HIVE-2781: nix terminateWhenFilesChange()

We used to mount credentials Secrets on deprovision pods. When we were
doing that, if the Secret changed, the data in the mounted directory
would get updated dynamically by kube. We had code in place to terminate
the deprovision command in that scenario, since it would presumably fail
401 the next time it needed to create a cloud client.

Via HIVE-2021 / #1874 / 0f4b1de we stopped with the mounting, and
started loading the Secrets explicitly from the deprovision pods.
Although we're still laying the data down in the same kind of directory
structure, it is no longer possible for the values to change
dynamically. This renders the aforementioned code obsolete.

So we're ripping it out.

HIVE-2781

Author: 2uasimojo

contrib/pkg/deprovision/awstagdeprovision.go

@@ -28,10 +28,6 @@ func NewDeprovisionAWSWithTagsCommand() *cobra.Command {
 				return
 			}
 
-			if credsDir != "" {
-				go terminateWhenFilesChange(credsDir)
-			}
-
 			log.Infof("Running destroyer with ClusterUninstall %#v", *opt)
 			// ClusterQuota stomped in return
 			if _, err := opt.Run(); err != nil {

contrib/pkg/deprovision/deprovision.go

@@ -1,15 +1,7 @@
 package deprovision
 
 import (
-	"os"
-	"path/filepath"
-	"time"
-
-	"github.com/pkg/errors"
-	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
-
-	"github.com/openshift/library-go/pkg/controller/fileobserver"
 )
 
 // NewDeprovisionCommand is the entrypoint to create the 'deprovision' subcommand
@@ -21,12 +13,6 @@ func NewDeprovisionCommand() *cobra.Command {
 		Run: func(cmd *cobra.Command, args []string) {
 			cmd.Usage()
 		},
-		PersistentPreRun: func(cmd *cobra.Command, args []string) {
-			if credsDir == "" {
-				return
-			}
-			go terminateWhenFilesChange(credsDir)
-		},
 	}
 	flags := cmd.PersistentFlags()
 	flags.StringVar(&credsDir, "creds-dir", "", "directory of the creds. Changes in the creds will cause the program to terminate")
@@ -38,51 +24,3 @@ func NewDeprovisionCommand() *cobra.Command {
 	cmd.AddCommand(NewDeprovisionOvirtCommand())
 	return cmd
 }
-
-func terminateWhenFilesChange(dir string) {
-	fileContents := map[string][]byte{}
-	var filenames []string
-	if err := filepath.Walk(
-		dir,
-		func(path string, info os.FileInfo, err error) error {
-			if err != nil {
-				return errors.Wrapf(err, "problem encountered walking %s", path)
-			}
-			if info.IsDir() {
-				// skip directories
-				return nil
-			}
-			if info.Mode()&os.ModeSymlink != 0 {
-				// skip symlinks
-				return nil
-			}
-			data, err := os.ReadFile(path)
-			if err != nil {
-				return errors.Wrapf(err, "could not read contents of %s", path)
-			}
-			fileContents[path] = data
-			filenames = append(filenames, path)
-			return nil
-		},
-	); err != nil {
-		log.WithError(err).Fatal("could not read files for creds watch")
-	}
-	obs, err := fileobserver.NewObserver(10 * time.Second)
-	if err != nil {
-		log.WithError(err).Fatal("could not set up file observer for creds watch")
-	}
-	obs.AddReactor(
-		func(filename string, action fileobserver.ActionType) error {
-			log.WithField("filename", filename).Fatal("exiting because creds file changed")
-			return nil
-		},
-		fileContents,
-		filenames...,
-	)
-	stop := make(chan struct{})
-	go func() {
-		log.WithField("files", filenames).Info("running file observer")
-		obs.Run(stop)
-		log.Fatal("file observer stopped")
-	}()
-}