AWS Lambda: /tmp/0003.mp4: Permission denied

Question

/tmp/0003.mp4: Permission denied

1. I have set AWSLambdaBasicExecutionRole for user role
2. have following line in code:

        execSync(
            'touch /tmp/0001.mp4 /tmp/0003.mp4 /tmp/image.mp4 /tmp/dance.mp4',
            { stdio: 'ignore' }
        )
        execSync('chmod 777 /tmp')

Anyway the rest of the code is here:

import { execSync } from 'child_process'
import {
    S3Client,
    GetObjectCommand,
    PutObjectCommand,
} from '@aws-sdk/client-s3'
import * as fs from 'fs'

const s3Client = new S3Client({ region: 'eu-central-1' })

export const handler = async (event) => {
    try {
        const imageParams = {
            Bucket: 't44-admin',
            Key: 'dance.png',
        }

        const firstVideoParams = {
            Bucket: 't44-admin',
            Key: '0001.mp4',
        }

        const secondVideoParams = {
            Bucket: 't44-admin',
            Key: '0003.mp4',
        }

        const imageResponse = await s3Client.send(new GetObjectCommand(imageParams))
        const loopedImageChunks = []

        imageResponse.Body.on('data', (chunk) => {
            loopedImageChunks.push(chunk)
        })

        await new Promise((resolve, reject) => {
            imageResponse.Body.on('error', reject)
            imageResponse.Body.on('end', resolve)
        })

        const looedImageBuffer = Buffer.concat(loopedImageChunks)

        const firstVideoResponse = await s3Client.send(
            new GetObjectCommand(firstVideoParams)
        )
        const firstVideoChunks = []

        firstVideoResponse.Body.on('data', (chunk) => {
            firstVideoChunks.push(chunk)
        })

        await new Promise((resolve, reject) => {
            firstVideoResponse.Body.on('error', reject)
            firstVideoResponse.Body.on('end', resolve)
        })

        const firstVideoFileBuffer = Buffer.concat(firstVideoChunks)

        const secondVideoResponse = await s3Client.send(
            new GetObjectCommand(secondVideoParams)
        )
        const secondVideoChunks = []

        secondVideoResponse.Body.on('data', (chunk) => {
            secondVideoChunks.push(chunk)
        })

        await new Promise((resolve, reject) => {
            secondVideoResponse.Body.on('error', reject)
            secondVideoResponse.Body.on('end', resolve)
        })

        const secondVideoFileBuffer = Buffer.concat(secondVideoChunks)

        const imageFilePath = '/tmp/dance.png'
        const loopedImageFilePath = '/tmp/image.mp4'
        const firstVideoFilePath = '/tmp/0001.mp4'
        const secondVideoFilePath = '/tmp/0003.mp4'

        execSync(
            'touch /tmp/0001.mp4 /tmp/0003.mp4 /tmp/image.mp4 /tmp/dance.mp4',
            { stdio: 'ignore' }
        )
        execSync('chmod 777 /tmp')

        fs.writeFileSync(imageFilePath, looedImageBuffer)
        fs.writeFileSync(firstVideoFilePath, firstVideoFileBuffer)
        fs.writeFileSync(secondVideoFilePath, secondVideoFileBuffer)

        // Run ffmpeg command from the layer
        const ffmpegCommand1 = `/opt/nodejs/ffmpeg -loop 1 -i ${imageFilePath} -c:v libx264 -t 2 -pix_fmt yuv420p -vf "fade=t=in:st=0:d=0.2" -y ${loopedImageFilePath}`
        execSync(ffmpegCommand1)

        const ffmpegCommand2 = `/opt/nodejs/ffmpeg -i concat:${firstVideoFilePath}|${loopedImageFilePath}|${secondVideoFilePath} -c copy /tmp/output.mp4`
        execSync(ffmpegCommand2)

        // Upload the output video to S3
        const outputKey = 'output.mp4'
        const outputParams = {
            Bucket: 't44-admin',
            Key: outputKey,
            Body: fs.createReadStream('/tmp/output.mp4'),
            ACL: 'public-read',
            ContentType: 'video/mp4',
        }
        await s3Client.send(new PutObjectCommand(outputParams))

        // Upload the looped video to S3
        const loopedKey = 'looped.mp4'
        const loopedParams = {
            Bucket: 't44-admin',
            Key: loopedKey,
            Body: fs.createReadStream('/tmp/image.mp4'),
            ACL: 'public-read',
            ContentType: 'video/mp4',
        }
        await s3Client.send(new PutObjectCommand(loopedParams))

        return {
            statusCode: 200,
            body: 'Success',
        }
    } catch (error) {
        console.error('Error:', error)

        return {
            statusCode: 500,
            body: 'Error',
        }
    }
}

Answer 1

You only modified the permissions for the directory, but not the files inside. Use chmod -R 666 /tmp/* to recursively give read-write (666) permissions for the contents.