How to use the Node.js axios library for making HTTP requests with automatic retries in Nest.js

  Arif Babu

         

  NodeJS



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To use the Node.js Axios library for making HTTP requests with automatic retries in Nest.js, you can integrate Axios with Nest.js and then utilize Axios' built-in retry functionality along with Nest.js' features. Here's how you can achieve this:

  1. Install Axios: First, make sure you have Axios installed in your Nest.js project. If not, you can install it using npm or yarn:

    npm install axios

    or

    csharp
    yarn add axios

  2. Create a RetryInterceptor: Nest.js allows you to create interceptors to intercept and modify requests and responses. We'll create a custom interceptor to handle automatic retries using Axios.

    typescript
    // retry.interceptor.ts

import { Injectable, NestInterceptor, ExecutionContext, CallHandler, BadGatewayException } from '@nestjs/common';
import { Observable, throwError } from 'rxjs';
import { catchError, retryWhen, mergeMap } from 'rxjs/operators';
import axios, { AxiosRequestConfig, AxiosResponse } from 'axios';

@Injectable()
export class RetryInterceptor implements NestInterceptor {
    intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
        return next.handle().pipe(
            retryWhen(errors =>
                errors.pipe(
                    mergeMap((error, count) => {
                        if (count >= 3) { // Maximum retry attempts
                            return throwError(error);
                        }
                        if (axios.isAxiosError(error) && error.response?.status === 502) { // Retry only on 502 Bad Gateway
                            return new Observable<AxiosResponse<any>>(observer => {
                                setTimeout(() => {
                                    observer.next();
                                    observer.complete();
                                }, 2000); // Wait 2 seconds before retrying
                            });
                        }
                        return throwError(error);
                    })
                )
            ),
            catchError(error => {
                throw new BadGatewayException(error.message); // Throw custom exception if retries fail
            })
        );
    }
}

  3. Register the RetryInterceptor: Now, you need to register the RetryInterceptor in your Nest.js module.

    typescript
    // app.module.ts

import { Module } from '@nestjs/common';
import { APP_INTERCEPTOR } from '@nestjs/core';
import { RetryInterceptor } from './retry.interceptor';

@Module({
    providers: [
        {
            provide: APP_INTERCEPTOR,
            useClass: RetryInterceptor,
        },
    ],
})
export class AppModule {}

  4. Use Axios for HTTP Requests: You can now use Axios for making HTTP requests within your Nest.js services or controllers. The interceptor will handle automatic retries for 502 Bad Gateway errors.

    typescript
    import { Injectable } from '@nestjs/common';
import axios from 'axios';

@Injectable()
export class ApiService {
    async fetchData(): Promise<any> {
        try {
            const response = await axios.get('https://example.com/api/data');
            return response.data;
        } catch (error) {
            throw error; // Let Nest.js handle error responses
        }
    }
}

With this setup, Axios will automatically retry requests that fail due to a 502 Bad Gateway error, up to a maximum of three attempts. Adjust the conditions and retry logic in the interceptor according to your requirements.

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