assets: use embed instead of statik (#1960)

* assets: use embed instead of statik

* remove empty line

* maybe fix precommit

authorize/evaluator/evaluator.go

@@ -38,7 +38,7 @@ func New(options *config.Options, store *Store) (*Evaluator, error) {
 		return nil, fmt.Errorf("authorize: couldn't create signer: %w", err)
 	}
 
-	authzPolicy, err := readPolicy("/authz.rego")
+	authzPolicy, err := readPolicy()
 	if err != nil {
 		return nil, fmt.Errorf("error loading rego policy: %w", err)
 	}

authorize/evaluator/functions.go

@@ -4,12 +4,10 @@ import (
 	"crypto/x509"
 	"encoding/pem"
 	"fmt"
-	"io/ioutil"
 
 	lru "github.com/hashicorp/golang-lru"
-	"github.com/rakyll/statik/fs"
 
-	_ "github.com/pomerium/pomerium/authorize/evaluator/opa/policy" // load static assets
+	"github.com/pomerium/pomerium/authorize/evaluator/opa"
 	"github.com/pomerium/pomerium/internal/log"
 )
 
@@ -67,17 +65,6 @@ func parseCertificate(pemStr string) (*x509.Certificate, error) {
 	return x509.ParseCertificate(block.Bytes)
 }
 
-const statikNamespace = "rego"
-
-func readPolicy(fn string) ([]byte, error) {
-	statikFS, err := fs.NewWithNamespace(statikNamespace)
-	if err != nil {
-		return nil, err
-	}
-	r, err := statikFS.Open(fn)
-	if err != nil {
-		return nil, err
-	}
-	defer r.Close()
-	return ioutil.ReadAll(r)
+func readPolicy() ([]byte, error) {
+	return opa.FS.ReadFile("policy/authz.rego")
 }

authorize/evaluator/opa/opa.go

@@ -2,5 +2,8 @@
 // decisions.
 package opa
 
-//go:generate go run github.com/rakyll/statik -m -src=./policy -include=*.rego -ns rego -p policy
-//go:generate go fmt ./policy/statik.go
+import "embed"
+
+// FS is the filesystem for OPA files.
+//go:embed policy
+var FS embed.FS

authorize/evaluator/opa_test.go

@@ -35,7 +35,7 @@ func TestOPA(t *testing.T) {
 	require.NoError(t, err)
 
 	eval := func(policies []config.Policy, data []proto.Message, req *Request, isValidClientCertificate bool) rego.Result {
-		authzPolicy, err := readPolicy("/authz.rego")
+		authzPolicy, err := readPolicy()
 		require.NoError(t, err)
 		store := NewStoreFromProtos(data...)
 		store.UpdateIssuer("authenticate.example.com")