external-dns/source/contour_httpproxy.go
John Gardiner Myers 17e9637f11
Refactor getTTLFromAnnotations() to not return error (#3939)
* Refactor getTTLFromAnnotations() to not return error

* Improve log messages
2023-10-02 03:56:45 -07:00

297 lines
9.5 KiB
Go

/*
Copyright 2020 The Kubernetes Authors.
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 source
import (
"context"
"fmt"
"sort"
"text/template"
"github.com/pkg/errors"
projectcontour "github.com/projectcontour/contour/apis/projectcontour/v1"
log "github.com/sirupsen/logrus"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/client-go/dynamic"
"k8s.io/client-go/dynamic/dynamicinformer"
"k8s.io/client-go/informers"
"k8s.io/client-go/tools/cache"
"sigs.k8s.io/external-dns/endpoint"
)
// HTTPProxySource is an implementation of Source for ProjectContour HTTPProxy objects.
// The HTTPProxy implementation uses the spec.virtualHost.fqdn value for the hostname.
// Use targetAnnotationKey to explicitly set Endpoint.
type httpProxySource struct {
dynamicKubeClient dynamic.Interface
namespace string
annotationFilter string
fqdnTemplate *template.Template
combineFQDNAnnotation bool
ignoreHostnameAnnotation bool
httpProxyInformer informers.GenericInformer
unstructuredConverter *UnstructuredConverter
}
// NewContourHTTPProxySource creates a new contourHTTPProxySource with the given config.
func NewContourHTTPProxySource(
ctx context.Context,
dynamicKubeClient dynamic.Interface,
namespace string,
annotationFilter string,
fqdnTemplate string,
combineFqdnAnnotation bool,
ignoreHostnameAnnotation bool,
) (Source, error) {
tmpl, err := parseTemplate(fqdnTemplate)
if err != nil {
return nil, err
}
// Use shared informer to listen for add/update/delete of HTTPProxys in the specified namespace.
// Set resync period to 0, to prevent processing when nothing has changed.
informerFactory := dynamicinformer.NewFilteredDynamicSharedInformerFactory(dynamicKubeClient, 0, namespace, nil)
httpProxyInformer := informerFactory.ForResource(projectcontour.HTTPProxyGVR)
// Add default resource event handlers to properly initialize informer.
httpProxyInformer.Informer().AddEventHandler(
cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
},
},
)
informerFactory.Start(ctx.Done())
// wait for the local cache to be populated.
if err := waitForDynamicCacheSync(context.Background(), informerFactory); err != nil {
return nil, err
}
uc, err := NewUnstructuredConverter()
if err != nil {
return nil, errors.Wrap(err, "failed to setup Unstructured Converter")
}
return &httpProxySource{
dynamicKubeClient: dynamicKubeClient,
namespace: namespace,
annotationFilter: annotationFilter,
fqdnTemplate: tmpl,
combineFQDNAnnotation: combineFqdnAnnotation,
ignoreHostnameAnnotation: ignoreHostnameAnnotation,
httpProxyInformer: httpProxyInformer,
unstructuredConverter: uc,
}, nil
}
// Endpoints returns endpoint objects for each host-target combination that should be processed.
// Retrieves all HTTPProxy resources in the source's namespace(s).
func (sc *httpProxySource) Endpoints(ctx context.Context) ([]*endpoint.Endpoint, error) {
hps, err := sc.httpProxyInformer.Lister().ByNamespace(sc.namespace).List(labels.Everything())
if err != nil {
return nil, err
}
// Convert to []*projectcontour.HTTPProxy
var httpProxies []*projectcontour.HTTPProxy
for _, hp := range hps {
unstructuredHP, ok := hp.(*unstructured.Unstructured)
if !ok {
return nil, errors.New("could not convert")
}
hpConverted := &projectcontour.HTTPProxy{}
err := sc.unstructuredConverter.scheme.Convert(unstructuredHP, hpConverted, nil)
if err != nil {
return nil, errors.Wrap(err, "failed to convert to HTTPProxy")
}
httpProxies = append(httpProxies, hpConverted)
}
httpProxies, err = sc.filterByAnnotations(httpProxies)
if err != nil {
return nil, errors.Wrap(err, "failed to filter HTTPProxies")
}
endpoints := []*endpoint.Endpoint{}
for _, hp := range httpProxies {
// Check controller annotation to see if we are responsible.
controller, ok := hp.Annotations[controllerAnnotationKey]
if ok && controller != controllerAnnotationValue {
log.Debugf("Skipping HTTPProxy %s/%s because controller value does not match, found: %s, required: %s",
hp.Namespace, hp.Name, controller, controllerAnnotationValue)
continue
} else if hp.Status.CurrentStatus != "valid" {
log.Debugf("Skipping HTTPProxy %s/%s because it is not valid", hp.Namespace, hp.Name)
continue
}
hpEndpoints, err := sc.endpointsFromHTTPProxy(hp)
if err != nil {
return nil, errors.Wrap(err, "failed to get endpoints from HTTPProxy")
}
// apply template if fqdn is missing on HTTPProxy
if (sc.combineFQDNAnnotation || len(hpEndpoints) == 0) && sc.fqdnTemplate != nil {
tmplEndpoints, err := sc.endpointsFromTemplate(hp)
if err != nil {
return nil, errors.Wrap(err, "failed to get endpoints from template")
}
if sc.combineFQDNAnnotation {
hpEndpoints = append(hpEndpoints, tmplEndpoints...)
} else {
hpEndpoints = tmplEndpoints
}
}
if len(hpEndpoints) == 0 {
log.Debugf("No endpoints could be generated from HTTPProxy %s/%s", hp.Namespace, hp.Name)
continue
}
log.Debugf("Endpoints generated from HTTPProxy: %s/%s: %v", hp.Namespace, hp.Name, hpEndpoints)
endpoints = append(endpoints, hpEndpoints...)
}
for _, ep := range endpoints {
sort.Sort(ep.Targets)
}
return endpoints, nil
}
func (sc *httpProxySource) endpointsFromTemplate(httpProxy *projectcontour.HTTPProxy) ([]*endpoint.Endpoint, error) {
hostnames, err := execTemplate(sc.fqdnTemplate, httpProxy)
if err != nil {
return nil, err
}
resource := fmt.Sprintf("HTTPProxy/%s/%s", httpProxy.Namespace, httpProxy.Name)
ttl := getTTLFromAnnotations(httpProxy.Annotations, resource)
targets := getTargetsFromTargetAnnotation(httpProxy.Annotations)
if len(targets) == 0 {
for _, lb := range httpProxy.Status.LoadBalancer.Ingress {
if lb.IP != "" {
targets = append(targets, lb.IP)
}
if lb.Hostname != "" {
targets = append(targets, lb.Hostname)
}
}
}
providerSpecific, setIdentifier := getProviderSpecificAnnotations(httpProxy.Annotations)
var endpoints []*endpoint.Endpoint
for _, hostname := range hostnames {
endpoints = append(endpoints, endpointsForHostname(hostname, targets, ttl, providerSpecific, setIdentifier, resource)...)
}
return endpoints, nil
}
// filterByAnnotations filters a list of configs by a given annotation selector.
func (sc *httpProxySource) filterByAnnotations(httpProxies []*projectcontour.HTTPProxy) ([]*projectcontour.HTTPProxy, error) {
labelSelector, err := metav1.ParseToLabelSelector(sc.annotationFilter)
if err != nil {
return nil, err
}
selector, err := metav1.LabelSelectorAsSelector(labelSelector)
if err != nil {
return nil, err
}
// empty filter returns original list
if selector.Empty() {
return httpProxies, nil
}
filteredList := []*projectcontour.HTTPProxy{}
for _, httpProxy := range httpProxies {
// convert the HTTPProxy's annotations to an equivalent label selector
annotations := labels.Set(httpProxy.Annotations)
// include HTTPProxy if its annotations match the selector
if selector.Matches(annotations) {
filteredList = append(filteredList, httpProxy)
}
}
return filteredList, nil
}
// endpointsFromHTTPProxyConfig extracts the endpoints from a Contour HTTPProxy object
func (sc *httpProxySource) endpointsFromHTTPProxy(httpProxy *projectcontour.HTTPProxy) ([]*endpoint.Endpoint, error) {
if httpProxy.Status.CurrentStatus != "valid" {
log.Warn(errors.Errorf("cannot generate endpoints for HTTPProxy with status %s", httpProxy.Status.CurrentStatus))
return nil, nil
}
resource := fmt.Sprintf("HTTPProxy/%s/%s", httpProxy.Namespace, httpProxy.Name)
ttl := getTTLFromAnnotations(httpProxy.Annotations, resource)
targets := getTargetsFromTargetAnnotation(httpProxy.Annotations)
if len(targets) == 0 {
for _, lb := range httpProxy.Status.LoadBalancer.Ingress {
if lb.IP != "" {
targets = append(targets, lb.IP)
}
if lb.Hostname != "" {
targets = append(targets, lb.Hostname)
}
}
}
providerSpecific, setIdentifier := getProviderSpecificAnnotations(httpProxy.Annotations)
var endpoints []*endpoint.Endpoint
if virtualHost := httpProxy.Spec.VirtualHost; virtualHost != nil {
if fqdn := virtualHost.Fqdn; fqdn != "" {
endpoints = append(endpoints, endpointsForHostname(fqdn, targets, ttl, providerSpecific, setIdentifier, resource)...)
}
}
// Skip endpoints if we do not want entries from annotations
if !sc.ignoreHostnameAnnotation {
hostnameList := getHostnamesFromAnnotations(httpProxy.Annotations)
for _, hostname := range hostnameList {
endpoints = append(endpoints, endpointsForHostname(hostname, targets, ttl, providerSpecific, setIdentifier, resource)...)
}
}
return endpoints, nil
}
func (sc *httpProxySource) AddEventHandler(ctx context.Context, handler func()) {
log.Debug("Adding event handler for httpproxy")
// Right now there is no way to remove event handler from informer, see:
// https://github.com/kubernetes/kubernetes/issues/79610
sc.httpProxyInformer.Informer().AddEventHandler(eventHandlerFunc(handler))
}