The following code constructs a redis client and exports. I am fetching the redis password from vault secret management service and that call is a promise/async. The code doesnt wait for that call and it exports the redis client before async call completes. I am not sure what I am doing wrong here. Any idea?
import redis from 'redis';
import bluebird from 'bluebird';
import logger from '../logger';
import srvconf from '../srvconf';
import { getVaultSecret } from '../services/vault.service';
const vaultConfig = srvconf.get('vault');
bluebird.promisifyAll(redis);
let redisUrl = '';
const maskRedisUrl = (url) => url.replace(/password=.*/, 'password=*****');
const setRedisUrl = (host, port, pw) => {
const pwstring = pw ? `?password=${pw}` : '';
const url = `redis://${host}:${port}${pwstring}`;
console.log(`Setting redis_url to '${maskRedisUrl(url)}'`);
return url;
}
if (vaultConfig.use_vault) {
(async () => {
const secret = await getVaultSecret(`${vaultConfig.redis.secrets_path + vaultConfig.redis.key}`)
redisUrl = setRedisUrl(srvconf.get('redis_host'), srvconf.get('redis_port'), secret.PASSWORD);
})().catch(err => console.log(err));
} else {
if (!srvconf.get('redis_url')) {
redisUrl = setRedisUrl(srvconf.get('redis_host'), srvconf.get('redis_port'), srvconf.get('redis_password'));;
} else {
redisUrl = srvconf.get('redis_url');
console.log(`Found redis_url ${maskRedisUrl(redisUrl)}`);
}
}
const options = redisUrl
? { url: redisUrl }
: {};
const redisClient = redis.createClient(options);
redisClient.on('error', err => {
logger.error(err);
});
export default redisClient;
The problem is that (async () => {...})() returns a Promise and you are not awaiting it at the top-level, so the script continues to run past that line, sets options = {} and returns the redisClient.
What you need is a top-level await which is enabled by default in Node versions >= 14.8.0. However, if your project uses a version older than that, there is a workaround as shown below.
Please note that the below code is NOT tested since I do not have the same project setup locally.
Module
import redis from "redis";
import bluebird from "bluebird";
import logger from "../logger";
import srvconf from "../srvconf";
import { getVaultSecret } from "../services/vault.service";
const vaultConfig = srvconf.get("vault");
bluebird.promisifyAll(redis);
let redisUrl = "";
let redisClient = null;
const initRedisClient = () => {
const options = redisUrl ? { url: redisUrl } : {};
redisClient = redis.createClient(options);
redisClient.on("error", (err) => {
logger.error(err);
});
};
const maskRedisUrl = (url) => url.replace(/password=.*/, "password=*****");
const setRedisUrl = (host, port, pw) => {
const pwstring = pw ? `?password=${pw}` : "";
const url = `redis://${host}:${port}${pwstring}`;
console.log(`Setting redis_url to '${maskRedisUrl(url)}'`);
return url;
};
(async () => {
if (vaultConfig.use_vault) {
try {
const secret = await getVaultSecret(
`${vaultConfig.redis.secrets_path + vaultConfig.redis.key}`
);
redisUrl = setRedisUrl(
srvconf.get("redis_host"),
srvconf.get("redis_port"),
secret.PASSWORD
);
} catch (err) {
console.log(err);
}
} else {
if (!srvconf.get("redis_url")) {
redisUrl = setRedisUrl(
srvconf.get("redis_host"),
srvconf.get("redis_port"),
srvconf.get("redis_password")
);
} else {
redisUrl = srvconf.get("redis_url");
console.log(`Found redis_url ${maskRedisUrl(redisUrl)}`);
}
}
// Initialize Redis client after vault secrets are loaded
initRedisClient();
})();
export default redisClient;
Usage
At all places where you import and use the client, you always need to check if it is actually initialized successfully, and throw (and catch) a well defined error if it is not.
const redisClient = require("path/to/module");
...
if (redisClient) {
// Use it
} else {
throw new RedisClientNotInitializedError();
}
...
Related
I was running my next.js app and trying to fetch user I am getting "cannot read properties of undefined" error
And following error in the console
Below is the code I was using
import Ewitter from './Ewitter.json';
import ethers from 'ethers';
import { useState, useEffect } from 'react';
const ContractABI = Ewitter.abi;
const ContractAddress = '0x5FbDB2315678afecb367f032d93F642f64180aa3';
const Ethereum = typeof window !== 'undefined' && (window as any).ethereum;
const getEwitterContract = () => {
const provider = new ethers.providers.Web3Provider(Ethereum);
const signer = provider.getSigner();
const EwitterContract = new ethers.Contract(
ContractAddress,
ContractABI,
signer
);
return EwitterContract;
};
const useEwitter = () => {
// const Ewitter = getEwitterContract();
const [currentAccount, setCurrentAccount] = useState<string>('');
const [currentUser, setCurrentUser] = useState<string>('');
const connect = async () => {
try {
if (!Ethereum) {
alert('Please install MetaMask');
return;
}
const accounts = await Ethereum.request({
method: 'eth_requestAccounts',
});
if (accounts.length === 0) {
alert('Please unlock MetaMask');
return;
}
const account = accounts[0];
console.log('connected to account: ', account);
setCurrentAccount(account);
} catch (errors) {
console.log(errors);
}
};
useEffect(() => {
if(!Ethereum){
console.log("No ethereum wallet found, please install metamask")
return ;
}
connect();
}, []);
useEffect(() =>{
if(currentAccount){
getUser();
}
}, [currentAccount])
const getUser = async ()=>{
const contract = getEwitterContract();
const user = await contract.getUser(currentAccount);
const {avatar, bio, name, username, wallet} = user;
console.log(user);
return user;
}
return { connect, account: currentAccount };
};
export default useEwitter;
#Update1
I've changed import ethers from 'ethers' to import {ethers} from 'ethers' and now I'm facing this error
If unable to understand properly or if you want to see the whole codebase then this is the link to the github repo
https://github.com/ChiragDogra/ewitter/blob/userIssue/dapp/hooks/useEwitter.ts
believe or not I just had that issue.
the problem is how you are importing ethers. Should be
import { ethers } from "ethers";
I'm having a problem executing my smart contract. From the error code, I figured it is must be a gas limit problem, although I don't know where I would place the code in order for it to execute properly. Any suggestions?
Solidity code:
pragma solidity ^0.8.0;
import 'hardhat/console.sol';
contract WavePort {
//TrackWaves
uint totalWaves; //State Variable, Permanetly Stored In Contract Storage
constructor() {
console.log("Yo, I am I contract");
}
//Function Increments Waves On The Blockchain/ Immutable Never Decreasing
function wave() public {
totalWaves += 1;
console.log("%s has waved!", msg.sender);
}
//Function Returns Us the The Total Waves To Be Viewed
function getTotalWaves()public view returns(uint256) {
console.log("We have %d total waves", totalWaves);
return totalWaves;
}
}
JavaScript code:
const App = () => {
const [currentAccount, setCurrentAccount] = useState("")
const contractAddress = "contractAddress"
const contractABI = abi.abi
const checkIfWalletConnected = async () => {
let web3
try {
const {ethereum} = window;
if(!ethereum) {
window.alert("Make sure you have metamask !");
return;
}else {
web3 = new Web3(window.ethereum)
console.log("We have the ethereum object", ethereum)}
const accounts = await ethereum.request({method: 'eth_accounts'})
if(accounts.length !== 0) {
const account = accounts[0]
console.log("Found an Authorized account:", account, );
setCurrentAccount(account)
} else {
window.alert("NO authorized account found")
}
const EthBalance = await web3.eth.getBalance(accounts[0])
console.log(EthBalance)
}catch(err) {console.log(err)}
}
const connectWallet = async () => {
try {
const {ethereum} = window;
if(!ethereum) {alert("Get Metamask extenstion")
return
} else {
const accounts = await ethereum.request({method: 'eth_accounts'})
console.log("Connected", accounts[0])
window.alert("Wallet is Connected")
setCurrentAccount(accounts[0])
const ethBlance = await Web3.eth.getBalance(currentAccount)
console.log(ethBlance)
}
}catch(err) {
console.log(err)
}
}
const wave = async () => {
try {
const {ethereum} = window;
if(ethereum) {
const provider = new ethers.providers.Web3Provider(ethereum);
const signer = provider.getSigner();
const wavePortalContract = new ethers.Contract(contractAddress, contractABI, signer);
let count = await wavePortalContract.getTotalWaves( );
const waveTxn = await wavePortalContract.wave({gas:10000000 }, {gasPrice:80000000000});
console.log("Mining....", waveTxn.hash)
await waveTxn.wait( );
console.log("Mined-- ", waveTxn.hash)
count = await await wavePortalContract.getTotalWaves( );
console.log("Retrieved total wave count.. ", count.toNumber())
}else {
console.log("Eth Object doesn't exist!")
}
} catch(err) {console.log(`${err} hello world`) }
}
useEffect(() => {
checkIfWalletConnected();
}, [])
The error code I get:
Error: cannot estimate gas; transaction may fail or may require manual gas limit (error={"code":-32000,"message":"execution reverted"}, method="call", transaction={"from":"0xD49a9a33F180D1e35A30F0ae2Dbfe5716a740Ebc","to":"0x5FbDB2315678afecb367f032d93F642f64180aa3","data":"0x9a2cdc08","accessList":null}, code=UNPREDICTABLE_GAS_LIMIT, version=providers/5.5.1)
While calling a contract Abi method, you can pass an object of additional gas-related params in the second argument (or first if you don't have any arguments in your method).
So calling of wave function should looks like following:
const waveTxn = await wavePortalContract.wave({gasLimit:30000});
Check all additional params in the below documentation.
https://docs.ethers.io/v5/api/contract/contract/#contract-functionsSend
I'm coming from React/Redux-land and am slowly getting acquainted to Svelte design patterns using stores.
Currently I'm curious to figure out if this is an acceptable pattern or if not, what is a better way to pursue this kind of communication. The basic premise is I want to be able to update multiple custom stores (which are using writable) from an adjacent store.
In the example below I have "loading.js" and "error.js" stores which would be used globally, commented out in the "session.js" store. I'd like to update these based on the result of an API request to create a session, in order to keep most of my heavy lifting out side of components.
My current thinking is that I'd pass each store needed through the "createSessionStore" function, but it feels a little clunky as it would highly depend on the declaration order of each store within "store.js"
The long term intention for wishing to do it this way is so I can add any kind of communication layer (such as web sockets) in to the mix and update the global loading or error store from any layer.
Thanks for the help.
Component.svelte
<script>
import { onMount } from "svelte";
import { error, loading, session } from "./store";
onMount(() => {
session.fetchSession();
});
</script>
{#if $loading}
<div>Loading...</div>
{/if}
{#if $error}
<div>Something went wrong: {$error}</div>
{/if}
store.js
import { createErrorStore } from "./error";
import { createLoadingStore } from "./loading";
import { createSessionStore } from "./session";
export const error = createErrorStore();
export const loading = createLoadingStore();
export const session = createSessionStore();
session.js
import { writable } from "svelte/store";
const INITIAL_STORE = {
token: null
};
export const createSessionStore = (initialStore = INITIAL_STORE) => {
const { subscribe, set } = writable(initialStore);
const fetchSession = async () => {
// loading.set(true);
try {
const response = await fetch("MY_API_ENDPOINT/auth/token", {
method: "POST",
});
if (!response.ok) {
const err = new Error("Network response was not ok.");
// error.set(err);
// loading.set(false);
return;
}
const data = await response.json();
set(data.token);
// loading.set(false);
} catch (err) {
// error.set(err);
// loading.set(false);
}
};
const reset = () => {
set(initialStore);
};
return {
subscribe,
fetchSession,
reset
};
};
error.js
import { writable } from "svelte/store";
const INITIAL_STORE = false;
export const createErrorStore = (initialStore = INITIAL_STORE) => {
const { subscribe, set } = writable(initialStore);
const reset = () => {
set(initialStore);
};
return {
subscribe,
set,
reset
};
};
loading.js
import { writable } from "svelte/store";
const INITIAL_STORE = false;
export const createLoadingStore = (initialStore = INITIAL_STORE) => {
const { subscribe, set } = writable(initialStore);
const reset = () => {
set(initialStore);
};
return {
subscribe,
set,
reset
};
};
Interesting idea.
The problem here is that during the creation of the stores, not all of them exists yet. The only solution that I see for this is to add the references after creating them.
Here's my idea:
In the session.js:
import { writable } from "svelte/store";
const INITIAL_STORE = {
token: null
};
export const createSessionStore = (initialStore = INITIAL_STORE) => {
const { subscribe, set } = writable(initialStore);
const fetchSession = async () => {
// loading.set(true);
try {
otherStores.loading && otherStores.loading.set(true);
const response = await fetch("MY_API_ENDPOINT/auth/token", {
method: "POST",
});
if (!response.ok) {
const err = new Error("Network response was not ok.");
otherStores.error && otherStores.error.set(err);
otherStores.loading && otherStores.loading.set(false);
return;
}
const data = await response.json();
set(data.token);
} catch (err) {
otherStores.error && otherStores.error.set(err);
otherStores.loading && otherStores.loading.set(false);
}
};
const reset = () => {
set(initialStore);
};
let otherStores = {}
const setOtherStores = (stores) => {
otherStores=stores
};
return {
subscribe,
fetchSession,
reset,
setOtherStores
};
};
In the store.js:
import { createErrorStore } from "./error";
import { createLoadingStore } from "./loading";
import { createSessionStore } from "./session";
export const error = createErrorStore();
export const loading = createLoadingStore();
export const session = createSessionStore();
session.setOtherStores({error,loading})
You can use the same pattern for any of the other stores (if needed), and after creation pass them the references to the other stores.
I am trying to implement separation of concerns by using export module. All the code is working if used without separation of concern but as soon as I am trying to import generateUrlArray() from const db = require('../db') nothing is working. Nodejs is not giving me any error on the back-end. The error I am getting on front-end is Error: SyntaxError: Unexpected end of JSON input . I am positive that the error is coming from back-end. Let me know if you have any ideas.
controller.js
const db = require('../db')
exports.getWebApiList = (req, res) => {
(async function fetchDataList() {
try {
const urlArray = await db.generateUrlArray({}, { _id: 0 })
return res.send(urlArray)
} catch (ex) {
console.log(`fetchDataList error: ${ex}`)
}
})()
}
..db/index.js
const { List } = require('./models/List')
const generateUrlArray = (query, projection) => {
const dataFromDB = List.find(query, projection).select('symbol')
return linkArray = dataFromDB.map(item => {
return link = `https://www.alphavantage.co/query?function=GLOBAL_QUOTE&symbol=${item.symbol}&apikey=6BUYSS9QR8Y9HH15`
})
}
module.exports = { generateUrlArray }
.models/List.js
const mongoose = require('mongoose')
mongoose.Promise = global.Promise
const ParentSchemaSymbolList = new mongoose.Schema({
symbol: String
})
module.exports.List = mongoose.model('List', ParentSchemaSymbolList)
const generateUrlArray = async (query, projection) => {
const dataFromDB = await List.find(query, projection).select('symbol')
const linkArray = dataFromDB.map(item => {
return link = `https://www.alphavantage.co/query?function=GLOBAL_QUOTE&symbol=${item.symbol}&apikey=6BUYSS9QR8Y9HH15`
})
return linkArray
}
How do I prevent Service running ... msg from getting logged first? I would like the messages inside testDBConnection fn. to be logged first instead. When DB is not running I would like the Looks like DB is not running msg to be kept getting logged and once the DB kicks in the DB connection has been established and Service running ... msgs should follow. I tried multiple things, but I was not able to come up with proper code. Thanks for your help.
index.js
import app from './config/express';
import config from './config/config';
import logger from './config/winston';
import { initDbConnection } from './server/db';
app.listen(config.port, () => {
initDbConnection();
logger.info(`Service running and listening on port ${config.port}`);
});
db.js
import knex from 'knex';
import config from '../config/config';
import logger from '../config/winston';
const { db } = config;
let pool;
const testDBConnection = (client) => {
const intervalId = setInterval(async () => {
try {
await client.select(1);
logger.info('DB connection has been established');
clearInterval(intervalId);
} catch (error) {
logger.error('Looks like DB is not running');
}
}, 2000);
};
export const initDbConnection = (mock) => {
if (mock) {
pool = knex({});
} else {
pool = knex({
client: 'pg',
version: '7.4.2',
connection: db,
debug: true
});
testDBConnection(pool);
}
};
export const getDb = () => pool;
You could use async/await for that.
import app from './config/express';
import config from './config/config';
import logger from './config/winston';
import { initDbConnection } from './server/db';
app.listen(config.port, async () => {
await initDbConnection();
logger.info(`Service running and listening on port ${config.port}`);
});
db.js:
import knex from 'knex';
import config from '../config/config';
import logger from '../config/winston';
const { db } = config;
let pool, connected;
const testDBConnection = (client) => {
return new Promise(resolve => {
const intervalId = setInterval(async () => {
try {
await client.select(1);
if (connected) {
return;
}
connected = true;
logger.info('DB connection has been established');
clearInterval(intervalId);
resolve('success');
} catch (error) {
logger.error('Looks like DB is not running');
}
}, 2000);
});
};
export const initDbConnection = (mock) => {
if (mock) {
pool = knex({});
} else {
pool = knex({
client: 'pg',
version: '7.4.2',
connection: db,
debug: true
});
return testDBConnection(pool);
}
};
export const getDb = () => pool;
This way, the logger inside the app.listen cb won't be called until the initDbConnection is resolved. Another way would be to just use the promise then.