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}
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plan = plan.Calculate()
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err = c.Registry.ApplyChanges(plan.Changes)
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if err != nil {
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registryErrors.Inc()
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return err
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}
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return nil
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}
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// Run runs RunOnce in a loop with a delay until stopChan receives a value.
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func (c *Controller) Run(stopChan <-chan struct{}) {
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ticker := time.NewTicker(c.Interval)
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defer ticker.Stop()
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for {
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err := c.RunOnce()
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if err != nil {
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log.Error(err)
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}
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select {
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case <-ticker.C:
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case <-stopChan:
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log.Info("Terminating main controller loop")
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return
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}
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}
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}
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