Download file from a private bucket with cURL

This guide explains how to download a single file from a private Object Storage bucket using cURL and a bash script with Zerops object storage.

Prerequisites

• Access to Zerops Object Storage
• Storage credentials (ACCESS_KEY_ID and SECRET_ACCESS_KEY)
• Bash environment
• OpenSSL and cURL installed

Caution

Store your storage credentials securely and never commit them to version control.

Script

Save this script as download-storage.sh:

#!/bin/bash

server="${3:-storage-prg1.zerops.io}"
file_path=$2
bucket=$1
set -eu pipefail

contentType="application/octet-stream"
dateValue=`date -R`
signature_string="GET\n\n${contentType}\n${dateValue}\n/${bucket}/${file_path}"

signature_hash=`echo -en ${signature_string} | openssl sha1 -hmac ${SECRET_ACCESS_KEY} -binary | base64`

curl -sSo ${file_path} \
  -H "Date: ${dateValue}" \
  -H "Content-Type: ${contentType}" \
  -H "Authorization: AWS ${ACCESS_KEY_ID}:${signature_hash}" \
  "https://${server}/${bucket}/${file_path}"

Usage

1. Make the script executable:

chmod +x download-storage.sh

2. Set your storage credentials as environment variables:

export ACCESS_KEY_ID=your-access-key
export SECRET_ACCESS_KEY=your-secret-key

3. Run the script:

./download-storage.sh my-bucket file.pdf

Troubleshooting

• Permission Denied: Check your ACCESS_KEY_ID and SECRET_ACCESS_KEY
• File Not Found: Verify bucket name and file path
• Script Error: Ensure the script has execute permissions