docker-db-backup/save.go

67 lines
1.3 KiB
Go

package main
import (
"compress/gzip"
"context"
"fmt"
"io"
"os"
"github.com/docker/docker/api/types"
"github.com/docker/docker/client"
)
func runAndSaveCommandInContainer(c *client.Client, container *types.ContainerJSON, command string, args ...string) error {
ctx := context.Background()
filename := getDumpFilename(container.Name)
if config.CompressBackups {
filename += ".gz"
}
containerConfig := types.ExecConfig{
AttachStderr: true,
AttachStdout: true,
Cmd: append([]string{command}, args...),
}
r, err := c.ContainerExecCreate(ctx, container.ID, containerConfig)
if err != nil {
return err
}
resp, err := c.ContainerExecAttach(ctx, r.ID, types.ExecStartCheck{})
if err != nil {
return err
}
defer resp.Close()
f, err := os.Create(filename)
if err != nil {
return err
}
defer f.Close()
var target io.Writer = f
if config.CompressBackups {
gw, err := gzip.NewWriterLevel(f, gzip.BestCompression)
if err != nil {
return err
}
defer gw.Close()
target = gw
}
_, err = io.Copy(target, resp.Reader)
if err != nil {
return err
}
execInspect, err := c.ContainerExecInspect(ctx, r.ID)
if execInspect.ExitCode != 0 {
return fmt.Errorf("backup from container %s failed with exit code %d", container.Name, execInspect.ExitCode)
}
return err
}