feat: OnUpdate Host Catalog (#9)

* feat: OnUpdate Host Catalog

Add support for onUpdate host catalog

internal/credential/state.go

@@ -4,7 +4,15 @@
 package credential
 
 import (
+	"context"
+	"fmt"
 	"time"
+
+	"github.com/hashicorp/boundary-plugin-gcp/internal/values"
+	"google.golang.org/api/option"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/types/known/structpb"
 )
 
 type CredentialType int
@@ -29,13 +37,126 @@ func NewPersistedState(opt ...Option) (*PersistedState, error) {
 	return s, nil
 }
 
+// ReplaceCreds replaces the private key in the state with a new key.
+// If the existing key was rotated at any point in time, it is
+// deleted first, otherwise it's left alone. This method returns a
+// status error with PluginError details.
+func (s *PersistedState) ReplaceCreds(ctx context.Context, newCreds *Config, opts ...option.ClientOption) error {
+	if newCreds == nil {
+		return status.Errorf(codes.InvalidArgument, "missing new credentials")
+	}
+	if s.CredentialsConfig == nil {
+		return status.Errorf(codes.InvalidArgument, "missing existing credentials")
+	}
+
+	// Delete old/existing credentials.
+	// This is done with the same credentials to ensure that it has the proper permissions to do it.
+	if !s.CredsLastRotatedTime.IsZero() && s.CredentialsConfig.IsRotatable() {
+		if err := s.DeleteCreds(ctx, opts...); err != nil {
+			return err
+		}
+	}
+
+	// Set the new attributes and clear the rotated time.
+	s.CredentialsConfig = newCreds
+	s.CredsLastRotatedTime = time.Time{}
+	return nil
+}
+
+// DeleteCreds deletes the credentials in the state. The access key
+// ID, secret access key, and rotation time fields are zeroed out in
+// the state just to ensure that they cannot be re-used after. This
+// method returns a status error with PluginError details.
+func (s *PersistedState) DeleteCreds(ctx context.Context, opts ...option.ClientOption) error {
+	if s.CredentialsConfig == nil {
+		return status.Errorf(codes.InvalidArgument, "missing credentials config")
+	}
+	if !s.CredentialsConfig.IsRotatable() {
+		return status.Errorf(codes.InvalidArgument, "cannot delete credentials for non-rotatable credentials")
+	}
+
+	err := s.CredentialsConfig.DeletePrivateKey(ctx, opts...)
+	if err != nil {
+		return err
+	}
+
+	s.CredentialsConfig = nil
+	s.CredsLastRotatedTime = time.Time{}
+	return nil
+}
+
 // ToMap returns a map of the credentials stored in the persisted state.
 // ToMap will return a map for long-term credentials with following keys:
 // private_key_id, private_key & creds_last_rotated_time
 func (s *PersistedState) ToMap() map[string]any {
+	if !s.CredentialsConfig.IsRotatable() {
+		return map[string]any{}
+	}
 	return map[string]any{
 		ConstPrivateKey:           s.CredentialsConfig.PrivateKey,
 		ConstPrivateKeyId:         s.CredentialsConfig.PrivateKeyId,
 		ConstCredsLastRotatedTime: s.CredsLastRotatedTime.Format(time.RFC3339Nano),
 	}
 }
+
+// PersistedStateFromProto parses values out of a protobuf struct input
+// and returns a PersistedState used for GCP authentication.
+func PersistedStateFromProto(secrets *structpb.Struct, attrs *CredentialAttributes, opts ...Option) (*PersistedState, error) {
+	if secrets == nil {
+		secrets = &structpb.Struct{
+			Fields: map[string]*structpb.Value{},
+		}
+	}
+
+	if attrs == nil {
+		return nil, fmt.Errorf("missing credential attributes")
+	}
+
+	privateKeyId, err := values.GetStringValue(secrets, ConstPrivateKeyId, false)
+	if err != nil {
+		return nil, fmt.Errorf("persisted state integrity error: %w", err)
+	}
+
+	privateKey, err := values.GetStringValue(secrets, ConstPrivateKey, false)
+	if err != nil {
+		return nil, fmt.Errorf("persisted state integrity error: %w", err)
+	}
+
+	credsLastRotatedTime, err := values.GetTimeValue(secrets, ConstCredsLastRotatedTime)
+	if err != nil {
+		return nil, fmt.Errorf("persisted state integrity error: %w", err)
+	}
+
+	s, err := NewPersistedState(opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	cfgOpts := []Option{}
+	if privateKeyId != "" && privateKey != "" {
+		cfgOpts = append(cfgOpts,
+			WithPrivateKey(privateKey),
+			WithPrivateKeyId(privateKeyId))
+	}
+
+	if attrs.Zone != "" {
+		cfgOpts = append(cfgOpts, WithZone(attrs.Zone))
+	}
+	if attrs.ProjectId != "" {
+		cfgOpts = append(cfgOpts, WithProjectId(attrs.ProjectId))
+	}
+	if attrs.ClientEmail != "" {
+		cfgOpts = append(cfgOpts, WithClientEmail(attrs.ClientEmail))
+	}
+	if attrs.TargetServiceAccountId != "" {
+		cfgOpts = append(cfgOpts, WithTargetServiceAccountId(attrs.TargetServiceAccountId))
+	}
+	credentialsConfig, err := NewConfig(cfgOpts...)
+	if err != nil {
+		return nil, err
+	}
+	s.CredentialsConfig = credentialsConfig
+	s.CredsLastRotatedTime = credsLastRotatedTime
+
+	return s, nil
+}