What is a dangling volume?
- The default volume for the container file system that’s unpacked from the image
- A volume that’s removed from a running container
- A volume that’s not associated with a container (Ans)
- A volume created without a name
Which of the following Windows Features do you need to use Windows Server containers?
- Hyper-V and Containers
- Containers (Ans)
Which of the following stops all running containers?
- docker rmi $(docker ps -q)
- docker rm -f $(docker ps -q)
- docker rm -f $(docker ps -q) (Ans)
- docker halt $(docker ps -q)
In the past, to find software, we often used standalone web sites hosted by the creator of the software. Now, with Docker, how do we discover software?
- Docker Engine
- Docker Hub (Ans)
- App Stores
- Package Managers
- Still use standalone web sites
What does docker history do?
- Shows container history
- Shows commands that we ran inside a given container
- Shows a diff of changes in the container layer
- Shows image history (Ans)
When executing the command “docker pull microsoft/aspnet:4.6.2” what is the “microsoft” piece called?
- User (Ans)
How are image layers coalesced to form a container’s file system?
- A union file system is used to create a union mount point (Ans)
- Files are copied out of layers when creating a container into a union mount point
- Container file systems exist in memory, in a RAM disk, aggregated from image layers
What docker command executes software?
Images contain the entire user space, in other words the entire file system for a container. How is this not horribly inefficient in terms of disk space?
- Images use state of the art compression to reduce the disk space requirements
- Image layers are highly optimized to reduce unnecessary components.
- You only pull down the image layers that you need to run your application
- Images are layered and common layers are shared (Ans)
With Docker for Windows, what container types can you run?
- Windows and Linux (Ans)
- Windows and macOS
- Only Windows
- Only Linux
When executing the command “docker pull microsoft/aspnet:4.6.2” what is the “aspnet” piece called?
- Repository (Ans)
What’s a good analogy for
- Removes the container
- Stops the processes running in a container (Ans)
- Stops a single process in a container
- Uninstalls the container
Removing an image is akin to what in traditional software management?
- Uninstalling an application
- Restarting an application
- Stopping an application
- Deleting an installer file or zip file (Ans)
Which of the following commands will start a new container on the same nodes as container C1?
- docker run -d -e affinity==c1 nginx
- docker run -d -e constraint:container==c1 nginx
- docker run -d -e affinity:container==c1 nginx (Ans)
- docker run -d -e constraint==c1 nginx
Which of the following flags tells the Docker daemon to listen on the network using the default secured Docker port?
- -H tcp://0.0.0.0:3375
- -H tcp://0.0.0.0:2376 (Ans)
- -H tcp://0.0.0.0:2375
- -H tcp://0.0.0.0:3376
Which of the following flags turns on TLS authentication for the Docker daemon?
- –tlsverify (Ans)
How are custom labels implemented?
- They are stored in an external KV store
- They are applied to the Docker Engine daemon at startup (Ans)
- They are applied to the Docker host as environment variables
- A custom metadata container runs on the Docker host
How does Swarm support a pluggable discovery service backend?
- Using libstorage as an abstraction layer
- Using libkv as an abstraction layer (Ans)
- By publishing an open API that key-value stores can work with
Which of the following is the default scheduling strategy for Swarm clusters?
- Spread (Ans)
Which of the following Swarm components support High Availability?
- Swarm manager and directory service
- Swarm manager and discovery service (Ans)
- Swarm manager and scheduling service
- Just the Swarm manager