title: Azure App Service using Containers: When is the container updated?
body: <p>I am running Azure App Service using Docker containers.
  I don't really find a documentation, under which circumstances a container is updated.</p>
  <p>In addition I would like to use app service slots and I am not sure, if this changes anything.</p>
  <p>I assume, if one can control updates (especially with swapping slots) the tag in siteconfig/linux_fx_version can be set to latest. If it can not be controlled (for example container updates can occur at random times) the best option is to use explicit version tags and update them on each deployment.</p>
  <p>I am not sure if my assumption is correct.</p>
  <p>A reduced example of my according terraform code:</p>
  <pre><code>resource &quot;azurerm_app_service&quot; &quot;example&quot; {
    name                = &quot;example&quot;
    resource_group_name       = &quot;example&quot;
    location                  = ..
    app_service_plan_id = &quot;example&quot;
  
    app_settings = local.env_vars
  
    site_config {
      linux_fx_version = &quot;DOCKER|someimage:latest&quot;
    }
  
  }
  
  resource &quot;azurerm_app_service_slot&quot; &quot;staging&quot; {
    name                       = &quot;staging&quot;
    location                   = ..
    resource_group_name        = &quot;example&quot;
    app_service_plan_id        = &quot;example&quot;
  
    app_settings = local.env_vars
  
    site_config {
      linux_fx_version = &quot;DOCKER|someimage:latest&quot;
    }
  
  }
  </code></pre>