Container Orchestration

Question 1

How applications talk to each other when service mesh is present?

Answer 1

Through proxies

Question 2

What forms data plane?

Answer 2

Proxies in service mesh

Question 3

What data plane is responsible for

Answer 3

Load balancing
Application traffic
Observability
Routing

Question 4

What is proxy used for?

Answer 4

Filtering and/or modifying traffic before it reaches the server.

Question 5

popular proxies

Answer 5

nginx
haproxy
envoy

Question 6

Standard for service mesh

Answer 6

Doesn’t exist yet. Service Mesh Interface(SMI) project aimed to change that but it got archived in october

Question 7

Popular service meshes

Answer 7

linkerd
istio

Question 8

Service mesh

Answer 8

Adds sidecar container proxy server to every container

Question 9

What network plugins must follow in kubernetes?

Answer 9

CNI standard

Question 10

Most modern implementations of container networking are based on the

Answer 10

Container Networking Interface(CNI)

Question 11

What takes care of containers IP management?

Answer 11

most overlay networks

Question 12

How to allow communication between containers across hosts

Answer 12

overlay network which puts them in a virtual network that is spanned across the host systems

Question 13

How to make container accessible from outside the system?

Answer 13

By mapping container port to host system port

Question 14

Can multiple containers in the same cluster expose the same port number?

Answer 14

Yes

Question 15

What allows each container to have its own unique ip address?

Answer 15

network namespaces

Question 16

Are containers as well isolated as virtual machines?

Answer 16

No

Question 17

What containers share with host machine

Answer 17

kernel

Question 18

4C of Cloud Native security

Answer 18

Code
Container
Cluster
Cloud

Question 19

Docker drop-in replacement

Answer 19

podman

Question 20

Used only for image building

Answer 20

kaniko
buildah

Question 21

what runtime-spec describes?

Answer 21

unpack container image
manage complete container lifecycle
creating container environment
starting the process
stopping the process
deleting the process

Question 22

Container runtime reference implementation

Answer 22

runC

Question 23

What every container runtime must follow

Answer 23

OCI runtime-spec standard

Question 24

Why storage for containers is hard

Answer 24

because containers are ephemeral

Question 25

What layer is put on top of the container image when you start a container from an image

Answer 25

read-write layer

Question 26

What happens to read-write layer when container is stopped or deleted?

Answer 26

It dissapears

Question 27

How to persist data on a host?

Answer 27

with volume

Question 28

How does volumes work?

Answer 28

They map directory/file in host filesystem to directory/file in container filesystem