feat: migrate from Cedar to SpiceDB authorization system

This is a major architectural change that replaces the Cedar policy-based
authorization system with SpiceDB's relation-based authorization.

Key changes:

- Migrate from Rust to Go implementation
- Replace Cedar policies with SpiceDB schema and relationships
- Switch from envoy `ext_authz` with Cedar to SpiceDB permission checks
- Update build system and dependencies for Go ecosystem
- Maintain Envoy integration for external authorization

This change enables more flexible permission modeling through SpiceDB's
Google Zanzibar inspired relation-based system, supporting complex
hierarchical permissions that were difficult to express in Cedar.

Breaking change: Existing Cedar policies and Rust-based configuration
will no longer work and need to be migrated to SpiceDB schema.

1 files changed, 40 insertions, 0 deletions

diff --git a/cmd/authzd/main.go b/cmd/authzd/main.go
new file mode 100644
index 00000000..809916c9
--- /dev/null
+++ b/cmd/authzd/main.go
@@ -0,0 +1,40 @@
+package main
+
+import (
+	"context"
+	"net"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/xlgmokha/x/pkg/env"
+	"github.com/xlgmokha/x/pkg/log"
+	"github.com/xlgmokha/x/pkg/x"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/authzd.git/pkg/authz"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/authzd.git/pkg/pls"
+)
+
+func main() {
+	logger := log.New(os.Stdout, log.Fields{"app": "authzd"})
+	ctx := logger.WithContext(context.Background())
+
+	client := x.Must(authz.NewClient(ctx,
+		env.Fetch("SPICEDB_ENDPOINT", ":50051"),
+		env.Fetch("SPICEDB_SECRET", "secret"),
+	))
+	server := authz.New(authz.Connection.With(ctx, client))
+	defer client.Close()
+
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		<-c
+		server.GracefulStop()
+		logger.Log().Str("status", "goodbye").Send()
+	}()
+
+	defer server.GracefulStop()
+	logger.Log().Str("status", "ready").Send()
+	socket := x.Must(net.Listen("tcp", ":50052"))
+	pls.LogErrorNow(ctx, server.Serve(socket))
+}