factory_discovery.go

package resource

import (
	"path/filepath"
	"regexp"
	"strings"
	"time"

	"k8s.io/client-go/discovery"
	"k8s.io/client-go/discovery/cached/disk"
	"k8s.io/client-go/rest"
)

func getDiscoveryClient(config *rest.Config, cacheDir string) (discovery.CachedDiscoveryInterface, error) {
	config.Burst = 100
	httpCacheDir := filepath.Join(cacheDir, ".kube", "http-cache")
	discoveryCacheDir := computeDiscoverCacheDir(filepath.Join(cacheDir, ".kube", "cache", "discovery"), config.Host)
	return disk.NewCachedDiscoveryClientForConfig(config, discoveryCacheDir, httpCacheDir, time.Duration(10*time.Minute))
}

// overlyCautiousIllegalFileCharacters matches characters that *might* not be supported.  Windows is really restrictive, so this is really restrictive
var overlyCautiousIllegalFileCharacters = regexp.MustCompile(`[^(\w/\.)]`)

// computeDiscoverCacheDir takes the parentDir and the host and comes up with a "usually non-colliding" name.
func computeDiscoverCacheDir(parentDir, host string) string {
	// strip the optional scheme from host if its there:
	schemelessHost := strings.Replace(strings.Replace(host, "https://", "", 1), "http://", "", 1)
	// now do a simple collapse of non-AZ09 characters.  Collisions are possible but unlikely.  Even if we do collide the problem is short lived
	safeHost := overlyCautiousIllegalFileCharacters.ReplaceAllString(schemelessHost, "_")
	return filepath.Join(parentDir, safeHost)
}