Add wwctl container <exec|shell> --build=false

- Closes #1490
- Closes #1489

Signed-off-by: Jonathon Anderson <janderson@ciq.com>

CHANGELOG.md

@@ -33,6 +33,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Support defining a symlink with an overlay template. #1303
 - New "localtime" overlay to define the system time zone. #1303
 - Add support for nested profiles. #1572, #1598
+- Adds `wwctl container <exec|shell> --build=false` to prevent automatically (re)building the container. #1490, #1489
 
 ### Changed
 

internal/app/wwctl/container/exec/child/main.go

@@ -21,9 +21,6 @@ import (
 )
 
 const exitEval = `$(VALU="$?" ; if [ $VALU == 0 ]; then echo write; else echo discard; fi)`
-const msgStr = `Container image is rebuilt depending on the exit status of the last command.
-
-Run "true" or "false" to enforce or abort image rebuild.`
 
 func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 	if os.Getpid() != 1 {
@@ -82,7 +79,6 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 		return fmt.Errorf("failed to mount: %w", err)
 	}
 	ps1Str := fmt.Sprintf("[%s|%s] Warewulf> ", containerName, exitEval)
-	wwlog.Info(msgStr)
 	if len(lowerObjects) != 0 && nodename == "" {
 		options := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s",
 			path.Join(runDir, "lower"), containerPath, path.Join(runDir, "work"))

internal/app/wwctl/container/exec/main.go

@@ -145,14 +145,16 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 	if userdbChanged && SyncUser {
 		err = container.SyncUids(containerName, false)
 		if err != nil {
-			wwlog.Error("Error in user sync, fix error and run 'syncuser' manually, but trying to build container: %s", err)
+			wwlog.Error("Error in user sync, fix error and run 'syncuser' manually: %s", err)
 		}
 	}
 
-	fmt.Printf("Rebuilding container...\n")
-	err = container.Build(containerName, false)
-	if err != nil {
-		return fmt.Errorf("could not build container %s: %s", containerName, err)
+	if Build {
+		wwlog.Info("Building container image: %s", containerName)
+		err = container.Build(containerName, false)
+		if err != nil {
+			return fmt.Errorf("could not build container image: %s: %s", containerName, err)
+		}
 	}
 	return nil
 }

internal/app/wwctl/container/exec/main_test.go

@@ -2,15 +2,14 @@ package exec
 
 import (
 	"bytes"
+	"os"
 	"os/exec"
 	"testing"
 
 	"github.com/spf13/cobra"
 	"github.com/stretchr/testify/assert"
-	"github.com/warewulf/warewulf/internal/pkg/testenv"
-	"path"
-	"strings"
 
+	"github.com/warewulf/warewulf/internal/pkg/testenv"
 	"github.com/warewulf/warewulf/internal/pkg/warewulfd"
 )
 
@@ -25,7 +24,7 @@ func mockChildCmd(cmd *cobra.Command, args []string) error {
 func Test_Exec(t *testing.T) {
 	env := testenv.New(t)
 	defer env.RemoveAll(t)
-	env.MkdirAll(t, path.Join(testenv.WWChrootdir, "test/rootfs"))
+	env.MkdirAll(t, "/var/lib/warewulf/chroots/test/rootfs")
 	childCommandFunc = mockChildCmd
 	defer func() {
 		childCommandFunc = runChildCmd
@@ -36,40 +35,55 @@ func Test_Exec(t *testing.T) {
 		name   string
 		args   []string
 		stdout string
+		build  bool
 	}{
 		{
 			name:   "plain test",
 			args:   []string{"test", "/bin/true"},
 			stdout: `--loglevel 20 container exec __child test -- /bin/true`,
+			build:  true,
 		},
 		{
 			name:   "test with --bind",
 			args:   []string{"test", "--bind", "/tmp", "/bin/true"},
 			stdout: `--loglevel 20 container exec __child test --bind /tmp -- /bin/true`,
+			build:  true,
 		},
 		{
 			name:   "test with --node",
 			args:   []string{"test", "--node", "node1", "/bin/true"},
 			stdout: `--loglevel 20 container exec __child test --node node1 -- /bin/true`,
+			build:  true,
+		},
+		{
+			name:   "test with --build=false",
+			args:   []string{"test", "--build=false", "/bin/true"},
+			stdout: `--loglevel 20 container exec __child test -- /bin/true`,
+			build:  false,
 		},
 		{
 			name:   "test with --node and --bind",
 			args:   []string{"test", "--bind", "/tmp", "--node", "node1", "/bin/true"},
 			stdout: `--loglevel 20 container exec __child test --bind /tmp --node node1 -- /bin/true`,
+			build:  true,
 		},
 		{
 			name:   "test with complex command",
 			args:   []string{"test", "/bin/bash", "echo 'hello'"},
 			stdout: `--loglevel 20 container exec __child test -- /bin/bash echo 'hello'`,
+			build:  true,
 		},
 	}
 
 	for _, tt := range tests {
-		t.Logf("Running test: %s\n", tt.name)
 		t.Run(tt.name, func(t *testing.T) {
 			defer func() {
 				binds = []string{}
 				nodeName = ""
+				Build = true
+				SyncUser = false
+				os.Remove(env.GetPath("/srv/warewulf/container/test.img"))
+				os.Remove(env.GetPath("/srv/warewulf/container/test.img.gz"))
 			}()
 			cmd := GetCommand()
 			cmd.SetArgs(tt.args)
@@ -77,14 +91,15 @@ func Test_Exec(t *testing.T) {
 			err := bytes.NewBufferString("")
 			cmd.SetOut(out)
 			cmd.SetErr(err)
-			if err := cmd.Execute(); err != nil {
-				t.Errorf("Received error when running command, err: %v", err)
-				t.FailNow()
-			}
-			assert.NotEmpty(t, out.String(), "os.stdout should not be empty")
-			if !strings.Contains(out.String(), tt.stdout) {
-				t.Errorf("Got wrong output, got:\n '%s'\n, but want:\n '%s'\n", out.String(), tt.stdout)
-				t.FailNow()
+			assert.NoError(t, cmd.Execute())
+			assert.NotEmpty(t, out.String())
+			assert.Contains(t, out.String(), tt.stdout)
+			if tt.build {
+				assert.FileExists(t, env.GetPath("/srv/warewulf/container/test.img"))
+				assert.FileExists(t, env.GetPath("/srv/warewulf/container/test.img.gz"))
+			} else {
+				assert.NoFileExists(t, env.GetPath("/srv/warewulf/container/test.img"))
+				assert.NoFileExists(t, env.GetPath("/srv/warewulf/container/test.img.gz"))
 			}
 		})
 	}

internal/app/wwctl/container/exec/root.go

@@ -26,6 +26,7 @@ var (
 		FParseErrWhitelist: cobra.FParseErrWhitelist{UnknownFlags: true},
 	}
 	SyncUser bool
+	Build    bool
 	binds    []string
 	nodeName string
 )
@@ -37,6 +38,7 @@ Bind a local path which must exist into the container. If destination is not
 set, uses the same path as source. "ro" binds read-only. "copy" temporarily
 copies the file into the container.`)
 	baseCmd.PersistentFlags().BoolVar(&SyncUser, "syncuser", false, "Synchronize UIDs/GIDs from host to container")
+	baseCmd.PersistentFlags().BoolVar(&Build, "build", true, "(Re)build the container image automatically")
 	baseCmd.PersistentFlags().StringVarP(&nodeName, "node", "n", "", "Create a read only view of the container for the given node")
 }
 

internal/app/wwctl/container/shell/main.go

@@ -44,5 +44,9 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 	cntexec.SetBinds(binds)
 	cntexec.SetNode(nodeName)
 	cntexec.SyncUser = syncUser
+	cntexec.Build = build
+	if cntexec.Build {
+		wwlog.Info("Container image build will be skipped if the shell ends with a non-zero exit code.")
+	}
 	return cntexec.CobraRunE(cmd, allargs)
 }

internal/app/wwctl/container/shell/root.go

@@ -26,6 +26,7 @@ var (
 	binds    []string
 	nodeName string
 	syncUser bool
+	build    bool
 )
 
 func init() {
@@ -35,6 +36,7 @@ set, uses the same path as source. "ro" binds read-only. "copy" temporarily
 copies the file into the container.`)
 	baseCmd.PersistentFlags().StringVarP(&nodeName, "node", "n", "", "Create a read only view of the container for the given node")
 	baseCmd.PersistentFlags().BoolVar(&syncUser, "syncuser", false, "Synchronize UIDs/GIDs from host to container")
+	baseCmd.PersistentFlags().BoolVar(&build, "build", true, "(Re)build the container image automatically")
 }
 
 // GetRootCommand returns the root cobra.Command for the application.

userdocs/contents/containers.rst

@@ -229,7 +229,7 @@ when using the exec command. This works as follows:
 
 .. code-block:: console
 
-   # wwctl container exec --bind /tmp:/mnt rocky-8 /bin/sh
+   # wwctl container shell --bind /tmp:/mnt rocky-8
    [rocky-8] Warewulf>
 
 .. note::
@@ -257,7 +257,7 @@ can be specified in ``warewulf.conf``:
 
 When the command completes, if anything within the container changed,
 the container will be rebuilt into a bootable static object
-automatically.
+automatically. (To skip the automatic container rebuild, specify ``--build=false``.)
 
 If the files ``/etc/passwd`` or ``/etc/group`` were updated, there
 will be an additional check to confirm if the users are in sync as