Documentation
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Overview ¶
Package validator
`validator` is a generic request contents validator server-side middleware for gRPC.
Request Validator Middleware ¶
Validating input is important, and hard. It also causes a lot of boilerplate code. This middleware checks for the existence of a `Validate` method on each of the messages of a gRPC request. This includes the single request of the `Unary` calls, as well as each message of the inbound Stream calls. In case of a validation failure, an `InvalidArgument` gRPC status is returned, along with a description of the validation failure.
While it is generic, it was intended to be used with https://github.com/mwitkow/go-proto-validators, a Go protocol buffers codegen plugin that creates the `Validate` methods (including nested messages) based on declarative options in the `.proto` files themselves. For example:
syntax = "proto3";
package validator.examples;
import "github.com/mwitkow/go-proto-validators/validator.proto";
message InnerMessage {
// some_integer can only be in range (1, 100).
int32 some_integer = 1 [(validator.field) = {int_gt: 0, int_lt: 100}];
// some_float can only be in range (0;1).
double some_float = 2 [(validator.field) = {float_gte: 0, float_lte: 1}];
}
message OuterMessage {
// important_string must be a lowercase alpha-numeric of 5 to 30 characters (RE2 syntax).
string important_string = 1 [(validator.field) = {regex: "^[a-z]{2,5}$"}];
// proto3 doesn't have `required`, the `msg_exist` enforces presence of InnerMessage.
InnerMessage inner = 2 [(validator.field) = {msg_exists : true}];
}
The `OuterMessage.Validate` would include validation of regexes, existence of the InnerMessage and the range values within it. The `grpc_validator` middleware would then automatically use that to check all messages processed by the server.
Please consult https://github.com/mwitkow/go-proto-validators for details on `protoc` invocation and other parameters of customization.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func StreamServerInterceptor ¶
func StreamServerInterceptor(opts ...Option) grpc.StreamServerInterceptor
StreamServerInterceptor returns a new streaming server interceptor that validates incoming messages.
Note that generated codes prior to protoc-gen-validate v0.6.0 do not provide an all-validation interface. In this case the interceptor fallbacks to legacy validation and `all` is ignored. The stage at which invalid messages will be rejected with `InvalidArgument` varies based on the type of the RPC. For `ServerStream` (1:m) requests, it will happen before reaching any userspace handlers. For `ClientStream` (n:1) or `BidiStream` (n:m) RPCs, the messages will be rejected on calls to `stream.Recv()`.
func UnaryClientInterceptor ¶
func UnaryClientInterceptor(opts ...Option) grpc.UnaryClientInterceptor
UnaryClientInterceptor returns a new unary client interceptor that validates outgoing messages.
Invalid messages will be rejected with `InvalidArgument` before sending the request to server. Note that generated codes prior to protoc-gen-validate v0.6.0 do not provide an all-validation interface. In this case the interceptor fallbacks to legacy validation and `all` is ignored.
func UnaryServerInterceptor ¶
func UnaryServerInterceptor(opts ...Option) grpc.UnaryServerInterceptor
UnaryServerInterceptor returns a new unary server interceptor that validates incoming messages.
Invalid messages will be rejected with `InvalidArgument` before reaching any userspace handlers. Note that generated codes prior to protoc-gen-validate v0.6.0 do not provide an all-validation interface. In this case the interceptor fallbacks to legacy validation and `all` is ignored.
Types ¶
type OnValidationErrCallback ¶
type Option ¶
type Option func(*options)
func WithFailFast ¶
func WithFailFast() Option
WithFailFast tells validator to immediately stop doing further validation after first validation error. This option is ignored if message is only supporting validator.validatorLegacy interface.
func WithOnValidationErrCallback ¶
func WithOnValidationErrCallback(onValidationErrCallback OnValidationErrCallback) Option
WithOnValidationErrCallback registers function that will be invoked on validation error(s).
Source Files