fix(boot.go,pkg/cleaner,pkg/k8s): adding and wiring up a deleted app cleaner

also adding an interface for listing kubernetes namespaces

Author: Aaron Schlesinger

boot.go

@@ -9,6 +9,7 @@ import (
 	cookoolog "github.com/Masterminds/cookoo/log"
 	"github.com/codegangsta/cli"
 	"github.com/deis/builder/pkg"
+	"github.com/deis/builder/pkg/cleaner"
 	"github.com/deis/builder/pkg/conf"
 	"github.com/deis/builder/pkg/gitreceive"
 	"github.com/deis/builder/pkg/gitreceive/storage"
@@ -68,6 +69,13 @@ func main() {
 						healthSrvCh <- err
 					}
 				}()
+				log.Printf("Starting deleted app cleaner")
+				cleanerErrCh := make(chan error)
+				go func() {
+					if err := cleaner.Run(gitHomeDir, kubeClient.Namespaces(), cleanerPollDuration); err != nil {
+						cleanerErrCh <- err
+					}
+				}()
 
 				log.Printf("Starting SSH server on %s:%d", cnf.SSHHostIP, cnf.SSHHostPort)
 				sshCh := make(chan int)
@@ -82,6 +90,9 @@ func main() {
 				case i := <-sshCh:
 					log.Printf("Unexpected SSH server stop with code %d", i)
 					os.Exit(i)
+				case err := <-cleanerErrCh:
+					log.Printf("Error running the deleted app cleaner (%s)", err)
+					os.Exit(1)
 				}
 			},
 		},

pkg/cleaner/cleaner.go

@@ -0,0 +1,94 @@
+// Package cleaner is a background process that compares the kubernetes namespace list with the folders in the local git home directory, deleting what's not in the namespace list
+package cleaner
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/deis/builder/pkg/k8s"
+	"github.com/deis/pkg/log"
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/fields"
+	"k8s.io/kubernetes/pkg/labels"
+)
+
+func localDirs(gitHome string) ([]string, error) {
+	var ret []string
+	err := filepath.Walk(gitHome, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if info.IsDir() {
+			return filepath.SkipDir
+		}
+		ret = append(ret, filepath.Join(gitHome, path))
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+// getDisjunction gets the items that are in namespaceList and not in dirs or vice versa
+func getDisjunction(namespaceList []api.Namespace, dirs []string) []string {
+	var ret []string
+	namespacesSet := make(map[string]struct{})
+	dirsSet := make(map[string]struct{})
+
+	// create sets of the namespaces and dirs
+	for _, ns := range namespaceList {
+		lowerName := strings.ToLower(ns.Name)
+		namespacesSet[lowerName] = struct{}{}
+	}
+
+	for _, dir := range dirs {
+		lowerName := strings.ToLower(dir)
+		dirsSet[lowerName] = struct{}{}
+	}
+
+	// get dirs not in the namespaces set
+	for _, dir := range dirs {
+		lowerName := strings.ToLower(dir)
+		if _, ok := namespacesSet[lowerName]; !ok {
+			ret = append(ret, lowerName)
+		}
+	}
+
+	// get namespaces not in the dirs set
+	for _, ns := range namespaceList {
+		lowerName := strings.ToLower(ns.Name)
+		if _, ok := dirsSet[lowerName]; !ok {
+			ret = append(ret, lowerName)
+		}
+	}
+
+	return ret
+}
+
+func Run(gitHome string, nsLister k8s.NamespaceLister, pollInterval time.Duration) error {
+	for {
+		nsList, err := nsLister.List(labels.Everything(), fields.Everything())
+		if err != nil {
+			log.Debug("Cleaner error listing namespaces (%s)", err)
+			continue
+		}
+
+		gitDirs, err := localDirs(gitHome)
+		if err != nil {
+			log.Debug("Cleaner error listing local git directories (%s)", err)
+		}
+
+		disjunctions := getDisjunction(nsList.Items, gitDirs)
+		for _, disj := range disjunctions {
+			if err := os.RemoveAll(disj); err != nil {
+				log.Debug("Cleaner error removing deleted app %s (%s)", disj, err)
+			}
+		}
+
+		time.Sleep(pollInterval)
+	}
+}

pkg/k8s/namespace.go

@@ -0,0 +1,17 @@
+package k8s
+
+import (
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/fields"
+	"k8s.io/kubernetes/pkg/labels"
+)
+
+// NamespaceLister is a (k8s.io/kubernetes/pkg/client/unversioned).NamespaceInterface compatible interface which only has the List function. It's used in places that only need List to make them easier to test and more easily swappable with other implementations.
+//
+// Example usage:
+//
+//	var nsl NamespaceLister
+//	nsl = kubeClient.Namespaces()
+type NamespaceLister interface {
+	List(labels.Selector, fields.Selector) (*api.NamespaceList, error)
+}