title: How to run "docker login azure" from Azure DevOps pipeline
body: <p>I have a shell script that deploys containers to Azure Container Instances that runs fine locally using the Azure CLI (on Linux) but I'm having trouble performing the login to Azure from a pipeline task.</p>
  <p>Locally the following command will open a browser to login:</p>
  <p><code>docker login azure</code></p>
  <p>The docs suggest that to do the same in a pipeline task I can pass in a client id and client secret. I <em>think</em> that it should look like this:</p>
  <p><code>docker login azure --client-id $servicePrincipalId --client-secret $servicePrincipalKey --tenant-id $tenantId</code></p>
  <p>However, when I run this in my pipeline I get this error:</p>
  <p><code>unknown flag: --client-id</code></p>
  <p><code>docker login azure --help</code> run locally tells me that <code>--client-id</code> is a valid flag, so I'm wondering is there another way to do this in an Azure DevOps pipeline?</p>