What happens when the following command is executed twice in succession? docker run -tid -v data:/data debian bash
Correct Answer: D
Question 12
What is the purpose of capabilities in the context of container virtualization?
Correct Answer: E
Explanation Capabilities are a way of implementing fine-grained access control in Linux. They are a set of flags that define the privileges that a process can have. By default, a process inherits the capabilities of its parent, but some capabilities can be dropped or added by the process itself or by the kernel. In the context of container virtualization, capabilities are used to prevent processes from performing actions that might infringe the container, such as accessing the host's devices, mounting filesystems, changing the system time, or killing other processes. Capabilities allow containers to run with a reduced set of privileges, enhancing the security and isolation of the container environment. For example, Docker uses a default set of capabilities that are granted to the processes running inside a container, and allows users to add or drop capabilities as needed12. References: * Capabilities | Docker Documentation1 * Linux Capabilities: Making Them Work in Containers2
Question 13
Which of the following commands executes a command in a running LXC container?
Correct Answer: A
Explanation The command lxc-attach is used to execute a command in a running LXC container. It allows the user to start a process inside the container and attach to its standard input, output, and error streams1. For example, the command lxc-attach -n mycontainer -- ls -lh /home will list all the files and directories in the /home directory of the container named mycontainer1. The other options are not valid LXC commands. The command lxc-batch does not exist. The command lxc-run is an alias for lxc-start, which is used to start a container, not to execute a command in it2. The command lxc-enter is also an alias for lxc-attach, but it is deprecated and should not be used3. The command lxc-eval is also not a valid LXC command. References: * 1: Executing a command inside a running LXC - Unix & Linux Stack Exchange. * 2: lxc-start: start a container. - SysTutorials. * 3: lxc-attach: start a process inside a running container. - SysTutorials.
Question 14
What is the purpose of a .dockerignore file?
Correct Answer: D
Question 15
A clone of a previously used virtual machine should be created. All VM specific information, such as user accounts, shell histories and SSH host keys should be removed from the cloned disk image. Which of the following tools can perform these tasks?
Correct Answer: E
Explanation Sysprep is a tool that removes all your personal account and security information, and then prepares the machine to be used as an image. It is supported by Windows and some Linux distributions. It can also remove drivers and other machine-specific settings. Sysprep is required when creating a managed image outside of a gallery in Azure https://learn.microsoft.com/en-us/azure/virtual-machines/generalize
