We added the ability to filter the ingresses used by traefik based on a label selector, but we shouldn't need to have matching labels on every other resource, Ingress allready has a way to explicty choose which pods end up in the load ballancer (by refering to the membership of a particular service)
296 lines
8.9 KiB
Go
296 lines
8.9 KiB
Go
package k8s
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import (
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"crypto/tls"
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"crypto/x509"
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"encoding/json"
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"fmt"
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log "github.com/Sirupsen/logrus"
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"github.com/parnurzeal/gorequest"
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"net/http"
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"net/url"
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"strings"
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)
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const (
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// APIEndpoint defines the base path for kubernetes API resources.
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APIEndpoint = "/api/v1"
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extentionsEndpoint = "/apis/extensions/v1beta1"
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defaultIngress = "/ingresses"
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namespaces = "/namespaces/"
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)
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// Client is a client for the Kubernetes master.
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type Client interface {
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GetIngresses(labelSelector string, predicate func(Ingress) bool) ([]Ingress, error)
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GetService(name, namespace string) (Service, error)
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GetEndpoints(name, namespace string) (Endpoints, error)
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WatchAll(labelSelector string, stopCh <-chan bool) (chan interface{}, chan error, error)
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}
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type clientImpl struct {
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endpointURL string
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tls *tls.Config
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token string
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caCert []byte
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}
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// NewClient returns a new Kubernetes client.
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// The provided host is an url (scheme://hostname[:port]) of a
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// Kubernetes master without any path.
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// The provided client is an authorized http.Client used to perform requests to the Kubernetes API master.
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func NewClient(baseURL string, caCert []byte, token string) (Client, error) {
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validURL, err := url.Parse(baseURL)
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if err != nil {
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return nil, fmt.Errorf("failed to parse URL %q: %v", baseURL, err)
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}
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return &clientImpl{
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endpointURL: strings.TrimSuffix(validURL.String(), "/"),
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token: token,
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caCert: caCert,
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}, nil
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}
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func makeQueryString(baseParams map[string]string, labelSelector string) (string, error) {
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if labelSelector != "" {
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baseParams["labelSelector"] = labelSelector
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}
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queryData, err := json.Marshal(baseParams)
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if err != nil {
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return "", err
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}
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return string(queryData), nil
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}
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// GetIngresses returns all ingresses in the cluster
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func (c *clientImpl) GetIngresses(labelSelector string, predicate func(Ingress) bool) ([]Ingress, error) {
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getURL := c.endpointURL + extentionsEndpoint + defaultIngress
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queryParams := map[string]string{}
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queryData, err := makeQueryString(queryParams, labelSelector)
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if err != nil {
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return nil, fmt.Errorf("Had problems constructing query string %s : %v", queryParams, err)
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}
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body, err := c.do(c.request(getURL, queryData))
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if err != nil {
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return nil, fmt.Errorf("failed to create ingresses request: GET %q : %v", getURL, err)
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}
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var ingressList IngressList
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if err := json.Unmarshal(body, &ingressList); err != nil {
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return nil, fmt.Errorf("failed to decode list of ingress resources: %v", err)
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}
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ingresses := ingressList.Items[:0]
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for _, ingress := range ingressList.Items {
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if predicate(ingress) {
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ingresses = append(ingresses, ingress)
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}
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}
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return ingresses, nil
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}
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// WatchIngresses returns all ingresses in the cluster
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func (c *clientImpl) WatchIngresses(labelSelector string, stopCh <-chan bool) (chan interface{}, chan error, error) {
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getURL := c.endpointURL + extentionsEndpoint + defaultIngress
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return c.watch(getURL, labelSelector, stopCh)
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}
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// GetService returns the named service from the named namespace
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func (c *clientImpl) GetService(name, namespace string) (Service, error) {
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getURL := c.endpointURL + APIEndpoint + namespaces + namespace + "/services/" + name
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body, err := c.do(c.request(getURL, ""))
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if err != nil {
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return Service{}, fmt.Errorf("failed to create services request: GET %q : %v", getURL, err)
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}
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var service Service
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if err := json.Unmarshal(body, &service); err != nil {
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return Service{}, fmt.Errorf("failed to decode service resource: %v", err)
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}
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return service, nil
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}
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// WatchServices returns all services in the cluster
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func (c *clientImpl) WatchServices(stopCh <-chan bool) (chan interface{}, chan error, error) {
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getURL := c.endpointURL + APIEndpoint + "/services"
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return c.watch(getURL, "", stopCh)
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}
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// GetEndpoints returns the named Endpoints
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// Endpoints have the same name as the coresponding service
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func (c *clientImpl) GetEndpoints(name, namespace string) (Endpoints, error) {
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getURL := c.endpointURL + APIEndpoint + namespaces + namespace + "/endpoints/" + name
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body, err := c.do(c.request(getURL, ""))
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if err != nil {
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return Endpoints{}, fmt.Errorf("failed to create endpoints request: GET %q : %v", getURL, err)
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}
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var endpoints Endpoints
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if err := json.Unmarshal(body, &endpoints); err != nil {
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return Endpoints{}, fmt.Errorf("failed to decode endpoints resources: %v", err)
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}
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return endpoints, nil
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}
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// WatchEndpoints returns endpoints in the cluster
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func (c *clientImpl) WatchEndpoints(stopCh <-chan bool) (chan interface{}, chan error, error) {
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getURL := c.endpointURL + APIEndpoint + "/endpoints"
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return c.watch(getURL, "", stopCh)
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}
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// WatchAll returns events in the cluster
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func (c *clientImpl) WatchAll(labelSelector string, stopCh <-chan bool) (chan interface{}, chan error, error) {
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watchCh := make(chan interface{}, 10)
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errCh := make(chan error, 10)
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stopIngresses := make(chan bool)
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chanIngresses, chanIngressesErr, err := c.WatchIngresses(labelSelector, stopIngresses)
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if err != nil {
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return watchCh, errCh, fmt.Errorf("failed to create watch: %v", err)
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}
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stopServices := make(chan bool)
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chanServices, chanServicesErr, err := c.WatchServices(stopServices)
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if err != nil {
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return watchCh, errCh, fmt.Errorf("failed to create watch: %v", err)
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}
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stopEndpoints := make(chan bool)
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chanEndpoints, chanEndpointsErr, err := c.WatchEndpoints(stopEndpoints)
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if err != nil {
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return watchCh, errCh, fmt.Errorf("failed to create watch: %v", err)
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}
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go func() {
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defer close(watchCh)
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defer close(errCh)
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defer close(stopIngresses)
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defer close(stopServices)
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defer close(stopEndpoints)
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for {
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select {
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case <-stopCh:
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stopIngresses <- true
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stopServices <- true
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stopEndpoints <- true
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return
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case err := <-chanIngressesErr:
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errCh <- err
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case err := <-chanServicesErr:
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errCh <- err
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case err := <-chanEndpointsErr:
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errCh <- err
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case event := <-chanIngresses:
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watchCh <- event
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case event := <-chanServices:
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watchCh <- event
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case event := <-chanEndpoints:
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watchCh <- event
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}
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}
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}()
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return watchCh, errCh, nil
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}
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func (c *clientImpl) do(request *gorequest.SuperAgent) ([]byte, error) {
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res, body, errs := request.EndBytes()
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if errs != nil {
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return nil, fmt.Errorf("failed to create request: GET %q : %v", request.Url, errs)
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}
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defer res.Body.Close()
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if res.StatusCode != http.StatusOK {
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return nil, fmt.Errorf("http error %d GET %q: %q", res.StatusCode, request.Url, string(body))
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}
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return body, nil
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}
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func (c *clientImpl) request(reqURL string, queryContent interface{}) *gorequest.SuperAgent {
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// Make request to Kubernetes API
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parsedURL, parseErr := url.Parse(reqURL)
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if parseErr != nil {
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log.Errorf("Had issues parsing url %s. Trying anyway.", reqURL)
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}
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request := gorequest.New().Get(reqURL)
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request.Transport.DisableKeepAlives = true
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if parsedURL.Scheme == "https" {
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pool := x509.NewCertPool()
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pool.AppendCertsFromPEM(c.caCert)
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c.tls = &tls.Config{RootCAs: pool}
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request.TLSClientConfig(c.tls)
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}
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if len(c.token) > 0 {
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request.Header["Authorization"] = "Bearer " + c.token
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}
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request.Query(queryContent)
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return request
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}
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// GenericObject generic object
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type GenericObject struct {
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TypeMeta `json:",inline"`
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ListMeta `json:"metadata,omitempty"`
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}
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func (c *clientImpl) watch(url string, labelSelector string, stopCh <-chan bool) (chan interface{}, chan error, error) {
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watchCh := make(chan interface{}, 10)
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errCh := make(chan error, 10)
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// get version
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body, err := c.do(c.request(url, ""))
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if err != nil {
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return watchCh, errCh, fmt.Errorf("failed to do version request: GET %q : %v", url, err)
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}
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var generic GenericObject
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if err := json.Unmarshal(body, &generic); err != nil {
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return watchCh, errCh, fmt.Errorf("failed to decode version %v", err)
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}
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resourceVersion := generic.ResourceVersion
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queryParams := map[string]string{"watch": "", "resourceVersion": resourceVersion}
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queryData, err := makeQueryString(queryParams, labelSelector)
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if err != nil {
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return watchCh, errCh, fmt.Errorf("Unable to construct query args")
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}
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request := c.request(url, queryData)
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req, err := request.MakeRequest()
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if err != nil {
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return watchCh, errCh, fmt.Errorf("failed to make watch request: GET %q : %v", url, err)
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}
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request.Client.Transport = request.Transport
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res, err := request.Client.Do(req)
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if err != nil {
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return watchCh, errCh, fmt.Errorf("failed to do watch request: GET %q: %v", url, err)
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}
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go func() {
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finishCh := make(chan bool)
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defer close(finishCh)
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defer close(watchCh)
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defer close(errCh)
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go func() {
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defer res.Body.Close()
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for {
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var eventList interface{}
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if err := json.NewDecoder(res.Body).Decode(&eventList); err != nil {
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if !strings.Contains(err.Error(), "net/http: request canceled") {
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errCh <- fmt.Errorf("failed to decode watch event: GET %q : %v", url, err)
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}
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finishCh <- true
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return
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}
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watchCh <- eventList
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}
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}()
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select {
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case <-stopCh:
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go func() {
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request.Transport.CancelRequest(req)
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}()
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<-finishCh
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return
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}
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}()
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return watchCh, errCh, nil
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}
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