evalle/dca

Docker Certified Associate Exam Preparation Guide

Docker Certified Associate Exam Preparation Guide (v1.5 December 2022)

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Introduction

This guide is intended to be a point of knowledge for everyone who wants to pass Docker Certified Associate Exam. The main idea is to provide links to every topic in each domain. Preference will always be the official documentation, but feel free to add useful links.

Web version can be found here: DCA website

Important Info

Some of the products have been renamed, there are no changes regarding this in the Official Study Guide yet.

• Docker Trusted Registry (DTR) was renamed to Mirantis Secure Registry (MSR) - announcement
• Docker Enterprise/UCP was renamed to Mirantis Kubernetes Engine (MKE) - announcement

Table of Contents

1. Orchestration
2. Image Creation, Management, and Registry
3. Installation and Configuration
4. Networking
5. Security
6. Storage and Volumes
7. Exam Details
8. Useful Links
9. Useful Preparation Links

Content

Domain 1: Orchestration (25% of exam)

• Complete the setup of a swarm mode cluster, with managers and worker nodes
• Describe and demonstrate how to extend the instructions to run individual containers into running services under swarm
• Describe the importance of quorum in a swarm cluster.
• Describe the difference between running a container and running a service.
• Interpret the output of “docker inspect” commands
• Convert an application deployment into a stack file using a YAML compose file with "docker stack deploy"
• Manipulate a running stack of services
• Describe and demonstrate orchestration activities
• Increase number of replicas
• Add networks, publish ports
• Mount volumes
• Describe and demonstrate how to run replicated and global services
• Apply node labels to demonstrate placement of tasks (Label a Swarm Node , Use Placement Constraints)
• Describe and demonstrate how to use templates with “docker service create”
• Identify the steps needed to troubleshoot a service not deploying
• Describe how a Dockerized application communicates with legacy systems
• Describe how to deploy containerized workloads as Kubernetes pods and deployments
• Describe how to provide configuration to Kubernetes pods using configMaps and secrets

Domain 2: Image Creation, Management, and Registry (20% of exam)

• Describe the use of Dockerfile
• Describe options, such as add, copy, volumes, expose, entry point
• Identify and display the main parts of a Dockerfile
• Describe and demonstrate how to create an efficient image via a Dockerfile
• Describe and demonstrate how to use CLI commands to manage images, such as list, delete, prune, rmi
• Describe and demonstrate how to inspect images and report specific attributes using filter and format
• Describe and demonstrate how to tag an image.
• Describe and demonstrate how to apply a file to create a Docker image
• Describe and demonstrate how to display layers of a Docker image
• Describe and demonstrate how to modify an image to a single layer (multi-stage build, single layer)
• Describe and demonstrate registry functions
• Deploy a registry
• Log into a registry
• Utilize search in a registry
• Push an image to a registry
• Sign an image in a registry
• Pull and delete images from a registry

Domain 3: Installation and Configuration (15% of exam)

• Describe sizing requirements for installation
• Describe and demonstrate the setup of repo, selection of a storage driver, and installation of the Docker engine on multiple platforms
• Describe and demonstrate configuration of logging drivers (splunk, journald, etc.)
• Describe and demonstrate how to set up swarm, configure managers, add nodes, and setup the backup schedule
• Describe and demonstrate how to create and manage user and teams
• Describe and demonstrate how to configure the Docker daemon to start on boot
• Describe and demonstrate how to use certificate-based client-server authentication to ensure a Docker daemon has the rights to access images on a registry
• Describe the use of namespaces, cgroups, and certificate configuration
• Describe and interpret errors to troubleshoot installation issues without assistance
• Describe and demonstrate the steps to deploy the docker engine in Docker, DTR, UCP, Docker on AWS and possibly on premises HA config
• Describe and demonstrate how to configure backups for UCP and DTR:
  • UCP
  • DTR

Domain 4: Networking (15% of exam)

• Describe the Container Network Model and how it interfaces with the Docker engine and network and IPAM drivers
• Describe the different types and use cases for the built-in network drivers
• Describe the types of traffic that flow between the Docker engine, registry and UCP controllers
• Describe and demonstrate how to create a Docker bridge network for developers to use for their containers
• Describe and demonstrate how to publish a port so that an application is accessible externally
• Identify which IP and port a container is externally accessible on
• Compare and contrast “host” and “ingress” publishing modes (Host, Ingress)
• Describe and demonstrate how to configure Docker to use external DNS
• Describe and demonstrate how to use Docker to load balance HTTP/HTTPs traffic to an application (Configure L7 load balancing with Docker EE)
• Describe and demonstrate how to deploy a service on a Docker overlay network
• Describe and demonstrate how to troubleshoot container and engine logs to resolve connectivity issues between containers
• (Since Study Guide 1.5) Describe how to route traffic to Kubernetes pods using ClusterIP and NodePort services
• (Since Study Guide 1.5) Describe the Kubernetes’ container network model

Domain 5: Security (15% of exam)

• (Since Study Guide 1.5) Describe security administration and tasks
• Describe the process of signing an image
• Describe default engine security
• Describe swarm default security
• Describe MTLS
• Identity roles
• Describe the difference between UCP workers and managers:
  • workers
  • managers
• Describe process to use external certificates with:
  1. UCP
  • from cli
  • from GUI
  • print the public certificates
  2. DTR is now Mirantis Secure Registry or MSR
• Describe and demonstrate that an image passes a security scan
• Describe and demonstrate how to enable Docker Content Trust.
• Describe and demonstrate how to configure RBAC with UCP
• Describe and demonstrate how to integrate UCP with LDAP/AD
• Describe and demonstrate how to create UCP client bundles

Domain 6: Storage and Volumes (10% of exam)

• Identify the correct graph drivers to uses with various operating systems
• Describe and demonstrate how to configure devicemapper
• Compare and contrast object and block storage and when they should be used
• Describe how an application is composed of layers and where these layers reside on the filesystem
• Describe how volumes are used with Docker for persistent storage
• Identify the steps you would take to clean up unused images on a filesystem, also on DTR. (image prune, system prune and from DTR)
• Demonstrate how storage can be used across cluster nodes, ex.
• (Since Study Guide 1.5) Describe how to provision persistent storage to a Kubernetes pod using persistentVolumes
• (Since Study Guide 1.5) Describe the relationship between container storage interface drivers, storageClass, persistentVolumeClaim and volume objects in Kubernetes

Exam Details

• 13 multiple choice and 42 discrete option multiple choice (DOMC) questions in 90 minutes
• Designed to validate professionals with a minimum of 6 to 12 months of Docker experience
• Remotely proctored on your Windows or Mac computer
• Available globally in English
• USD $195 or Euro €200 purchased online
• Results delivered immediately

Useful Links

• About the exam
• Official study guide (PDF)
• Schedule your Docker Certified Associate Exam

Preparation

• 250 Practice Questions

Contributors

Thanks to all contributors!

dca's Issues

Domain 1: Identify the steps needed to troubleshoot a service not deploying

https://success.mirantis.com/article/swarm-troubleshooting-methodology

This link is no longer available from Mirantis. 😞

Domain 1: Apply node labels to demonstrate placement of tasks

https://success.mirantis.com/article/using-contraints-and-labels-to-control-the-placement-of-containers

This link is no longer available at Mirantis 😞

try this as a replacement: https://docs.docker.com/engine/swarm/services/#control-service-placement

Add links with the answer to any question in any domain

See https://github.com/Evalle/DCA#domain-2-image-creation-management-and-registry-20-of-exam and https://docs.docker.com/engine/reference/builder/#from as an example. You can either
open one pull request for every question or have a bunch of answers in one PR - is up to you :)

Revised DCA prep guide

Official DCA prep guide is recently updated(May 2020) and contains some new topics. New topics also covers references to Kubernetes. Is it possible to update this study guide to include new entries in syllabus?

Replace Docker stack deploy link

The hyperlink "Convert an application deployment into a stack file using a YAML compose file with "docker stack deploy" in domain 1 currently refers to the corresponding command reference. IMO, the docs would be a better fit: https://docs.docker.com/engine/swarm/stack-deploy/

It is more comprehensive and the other links refer to the docs as well.

Preparation material info

this seems to be for paid members of medium - https://github.com/Evalle/DCA#preparation
is there a way to access these 250 Questions?

DCA

Evalle there is no link available for topic - "Display layers of a Docker image".
I found one link to define the layers under below URL - https://medium.com/@jessgreb01/digging-into-docker-layers-c22f948ed612

Thanks,
Snehil Belekar

Describe process to use external certificates with UCP and DTR

For UCP external certificates we can use the below links. Please check it.
from cli : https://success.docker.com/article/how-do-i-provide-an-externally-generated-security-certificate-during-the-ucp-command-line-installation

from gui : https://docs.docker.com/ee/ucp/admin/configure/use-your-own-tls-certificates/

print public certs : https://docs.docker.com/reference/ucp/3.0/cli/dump-certs/

Domain 4: Describe and demonstrate how to use Docker to load balance HTTP/HTTPs traffic to an application

Link redirects to docker main page

Maybe this is better? https://docs.mirantis.com/mke/3.4/ops/administer-cluster/join-nodes/use-a-load-balancer.html

Domain 4: Describe and demonstrate how to troubleshoot container and engine logs to resolve connectivity issues between containers

link redirects to main page: https://training.mirantis.com/

possible replacements:

• https://docs.docker.com/engine/reference/commandline/logs/
• https://docs.docker.com/config/daemon/logs/

Domain 3: Describe and demonstrate the steps to deploy the docker engine in Docker, DTR, UCP, Docker on AWS and possibly on premises HA config

The link for "UCP" doesn't exist (404)

Try this instead: https://docs.mirantis.com/mke/3.5/install/install-mke-image.html

DCA Study guide query

Hi guys,
is this the updated guide for the DCA exam? https://github.com/Evalle/DCA#useful-links
It looks published in August 2020
has anyone taken this exam recently?
thanks!