Technical Environment

--- primary_color: steelblue secondary_color: lightgray text_color: black shuffle_questions: false shuffle_answers: true --- # Which statement best describes a Docker container? 1. [ ] A lightweight virtual machine with its own kernel 2. [x] A running instance of an image with an isolated filesystem and process space 3. [ ] A software package that includes only application code 4. [ ] A hypervisor-compatible execution environment # In Docker, what does each instruction in a Dockerfile typically create? 1. [ ] A new container 2. [ ] A new image 3. [x] A new layer 4. [ ] A new network # What is the key benefit of UnionFS in Docker images? 1. [ ] It encrypts data stored in containers 2. [x] It merges multiple layers into a single unified filesystem 3. [ ] It ensures containers have direct access to host hardware 4. [ ] It removes the need for caching during builds # What happens when a running container modifies a file that resides in a read-only image layer? 1. [ ] The file is edited directly in the read-only layer 2. [x] Docker duplicates the file into the writable layer (copy-on-write) 3. [ ] The container is forced to restart 4. [ ] The change is discarded when the container exits # Which Docker network type is created automatically and used by default for containers? 1. [ ] host 2. [ ] verlay 3. [ ] none 4. [x] bridge # What is a major difference between the default bridge network and a user-defined bridge network? 1. [ ] The default bridge supports DNS-based container name resolution 2. [x] A user-defined bridge supports DNS-based container name resolution 3. [ ] The default bridge is faster than user-defined networks 4. [ ] User-defined bridges cannot be used with Docker Compose # Which command exposes container port 80 on host port 8080? 1. [ ] docker run -p 80:8080 myimage 2. [ ] docker run -p 8080 myimage 3. [x] docker run -p 8080:80 myimage 4. [ ] docker run --expose 8080 myimage # Why are named volumes generally recommended for databases? 1. [ ] They automatically encrypt data 2. [ ] They are easier to mount to multiple containers simultaneously 3. [x] They persist data independently of containers and avoid OS-specific paths 4. [ ] They automatically create database users and permissions # In Docker Compose, how do services communicate with each other by default? 1. [ ] By using their container IDs 2. [x] By using their service names as hostnames 3. [ ] By sharing the host network 4. [ ] By exposing all ports to each other # Which statement about bind mounts is TRUE? 1. [ ] They store data inside Docker’s internal storage 2. [ ] They are recommended for production database storage 3. [x] They map a host directory into the container’s filesystem 4. [ ] They cannot be used on Windows or macOS