[英]Serverless framework + AWS + Lambda + DynamoDB + GraphQL + Apollo Server = Can't make POST Request Work
好的,幾天以來我一直在解決這個問題。
我嘗試學習本教程: https : //serverless.com/blog/make-serverless-graphql-api-using-lambda-dynamodb/
並使其與apollo-server-lambda一起使用。 本教程幫助:
https://medium.com/vessels/apollo-server-serverless-graphql-bliss-68e8e15195ac
問題是,當您嘗試將apollo服務器lambda與DynamoDB進行真正的連接時,對我來說,什么都不起作用。 我得到了一個我已經不記得的錯誤列表了,這只是令人沮喪。
這是我的代碼:
# serverless.yml
service: graphql-api
provider:
name: aws
runtime: nodejs6.10
region: eu-west-3
stage: dev
environment:
DYNAMODB_TABLE: ${self:service}-${self:provider.stage}
iamRoleStatements:
- Effect: Allow
Action:
- dynamodb:GetItem
- dynamodb:UpdateItem
Resource: "arn:aws:dynamodb:${opt:region, self:provider.region}:*:table/${self:provider.environment.DYNAMODB_TABLE}"
resources:
Resources:
NicknamesTable:
Type: 'AWS::DynamoDB::Table'
Properties:
AttributeDefinitions:
- AttributeName: firstName
AttributeType: S
KeySchema:
- AttributeName: firstName
KeyType: HASH
ProvisionedThroughput:
ReadCapacityUnits: 1
WriteCapacityUnits: 1
TableName: ${self:provider.environment.DYNAMODB_TABLE}
functions:
graphql:
handler: handler.graphql
events:
- http:
path: graphql
method: post
cors: true
- http:
path: graphql
method: get
cors: true
而我的經理:
# handler.js
const AWS = require('aws-sdk');
const server = require("apollo-server-lambda");
const makeExecutableSchema = require('graphql-tools').makeExecutableSchema;
const dynamoDb = new AWS.DynamoDB.DocumentClient();
const promisify = foo => new Promise((resolve, reject) => {
foo((error, result) => {
if (error) {
reject(error)
} else {
resolve(result)
}
})
})
const getGreeting = firstName => promisify(callback =>
dynamoDb.get({
TableName: process.env.DYNAMODB_TABLE,
Key: { firstName },
}, callback))
.then(result => {
if (!result.Item) {
return firstName
}
return result.Item.nickname
})
.then(name => `Hello, ${name}.`)
// add method for updates
const changeNickname = (firstName, nickname) => promisify(callback =>
dynamoDb.update({
TableName: process.env.DYNAMODB_TABLE,
Key: { firstName },
UpdateExpression: 'SET nickname = :nickname',
ExpressionAttributeValues: {
':nickname': nickname
}
}, callback))
.then(() => nickname)
const typeDefs = `
type Query {
greeting(firstName: String!): String
}
type Mutation {
changeNickname(
firstName: String!
nickname: String!
): String
}
`;
const resolvers = {
Query: {
greeting: (_, { firstName }) => getGreeting(firstName),
},
Mutation: {
changeNickname: (_, { firstName, nickname }) => changeNickname(firstName, nickname),
}
};
exports.graphql = function (event, context, callback) {
const callbackFilter = function (error, output) {
output.headers = output.header || {};
output.headers['Access-Control-Allow-Origin'] = '*';
callback(error, output);
};
const handler = server.graphqlLambda({ schema: makeExecutableSchema({ typeDefs, resolvers }) });
return handler(event, context, callbackFilter);
};
我嘗試使用Apollo 1和2,沒有任何作用。 我回到了版本1,因為有更多關於它的論壇帖子。 通常,我有“內部服務器錯誤”。 我嘗試了在apollo文檔中找到的不同版本的服務器,但是所有請求都失敗了,在終端上或直接在AWS的API網關上進行curl測試功能。 我根據此文檔編寫了請求正文: https : //www.apollographql.com/docs/apollo-server/requests.html
這是我的cloudwatch日志:
(node:1) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): SyntaxError: Unexpected token = in JSON at position 8
任何幫助將不勝感激!
好的,我知道了問題所在。 使用put函數時,無法獲得僅插入dynamoDB中的新項。 您必須將“ ReturnValues:'ALL_OLD'”放入params對象(put函數的第一個參數)中,就像不會引發任何錯誤一樣,由於您剛剛在數據庫中輸入了值,因此您應該返回所需的值。
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