cloudapi: validate input

Validate incoming requests with openapi3. Remove unsupported
uuid format from the openapi spec. Similarly, change url to uri as
uri is a supported format and url is not.

Co-authored-by: Ondřej Budai <obudai@redhat.com>
Signed-off-by: Ondřej Budai <ondrej@budai.cz>

vendor/github.com/getkin/kin-openapi/openapi3/external_docs.go

@@ -1,15 +1,21 @@
 package openapi3
 
 import (
+	"context"
+	"errors"
+	"fmt"
+	"net/url"
+
 	"github.com/getkin/kin-openapi/jsoninfo"
 )
 
-// ExternalDocs is specified by OpenAPI/Swagger standard version 3.0.
+// ExternalDocs is specified by OpenAPI/Swagger standard version 3.
+// See https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#external-documentation-object
 type ExternalDocs struct {
 	ExtensionProps
 
-	Description string `json:"description,omitempty"`
-	URL         string `json:"url,omitempty"`
+	Description string `json:"description,omitempty" yaml:"description,omitempty"`
+	URL         string `json:"url,omitempty" yaml:"url,omitempty"`
 }
 
 func (e *ExternalDocs) MarshalJSON() ([]byte, error) {
@@ -19,3 +25,13 @@ func (e *ExternalDocs) MarshalJSON() ([]byte, error) {
 func (e *ExternalDocs) UnmarshalJSON(data []byte) error {
 	return jsoninfo.UnmarshalStrictStruct(data, e)
 }
+
+func (e *ExternalDocs) Validate(ctx context.Context) error {
+	if e.URL == "" {
+		return errors.New("url is required")
+	}
+	if _, err := url.Parse(e.URL); err != nil {
+		return fmt.Errorf("url is incorrect: %w", err)
+	}
+	return nil
+}