Container Orchestration Flashcards
How applications talk to each other when service mesh is present?
Through proxies
What forms data plane?
Proxies in service mesh
What data plane is responsible for
Load balancing
Application traffic
Observability
Routing
What is proxy used for?
Filtering and/or modifying traffic before it reaches the server.
popular proxies
nginx
haproxy
envoy
Standard for service mesh
Doesn’t exist yet. Service Mesh Interface(SMI) project aimed to change that but it got archived in october
Popular service meshes
linkerd
istio
Service mesh
Adds sidecar container proxy server to every container
What network plugins must follow in kubernetes?
CNI standard
Most modern implementations of container networking are based on the
Container Networking Interface(CNI)
What takes care of containers IP management?
most overlay networks
How to allow communication between containers across hosts
overlay network which puts them in a virtual network that is spanned across the host systems
How to make container accessible from outside the system?
By mapping container port to host system port
Can multiple containers in the same cluster expose the same port number?
Yes
What allows each container to have its own unique ip address?
network namespaces
Are containers as well isolated as virtual machines?
No
What containers share with host machine
kernel
4C of Cloud Native security
Code
Container
Cluster
Cloud
Docker drop-in replacement
podman
Used only for image building
kaniko
buildah
what runtime-spec describes?
unpack container image
manage complete container lifecycle
creating container environment
starting the process
stopping the process
deleting the process
Container runtime reference implementation
runC
What every container runtime must follow
OCI runtime-spec standard
Why storage for containers is hard
because containers are ephemeral
What layer is put on top of the container image when you start a container from an image
read-write layer
What happens to read-write layer when container is stopped or deleted?
It dissapears
How to persist data on a host?
with volume
How does volumes work?
They map directory/file in host filesystem to directory/file in container filesystem
