AWS Cloud Developer: Containers using Docker

Question 1

Common Deployment Headaches

Answer 1

Organizations often have different development environments. These often include development and production.

Deploying and testing the same code across different environments can be cumbersome

In practice, it’s difficult to keep a development and production environment perfectly synchronized with regards to their versions, operating systems, dependencies, etc.

It is common for code to work in a development environment and not behave as expected in production

Question 2

A property where a resource is expected to be terminated

Answer 2

Ephemeral

Question 3

Resources that are required in order to properly run an application

Answer 3

Dependencies

Question 4

The act of making new software changes available

Answer 4

Deployment

Question 5

Why should containers be stateless?

Answer 5

Containers are ephemiral and will eventually be destroyed.

Question 6

Containers

Answer 6

A Container is a unit of eployment. It’s a self-contained application with all the dependencies needed to run

Question 7

Docker command: Create Docker image

Answer 7

docker build -t

Question 8

Docker command: Show Docker images:

Answer 8

docker images

Question 9

Docker command: Run Docker image

Answer 9

docker run

Question 10

Docker command: Show running Docker containers

Answer 10

docker ps

Question 11

Docker command: Terminate a Docker container

Answer 11

docker kill

Question 12

What is a Dockerfile?

Answer 12

A Dockerfile defines the steps to create a Docker Image

Application code uses instructions in a Dockerfile to create a Docker Image which is deployed to Docker Container(s).

Question 13

Docker

Answer 13

Docker is a platform that helps us manage the process of creating and managing our containers.

Question 14

Docker Image

Answer 14

When we have an application that we want to deploy, we can package it into a Docker Image. The image contains all of your code and dependencies.

Question 15

Docker Container

Answer 15

A Docker Container is an ephemeral running instance of a Docker Image.

Question 16

Base image

Answer 16

A set of common dependencies built into a Docker image that acts as a starting point to build an application’s Docker images to reduce build times

Question 17

Container

Answer 17

Grouped software dependencies and packages that make it easier and more reliable to deploy software

Question 18

Container Registry

Answer 18

A centralized place to store container images

Question 19

Docker-compose

Answer 19

A tool used to run multiple Docker containers at once; often used to specify dependent relationships between containers

Question 20

image

Answer 20

A snapshot of dependencies and code used by Docker containers to run an application

Question 21

troubleshooting/debuggin docker

Answer 21

docker inspect
docker logs
docker ps

Attach to container:
docker exec -it sh

once inside run the following to see processes :
ps aux

Question 22

System Process

Answer 22

A computer program run by the operating system

Question 23

What are some reasons why a container may work in a local environment but not run successfully in a deployed environment?

Answer 23

Security restrictions

Not enough system resources

Credentials are different

Question 24

Container Registry

Answer 24

A container registry serves as a centralized place for us to store and version our images.

Question 25

DockerHub

Answer 25

DockerHub is a popular container registry run by the same organization that created Docker.

Question 26

Base Images

Answer 26

Base images reduce time that it takes to run redundant operations.