server/health: add health check handler

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

server/generate.go

@@ -0,0 +1,3 @@
+package server
+
+//go:generate protoc -I./health -I../ -I/home/vtolstov/.cache/go-path/pkg/mod/github.com/unistack-org/micro-proto@v0.0.1 --micro_out=components=micro|http|server,standalone=false,debug=true,paths=source_relative:./health health/health.proto

server/health/health.go

@@ -0,0 +1,87 @@
+package pb
+
+import (
+	"context"
+
+	"github.com/unistack-org/micro/v3/codec"
+	"github.com/unistack-org/micro/v3/errors"
+	"github.com/unistack-org/micro/v3/server"
+)
+
+var (
+	// guard to fail early
+	_ HealthServer = &handler{}
+)
+
+type handler struct {
+	server server.Server
+	opts   Options
+}
+
+type CheckFunc func(context.Context) error
+
+type Option func(*Options)
+
+type Options struct {
+	LiveChecks  []CheckFunc
+	ReadyChecks []CheckFunc
+	Version     string
+	Name        string
+}
+
+func LiveChecks(fns ...CheckFunc) Option {
+	return func(o *Options) {
+		o.LiveChecks = append(o.LiveChecks, fns...)
+	}
+}
+
+func ReadyChecks(fns ...CheckFunc) Option {
+	return func(o *Options) {
+		o.ReadyChecks = append(o.ReadyChecks, fns...)
+	}
+}
+
+func Name(name string) Option {
+	return func(o *Options) {
+		o.Name = name
+	}
+}
+
+func Version(version string) Option {
+	return func(o *Options) {
+		o.Version = version
+	}
+}
+
+func NewHealth(opts ...Option) *handler {
+	options := Options{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return &handler{opts: options}
+}
+
+func (h *handler) Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	var err error
+	for _, fn := range h.opts.LiveChecks {
+		if err = fn(ctx); err != nil {
+			return errors.ServiceUnavailable(h.opts.Name, "%v", err)
+		}
+	}
+	return nil
+}
+
+func (h *handler) Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	var err error
+	for _, fn := range h.opts.ReadyChecks {
+		if err = fn(ctx); err != nil {
+			return errors.ServiceUnavailable(h.opts.Name, "%v", err)
+		}
+	}
+	return nil
+}
+
+func (h *handler) Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	rsp.Data = []byte(h.opts.Version)
+	return nil
+}

server/health/health.proto

@@ -0,0 +1,62 @@
+syntax = "proto3";
+
+package health;
+option go_package = "github.com/unistack-org/micro/v3/server/health;pb";
+
+import "api/annotations.proto";
+import "openapiv2/annotations.proto";
+import "codec/frame.proto";
+
+service Health {
+	rpc Live(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv2.openapiv2_operation) = {
+      operation_id: "Live";
+        responses: {
+          key: "default";
+          value: {
+            description: "Error response";
+            schema: {
+              json_schema: {
+                ref: "micro.codec.Frame";
+              }
+            }
+          }
+        }
+    };
+		option (micro.api.http) = { get: "/live"; };
+  };
+	rpc Ready(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv2.openapiv2_operation) = {
+      operation_id: "Ready";
+        responses: {
+          key: "default";
+          value: {
+            description: "Error response";
+            schema: {
+              json_schema: {
+                ref: "micro.codec.Frame";
+              }
+            }
+          }
+        }
+    };
+		option (micro.api.http) = { get: "/ready"; };
+  };
+	rpc Version(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv2.openapiv2_operation) = {
+      operation_id: "Version";
+        responses: {
+          key: "default";
+          value: {
+            description: "Error response";
+            schema: {
+              json_schema: {
+                ref: "micro.codec.Frame";
+              }
+            }
+          }
+        }
+    };
+		option (micro.api.http) = { get: "/version"; };
+  };
+};

server/health/health_micro.pb.go

@@ -0,0 +1,38 @@
+// Code generated by protoc-gen-micro
+// source: health.proto
+package pb
+
+import (
+	context "context"
+	api "github.com/unistack-org/micro/v3/api"
+	codec "github.com/unistack-org/micro/v3/codec"
+)
+
+func NewHealthEndpoints() []*api.Endpoint {
+	return []*api.Endpoint{
+		&api.Endpoint{
+			Name:    "Health.Live",
+			Path:    []string{"/live"},
+			Method:  []string{"GET"},
+			Handler: "rpc",
+		},
+		&api.Endpoint{
+			Name:    "Health.Ready",
+			Path:    []string{"/ready"},
+			Method:  []string{"GET"},
+			Handler: "rpc",
+		},
+		&api.Endpoint{
+			Name:    "Health.Version",
+			Path:    []string{"/version"},
+			Method:  []string{"GET"},
+			Handler: "rpc",
+		},
+	}
+}
+
+type HealthServer interface {
+	Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+}

server/health/health_micro_http.pb.go

@@ -0,0 +1,43 @@
+// Code generated by protoc-gen-micro
+// source: health.proto
+package pb
+
+import (
+	context "context"
+	api "github.com/unistack-org/micro/v3/api"
+	codec "github.com/unistack-org/micro/v3/codec"
+	server "github.com/unistack-org/micro/v3/server"
+)
+
+type healthServer struct {
+	HealthServer
+}
+
+func (h *healthServer) Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServer.Live(ctx, req, rsp)
+}
+
+func (h *healthServer) Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServer.Ready(ctx, req, rsp)
+}
+
+func (h *healthServer) Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServer.Version(ctx, req, rsp)
+}
+
+func RegisterHealthServer(s server.Server, sh HealthServer, opts ...server.HandlerOption) error {
+	type health interface {
+		Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+		Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+		Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	}
+	type Health struct {
+		health
+	}
+	h := &healthServer{sh}
+	var nopts []server.HandlerOption
+	for _, endpoint := range NewHealthEndpoints() {
+		nopts = append(nopts, api.WithEndpoint(endpoint))
+	}
+	return s.Handle(s.NewHandler(&Health{h}, append(nopts, opts...)...))
+}