A Bash script to generate and send authenticated HTTP requests to the Exoscale API v2 using HMAC-SHA256 signatures.

exoscale-api-sign.bash

#!/bin/bash

if [ $# -lt 2 ] || [ $# -gt 3 ]; then
    echo "Usage: $0 <method> <url-path> [expiration]"
    echo "Example: $0 GET instance 1717430400"
    echo "Parameters:"
    echo "  method      - HTTP method (GET, POST, PUT, DELETE)"
    echo "  url-path    - API path without /v2/ prefix"
    echo "  expiration  - (optional) Unix epoch timestamp (default: now + 300s)"
    exit 1
fi

host="https://api-ch-gva-2.exoscale.com"

method="$1"
url="/v2/$2"
if [ -n "$3" ]; then
    expiration="$3"
else
    expiration=$(($(date +%s) + 300))
fi

if [ -z "$EXOSCALE_API_KEY" ] || [ -z "$EXOSCALE_API_SECRET" ]; then
    echo "Error: EXOSCALE_API_KEY and EXOSCALE_API_SECRET environment variables must be set."
    exit 1
fi

key="$EXOSCALE_API_KEY"
secret="$EXOSCALE_API_SECRET"

body=""
qparams=""
rheaders=""
msg="$method $url
$body
$qparams
$rheaders
$expiration"

signature=$( echo -n "$msg" | openssl dgst -sha256 -hmac "$secret" -binary | base64 )
authHeader="Authorization: EXO2-HMAC-SHA256 credential=$key,expires=$expiration,signature=$signature"

echo "########"
echo SIGNATURE: curl -v -X "$method" -H "\"$authHeader\"" "${host}${url}"
echo "########"

curl -X "$method" -H "$authHeader" "${host}${url}" && echo