Situation
Hi, I'm quite new to Angular, I've been doing some projects following tutorials, which then lead me to try to start my own project to practice my Postgres and newly acquired Angular "skills".
I am trying to do a webapp that connects to a postgres DB using the node pg module.
(I know sequelize is a thing and it seems to work better than pg but AFAIK sequelize doesn't let you run pure postgres commands through it) Please correct me if I am wrong about this
The problem
This is where I get stuck, I am trying to follow the instructions from the docs but it doesn't seem to work correctly.
I have tried:
const { Client } = require('pg');
import { Client } from 'pg';
Also tried importing it in the .angular-cli.json in the scripts array
All of these fail with errors similar to this
ERROR in ./node_modules/pg/lib/connection-parameters.js Module not found: Error: Can't resolve 'dns' in '[...]\node_modules\pg\lib'
ERROR in ./node_modules/pg/lib/native/client.js Module not found: Error: Can't resolve 'pg-native' in '[...]\node_modules\pg\lib\native'
But nothing seems to work properly. Am I doing this completely wrong?
Also, pretty dumb question. I believe angular does everything on the client side, this is a HUGE security risk for DB access in prod. If that is true, is there a way to write server-side .ts services? or are services server-side?
You could write your serverside code in node using compiled ts, but probably not with angular.
Related
I'm trying to use npm pg with pg-pool in my Next.js application.
I'm new to pooling connections but I gathered that I need to establish a pool connection whenever my Next.js server is initialized and I need to pass that connection as a module around my application.
From pg-pool docs:
a note on instances
The pool should be a long-lived object in your application. Generally you'll want to instantiate one pool when your app starts up and use the same instance of the pool throughout the lifetime of your application. If you are frequently creating a new pool within your code you likely don't have your pool initialization code in the correct place.
So, I created file my-app/lib/db.js to initialize my connection and hopefully pass that around my application whenever I need to run a query.
However, when I attempt to import { Pool } from 'pg'; I get an error:
Module not found: Can't resolve 'fs'
I found this question with the understanding now that..
You can't use Node.js libraries that use fs in Next.js Middleware. Try using a client-side library instead.
So, my question is, how can I initiate a postgres-pool connection on a Next.js server node and route all queries through it? Do I need use a different package? Really not sure where to place this in the Next.js architecture.
If you only import it with "import { Pool } from 'pg';" in a component (not an API route) without calling the "Pool" object inside "getServerSideProps" or "getStaticProps" it will fail because Nextjs will include the "Pool" object in the client bundle and this way you will try to import a server-side module "fs" in the browser.
If you call the "Pool" in "getServerSideProps" or "getStaticProps" Nextjs will know NOT to include the "Pool" object in the client bundle and the problem will be solved.
There is a very good explanation here: https://maikelveen.com/blog/how-to-solve-module-not-found-cant-resolve-fs-in-nextjs
We are trying to get gRPC to work with React (actually we were trying to get it to work with React-Native but gave up on that for now).
Using plain node.js things are pretty straight forward if you follow this example.
We started by using create-react-app but when we started the app, we got the following error:
existsSync is not a function
That was casued by this bit in pre-binding.js belonging to the node-pre-gyp package located in grpc:
var existsSync = require('fs').existsSync || require('path').existsSync;
My understanding is that something goes on with Webpack (or some other process run by create-react-app) that goes and returns and empty object instead of require('fs').
Any ideas of how to get this to work without having to give up on the wonders of create-react-app?
To test it out you can just follow these 2 easy steps:
create-react-app test-app
add import grpc from 'grpc'; in the App.js file
Basically, from what I understand now, you are not really supposed to use gRPC + Protobuf directly from any frontend but rather it is more common to use the grpc node package on node.js server-side code and then communicate with the browser-side code using Express.
The server-side code on node.js then communicates using grpc with the microservices.
We are testing out the use of Firebase Functions to communicate securely with the frontend and Firebase Functions communicate with the Go microservices using grpc.
I'm attempting to write an Azure Function, in Node, to connect into a MongoDB instance (Cosmos DB in this case).
However, as soon I run require("mongodb"), my function crashes, without throwing an error, or logging anything, with the HTTP response returning a 502 code.
My setup:
Creating a function app using all defaults through the Azure portal.
Creating a package.json with mongodb version 3.x.
Running npm install through the Kudu shell
Include the require statement in my code.
Make a request to the function
This doesn't throw an error in the code, and I see logging that's run before, but not after the require statement (which is making it pretty difficult to debug).
I've also tried following through this guide about running a mongo query from a function, and it fails in exactly the same way for me.
After putting some hooks into Node's module module, my attempts to debug this led to a line in one of mongo's dependencies that fails in a similar way when run in isolation (from saslprep), which seems to stem from running out of stack space.
However, this feels like its a pretty mainstream use for an Azure function, and I haven't seen any similar issues, so I'm inclined to suspect that its an issue with my setup, rather than the mongodb library, but I haven't been able to find a misconfiguration, as I haven't changed any defaults - right now, I'm stumped!
I don't have a full code example right now, as I'm away from my work computer, but the code is something like
const mongo = require('mongodb');
module.exports = function(context) {
context.res = {
body: 'Hello world'
};
context.done();
}
Without the require statement, the code runs fine, returning the response to the browser.
It turns out that this problem was caused by running out of stack space. After pushing a patch to the saslprep library (v1.0.1), this has now been fixed.
Im pretty sure that if you add to your require function the same as in Microsofts Cosmos DB guides for mongo the following it should work
var mongodb = require('mongodb').MongoClient;
you have it as:
const mongodb = require('mongodb');
Im curious to know if that makes a difference. After looking through Microsofts own docs nearly all of them are declared that way.
Here is the tutorial I found: MongoDB app using Node.js
Is there any way of wiping a mongo database in between Nightwatch e2e tests?
I'm coming from Ruby, where you can configure RSpec to use a package called database cleaner and wipe your db after each test, and I'm wondering if a similar setup exists in the javascript ecosystem.
I did some research and found a promising-looking package called node-database-cleaner, but at present it is throwing an error.
Code:
require('mongodb');
const DatabaseCleaner = require('database-cleaner');
const databaseCleaner = new DatabaseCleaner('mongodb');
...test assertions
databaseCleaner.clean('mongodb://localhost:27017/my-db')
Error:
TypeError: db.collections is not a function
I'm not bound to using node-database-cleaner—I'd be interested in any solution no matter what library it uses.
I'm new to using Derby.js, and have scaffolded out a project using the yeoman generator-derby package. I thought everything was going fine, but I can't figure out what I'm doing wrong here.
A breakdown:
I have an 'app/dbWp.js' controller that exports several functions, and requires the modules 'mysql', 'async', and 'needle'
In my app/index.js, I import this file and use it like so:
app.proto.submitWp = function() {
dbWp.createUser(this.model);
};
I call this function from the view/index.jade like so:
button.btn.btn-primary(type="button", on-click="submitWp()")
In the browser, I get numerous console.error message complaining about the 'fs' module not being defined. After much googling, I discover that it's due to Browserify ignoring the 'fs' module, which subsequently causes problems with modules 'mysql' and 'needle'. But that implies this code is being executed in the browser?
So my question is: why is this trying to call the function on the client side? Obviously if it executes on the server side, as I thought it was going to, there wouldn't be a problem requiring these modules.
How can I execute this function on the server? Had this working fine with express + socket.io before, but wanted to change frameworks and give Derby.js a shot.
I'm clearly misunderstanding something about how Derby.js is supposed to work; any help would be appreciated. Thanks!
I know this is like 4 months later, but being new to DerbyJs too, I thought I could try and help.
I personally with standard html code have the equivalent working.
<button on-click="editContact(#contact.id)">Edit Contact</button>
This indeed runs code on the server. Can you try writing your code in standard HTML, or perhaps better yet, see if you can do a console.log on the server method to see if it even is getting there?
Perhaps the best would be to call an empty function on the server with a console log and check both the browser console and the server console.