58 lines
1.4 KiB
Go
58 lines
1.4 KiB
Go
package docker
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import (
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"errors"
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"fmt"
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"os"
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"os/exec"
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"path/filepath"
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)
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type IClient interface {
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Save(imageName, dest string) (string, error)
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}
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var ErrDockerClientSave = errors.New("unable to save image into tar")
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// Client is a simple Docker client wrapping the local Docker daemon.
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// It does not use the Docker API but instead shell command and collect the output.
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//
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// NOTE: for now, it's ok, it only needs one command so, no need to add a fat dedicated
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// library with full Docker client API.
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type Client struct{}
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var _ IClient = (*Client)(nil)
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func NewClient() Client {
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return Client{}
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}
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// Save saves the `imageName` (tag included) in tar format in the target directory: `dest`.
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// The `dest` directory must exist with correct permissions.
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func (c *Client) Save(imageName, dest string) (string, error) {
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destInfo, err := os.Stat(dest)
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if err != nil {
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return "", fmt.Errorf("unable to stat file, dir=%s, err=%v", dest, err)
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}
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if !destInfo.IsDir() {
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return "", fmt.Errorf("dest file must be a directory, dir=%s, err=%v", dest, err)
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}
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tarFile := fmt.Sprintf("%s.tar", imageName)
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cmd := exec.Command("docker", "save", "-o", tarFile, imageName)
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cmd.Dir = dest
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if _, err := cmd.Output(); err != nil {
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return "", fmt.Errorf(
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"%w, dir=%s, image=%s, err=%v",
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ErrDockerClientSave,
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dest,
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imageName,
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err,
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)
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}
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return filepath.Join(dest, tarFile), nil
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}
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