Docker DCA Exam With Confidence Using Practice Dumps

Label constraints can be used to schedule containers to meet the security policy requirements. Label constraints allow you to specify which nodes a service can run on based on the labels assigned to the nodes1. For example, you can label the nodes that are intended for development with env=dev and the nodes that are intended for production with env=prod. Then, you can use the --constraint flag when creating a service to restrict it to run only on nodes with a certain label value. For example, docker service create --name dev-app --constraint 'node.labels.env == dev' ... will create a service that runs only on development nodes2. Similarly, docker service create --name prod-app --constraint 'node.labels.env == prod' ... will create a service that runs only on production nodes3. This way, you can ensure that development and production containers are running on separate nodes in a given Swarm cluster. References:

• Add labels to swarm nodes
• Using placement constraints with Docker Swarm
• Multiple label placement constraints in docker swarm

= Simultaneously creating and tagging multiple images is not an advantage of multi-stage builds. Multi-stage builds are a feature that allows you to use multiple FROM statements in your Dockerfile, each starting a new stage of the build1. You can selectively copy artifacts from one stage to another, leaving behind everything you don’t want in the final image. This helps you to optimize the size and security of your images, as well as to simplify your build process12. However, multi-stage builds do not create or tag multiple images at once. Each Dockerfile produces one final image, which is the result of the last stage in the Dockerfile1. If you want to create and tag multiple images from a single Dockerfile, you need to use the --target option with the docker build command, and specify the name of the stage you want to build and tag3. References:

• Multi-stage builds | Docker Docs
• What Are Multi-Stage Docker Builds? - How-To Geek
• Stop at a specific build stage | Docker Docs