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☣️ What is a Taint?A taint is applied to a node to mark it as unsuitable for certain pods, unless those pods explicitly tolerate the taint.It works like this:🛑 "This node doesn't want your pod... unless you're okay with my taint."  🔧 Taint Syntaxkubectl taint nodes key=value:effect 🧪 Examplekubectl taint nodes node1 key=env:NoSchedule🛡️ What is a Toleration?A toleration is added to a pod sp..

🧠 What is Scheduling in Kubernetes?Kubernetes scheduling is how the system decides which node should run a given Pod. The Kube-scheduler is the component that assigns Pods to Nodes.When you create a Pod, it starts in a "Pending" state. The scheduler looks at:The Pod’s requirements (like CPU, memory, labels)The cluster's current stateThe available nodesThen it picks the best node to run the Pod...

🌐 What is a Service in Kubernetes?A Service is an abstraction that defines a stable way to access a set of Pods (usually grouped by a label selector). It exposes an application running in your cluster behind a single outward-facing endpoint, even when the workload is split across multiple backends. Since Pods are ephemeral (they come and go), a Service ensures that your app always has a reliabl..

🔁 ReplicaSetA ReplicaSet (RS) ensures that a specified number of replica Pods are running at any given time. If a Pod goes down, the RS automatically creates a new one.🔧 Example YAML:apiVersion: apps/v1kind: ReplicaSetmetadata: name: my-replicasetspec: replicas: 3 selector: matchLabels: app: myapp template: metadata: labels: app: myapp spec: containers: ..

YAML (YAML Ain’t Markup Language) is a human-readable data serialization format, often used for configuration files, especially in tools like Kubernetes, Docker Compose, and Ansible.🧠 YAML ConceptsKey-Value PairsBasic structure is key: value.Indentation MattersYAML uses indentation (spaces only) to define structure. No tabs allowed.ListsRepresented with dashes -.Nested StructuresKeys can contai..

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. Here’s a breakdown of core concepts and main components:🔹 Core ConceptsClusterA set of machines (nodes) running Kubernetes. It consists of a control plane and worker nodes.NodeA physical or virtual machine in the cluster that runs pods. There are:Ma..

Docker image 파일 구조image : docker.io/nginx/nginxdocker.io : registry첫번째 nignx : 사용자 계정두번째 nginx : Image repos Docker registry 생성# Private docker registry logindocker login private-registry.io# Run private registrydocker run private-registry.io/apps/internal-app Docker registry 배포# Private registry registrationdocker run -d -p 5000:5000 --name registry registry:2# Tag docker image to private regis..

Docker network네트워크 확인# docker network 확인docker network ls# docker network 상세 정보 확인docker network inspect Docker에서 생성할 수 있는 네트워크는 bridge, host, none의 3 종류이다.bridge : 컨테이너가 동일한 네트워크 내에 존재한다. Default 설정host : 호스트 네트워크를 공유한다.none : 어떤 네트워크도 할당하지 않는다. 네트워크 생성 및 지정 실행docker network create# --subnet : 네트워크 대역 설정 -> --subnet 10.10.0.0/16# --ip-range : IP 범위 지정 -> --ip-range # --driver : bridge..

Dockerfile 은 Docker image를 어떻게 build 할지 지정하는 명령어 집합을 다룬 스크립트다. Dockerfile 내부 구조# OS - UbuntuFROM Ubuntu# Update pip and install dependencies using pipRUN apt-get updateRUN apt-get install python# Install python dependencies using pipRUN pip install flaskRUN pip install flask-mysql# Copy source code to /opt folderCOPY . /opt/source-code# Run the wbe server using 'flask' commandENTRYPOINT FLASK_AP..

Docker build Docker 이미지를 생성하는 명령어 1. -t, --tag -t : myapp:latest 순으로 이름과 tag(선택)를 명시한다.. : 현재 디렉터리# docker build -t : .docker build -t myapp:1.0 .  2. --build-argDockerfile 내에 'ARG', 'ARG_NAME'을 설정하여 이미지 빌드 시 변수를 정의한다.# docker build --build-arg = -t .docker build --build-arg APP_ENV=prod -t myapp:prod . Docker run 생성한 Docker 이미지 실행 및 이미지가 존재하지 않을 경우 외부 Docker hub에서 이미지를 import 하여 실행한다. 1. 기본 구조..