releases/bundle/store.go

// Copyright 2019 The OPA Authors.  All rights reserved.
// Use of this source code is governed by an Apache2
// license that can be found in the LICENSE file.

package bundle

import (
	"context"
	"fmt"

	"github.com/open-policy-agent/opa/storage"
	"github.com/open-policy-agent/opa/util"
)

var bundlesBasePath = storage.MustParsePath("/system/bundles")

// Note: As needed these helpers could be memoized.

// ManifestStoragePath is the storage path used for the given named bundle manifest.
func ManifestStoragePath(name string) storage.Path {
	return append(bundlesBasePath, name, "manifest")
}

func namedBundlePath(name string) storage.Path {
	return append(bundlesBasePath, name)
}

func rootsPath(name string) storage.Path {
	return append(bundlesBasePath, name, "manifest", "roots")
}

func revisionPath(name string) storage.Path {
	return append(bundlesBasePath, name, "manifest", "revision")
}

// ReadBundleNamesFromStore will return a list of bundle names which have had their metadata stored.
func ReadBundleNamesFromStore(ctx context.Context, store storage.Store, txn storage.Transaction) ([]string, error) {
	value, err := store.Read(ctx, txn, bundlesBasePath)
	if err != nil {
		return nil, err
	}

	bundleMap, ok := value.(map[string]interface{})
	if !ok {
		return nil, fmt.Errorf("corrupt manifest roots")
	}

	bundles := make([]string, len(bundleMap))
	idx := 0
	for name := range bundleMap {
		bundles[idx] = name
		idx++
	}
	return bundles, nil
}

// WriteManifestToStore will write the manifest into the storage. This function is called when
// the bundle is activated.
func WriteManifestToStore(ctx context.Context, store storage.Store, txn storage.Transaction, name string, manifest Manifest) error {
	return write(ctx, store, txn, ManifestStoragePath(name), manifest)
}

func write(ctx context.Context, store storage.Store, txn storage.Transaction, path storage.Path, manifest Manifest) error {
	var value interface{} = manifest
	if err := util.RoundTrip(&value); err != nil {
		return err
	}

	var dir []string
	if len(path) > 1 {
		dir = path[:len(path)-1]
	}

	if err := storage.MakeDir(ctx, store, txn, dir); err != nil {
		return err
	}

	return store.Write(ctx, txn, storage.AddOp, path, value)
}

// EraseManifestFromStore will remove the manifest from storage. This function is called
// when the bundle is deactivated.
func EraseManifestFromStore(ctx context.Context, store storage.Store, txn storage.Transaction, name string) error {
	path := namedBundlePath(name)
	err := store.Write(ctx, txn, storage.RemoveOp, path, nil)
	if err != nil && !storage.IsNotFound(err) {
		return err
	}
	return nil
}

// ReadBundleRootsFromStore returns the roots in the specified bundle.
// If the bundle is not activated, this function will return
// storage NotFound error.
func ReadBundleRootsFromStore(ctx context.Context, store storage.Store, txn storage.Transaction, name string) ([]string, error) {
	value, err := store.Read(ctx, txn, rootsPath(name))
	if err != nil {
		return nil, err
	}

	sl, ok := value.([]interface{})
	if !ok {
		return nil, fmt.Errorf("corrupt manifest roots")
	}

	roots := make([]string, len(sl))

	for i := range sl {
		roots[i], ok = sl[i].(string)
		if !ok {
			return nil, fmt.Errorf("corrupt manifest root")
		}
	}

	return roots, nil
}

// ReadBundleRevisionFromStore returns the revision in the specified bundle.
// If the bundle is not activated, this function will return
// storage NotFound error.
func ReadBundleRevisionFromStore(ctx context.Context, store storage.Store, txn storage.Transaction, name string) (string, error) {
	return readRevisionFromStore(ctx, store, txn, revisionPath(name))
}

func readRevisionFromStore(ctx context.Context, store storage.Store, txn storage.Transaction, path storage.Path) (string, error) {
	value, err := store.Read(ctx, txn, path)
	if err != nil {
		return "", err
	}

	str, ok := value.(string)
	if !ok {
		return "", fmt.Errorf("corrupt manifest revision")
	}

	return str, nil
}

// Helpers for the older single (unnamed) bundle style manifest storage.

// LegacyManifestStoragePath is the older unnamed bundle path for manifests to be stored.
// Deprecated: Use ManifestStoragePath and named bundles instead.
var legacyManifestStoragePath = storage.MustParsePath("/system/bundle/manifest")
var legacyRevisionStoragePath = append(legacyManifestStoragePath, "revision")

// LegacyWriteManifestToStore will write the bundle manifest to the older single (unnamed) bundle manifest location.
// Deprecated: Use WriteManifestToStore and named bundles instead.
func LegacyWriteManifestToStore(ctx context.Context, store storage.Store, txn storage.Transaction, manifest Manifest) error {
	return write(ctx, store, txn, legacyManifestStoragePath, manifest)
}

// LegacyEraseManifestFromStore will erase the bundle manifest from the older single (unnamed) bundle manifest location.
// Deprecated: Use WriteManifestToStore and named bundles instead.
func LegacyEraseManifestFromStore(ctx context.Context, store storage.Store, txn storage.Transaction) error {
	err := store.Write(ctx, txn, storage.RemoveOp, legacyManifestStoragePath, nil)
	if err != nil {
		return err
	}
	return nil
}

// LegacyReadRevisionFromStore will read the bundle manifest revision from the older single (unnamed) bundle manifest location.
// Deprecated: Use ReadBundleRevisionFromStore and named bundles instead.
func LegacyReadRevisionFromStore(ctx context.Context, store storage.Store, txn storage.Transaction) (string, error) {
	return readRevisionFromStore(ctx, store, txn, legacyRevisionStoragePath)
}