Tag: docker

Enable buildkit in docker and use heredoc feature

Why buildkit?
– Better build logs
– Better build cache

Temp enable buildkit

nginx.Dockerfile

# syntax=docker/dockerfile:1.3-labs
FROM nginx

COPY <<EOF /usr/share/nginx/html/index.html
"hola Duniya"
EOF

DOCKER_BUILDKIT=1 docker build -t here-nginx -f nginx.Dockerfile .

Enable buildkit permanently :

echo "{ "features": { "buildkit": true } }" > /etc/docker/daemon.json


systemctl restart docker

More : https://github.com/moby/buildkit

Introduction to heredocs in Dockerfiles

Mount single file in docker

We can use –mount type=bind parameter to mount single file

docker run  -d -p 9090:9090 --mount type=bind,source=/opt/prometheus/prometheus.yml,target=/etc/prometheus/prometheus.yml prom/prometheus:v2.22.0

Using docker-compose file

version: "3.7"    
services:
  prometheus:
    image: prom/prometheus:v2.22.0
    volumes:
      - type: bind
        source: /opt/prometheus/prometheus.yml
        target: /etc/prometheus/prometheus.yml
    ports:
      - 9090:9090

More : https://stackoverflow.com/questions/42248198/how-to-mount-a-single-file-in-a-volume

https://docs.docker.com/storage/bind-mounts/

ELK on docker-compose

version: '2.2'
services:
  elasticsearch:
    image: docker.elastic.co/elasticsearch/elasticsearch:7.12.0
    container_name: elasticsearch
    environment:
      discovery.type: "single-node"
    volumes:
      - /root/elasticsearch:/usr/share/elasticsearch/data
    ports:
      - 9200:9200

  kibana:
    image: docker.elastic.co/kibana/kibana:7.12.0
    container_name: kibana
    environment:
      elasticsearch.hosts: "elasticsearch:9200"
    ports:
      - 5601:5601

Rabbitmq docker-compose

version: '3'
services:
  rabbitmq:
    image: rabbitmq:3-management
    restart: always
    container_name: rabbitmq
    environment:
      TZ: "Asia/Kolkata"
      RABBITMQ_DEFAULT_USER: username
      RABBITMQ_DEFAULT_PASS: password
    volumes:
      - /opt/rabbitmq/data:/var/lib/rabbitmq
    ports:
      - 5671:5671
      - 5672:5672
      - 15672:15672

Docker command :

dodocker run -d -p 5671:5671 -p 5672:5672 -p 15672:15672 -v /opt/rabbitmq/data:/var/lib/rabbitmq -e RABBITMQ_DEFAULT_USER=user -e RABBITMQ_DEFAULT_PASS=password  -e TZ="Asia/Kolkata" --restart unless-stopped rabbitmq:3-management

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