podman

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package mkcw
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import (
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	"fmt"
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	"os/exec"
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	"strings"
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	"github.com/sirupsen/logrus"
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)
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// MakeFS formats the imageFile as a filesystem of the specified type,
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// populating it with the contents of the directory at sourcePath.
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// Recognized filesystem types are "ext2", "ext3", "ext4", and "btrfs".
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// Note that krun's init is currently hard-wired to assume "ext4".
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// Returns the stdout, stderr, and any error returned by the mkfs command.
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func MakeFS(sourcePath, imageFile, filesystem string) (string, string, error) {
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	var stdout, stderr strings.Builder
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	// N.B. mkfs.xfs can accept a protofile via its -p option, but the
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	// protofile format doesn't allow us to supply timestamp information or
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	// specify that files are hard linked
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	switch filesystem {
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	case "ext2", "ext3", "ext4":
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		logrus.Debugf("mkfs -t %s --rootdir %q %q", filesystem, sourcePath, imageFile)
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		cmd := exec.Command("mkfs", "-t", filesystem, "-d", sourcePath, imageFile)
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		cmd.Stdout = &stdout
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		cmd.Stderr = &stderr
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		err := cmd.Run()
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		return stdout.String(), stderr.String(), err
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	case "btrfs":
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		logrus.Debugf("mkfs -t %s --rootdir %q %q", filesystem, sourcePath, imageFile)
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		cmd := exec.Command("mkfs", "-t", filesystem, "--rootdir", sourcePath, imageFile)
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		cmd.Stdout = &stdout
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		cmd.Stderr = &stderr
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		err := cmd.Run()
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		return stdout.String(), stderr.String(), err
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	}
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	return "", "", fmt.Errorf("don't know how to make a %q filesystem with contents", filesystem)
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}
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