Category: Uncategorized

Jenkins questions list

  • install jenkins using docker-compose
  • default port for jenkins 8080
  • Explain the your CICD pipeline
  • What is DSL?
  • How do you manage credentials in jenkins?
  • explain the basic structure of Jenkinsfile?
  • how jobs are managed for different branch/ multibranch?
  • What issues you faced in jenkins? = plugin high disk IO
  • build trigger?
  • how to configure webhook?
  • poll SCM?
  • light checkout in jekins?
  • groovy sandbox?
  • add worker node in jenkins? types of method?

Sonatype Nexus3 – Docker compose

version: '3'
services:
  jenkins:
    image: sonatype/nexus3:3.29.0
    user: root:root
    restart: always
    container_name: nexus
    environment:
      TZ: "Asia/Kolkata"
    volumes:
      - /opt/nexus-data:/nexus-data
    ports:
      - 8081:8081

Get admin passwords:

docker exec -it nexus bash

find / -iname admin.*

#OR

docker exec -it nexus  cat /nexus-data/admin.password

More : https://hub.docker.com/r/sonatype/nexus3#user-content-persistent-data

Nomad – Container orchestration example for Dev environment

#Install nomad

-Download the stable release form https://www.nomadproject.io/downloads

wget https://releases.hashicorp.com/nomad/1.0.1/nomad_1.0.1_linux_amd64.zip

unzip nomad_1.0.1_linux_amd64.zip

mv nomad /usr/local/bin/

#start nomad in dev mode

nomad agent -dev

nomad node status

#Install docker https://docs.docker.com/engine/install/centos/

yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo

yum install docker-ce docker-ce-cli containerd.io

systemctl start docker
systemctl enable docker

#Create simple nginx job file (nginx.nomad)

job "nginx" {
  datacenters = ["dc1"]
  type = "service"

  update {
    max_parallel = 1
    min_healthy_time = "10s"
    healthy_deadline = "3m"
    progress_deadline = "10m"
    auto_revert = false

    canary = 0
  }
  migrate {
    max_parallel = 1
    health_check = "checks"
    min_healthy_time = "10s"
    healthy_deadline = "5m"
  }
  group "cache" {
    count = 1

    network {
      port "nginx-port" {
        to = 80
      }
    }

    service {
      name = "nginx-port"
      tags = ["nginx", "web"]
      port = "nginx-port"

    }

    restart {
      attempts = 2
      interval = "30m"
      delay = "15s"
      mode = "fail"
    }

    ephemeral_disk {
      size = 300
    }


    task "nginx" {
      driver = "docker"

      config {
        image = "nginx"
        ports = ["nginx-port"]
      }

      resources {
        cpu    = 500
        memory = 256
      }

    }
  }
}

#Nomand commands for Run,Stop, job status and logs

nomad job status

nomad job run nginx.nomad

nomad job stop nginx

nomad job status nginx

nomad alloc status <Allocations ID>

nomad alloc logs <Allocations ID>

#Access webUI at http://127.0.0.1:4646

Rancher proxy rule in httpd with websocket secure (wss)

<VirtualHost *:80>
	ServerName rancher.initedit.com
	Redirect permanent / https://rancher.initedit.com/
	RewriteEngine on
	RewriteCond %{SERVER_NAME} =rancher.initedit.com [OR]
	RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,QSA,R=permanent]
</VirtualHost>

<VirtualHost *:443>
    ServerName rancher.initedit.com
    AllowEncodedSlashes on
    SSLEngine On
    SSLProxyEngine On
    RewriteEngine on
    SSLProxyVerify none
    SSLProxyCheckPeerCN off
    SSLProxyCheckPeerName off
    SSLProxyCheckPeerExpire off
    RequestHeader set X-Forwarded-Proto "https"
    RewriteCond %{HTTP:Upgrade} =websocket [NC]
    RewriteRule /(.*)   wss://192.168.0.183:8443/$1 [P,L]
    RewriteCond %{HTTP:Upgrade} !=websocket [NC]
    RewriteRule /(.*)   https://192.168.0.183:8443/$1 [P,L]
    ProxyPassReverse / https://192.168.0.183:8443/
    ProxyPreserveHost On
    SSLCertificateFile /etc/letsencrypt/live/rancher.initedit.com/cert.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/rancher.initedit.com/privkey.pem
    SSLCertificateChainFile /etc/letsencrypt/live/rancher.initedit.com/fullchain.pem
    Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>

More info : https://stackoverflow.com/questions/27526281/websockets-and-apache-proxy-how-to-configure-mod-proxy-wstunnel

run postgres with docker-compose

postgres.yml

version: '3'
services:
  postgres:
    image: postgres
    restart: always
    container_name: postgres
    environment:
      POSTGRES_PASSWORD: "password"
    volumes:
      - /opt/docker/postgres:/var/lib/postgresql/data
    ports:
      - 5432:5432

start : docker-compose -f postgres.yml up -d
stop : docker-compose -f postgres.yml down