Graphql In Golang

1. Why we moving API from REST to Graphql?
2. What is Graphql?
3. Graphql in Golang (Why we choose Golang)
4. How to testing Graphql in Golang
5. Deploy Graphql application

Transcript

1. GRAPHQL IN GO MODERNWEB 2018
2. ABOUT ME Open source contributor 1. Gitea 2. Drone 3. Gin appleboy @ GitHub appleboy @ twitter appleboy @ slideshare appleboy46 @ facebook 2
3. AGENDA ▸ Why we moving API from REST to Graphql? ▸ What is Graphql? ▸ Graphql in Golang (Why we choose Golang) ▸ How to testing Graphql in Golang ▸ Deploy Graphql application
4. MOVING REST TO GRAPHQL icon from https://bit.ly/2LhOpZA
5. 1. LARGE REQUEST IN SINGLE PAGE https://bit.ly/2NpS4Fu
6. 1. LARGE REQUEST IN SINGLE PAGE
7. CUSTOM FIELDS /api/scene/1?field=name,description,created_at
8. CUSTOM ENDPOINT /api/scene/1/mobile?field=name,description /api/scene/1/web?field=name,description
9. DOCUMENTATION? HOW TO GENERATE DOCUMENT AUTOMATICALLY? API DOC Swagger
10. UPDATE API GENERATE DOC BACKEND FRONTEND MOBILE TESTING
11. /** * @api {get} /scene/:id Request Scene information * @apiName GetScene * @apiGroup Scene * * @apiParam {Number} id Scenes unique ID. * * @apiSuccess {String} title Title of the Scene. * @apiSuccess {String} desc Description of the Scene. */
12. GRAPHQL
13. WHAT IS GRAPHQL? IT IS A QUERY LANGUAGE
14. { myScene { name description } } LEXED PARSED VALIDATED EXECUTED
15. { scene(id: 1) { name description } } LEXED PARSED VALIDATED EXECUTED
16. { scene(id: 1) { name description items(type: DEVICE) { id name url } } } Graphql Request
17. { "scene": { "name": "foo", "description": “bar", "items": [{ "id": 1, "name": "test_1", "url": "http://foo.com" }, { "id": 2, "name": "test_2", "url": "http://bar.com" }] } } JSON Response
18. /api/scene/1 /api/scene/1/item /api/scene/1/all
19. TYPE SYSTEM GRAPHQL LANGUAGE
20. { myScene { name description } }
21. { scene(id: 1) { name description items(type: DEVICE) { id name url } } }
22. type QueryRoot { myScene: Scene scene(id: ID!): Scene }
23. { scene(id: 1) { name description items(type: DEVICE) { id name url } } } Graphql Request
24. type Scene { name: String! description: String items(type: ItemEnum): [Item] } enum ItemEnum { DEVICE, TEST_DEVICE, URL }
25. { scene(id: 1) { name description items(type: DEVICE) { id name url } } } Graphql Request
26. type Item { id: ID! name: String! url: String }
27. INTROSPECTION GRAPHQL LANGUAGE
28. { __schema { queryType { name } } }
29. { "data": { "__schema": { "queryType": { "name": "Query" } } } }
30. WHY NEED THE INTROSPECTION ▸code generation ▸auto documentation ▸static validation ▸IDE Integration
31. https://github.com/prismagraphql/graphql-playground
32. https://www.prisma.io/blog/introducing-graphql-playground-f1e0a018f05d/
33. RESOLVING FIELDS GRAPHQL LANGUAGE
34. type Item { id: ID type: sceneEnum name: String }
35. "id": &graphql.Field{ Type: graphql.Int, }, INT FLOAT STRING BOOLEAN ID
36. type Item { id: ID type: sceneEnum name: String }
37. "TEST_DEVICE": &graphql.EnumValueConfig{ Value: int(model.TypeTestDevice), Description: "test device.", }, "DEVICE": &graphql.EnumValueConfig{ Value: int(model.TypeDevice), Description: "device.", }, "URL": &graphql.EnumValueConfig{ Value: int(model.TypeURL), Description: "url.", },
38. "name": &graphql.Field{ Type: graphql.String, Resolve: func(p graphql.ResolveParams) (interface{}, error) { o, _ := p.Source.(*model.Scene) return "Hello, " + o.Name, nil }, }, Return Custom Value
39. MUTATION GRAPHQL LANGUAGE
40. mutation { createScene( title: "foo", description: "bar" ) { id title description url } }
41. // Schema is the GraphQL schema served by the server. var Schema, _ = graphql.NewSchema(graphql.SchemaConfig{ Query: rootQuery, Mutation: rootMutation, Types: types, }) Query and Mutation
42. SINGLE ENDPOINT POST /graphql
43. GRAPHQL IN GOLANG WHY WE CHOOSE GOLANG?
44. WHY WE CHOOSE GOLANG? ▸Compiles Into Single Binary ▸Static Type System ▸Performance ▸Easy to Deploy ▸Learning Curve
45. BENCHMARK OF GRAPHQL FRAMEWORK IN GOLANG ▸graphql-go/graphql ▸playlyfe/go-graphql ▸graph-gophers/graphql-go ▸samsarahq/thunder
46. https://github.com/appleboy/golang-graphql-benchmark $ go test -v -bench=. -benchmem
47. VEKTAH/GQLGEN GO GENERATE BASED GRAPHQL SERVER LIBRARY https://github.com/vektah/gqlgen https://youtu.be/3dpqYMqyiOg
49. API SERVER API SERVER GRAPHQL SERVER GRAPHQL GATEWAY
50. GRAPHQL IN GOLANG PACKAGE IN GOLANG
51. FRAMEWORK IN GO
52. func Handler() gin.HandlerFunc { h := handler.New(&handler.Config{ Schema: &schema.Schema, Pretty: true, }) return func(c *gin.Context) { h.ServeHTTP(c.Writer, c.Request) } } graphql schema
53. JWT TOKEN SERVER GRAPHQL SERVER
54. func Check() gin.HandlerFunc { return func(c *gin.Context) { token := c.GetHeader("Authorization") user, err := authUser(token) if token != "" && err != nil { logrus.Errorf("authUser error: %s", err.Error()) } if user != nil && user.Email != "" { c.Set("email", user.Email) c.Set("user_id", user.UserID) } ctx := context.WithValue( c.Request.Context(), config.ContextKeyUser, user, ) c.Request = c.Request.WithContext(ctx) } } store user data
55. var Schema, _ = graphql.NewSchema(graphql.SchemaConfig{ Query: rootQuery, Mutation: rootMutation, }) var rootMutation = graphql.NewObject( graphql.ObjectConfig{ Name: "RootMutation", Description: "Root Mutation", Fields: graphql.Fields{ "updateUser": &updateUser, "createScene": &createScene, "updateScene": &updateScene, "deleteScene": &deleteScene, }, }) var rootQuery = graphql.NewObject( graphql.ObjectConfig{ Name: "RootQuery", Description: "Root Query", Fields: graphql.Fields{ "queryUser": &queryUser, "searchUser": &searchUser, "queryScene": &queryScene, }, }) query mutation
56. GRAPHQL ERROR BETTER ERROR HANDLING
57. { "data": { "post": null }, "errors": [ { "message": "Internal Error: 404 not found", "locations": [ { "line": 2, "column": 3 } ], "path": [ "post" ] } ] } single message error location
58. func (g FormattedError) MarshalJSON() ([]byte, error) { m := map[string]interface{}{} for k, v := range g.Extensions { m[k] = v } m["message"] = g.Message m["locations"] = g.Locations return json.Marshal(m) } Marshal JSON custom key value
59. func FormatError(err error, arg ...interface{}) gqlerrors.FormattedError { switch err := err.(type) { case gqlerrors.FormattedError: return err case *Error: return gqlerrors.FormattedError{ Message: fmt.Sprintf(err.Error(), arg...), Extensions: gqlerrors.ErrorExtensions{ "code": err.Type.Code(), "type": err.Type, }, } } custom error original error
60. GRAPHQL N+1 DATA LOADER
61. 1. LARGE REQUEST IN SINGLE PAGE
62. { myScene(id: 1) { name description role { id user { email } model } } }
63. ORM IN GOLANG GOORM VS XORM
64. type Scene struct { ID int64 `xorm:"pk autoincr" json:"id"` Image string `json:"image,omitempty"` CreatedAt time.Time `json:"createdAt,omitempty"` UpdatedAt time.Time `json:"updatedAt,omitempty"` DeletedAt time.Time `xorm:"deleted"` // reference Items []*SceneItem `xorm:"-" json:"items,omitempty"` User *User `xorm:"-" json:"user,omitempty"` Role *SceneAccess `xorm:"-" json:"role,omitempty"` } Data Model user role permission
65. "user": &graphql.Field{ Type: userType, Resolve: func(p graphql.ResolveParams) (interface{}, error) { o, ok := p.Source.(*model.Shorten) if !ok { return nil, errMissingSource } if o.User != nil { return o.User, nil } return getUserFromLoader(p.Context, o.UserID) }, }, exist in model? fetch from loader
66. GET DATA FROM DATABASE IF NOT EXIST func userBatch(ctx context.Context, keys dataloader.Keys) []*dataloader.Result { var results []*dataloader.Result id, _ := helper.GetCacheID(keys[0].String()) user, err := model.GetUserByID(id.(int64)) results = append(results, &dataloader.Result{ Data: user, Error: err, }) return results } fetch from DB
67. GRAPHQL DATALOADER ONLY SUPPORT MEMORY, LRU OR TTL CACHE
68. INTEGRATE WITH REDIS SERVICE GRAPHQL DATALOADER
69. func batchFunc(_ context.Context, keys dataloader.Keys) []*dataloader.Result { results := make([]*dataloader.Result, len(keys)) // get what you can from redis values, _ := redisClient.MGet(...keys.Keys()).Result() // make a list of everything that was not found in redis var cacheMisses map[int]string for i := range keys { if values[i] == redis.Nil { cacheMisses[i] = keys[i].String() } else { results[i] = &dataloader.Result{values[i], nil} } } // get the missing items from more expensive location (like DB) for idx, key := range cacheMisses { value, err := db.GetValues(key) // Pseudo code! redisClient.Set(key, value) results[idx] = &dataloader.Result{value, err} } return results } miss from redis fetch from DB
70. HOW TO TEST GRAPHQL SCHEMA? GRAPHQL TESTING
71. https://code.likeagirl.io/the-7-steps-to-a-complete-code-review-abdfd39e75f1
72. RAILS-LIKE TEST FIXTURES FOR GO GO TEST FIXTURES https://github.com/go-testfixtures/testfixtures
73. - id: 1 email: foo@gmail.com full_name: foo avatar: http://foo.com avatar_email: foo@gmail.com - id: 2 email: bar@gmail.com full_name: bar avatar: http://bar.com avatar_email: bar@gmail.com real data in DB
74. test := T{ Query: ` query QueryShortenURL ( $slug: String! ) { QueryShortenURL(slug: $slug) { url } } `, Schema: Schema, Expected: &graphql.Result{ Data: map[string]interface{}{ "QueryShortenURL": map[string]interface{}{ "url": "http://example.com", }, }, }, } graphql query expect data
75. params := graphql.Params{ Schema: test.Schema, RequestString: test.Query, Context: ctx, VariableValues: map[string]interface{}{ "slug": "abcdef", }, } testGraphql(test, params, t) ctx := newContextWithUser(context.TODO(), user) user data in context graphql variable
76. all pass testing in sqlite
77. GRAPHQL DEPLOYMENT HOW TO DEPLOY GOLANG APP?
78. GO-GGZ/GGZ AN URL SHORTENER SERVICE WRITTEN IN GO https://github.com/go-ggz/ggz
79. Thanks