Merge pull request #21332 from rhatdan/timezone

Reuse timezone code from containers/common

libpod/container_internal.go

@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/fs"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -25,6 +24,7 @@ import (
 	"github.com/containers/common/pkg/config"
 	"github.com/containers/common/pkg/hooks"
 	"github.com/containers/common/pkg/hooks/exec"
+	"github.com/containers/common/pkg/timezone"
 	cutil "github.com/containers/common/pkg/util"
 	"github.com/containers/podman/v4/libpod/define"
 	"github.com/containers/podman/v4/libpod/events"
@@ -1722,45 +1722,18 @@ func (c *Container) mountStorage() (_ string, deferredErr error) {
 	}
 
 	tz := c.Timezone()
-	if tz != "" {
-		timezonePath := filepath.Join("/usr/share/zoneinfo", tz)
-		if tz == "local" {
-			timezonePath, err = filepath.EvalSymlinks("/etc/localtime")
-			if err != nil {
-				return "", fmt.Errorf("finding local timezone for container %s: %w", c.ID(), err)
-			}
+	localTimePath, err := timezone.ConfigureContainerTimeZone(tz, c.state.RunDir, mountPoint, etcInTheContainerPath, c.ID())
+	if err != nil {
+		return "", fmt.Errorf("configuring timezone for container %s: %w", c.ID(), err)
+	}
+	if localTimePath != "" {
+		if err := c.relabel(localTimePath, c.config.MountLabel, false); err != nil {
+			return "", err
 		}
-		// make sure to remove any existing localtime file in the container to not create invalid links
-		err = unix.Unlinkat(etcInTheContainerFd, "localtime", 0)
-		if err != nil && !errors.Is(err, fs.ErrNotExist) {
-			return "", fmt.Errorf("removing /etc/localtime: %w", err)
-		}
-
-		hostPath, err := securejoin.SecureJoin(mountPoint, timezonePath)
-		if err != nil {
-			return "", fmt.Errorf("resolve zoneinfo path in the container: %w", err)
-		}
-
-		_, err = os.Stat(hostPath)
-		if err != nil {
-			// file does not exists which means tzdata is not installed in the container, just create /etc/locatime which a copy from the host
-			logrus.Debugf("Timezone %s does not exist in the container, create our own copy from the host", timezonePath)
-			localtimePath, err := c.copyTimezoneFile(timezonePath)
-			if err != nil {
-				return "", fmt.Errorf("setting timezone for container %s: %w", c.ID(), err)
-			}
-			if c.state.BindMounts == nil {
-				c.state.BindMounts = make(map[string]string)
-			}
-			c.state.BindMounts["/etc/localtime"] = localtimePath
-		} else {
-			// file exists lets just symlink according to localtime(5)
-			logrus.Debugf("Create locatime symlink for %s", timezonePath)
-			err = unix.Symlinkat(".."+timezonePath, etcInTheContainerFd, "localtime")
-			if err != nil {
-				return "", fmt.Errorf("creating /etc/localtime symlink: %w", err)
-			}
+		if c.state.BindMounts == nil {
+			c.state.BindMounts = make(map[string]string)
 		}
+		c.state.BindMounts["/etc/localtime"] = localTimePath
 	}
 
 	// Request a mount of all named volumes

libpod/container_internal_common.go

@@ -2782,38 +2782,6 @@ func (c *Container) generatePasswdAndGroup() (string, string, error) {
 	return passwdPath, groupPath, nil
 }
 
-func (c *Container) copyTimezoneFile(zonePath string) (string, error) {
-	localtimeCopy := filepath.Join(c.state.RunDir, "localtime")
-	file, err := os.Stat(zonePath)
-	if err != nil {
-		return "", err
-	}
-	if file.IsDir() {
-		return "", errors.New("invalid timezone: is a directory")
-	}
-	src, err := os.Open(zonePath)
-	if err != nil {
-		return "", err
-	}
-	defer src.Close()
-	dest, err := os.Create(localtimeCopy)
-	if err != nil {
-		return "", err
-	}
-	defer dest.Close()
-	_, err = io.Copy(dest, src)
-	if err != nil {
-		return "", err
-	}
-	if err := c.relabel(localtimeCopy, c.config.MountLabel, false); err != nil {
-		return "", err
-	}
-	if err := dest.Chown(c.RootUID(), c.RootGID()); err != nil {
-		return "", err
-	}
-	return localtimeCopy, err
-}
-
 func (c *Container) cleanupOverlayMounts() error {
 	return overlay.CleanupContent(c.config.StaticDir)
 }

vendor/github.com/containers/common/pkg/timezone/timezone.go

@@ -0,0 +1,103 @@
+//go:build !windows
+
+package timezone
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+
+	securejoin "github.com/cyphar/filepath-securejoin"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+// ConfigureContainerTimeZone configure the time zone for a container.
+// It returns the path of the created /etc/localtime file if needed.
+func ConfigureContainerTimeZone(timezone, containerRunDir, mountPoint, etcPath, containerID string) (localTimePath string, err error) {
+	var timezonePath string
+	switch {
+	case timezone == "":
+		return "", nil
+	case os.Getenv("TZDIR") != "":
+		// Allow using TZDIR per:
+		// https://sourceware.org/git/?p=glibc.git;a=blob;f=time/tzfile.c;h=8a923d0cccc927a106dc3e3c641be310893bab4e;hb=HEAD#l149
+
+		timezonePath = filepath.Join(os.Getenv("TZDIR"), timezone)
+	case timezone == "local":
+		timezonePath, err = filepath.EvalSymlinks("/etc/localtime")
+		if err != nil {
+			return "", fmt.Errorf("finding local timezone for container %s: %w", containerID, err)
+		}
+	default:
+		timezonePath = filepath.Join("/usr/share/zoneinfo", timezone)
+	}
+
+	etcFd, err := openDirectory(etcPath)
+	if err != nil {
+		return "", fmt.Errorf("open /etc in the container: %w", err)
+	}
+	defer unix.Close(etcFd)
+
+	// Make sure to remove any existing localtime file in the container to not create invalid links
+	err = unix.Unlinkat(etcFd, "localtime", 0)
+	if err != nil && !errors.Is(err, fs.ErrNotExist) {
+		return "", fmt.Errorf("removing /etc/localtime: %w", err)
+	}
+
+	hostPath, err := securejoin.SecureJoin(mountPoint, timezonePath)
+	if err != nil {
+		return "", fmt.Errorf("resolve zoneinfo path in the container: %w", err)
+	}
+
+	var localtimePath string
+	if _, err := os.Stat(hostPath); err != nil {
+		// File does not exist, which means tzdata is not installed in the container.
+		// Create /etc/localtime as a copy from the host.
+		logrus.Debugf("Timezone %s does not exist in the container, create our own copy from the host", timezonePath)
+		localtimePath, err = copyTimezoneFile(containerRunDir, timezonePath)
+		if err != nil {
+			return "", fmt.Errorf("setting timezone for container %s: %w", containerID, err)
+		}
+	} else {
+		// File exists, let's create a symlink according to localtime(5)
+		logrus.Debugf("Create localtime symlink for %s", timezonePath)
+		err = unix.Symlinkat(".."+timezonePath, etcFd, "localtime")
+		if err != nil {
+			return "", fmt.Errorf("creating /etc/localtime symlink: %w", err)
+		}
+	}
+	return localtimePath, nil
+}
+
+// copyTimezoneFile copies the timezone file from the host to the container.
+func copyTimezoneFile(containerRunDir, zonePath string) (string, error) {
+	localtimeCopy := filepath.Join(containerRunDir, "localtime")
+	file, err := os.Stat(zonePath)
+	if err != nil {
+		return "", err
+	}
+	if file.IsDir() {
+		return "", errors.New("invalid timezone: is a directory")
+	}
+	src, err := os.Open(zonePath)
+	if err != nil {
+		return "", err
+	}
+	defer src.Close()
+
+	dest, err := os.Create(localtimeCopy)
+	if err != nil {
+		return "", err
+	}
+	defer dest.Close()
+
+	_, err = io.Copy(dest, src)
+	if err != nil {
+		return "", err
+	}
+	return localtimeCopy, err
+}

vendor/github.com/containers/common/pkg/timezone/timezone_linux.go

@@ -0,0 +1,9 @@
+package timezone
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+func openDirectory(path string) (fd int, err error) {
+	return unix.Open(path, unix.O_RDONLY|unix.O_PATH|unix.O_CLOEXEC, 0)
+}

vendor/github.com/containers/common/pkg/timezone/timezone_unix.go

@@ -0,0 +1,12 @@
+//go:build !windows && !linux
+
+package timezone
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+func openDirectory(path string) (fd int, err error) {
+	const O_PATH = 0x00400000
+	return unix.Open(path, unix.O_RDONLY|O_PATH|unix.O_CLOEXEC, 0)
+}

vendor/github.com/containers/common/pkg/timezone/timezone_windows.go

@@ -0,0 +1,5 @@
+package timezone
+
+func ConfigureContainerTimeZone(timezone, containerRunDir, mountPoint, etcPath, containerID string) (string, error) {
+	return "", nil
+}

vendor/modules.txt

@@ -229,6 +229,7 @@ github.com/containers/common/pkg/supplemented
 github.com/containers/common/pkg/sysinfo
 github.com/containers/common/pkg/systemd
 github.com/containers/common/pkg/timetype
+github.com/containers/common/pkg/timezone
 github.com/containers/common/pkg/umask
 github.com/containers/common/pkg/util
 github.com/containers/common/pkg/version