pomerium/internal/zero/bootstrap/writers/filesystem/file.go
Joe Kralicky de603f87de
Add new configurable bootstrap writers (#2405) (#5114)
* Add new configurable bootstrap writers (#2405)

This PR adds the ability to configure different backends to use for
storing modifications to the zero bootstrap config. The two currently
implemented backends allow writing changes to a file or to a Kubernetes
secret. Backend selection is determined by the scheme in a URI passed to
the flag '--config-writeback-uri'.

In a Kubernetes environment, where the bootstrap config is mounted into
the pod from a secret, this option allows Pomerium to write changes back
to the secret, as writes to the mounted secret file on disk are not
persisted.

* Use env vars for bootstrap config filepath/writeback uri

* linter pass and code cleanup

* Add new config writer options mechanism

This moves the encryption cipher parameter out of the WriteConfig()
method in the ConfigWriter interface and into a new ConfigWriterOptions
struct. Options (e.g. cipher) can be applied to an existing ConfigWriter
to allow customizing implementation-specific behavior.

* Code cleanup/lint fixes

* Move vendored k8s code into separate package, and add license header and package comment
2024-05-31 12:26:17 -04:00

58 lines
1.4 KiB
Go

package filesystem
import (
"context"
"encoding/json"
"fmt"
"net/url"
"os"
"github.com/pomerium/pomerium/internal/zero/bootstrap/writers"
"github.com/pomerium/pomerium/pkg/cryptutil"
cluster_api "github.com/pomerium/pomerium/pkg/zero/cluster"
)
func init() {
writers.RegisterBuilder("file", newFileWriter)
}
func newFileWriter(uri *url.URL) (writers.ConfigWriter, error) {
if uri.Host != "" {
// prevent the common mistake of "file://path/to/file"
return nil, fmt.Errorf(`invalid file uri %q (did you mean "file:///%s%s"?)`, uri.String(), uri.Host, uri.Path)
}
return &fileWriter{
filePath: uri.Path,
}, nil
}
type fileWriter struct {
opts writers.ConfigWriterOptions
filePath string
}
// WithOptions implements writers.ConfigWriter.
func (w *fileWriter) WithOptions(opts writers.ConfigWriterOptions) writers.ConfigWriter {
clone := *w
clone.opts = opts
return &clone
}
// WriteConfig implements ConfigWriter.
func (w *fileWriter) WriteConfig(_ context.Context, src *cluster_api.BootstrapConfig) error {
data, err := json.Marshal(src)
if err != nil {
return fmt.Errorf("marshal file config: %w", err)
}
if w.opts.Cipher != nil {
data = cryptutil.Encrypt(w.opts.Cipher, data, nil)
}
err = os.WriteFile(w.filePath, data, 0o600)
if err != nil {
return fmt.Errorf("write bootstrap config: %w", err)
}
return nil
}
var _ writers.ConfigWriter = (*fileWriter)(nil)