TemplateHandler (Serving templated contents)

apiVersion: core/v1
kind: TemplateHandler
metadata:
  name: "default"
  namespace: "default"
spec: {}

syntax = "proto3";
package core.v1;

import "buf/validate/validate.proto";
import "core/v1/http.proto";
import "kernel/resource.proto";

option go_package = "github.com/aileron-gateway/aileron-gateway/apis/core/v1";

// TemplateHandler resource definition.
// apiVersion="core/v1", kind="TemplateHandler".
message TemplateHandler {
    string              APIVersion = 1 [json_name = "apiVersion"];
    string              Kind       = 2 [json_name = "kind"];
    kernel.Metadata     Metadata   = 3 [json_name = "metadata"];
    TemplateHandlerSpec Spec       = 4 [json_name = "spec"];
}

// TemplateHandlerSpec is the specifications for the TemplateHandler object.
message TemplateHandlerSpec {
    // [OPTIONAL]
    // ErrorHandler is the reference to a ErrorHandler object.
    // Referred object must implement ErrorHandler interface.
    // Default error handler is used when not set.
    kernel.Reference ErrorHandler = 1 [json_name = "errorHandler"];

    // [OPTIONAL]
    // Patterns is path patterns that this handler
    // is registered to a server.
    // Default is not set.
    repeated string Patterns = 2 [json_name = "patterns", (buf.validate.field).repeated.unique = true];

    // [OPTIONA]
    // Methods is the list of HTTP method this handler can handle.
    // Note that it depends on the multiplexer, or HTTP router
    // if this field can be used.
    // If not set, all methods are accepted.
    // Default is not set.
    repeated HTTPMethod Methods = 3 [json_name = "methods", (buf.validate.field).repeated.unique = true];

    // [REQUIRED]
    // MIMEContents is the list of content that will be returned by this handler.
    // When no appropriate content were found,
    // not acceptable error will be returned to clients.
    // Default is not set.
    repeated MIMEContentSpec MIMEContents = 4 [json_name = "mimeContents"];
}

// MIMEContentSpec is the specification for the MIMEContent.
message MIMEContentSpec {
    // [REQUIRED]
    // MIMEType is the mediatype of this content.
    // See the following documents for available type.
    // https://www.iana.org/assignments/media-types/media-types.xhtml
    // Default is not set.
    string MIMEType = 1 [json_name = "mimeType", (buf.validate.field).string.pattern = "^[a-z]+/[0-9a-zA-Z.+-]+$"];

    // [OPTIONAL]
    // StatusCode is the http status code used to respond this content.
    // Default is [200].
    int32 StatusCode = 2 [json_name = "statusCode", (buf.validate.field).int32 = {gte : 0, lte : 999}];

    // [OPTIONAL]
    // Header is the key-value pairs of HTTP headers
    // to add to the response.
    // Keys must be a valid http header name.
    // Default is not set.
    map<string, string> Header = 3 [json_name = "header"];

    // [OPTIONAL]
    // TemplateType is the template engine type of this content.
    // Default is [Text].
    TemplateType TemplateType = 4 [json_name = "templateType"];

    // [OPTIONAL]
    // Template is the template text to generate response body.
    // TemplateFile is prior to Template if both parameters are set.
    // Default is not set.
    string Template = 5 [json_name = "template"];

    // [OPTIONAL]
    // TemplateFile is the fail path to read template from.
    // TemplateFile is prior to Template if both parameters are set.
    // It does not matter wheather the path is relative or absolute.
    // Default is not set.
    string TemplateFile = 6 [json_name = "templateFile"];
}

// TemplateType is the type of template document.
enum TemplateType {
    Text   = 0;  // Text is a standard text type. Content will be used as it is.
    GoText = 1;  // GoText is Go's text template type. See https://pkg.go.dev/text/template.
    GoHTML = 2;  // GoHTML is Go's HTML template type. See https://pkg.go.dev/html/template.
}