35 lines
884 B
Go
35 lines
884 B
Go
package layer // import "github.com/docker/docker/layer"
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import (
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"fmt"
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"io/ioutil"
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"os"
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"strings"
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)
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// setOS writes the "os" file to the layer filestore
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func (fm *fileMetadataTransaction) setOS(os string) error {
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if os == "" {
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return nil
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}
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return fm.ws.WriteFile("os", []byte(os), 0644)
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}
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// getOS reads the "os" file from the layer filestore
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func (fms *fileMetadataStore) getOS(layer ChainID) (string, error) {
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contentBytes, err := ioutil.ReadFile(fms.getLayerFilename(layer, "os"))
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if err != nil {
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// For backwards compatibility, the os file may not exist. Default to "windows" if missing.
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if os.IsNotExist(err) {
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return "windows", nil
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}
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return "", err
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}
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content := strings.TrimSpace(string(contentBytes))
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if content != "windows" && content != "linux" {
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return "", fmt.Errorf("invalid operating system value: %s", content)
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}
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return content, nil
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}
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