teleren/devto huggingface dataset:
Nodejs Fix Error connect ECONNREFUSED ::1:80 while using localhost
Published: 2023-12-19 13:05:13

---
title: Nodejs Fix Error connect ECONNREFUSED ::1:80 while using localhost
published: true
date: 2023-12-16 16:18:24 UTC
tags: 
canonical_url: 
---

# Introduction

Node.js serves as a powerful platform for building server-side applications, but encountering errors, especially during local development, can disrupt progress. One such error is `connect ECONNREFUSED ::1:80`, commonly faced while attempting to connect to a local server.

# Understanding the Error

The error message `connect ECONNREFUSED ::1:80` signifies that the Node.js application is attempting to connect to the IPv6 loopback address (::1) on port 80, commonly used for HTTP traffic. However, the connection is being refused, leading to the error.

```
const axios = require("axios")try { const { data } = await axios.get('http://localhost')} catch (error) { console.log(error.message) // output: "connect ECONNREFUSED ::1:80"}
```

# Solution 1

You can fix the `connect ECONNREFUSED ::1:80` error by explicitly specifying the IPv4 loopback address (127.0.0.1) instead of relying on the IPv6 (::1) address.

```
const axios = require("axios")try { const { data } = await axios.get('http://127.0.0.1') // Success Response} catch (error) { console.log(error.message)}
```

# Solution 2

Starting from Node.js 17 IPv6 connections are prioritized when making network calls. This is great for future-proofing your code, but it can cause problems if the server you're trying to reach only supports IPv4. This is where `setDefaultResultOrder()` comes in like a knight in shining armor.

```
const axios = require("axios")const { setDefaultResultOrder } = require("dns");setDefaultResultOrder("ipv4first");try { const { data } = await axios.get('http://localhost') // Success Response} catch (error) { console.log(error.message)}
```

# Solution 3

Degrading the version of Nodejs runtime to Nodejs 16 or lower can also fix the issue but it is not recommended.

# Try Yourself

[https://runkit.com/gitsambhal/nodejs-fix-error-connect-econnrefused-1-80-while-using-localhost](https://runkit.com/gitsambhal/nodejs-fix-error-connect-econnrefused-1-80-while-using-localhost)

# **Conclusion**

Resolving the `connect ECONNREFUSED ::1:80` error involves understanding the intricacies of local network configurations and resolving conflicts that prevent the successful connection of your Node.js application. By implementing the suggested troubleshooting steps and potential fixes, developers can overcome this error, ensuring uninterrupted progress in their development environment.

We hope this guide helps you tackle the `connect ECONNREFUSED ::1:80` error, enabling you to focus on building your Node.js applications without connectivity hurdles during local development.

Stay tuned for more insightful troubleshooting tips and solutions!
Lịch thi đấu 7M
Published: 2023-12-16 16:03:28

Lịch thi đấu 7m cung cấp đầy đủ toàn bộ các giải đấu trong và ngoài nước. Cập nhật Lịch thi đấu ngoại hạng anh, La liga, Bundeslia,... hoàn toàn miễn phí
Thông tin chi tiết:
Website: https://7mvns.com/lich-thi-dau-7m/
Địa chỉ: 28 P. Lương Định Của, Kim Liên, Đống Đa, Hà Nội, Vietnam
Zipcode: 100000
Email: 7mvnscom@gmail.com
Điện thoại: 0866205846
#7m, #7mvn, #7mcn, #tyso7m, #tysotructuyen7m, #7mtyso, #7mlive, #7msports #livescore7m
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https://gravatar.com/lichthidau7m
https://about.me/lichthidau7m
Get OpenSearch mapping with Python
Tags: opensearch, elasticsearch, python, mapping
Published: 2023-12-16 15:58:11

When no data structure is specified when loading the data, OpenSearch uses dynamic mapping to automatically detect the fields. To check the mapping definition of your data, OpenSearch client provides a function called ``get_mapping`` as shown:

```python
    import pprint

    INDEX_NAME = 'epicurious-recipes'
    mapping_data = os_client.indices.get_mapping(INDEX_NAME)

    # Find index doc_type
    doc_type = list(mapping_data[INDEX_NAME]["mappings"].keys())[0]

    schema = mapping_data[INDEX_NAME]["mappings"][doc_type]
    fields =  list(schema.keys())
    pprint(fields)
    pprint(schema)
```

You should be able to see the fields's output:

```python

    ['calories',
    'categories',
    'date',
    'desc',
    'directions',
    'fat',
    'ingredients',
    'protein',
    'rating',
    'sodium',
    'title']
```

And the mapping with the fields and their respective types.

```

        {'calories': {'type': 'float'},
         'categories': {'fields': {'keyword': {'ignore_above': 256, 'type': 'keyword'}},
                        'type': 'text'},
         'date': {'type': 'date'},
         'desc': {'fields': {'keyword': {'ignore_above': 256, 'type': 'keyword'}},
                  'type': 'text'},
         'directions': {'fields': {'keyword': {'ignore_above': 256, 'type': 'keyword'}},
                        'type': 'text'},
         'fat': {'type': 'float'},
         'ingredients': {'fields': {'keyword': {'ignore_above': 256,
                                                'type': 'keyword'}},
                         'type': 'text'},
         'protein': {'type': 'float'},
         'rating': {'type': 'float'},
         'sodium': {'type': 'float'},
         'title': {'fields': {'keyword': {'ignore_above': 256, 'type': 'keyword'}},
                   'type': 'text'}}
        
```

Read more about OpenSearch mapping in the [official OpenSearch documentation](https://opensearch.org/docs/latest/opensearch/rest-api/index-apis/create-index/#mappings).
vibrant & dark vscode
Tags: vscode, themes
Published: 2023-12-16 15:51:18

**A vibrant and dark VSCode theme**

I have recently created a dark theme using my poprock color palette for VSCode.

Check it out here:  https://github.com/exoad/poprock-vscode

<3

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/q3rveclm6h45lqtm18eh.png)
BITCOIN RECOVERY COMPANY - WIZARD WEB RECOVERY
Published: 2023-12-16 15:44:21

It can be extremely distressing to lose your hard-earned cryptocurrencies to a cybercriminal. Still, WIZARD WEB RECOVERY has repeatedly shown that they are experts at retrieving monies that have been pilfered. I explore my experience as a victim of cryptocurrency theft in this case study. WIZARD WEB RECOVERY saved the day just when I gave up hope! My cryptocurrency was taken, but their team of cryptographers never gave up. They were trustworthy, competent, and genuinely interested in assisting me. I got a good chunk of my money back because of their knowledge. WIZARD WEB RECOVERY is without a doubt the finest in the industry. With its unique approach, personalized strategies, advanced technology, and extensive knowledge of the crypto landscape, Wizard Web Recovery stands out as the leading crypto recovery service. So, if you find yourself in a crypto predicament, don't lose hope – let the wizards at WIZARD WEB RECOVERY work their magic and bring your lost coins back to you. Security and privacy are top priorities at WIZARD WEB RECOVERY. They are aware that recovering cryptocurrency demands a great degree of secrecy. You may be sure that all client data and case specifics are handled in the strictest confidence. Strong security procedures are used by Wizard Web Recovery to safeguard customer information and uphold the confidence that has been placed in them. WIZARD WEB RECOVERY goes above and beyond to protect digital assets from potential threats, not just retrieving lost or stolen bitcoin. They provide insightful counsel and direction on putting extra security measures in place because they are aware of the constantly changing nature of cyber threats. WIZARD WEB RECOVERY makes sure that its clients are prepared to safeguard their money in the future by teaching them about the best practices for Bitcoin security. WIZARD WEB RECOVERY stands out as the greatest in the industry when it comes to saving your cryptocurrencies from the grasp of scammers.


CONTACT INFORMATION:

WIZARDWEBRECOVERY (@) PROGRAMMER (.) NET 

WWW (.) WIZARDWEBRECOVERY (.) NET 

TELEGRAM: @WIZARDWEBRECOVERYTEAM
REST API - Basic components of Authorization and Authentication
Tags: restapi, authorization, authentication, security
Published: 2023-12-16 15:30:00

Authentication and authorization are critical aspects of securing your RESTful API. They ensure that only authorized users or applications can access specific resources and perform certain actions. Here are some best practices for implementing authentication and authorization:


![Basic components of Authorization and Authentication](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/yzl7evub9l5zbj1fleis.png)

1. **Authentication**:
   - Use industry-standard authentication mechanisms such as OAuth 2.0 or JWT (JSON Web Tokens) to verify the identity of clients.
   - Provide clear documentation on how clients should authenticate themselves when making requests to the API.
   - Support various authentication methods, including API keys, OAuth tokens, and username/password, depending on the level of security required and the use case.

2. **Authorization**:
   - Implement role-based access control (RBAC) to define who can access specific resources and perform actions.
   - Enforce proper authorization checks for each API endpoint to ensure that only authorized users can perform specific operations.
   - Clearly define and document the roles and permissions associated with each user or client type.

3. **Token Management**:
   - If using tokens for authentication (e.g., JWTs or OAuth tokens), handle token expiration and refresh mechanisms properly.
   - Implement token revocation in case a token is compromised or a user's access needs to be revoked.

4. **Rate Limiting**:
   - Implement rate limiting to prevent abuse of the API. Rate limiting helps protect the server from excessive requests and ensures fair usage.

5. **Error Handling for Authentication and Authorization**:
   - Provide clear and informative error messages when authentication or authorization fails. Avoid exposing sensitive information in error messages.

6. **Monitoring and Logging**:
   - Set up monitoring and logging for authentication and authorization events. This helps detect and respond to suspicious or unauthorized access attempts.

7. **Secure Data Transmission**:
   - Use HTTPS to encrypt data transmitted between clients and the server to protect against eavesdropping and man-in-the-middle attacks.

8. **Security Testing**:
   - Regularly perform security assessments and penetration testing to identify and address potential vulnerabilities in your API's authentication and authorization mechanisms.

9. **Keep Credentials Secure**:
   - Store credentials (e.g., API keys, passwords) securely, following best practices such as encryption and hashing.

10. **Educate Users and Developers**:
    - Educate your API users and developers on best practices for securely handling API keys and tokens, including how to store and transmit them safely.

Proper authentication and authorization practices are crucial for safeguarding your API and the data it exposes. By following these best practices, you can help protect your API from unauthorized access and potential security threats.
Develop dynamic React forms with ease
Published: 2023-12-16 15:28:32

How would you create a form of multiple steps in which the questions asked in each step depend on the answers provided in the previous ones?

You may think that something you would have to do would be to code all the logic of this form. That's something you could certainly do, but it is tedious and cumbersome.

What if there was a better way? Well, now there is. [Formity](https://www.npmjs.com/package/formity) is an npm package that lets you create dynamic React forms with ease.

Dynamic forms are multi-step forms in which the questions asked in each step depend on the answers provided in the previous ones.

These forms are created using only JSON objects, so you are able to store them in JSON files, send them through the network and even store them in a database like MongoDB.

In these forms you can write all kinds of logic using variables, conditionals, loops and a lot of different types of operators (arithmetic, comparison...).

You can check out this package [here](https://www.npmjs.com/package/formity).
What Are The Types of Classes in C#?
Tags: csharp
Published: 2023-12-16 15:00:24

In C#, classes play a vital role in object-oriented programming. They serve as blueprints for creating objects with similar characteristics and behaviors. C# offers different types of classes to suit various programming needs. Here are some examples:

1. Regular Classes: These are the most common type of classes that developers create in C#. They encapsulate data and define methods to perform actions related to the data.

2. Abstract Classes: Abstract classes cannot be instantiated directly. Instead, other classes inherit from them to implement their functionality. They often provide a common base for multiple derived classes, allowing for code reuse and specialization.

3. Sealed Classes: Sealed classes are classes that cannot be inherited. They are typically used when you want to prevent further subclassing and ensure the class remains as is.

4. Static Classes: Static classes are used to define methods and members that are accessible without needing an instance of the class. They are commonly used to organize utility functions that don't require any specific state.

5. Partial Classes: Partial classes allow a class definition to be split into multiple files. This feature is especially useful in large projects with complex or autogenerated code. The compiler combines the partial classes into a single class during compilation.

Each type of class in C# has its specific purpose and usage. Developers choose the appropriate class type based on the requirements of their application. Understanding these class types is crucial in structuring code effectively and creating maintainable and scalable software solutions in C#.
Zod - TypeScript-first schema declaration and validation library #11
Tags: programming, javascript, typescript, zod
Published: 2023-12-16 15:00:00

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/48qq3vuocvbo5acsgrjx.jpg)

✨ **Transform Data from Within a Schema** ✨

Another useful feature of Zod is manipulating data from an API response after parsing.

We are going back to our Star Wars example:

```ts
import { z } from 'zod';

const StarWarsPerson = z.object({
  name: z.string(),
})

const StarWarsPeopleResults = z.object({
  results: z.array(StarWarsPerson),
})

export const fetchStarWarsPeople = async () => {
  const data = await fetch(
    'https://www.totaltypescript.com/swapi/people.json',
  ).then((res) => res.json());

  const parsedData = StarWarsPeopleResults.parse(data);

  return parsedData.results;
}
```

We created **StarWarsPeopleResults** with a results array of **StarWarsPerson** schemas.

When we get the **name** of a **StarWarsPerson** from the API, it's their full name.

What we want to do is add a transformation to **StarWarsPerson** itself.

We need to take our base StarWarsPerson and add a transformation that will split the names on space to give us a **nameAsArray**

👉 **Solution:**

Here is what **StarWarsPerson** looked like before the transformation:

```ts
const StarWarsPerson = z.object({
  name: z.string(),
})
```

When we parse the **name** in **.object()**, we are going to take the person we receive and transform it to add additional properties:

```ts
const StarWarsPerson = z
  .object({
    name: z.string(),
  })
  .transform((person) => ({
    ...person,
    nameAsArray: person.name.split(' '),
  }))
```

Inside of the **.transform()**, **person** is the object from above that includes the name.

This is also where we add the **nameAsArray** property that satisfies the test.

This occurs at the **StarWarsPerson** level instead of inside the fetch function or elsewhere.

---

I hope you found it useful. Thanks for reading. 🙏
Let's get connected! You can find me on:
- **Medium:** https://medium.com/@nhannguyendevjs/
- **Dev**: https://dev.to/nhannguyendevjs/
- **Hashnode**: [https://nhannguyen.hashnode.dev](https://nhannguyen.hashnode.dev/)/
- **Linkedin:** https://www.linkedin.com/in/nhannguyendevjs/
- **X (formerly Twitter)**: https://twitter.com/nhannguyendevjs/
Creating a Financial Math Calculator
Tags: beginners, python, programming
Published: 2023-12-16 14:56:07

Since I love Financial Math and investing, I thought about creating a program that would help me in the near future to make my calculations without having to do them manually with pen and paper as I usually like to do them. I know there are a lot of programs out there that help you calculate things like interest, account worth, periods, etcetera. I wanted to create something that is more descriptive and user-friendly avoiding as much financial jargon as possible and guiding the user through the calculations. So far what I accomplished now is a fully functional calculator that provides you with the account worth after a given number of years investing a certain amount at an interest rate compounded every 'n' periods. In the future, I am planning to give it more functionality like calculating the number of years it will take to reach a certain amount in your account or calculating how much you would need to invest to obtain a certain amount of money. 

Here is an example of what it does for now and the link to my project in GitHub:

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/8w2p5eos88f1ocmi2c3q.png)

https://github.com/bastianrecr/financial_calculator

I will keep you posted about new features added :).

Sebastian
How to do "ping" with a specific target-port
Tags: linux, windows, bash
Published: 2023-12-16 14:54:12

In this article we'll shortly see how to do _ping_ against a host or IP but pointing a specific port.

It can be very useful to see if your container/application is alive, for example.

---

## Using Powershell (windows)

We can use the `Test-NetConnection` function passing the port as a parameter, for example:

```
 Test-NetConnection <host-or-ip> -port <target-port>
```

---

## Using _cURL_

With _cURL_ is untill simplier, just type `curl <host-or-ip>:<target-port>`. Example:

```
curl 127.0.0.1:1433
```
Vuetify Components Explained: Vuetify components overview || Vuetify Bangla Tutorial Part 2
Published: 2023-12-16 14:48:50

Vuetify Components Explained, Vuetify components overview, Vuetify components tutorial, Vuetify component library overview, Introduction to Vuetify components

🚀 Welcome to our in-depth journey into Vuetify Components! 🎉

Are you ready to unlock the full potential of Vuetify and take your Vue.js projects to the next level? In this comprehensive tutorial, we dive deep into Vuetify Components, covering everything from the fundamentals to advanced usage.

🔍 What You'll Learn:

🌐 Understanding the basics of Vuetify UI library.
🚀 Exploring essential components for seamless development.
🛠️ Customizing and styling Vuetify components to match your design.
📊 Implementing advanced features and functionalities.
Whether you're a Vue.js beginner or an experienced developer looking to enhance your UI skills, this video has something for everyone. Join us as we break down each component, share best practices, and showcase real-world examples to empower you in building stunning and responsive web applications.

📚 Timestamps:

00:26 Introduction 
01:20 Features
03:10 Style and Animations
04:58 All Components
 
👨‍💻 Who Should Watch:

Vue.js enthusiasts looking to level up their UI development skills.
Developers seeking a comprehensive guide to Vuetify components.
Anyone interested in creating modern and visually appealing web applications.
🔗 Resources Mentioned:

[Link to Example Code on GitHub] : https://github.com/Minhazulmin/Vuejs3-Vuetify3-MINIT
[Vuetify Documentation] : https://vuetifyjs.com/
👍 Don't forget to like, subscribe, and hit the bell icon for more Vue.js and Vuetify tutorials! Let's build amazing things together. 💻✨

#Vuetify #VueJS #UIComponents #WebDevelopment #FrontendDevelopment #Tutorial
Understanding Trends in LLMs
Published: 2023-12-16 14:45:09

Understanding trends of LLMs :
LLMs are broadly categorized into 3 different types based on the intermittent components 
    - Encoder only [Feature Extraction Procedure] 
    - Encoder - Decoder [More specific of what need to be produced] 
    - Decoder only [Text Generation by predicting next literal]
 In 2023, the Decoder only models have got a good appreciation for some critical reasons 
    - Single stage process 
    - Easy to Train    
    - Wont get too specific
    - Relies on single Neural Net i.e., Decoder module 
These models are trained on a masked modelling methodology, i.e., with the current literal, model was forced to predict the next literal in the sequence making it more proficient in text generation and machine translation objectives.
 Con of Decoder only models, 
With the absence of the encoder component, Decoder only models cant percieve structured data efficiently. Therefore they wont generate the promising output on structured data.. Decoder only models have got a wide spread recognition and recent trends also proves this. [30 LLMs and 138 papers were published focusing Decoder only architectures..] 
Bard and ChatGPT are also belongs to this class.
How to start learning Rust in 2024
Tags: rust, beginners
Published: 2023-12-16 14:36:58

Rust is a hot programming language these days and it is easy to get starting with it. A lot of cool software is written using Rust like Deno fror example. This short blogpost will help you getting started learning Rust.

 The Book

The first contact point beside the official Rust hompage https://www.rust-lang.org/ is the the Rustlang book: https://doc.rust-lang.org/book/ Here you can start writing small Rust programms and learn the basics of the Rust programming language.


Rust by Example

Rust by Example is another great resource learning to write basic Rust programms. https://doc.rust-lang.org/rust-by-example/


 The Youtube channel

There is a Rust youtube channel showing you more advanced Rust concepts. https://www.youtube.com/@RustVideos



Rust in Action

There is a papercopy book written by  Tim McNamara providing you with a guide about Rusts basic concepts.

https://www.manning.com/books/rust-in-action



Conclusion

You see there are enough free resources getting started learning Rust I hope you enjouyed this short blogpost.