Implementation of Docker Batch Container Arrangement

Brief introduction

Dockerfile build run is a single container operated manually. If micro-service architecture is used, 100 + containers need to be started. How to maintain the dependency between them?
Docker Compose is used to manage containers easily and efficiently, defining multiple containers to run.

Three steps:

Dockerfile Services & docker-compose.yml docker-compose up

Initial experience

1.Dockerfile

FROM python:3.7-alpine
WORKDIR /code
ENV FLASK_APP app.py
ENV FLASK_RUN_HOST 0.0.0.0
RUN apk add --no-cache gcc musl-dev linux-headers
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
COPY . .
CMD ["flask", "run"]

2.Service

import time
import redis
from flask import Flask
app = Flask(__name__)
cache = redis.Redis(host='redis', port=6379)
def get_hit_count():
  retries = 5
  while True:
    try:
      return cache.incr('hits')
    except redis.exceptions.ConnectionError as exc:
      if retries == 0:
        raise exc
      retries -= 1
      time.sleep(0.5)
@app.route('/')
def hello():
  count = get_hit_count()
  return 'Hello World! I have been seen {} times.\n'.format(count)

docker-compose.yml

version: '3'
services:
web:
 build: .
 ports:
- "5000:5000"
 volumes:
- .:/code
 - logvolume01:/var/log
 links:
- redis
redis:
 image: redis
volumes:
logvolume01: {}
docker-compose up
Starting compose-demo_web_1  ... done
Starting compose-demo_redis_1 ... done
Attaching to compose-demo_redis_1, compose-demo_web_1
redis_1 | 1:C 12 Sep 2020 07:34:09.654 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
redis_1 | 1:C 12 Sep 2020 07:34:09.655 # Redis version=6.0.7, bits=64, commit=00000000, modified=0, pid=1, just started
redis_1 | 1:C 12 Sep 2020 07:34:09.655 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf
redis_1 | 1:M 12 Sep 2020 07:34:09.657 * Running mode=standalone, port=6379.
redis_1 | 1:M 12 Sep 2020 07:34:09.657 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
redis_1 | 1:M 12 Sep 2020 07:34:09.657 # Server initialized
redis_1 | 1:M 12 Sep 2020 07:34:09.658 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
redis_1 | 1:M 12 Sep 2020 07:34:09.658 * Loading RDB produced by version 6.0.7
redis_1 | 1:M 12 Sep 2020 07:34:09.658 * RDB age 156 seconds
redis_1 | 1:M 12 Sep 2020 07:34:09.658 * RDB memory usage when created 0.77 Mb
redis_1 | 1:M 12 Sep 2020 07:34:09.658 * DB loaded from disk: 0.000 seconds
web_1  | * Serving Flask app "app.py"
web_1  | * Environment: production
web_1  |  WARNING: This is a development server. Do not use it in a production deployment.
web_1  |  Use a production WSGI server instead.
web_1  | * Debug mode: off
YML  File rule 
version: "1.0" # Version 
services: # Service list 
  service1:
    # Service configuration 
    container_name: # Container name 
    depends_on: # Dependency list 
    - depend1
    - depend2
    images: # Mirror image 
    - image1
    - image2
    build:. # Build catalog 
    network: # Network 
    ......
  service2: test2
    ......
volumnes: # Mount directory list 
networks: # Network list 
configs: # Other configurations