feat(tools/nixery): Absorb Nixery into depot r/3978

This absorbs a josh-filtered Nix subtree into depot, at
//tools/nixery.

This subtree was created through `josh-filter ':prefix=tools/nixery'`,
which allows a filter on tools/nixery to yield the same commit hashes
as the original Nixery repository (allowing for history continuity).

Change-Id: Icc1a99bf1248226b91f437b0a90361d36fb0d327

1 files changed, 110 insertions, 0 deletions

diff --git a/tools/nixery/storage/filesystem.go b/tools/nixery/storage/filesystem.go
new file mode 100644
index 000000000000..2be3457f324a
--- /dev/null
+++ b/tools/nixery/storage/filesystem.go
@@ -0,0 +1,110 @@
+// Copyright 2019 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+// Filesystem storage backend for Nixery.
+package storage
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path"
+
+	"github.com/pkg/xattr"
+	log "github.com/sirupsen/logrus"
+)
+
+type FSBackend struct {
+	path string
+}
+
+func NewFSBackend() (*FSBackend, error) {
+	p := os.Getenv("STORAGE_PATH")
+	if p == "" {
+		return nil, fmt.Errorf("STORAGE_PATH must be set for filesystem storage")
+	}
+
+	p = path.Clean(p)
+	err := os.MkdirAll(p, 0755)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create storage dir: %s", err)
+	}
+
+	return &FSBackend{p}, nil
+}
+
+func (b *FSBackend) Name() string {
+	return fmt.Sprintf("Filesystem (%s)", b.path)
+}
+
+func (b *FSBackend) Persist(ctx context.Context, key, contentType string, f Persister) (string, int64, error) {
+	full := path.Join(b.path, key)
+	dir := path.Dir(full)
+	err := os.MkdirAll(dir, 0755)
+	if err != nil {
+		log.WithError(err).WithField("path", dir).Error("failed to create storage directory")
+		return "", 0, err
+	}
+
+	file, err := os.OpenFile(full, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		log.WithError(err).WithField("file", full).Error("failed to write file")
+		return "", 0, err
+	}
+	defer file.Close()
+
+	err = xattr.Set(full, "user.mime_type", []byte(contentType))
+	if err != nil {
+		log.WithError(err).WithField("file", full).Error("failed to store file type in xattrs")
+		return "", 0, err
+	}
+
+	return f(file)
+}
+
+func (b *FSBackend) Fetch(ctx context.Context, key string) (io.ReadCloser, error) {
+	full := path.Join(b.path, key)
+	return os.Open(full)
+}
+
+func (b *FSBackend) Move(ctx context.Context, old, new string) error {
+	newpath := path.Join(b.path, new)
+	err := os.MkdirAll(path.Dir(newpath), 0755)
+	if err != nil {
+		return err
+	}
+
+	return os.Rename(path.Join(b.path, old), newpath)
+}
+
+func (b *FSBackend) Serve(digest string, r *http.Request, w http.ResponseWriter) error {
+	p := path.Join(b.path, "layers", digest)
+
+	log.WithFields(log.Fields{
+		"digest": digest,
+		"path":   p,
+	}).Info("serving blob from filesystem")
+
+	contentType, err := xattr.Get(p, "user.mime_type")
+	if err != nil {
+		log.WithError(err).WithField("file", p).Error("failed to read file type from xattrs")
+		return err
+	}
+	w.Header().Add("Content-Type", string(contentType))
+
+	http.ServeFile(w, r, p)
+	return nil
+}