protoc-gen-atlas-query-validate

protoc-gen-atlas-query-validate

Purpose

A protobuf compiler plugin designed to simplify validation of Atlas gRPC List query parameters by generating .pb.atlas.query.validate.go files with validation rules and functions. Currently query.Filtering, query.Sorting and query.FieldSelection are supported for validation.

Prerequisites

1. Protobuf Compiler

The protobuf compiler (protoc) is required.

Official instructions

Abbreviated version

2. Golang Protobuf Code Generator

Get the golang protobuf code generator:

go get -u github.com/golang/protobuf/protoc-gen-go

3. Vendored Dependencies

Retrieve and install the vendored dependencies for this project with dep:

dep ensure

Installation

To use this tool, install it from code with make install, go install directly, or go get github.com/infobloxopen/protoc-gen-atlas-query-validate.

Usage

Once installed, the atlas-query-validate_out=. or --atlas-query-validate_out=${GOPATH}src option can be specified in a protoc command to generate the .pb.atlas.query.validate.go files.

Validation rules

Validation rules are generated for each gRPC method containing query.Filtering, query.Sorting or query.FieldSelection in it's request message based on the message included in the method's response message(will call it resource message for the rest of the document).

By default all fields of *resource message` are allowed for filtering/sorting.

The list of allowed filtering operators and filtering value type/condition type depends on the value_type of the field, which is either taken from (atlas.query.validate).value_type proto field option or is computed by the plugin based on the field type if the option is not supplied. Currently value_type can be either STRING or NUMBER. The following table shows what is allowed for each value_type:

The next table shows how value_type is computed from a proto field type:

Validation functions

Validation functions are the entry points for the generated functionality. The following validation functions are generated:

func {Proto_file_name}ValidateFiltering(methodName string, f *query.Filtering) error

func {Proto_file_name}ValidateSorting(methodName string, s *query.Sorting) error

func {Proto_file_name}ValidateFieldSelection(methodName string, s *query.FieldSelection) error

Non-nil error is returned by the functions if validation is not passed.

Customization

Currently only field-level proto options are supported as customization means. We're planning to add method-level options which will override field-level options in order to support different validation rules for List methods having the same resource message.

• In order to disable sorting for a field set (atlas.query.validate).sorting.disable option to true.

bool on_vacation = 3 [(atlas.query.validate).sorting.disable = true];

• In order to customize the list of allowed filtering operators pass either a set of (atlas.query.validate).filtering.allow or a set of (atlas.query.validate).filtering.deny options.
  • In case of using (atlas.query.validate).filtering.allow only specified filtering operators are allowed:

    string first_name = 1 [(atlas.query.validate).filtering = {allow: MATCH, allow: EQ}];
    

  • In case of using (atlas.query.validate).filtering.deny all appropriate(for the field type) filtering operators except specified ones are allowed:

    string first_name = 1 [(atlas.query.validate).filtering = {deny: GT, deny: GE, deny: LT, deny: LE}];
    

• In order to change default value_type for a field pass (atlas.query.validate).value_type option.

CustomType custom_type_string = 10 [(atlas.query.validate) = {value_type: STRING}];

• In order to enable filtering/sorting by nested fields set (atlas.query.validate).enable_nested_fields option to true on the field of a message type or as message option. Note that this overrides any field level settings.

message User {
  option (atlas.query.message) = {
    enable_nested_fields: true;
  };
  ...
}

message User {
    Address home_address = 11 [(atlas.query.validate) = {enable_nested_fields: true}];
    Address work_address = 12;
}

message Address {
    string city = 1 [(atlas.query.validate) = {filtering: {allow: EQ}, sorting: {disable: true}}];
    string country = 2;
}

• You can also specify the maximum nesting depth using the nested_field_depth_limit option at the message level (the default is second level fields only).

message User {
  option (atlas.query.message) = {
    enable_nested_fields: true;
    nested_field_depth_limit: 3;
  };
  ...
}

• Nesting and nested field depth can also be set for the entire code generation process as parameters on the protoc command

protoc ... \
 --atlas-query-validate_out="nested_field_depth_limit=3,enable_nested_fields=true:." \
 example/example.proto

Examples

The best way to get started with the plugin is to check out our example. Example .proto files and generated .pb.atlas.query.validate.go demonstrate most of the use cases of the plugin.

Running make example will recompile all these test proto files, if you want to test the effects of changing the options and fields.

Limitations

This project is currently in development, and is expected to undergo "breaking" (and fixing) changes