feat(auth): add policy caching

Cache policies when the first authorization request happens and delete them when removing policies

Signed-off-by: Rodney Osodo <[email protected]>

auth/README.md

@@ -89,6 +89,8 @@ The service is configured using the environment variables presented in the follo
 | MG_SPICEDB_PORT                | SpiceDB host port                                                       | 50051                            |
 | MG_SPICEDB_PRE_SHARED_KEY      | SpiceDB pre-shared key                                                  | 12345678                         |
 | MG_SPICEDB_SCHEMA_FILE         | Path to SpiceDB schema file                                             | ./docker/spicedb/schema.zed      |
+| MG_AUTH_CACHE_URL              | Cache server URL                                                        | "redis://localhost:6379/0"       |
+| MG_AUTH_CACHE_KEY_DURATION     | Cache key expiration period                                             | "1h"                             |
 | MG_JAEGER_URL                  | Jaeger server URL                                                       | <http://jaeger:14268/api/traces> |
 | MG_JAEGER_TRACE_RATIO          | Jaeger sampling ratio                                                   | 1.0                              |
 | MG_SEND_TELEMETRY              | Send telemetry to magistrala call home server                           | true                             |
@@ -142,6 +144,8 @@ MG_SPICEDB_HOST=localhost \
 MG_SPICEDB_PORT=50051 \
 MG_SPICEDB_PRE_SHARED_KEY=12345678 \
 MG_SPICEDB_SCHEMA_FILE=./docker/spicedb/schema.zed \
+MG_AUTH_CACHE_URL=redis://localhost:6379/0 \
+MG_AUTH_CACHE_KEY_DURATION=1h \
 MG_JAEGER_URL=http://localhost:14268/api/traces \
 MG_JAEGER_TRACE_RATIO=1.0 \
 MG_SEND_TELEMETRY=true \

auth/cache/doc.go

@@ -0,0 +1,6 @@
+// Copyright (c) Abstract Machines
+// SPDX-License-Identifier: Apache-2.0
+
+// Package cache contains the domain concept definitions needed to
+// support Magistrala auth cache service functionality.
+package cache

auth/cache/policies.go

@@ -0,0 +1,87 @@
+// Copyright (c) Abstract Machines
+// SPDX-License-Identifier: Apache-2.0
+
+package cache
+
+import (
+	"context"
+	"strings"
+	"time"
+
+	"github.com/absmach/magistrala/auth"
+	"github.com/absmach/magistrala/pkg/errors"
+	repoerr "github.com/absmach/magistrala/pkg/errors/repository"
+	"github.com/go-redis/redis/v8"
+)
+
+const defLimit = 100
+
+var _ auth.Cache = (*policiesCache)(nil)
+
+type policiesCache struct {
+	client      *redis.Client
+	keyDuration time.Duration
+}
+
+// NewPoliciesCache returns redis auth cache implementation.
+func NewPoliciesCache(client *redis.Client, duration time.Duration) auth.Cache {
+	return &policiesCache{
+		client:      client,
+		keyDuration: duration,
+	}
+}
+
+func (pc *policiesCache) Save(ctx context.Context, key, value string) error {
+	if err := pc.client.Set(ctx, key, value, pc.keyDuration).Err(); err != nil {
+		return errors.Wrap(repoerr.ErrCreateEntity, err)
+	}
+
+	return nil
+}
+
+func (pc *policiesCache) Contains(ctx context.Context, key, value string) bool {
+	rval, err := pc.client.Get(ctx, key).Result()
+	if err != nil {
+		return false
+	}
+	if rval == value {
+		return true
+	}
+
+	return false
+}
+
+func (pc *policiesCache) Remove(ctx context.Context, key string) error {
+	if strings.Contains(key, "*") {
+		return pc.delete(ctx, key)
+	}
+
+	if err := pc.client.Del(ctx, key).Err(); err != nil {
+		return errors.Wrap(repoerr.ErrRemoveEntity, err)
+	}
+
+	return nil
+}
+
+func (pc *policiesCache) delete(ctx context.Context, key string) error {
+	keys, cursor, err := pc.client.Scan(ctx, 0, key, defLimit).Result()
+	if err != nil {
+		return errors.Wrap(repoerr.ErrRemoveEntity, err)
+	}
+	for cursor != 0 {
+		var newKeys []string
+		newKeys, cursor, err = pc.client.Scan(ctx, cursor, key, defLimit).Result()
+		if err != nil {
+			return errors.Wrap(repoerr.ErrRemoveEntity, err)
+		}
+		keys = append(keys, newKeys...)
+	}
+
+	for _, key := range keys {
+		if err := pc.client.Del(ctx, key).Err(); err != nil {
+			return errors.Wrap(repoerr.ErrRemoveEntity, err)
+		}
+	}
+
+	return nil
+}