databricks-cli/bundle/deploy/terraform/state_pull.go

99 lines
2.0 KiB
Go
Raw Normal View History

package terraform
import (
"bytes"
"context"
"errors"
"io"
"io/fs"
"os"
"path/filepath"
"github.com/databricks/cli/bundle"
"github.com/databricks/cli/libs/filer"
"github.com/databricks/cli/libs/log"
)
type statePull struct {
filerFunc
}
func (l *statePull) Name() string {
return "terraform:state-pull"
}
func (l *statePull) remoteState(ctx context.Context, f filer.Filer) (*bytes.Buffer, error) {
// Download state file from filer to local cache directory.
remote, err := f.Read(ctx, TerraformStateFileName)
if err != nil {
// On first deploy this state file doesn't yet exist.
if errors.Is(err, fs.ErrNotExist) {
return nil, nil
}
return nil, err
}
defer remote.Close()
var buf bytes.Buffer
_, err = io.Copy(&buf, remote)
if err != nil {
return nil, err
}
return &buf, nil
}
func (l *statePull) Apply(ctx context.Context, b *bundle.Bundle) error {
f, err := l.filerFunc(b)
if err != nil {
return err
}
dir, err := Dir(ctx, b)
if err != nil {
return err
}
// Download state file from filer to local cache directory.
log.Infof(ctx, "Opening remote state file")
remote, err := l.remoteState(ctx, f)
if err != nil {
log.Infof(ctx, "Unable to open remote state file: %s", err)
return err
}
if remote == nil {
log.Infof(ctx, "Remote state file does not exist")
return nil
}
// Expect the state file to live under dir.
local, err := os.OpenFile(filepath.Join(dir, TerraformStateFileName), os.O_CREATE|os.O_RDWR, 0600)
if err != nil {
return err
}
defer local.Close()
if !IsLocalStateStale(local, bytes.NewReader(remote.Bytes())) {
log.Infof(ctx, "Local state is the same or newer, ignoring remote state")
return nil
}
// Truncating the file before writing
local.Truncate(0)
local.Seek(0, 0)
// Write file to disk.
log.Infof(ctx, "Writing remote state file to local cache directory")
_, err = io.Copy(local, bytes.NewReader(remote.Bytes()))
if err != nil {
return err
}
return nil
}
func StatePull() bundle.Mutator {
return &statePull{stateFiler}
}