add tracing and refactor some api pkgs

internal/api/grpc/server/probes.go

@@ -0,0 +1,53 @@
+package server
+
+import (
+	"context"
+
+	"github.com/caos/logging"
+	"github.com/golang/protobuf/ptypes/empty"
+	structpb "github.com/golang/protobuf/ptypes/struct"
+
+	"github.com/caos/zitadel/internal/errors"
+	"github.com/caos/zitadel/internal/proto"
+)
+
+type ValidationFunction func(ctx context.Context) error
+
+type Validator struct {
+	validations map[string]ValidationFunction
+}
+
+func NewValidator(validations map[string]ValidationFunction) *Validator {
+	return &Validator{validations: validations}
+}
+
+func (v *Validator) Healthz(_ context.Context, e *empty.Empty) (*empty.Empty, error) {
+	return e, nil
+}
+
+func (v *Validator) Ready(ctx context.Context, e *empty.Empty) (*empty.Empty, error) {
+	return e, ready(ctx, v.validations)
+}
+
+func (v *Validator) Validate(ctx context.Context, _ *empty.Empty) (*structpb.Struct, error) {
+	validations := validate(ctx, v.validations)
+	return proto.ToPBStruct(validations)
+}
+
+func ready(ctx context.Context, validations map[string]ValidationFunction) error {
+	if len(validate(ctx, validations)) == 0 {
+		return nil
+	}
+	return errors.ThrowInternal(nil, "API-2jD9a", "not ready")
+}
+
+func validate(ctx context.Context, validations map[string]ValidationFunction) map[string]error {
+	errors := make(map[string]error)
+	for id, validation := range validations {
+		if err := validation(ctx); err != nil {
+			logging.Log("API-vf823").WithError(err).Error("validation failed")
+			errors[id] = err
+		}
+	}
+	return errors
+}