jcoffey-dev
719a945d64
In-place upgrade tool for Stalwart Mail Server (0.15.5 -> latest) with checkpointed rollback and post-migration validation. Design stage; see ARCHITECTURE.md.
32 lines
1.1 KiB
Go
32 lines
1.1 KiB
Go
package backup
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import (
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"fmt"
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"os"
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)
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// PreserveBinary moves the currently-installed binary aside to
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// "<binaryPath>.v<sourceVersion>" so rollback can restart the exact old
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// binary without re-downloading anything, and cutover can install the new
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// one at the original path. It never deletes the old binary, and it's
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// idempotent: if a prior attempt at this run already preserved it, calling
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// this again just returns the existing preserved path rather than erroring
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// on a missing source file.
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func PreserveBinary(binaryPath, sourceVersion string) (preservedPath string, err error) {
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if sourceVersion == "" {
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return "", fmt.Errorf("backup: cannot preserve %s without a source version to suffix it with", binaryPath)
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}
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preservedPath = binaryPath + ".v" + sourceVersion
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if _, statErr := os.Stat(preservedPath); statErr == nil {
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return preservedPath, nil
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} else if !os.IsNotExist(statErr) {
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return "", fmt.Errorf("backup: stat %s: %w", preservedPath, statErr)
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}
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if err := os.Rename(binaryPath, preservedPath); err != nil {
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return "", fmt.Errorf("backup: preserve %s as %s: %w", binaryPath, preservedPath, err)
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}
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return preservedPath, nil
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}
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