title: call AWS Elasticsearch Service API with cURL --aws-sigv4
body: <p>when I execute</p>
  <pre class="lang-sh prettyprint-override"><code>curl --request GET &quot;https://${ES_DOMAIN_ENDPOINT}/my_index_pattern-*/my_type/_mapping&quot; \
  --user $AWS_ACCESS_KEY_ID:$AWS_SECRET_ACCESS_KEY \
  --aws-sigv4 &quot;aws:amz:ap-southeast-2:es&quot;
  </code></pre>
  <p>where <code>$ES_DOMAIN_ENDPOINT</code> is my AWS Elasticsearch endpoint, I'm getting the following response:</p>
  <blockquote>
  <p>{&quot;message&quot;:&quot;The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method. Consult the service documentation for details.&quot;}</p>
  </blockquote>
  <p>I'm confident that my <code>$AWS_ACCESS_KEY_ID:$AWS_SECRET_ACCESS_KEY</code> are correct.</p>
  <p>However, when I send the same postman request with the AWS Authentication and the parameters above, the response is coming through. I compared the verbose output of both requests and they have very minor differences, such as timestamps and signature.</p>
  <p>I'm wondering, what is wrong with the <code>--aws-sigv4</code> config?</p>