Debug School: Sruthi

Kubernetes

Sruthi — Tue, 18 Oct 2022 06:40:42 +0000

Kubernetes Architecture Kubernetes follows a client-server architecture and it has the master node and worker nodes.
Component of master kube-apiserver, an etcd storage, a kube-controller-manager and a kube-scheduler
Component of worker kubelet, kubeproxy and container engine

10 major problems solved by Kubernetes

Sruthi — Tue, 18 Oct 2022 04:47:22 +0000

1) Scalability - Add instances of your application services as needed
2) Auto-healing - It monitors the health state of the cluster and automatically repairs Kubernetes’ components that are unhealthy.
3) Networking challenges
4) Datacenter as computer - Kubernetes
5) Service Discovery - Kubernetes makes it easy for containers to communicate with each other
6) Self-monitoring: Checks the health of nodes and the container itself
7) Automating the deployment, management and scaling of containerized applications
8) Load balancing
9) Sharing of storage across multiple containers
10) Automatic resource allocation

Assignement 1

Sruthi — Mon, 17 Oct 2022 08:40:35 +0000

root@ip-172-31-18-66:/home/ubuntu# docker pause 38fc821c437d
38fc821c437d
root@ip-172-31-18-66:/home/ubuntu# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
38fc821c437d httpd "httpd-foreground" 15 minutes ago Up 10 seconds (Paused) 80/tcp srucon
root@ip-172-31-18-66:/home/ubuntu# docker unpause 38fc821c437d
38fc821c437d
root@ip-172-31-18-66:/home/ubuntu# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
38fc821c437d httpd "httpd-foreground" 15 minutes ago Up 19 seconds 80/tcp srucon

PAUSE and UNPAUSE docker commands are used to pause and resume containers using cgroup freezer

Assignment

Sruthi — Mon, 17 Oct 2022 07:22:43 +0000

root@ip-172-31-18-66:/home/ubuntu# docker stop 38fc821c437d
38fc821c437d
root@ip-172-31-18-66:/home/ubuntu# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
38fc821c437d httpd "httpd-foreground" 2 minutes ago Exited (0) 4 seconds ago srucon

Docker stop - sends SIGTERM signal to the running container to stop the processes gracefully.

root@ip-172-31-18-66:/home/ubuntu# docker kill 38fc821c437d
38fc821c437d
root@ip-172-31-18-66:/home/ubuntu# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
38fc821c437d httpd "httpd-foreground" 2 minutes ago Exited (137) 2 seconds ago srucon

Docker kill - kills the container and does not shutdown the process gracefully