# Docker Certified Associate – Domain 2: Image Creation, Management, and Registry (20% of exam)

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Docker Certified Associate - Domain 2: Image Creation, Management, and Registry (20% of exam)

1. Which of the following is needed to build an image with 'docker build' command ?
2. Which of the following does build-context refer to, while building image using docker build command ?
3. when running 'docker build' all files and folders in build context is sent to docker daemon first and only then the build begins. True or False ?
4. To avoid unused files from getting picked up from build context, which of the following can be done ?
5. Which of the following is true about docker image can be tags.
6. which of the following is true about docker image build ?
7. Which of the following is true about docker image build ?
8. When building image from Dockerfile, every time a 'FROM' instruction is encountered, a build stage is set and sets the base image for next coming instructions. True or False ?
9. ENV variables in Dockerfile can also be referenced as regular variables in docker file using ${varname} during image build stage. True or False ?} 10. ARG instructions are used to define variables to be used during build stage only and cannot be referenced in container. True or False ? 11. In which of the following scenarios, a reference to an ARG in docker file returns an empty string ? 12. If ARG is defined in Dockerfile and also passed as a build time argument using --build-arg, which one takes priority ? 13. When same variable is defined in ENV and ARG, which one takes priority when it is referenced during build time ? 14. When 'exec' form of instruction is defined for RUN or CMD, variable substitution does not happen since it does not invoke a shell. True or False ? 15. There can only be one CMD instruction in a Dockerfile. If you list more than one CMD then only the last CMD will take effect. True or False ? 16. Which of the following is the main purpose of CMD instruction in Dockerfile ? 17. Which of the following the difference between ENTRYPOINT and CMD instruction ? 18. What is the main purpose of using SHELL instruction in Dockerfile ? 19. If any build steps change the data within the docker volume after it has been declared, those changes will be discarded. True or False 20. Predefined vars such as FTP_PROXY or HTTP_PROXY is excluded from docker history to protect sensitive information. True or False ? 21. ONBUILD instruction in Dockerfile is only run when building another image that uses the original image as base image that used the Dockerfile. True or False ? 22. Image layers for ONBUILD instructions are cleared from cache and cannot be inherited. True or False ? 23. How to disable an health check instruction defined in base image ? 24. Which of the following is true about Dockerfile Instruction ? 25. ARG variables are not persisted into the built image as ENV variables are. True or False ? 26. for COPY and ADD instructions, if the source file hash has changed then the cache is invalidated and the instructions are built again. True or False ? 27. How to override ENV vars defined in image while running container ? 28. '--entrypoint ' can be passed to "docker run" command, to override the default ENTRYPOINT command defined in Dockerfile. True or False ? 29. What is the use of 'WORKDIR' instruction in Dockerfile ? 30. For any instruction such as RUN or ADD etc, if multiple WORKDIR is defined in Dockerfile, the last WORKDIR defined prior to the instruction is used. True or False ? 31. Building an image from a git URL as build context requires git installed for it to work.. True or False 32. Which of the following is the main advantage of using multi stage build ? 33. what is cache-busting ? 34. Which one of the following is the difference between "docker image import" and "docker image load" ? 35. Which of the following command(s) show the layers of an image ? 36. Which command is used to remove dangling images (images/layers that is not a part of any tagged image) 37. what is the difference between "docker image prune" and "docker image prune -a" ? 38. "docker image save" can not only archive(tar) multiple images but also all of the intermediate layers in that image. True or False ? 39. what does 'docker image ls --filter "dangling=true"' command do ? 40. When running "docker image ls --filter" argument 'before' lists all images created 'before' the specified image and 'since' lists the ones created since the creation of specified image. True or False ? 41. Which filter can be passed to "docker image ls --filter" to list images matching a specific pattern. Example "myimage*:tag*" 42. Which of the following is true about docker image naming rules ? 43. which one of the following is a valid example of tagging an image to a private registry ? 44. Which of the following is a valid example of pushing an image to a private registry ? 45. What are the environmental variables required to secure registry instance with TLS ? 46. To implement TLS in registry, an intermediate certificate can be concatenated to domain certificate to form a bundle. (example: cat domain.crt intermediate-certificates.pem > certs/domain.crt) True or False. 47. What are the environmental variables required to implement basic native auth in registry in order to restrict registry access ? 48. where is the docker auth credentials stored in docker host ? 49. how to allow push operation for non-distributed layers of an image to private registries ? 50. root user or sudo is required to run "docker login" command. True or False ? 51. In order to store registry credentials in credential store/key chain instead of storing in config.json, a credential helper program needs to be configured in config.json as "credsStore": "myhelperprogram". This helper program should be available in$PATH in docker host. True or False ?
52. As per credential helper protocol, what are the arguments the helper program used to interact with credential store ?
53. What does "docker commit "
54. How to control the maximum number of concurrent image layers pushed or pulled by docker daemon ?
55. Which of the following operations are supported by "docker trust" command ?