docker容器交付配置管理

参考 https://docs.docker.com/engine/reference/commandline/run/#set-environment-variables--e---env---env-file

Docker容器配置管理

Set environment variables (-e, --env, --env-file)

$ docker run -e MYVAR1 --env MYVAR2=foo --env-file ./env.list ubuntu bash

Use the -e, --env, and --env-file flags to set simple (non-array) environment variables in the container you’re running, or overwrite variables that are defined in the Dockerfile of the image you’re running.

You can define the variable and its value when running the container:

$ docker run --env VAR1=value1 --env VAR2=value2 ubuntu env | grep VAR

VAR1=value1

VAR2=value2

You can also use variables that you’ve exported to your local environment:

export VAR1=value1

export VAR2=value2

 

$ docker run --env VAR1 --env VAR2 ubuntu env | grep VAR

VAR1=value1

VAR2=value2

When running the command, the Docker CLI client checks the value the variable has in your local environment and passes it to the container. If no = is provided and that variable is not exported in your local environment, the variable won’t be set in the container.

You can also load the environment variables from a file. This file should use the syntax <variable>=value (which sets the variable to the given value) or <variable> (which takes the value from the local environment), and # for comments.

$ cat env.list

# This is a comment

VAR1=value1

VAR2=value2

USER

 

$ docker run --env-file env.list ubuntu env | grep VAR

VAR1=value1

VAR2=value2

USER=denis

通过env查看抓取环境变量

测试案例

root@playbook-master:~/test# cat Dockerfile

FROM ubuntu:16.04

RUN apt update && apt install -y python-pip lrzsz

ADD . /root

WORKDIR /root

CMD ["python","env_docker.py"]

root@playbook-master:~/test# cat redis.conf

{{var1}}

{{var2}}

{{password_redis}}

 

root@playbook-master:~/test# cat var.txt

var1=docker

var2=redis

password_redis=123456

__config_location=/root/redis.conf

root@playbook-master:~/test# docker run --name env1 -d --env-file ./var.txt env:test

eb6eb002f1d03d783d49fd17b872abf96370323d50f00fafba1fed4e23e91141

root@playbook-master:~/test# docker ps

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES

eb6eb002f1d0        env:test            "python env_docker.py"   2 seconds ago       Up 1 second                             env1

root@playbook-master:~/test# docker exec -it env1 /bin/bash

root@eb6eb002f1d0:~# cat redis.conf

docker

redis

123456

python 处理脚本Env_docker.py

# -*- coding:utf-8 -*-

#!/usr/bin/python

import os

import re

import time

def alter(file):

    dict = os.environ

   

    file_data = ""

    with open(file,"r") as f:

        for line in f:

            for key in dict.keys():

                if key in dict.keys():

                    keya = "{{"+key+"}}"

                    line = line.replace(keya,dict[key])

            file_data += line

    with open(file,"w") as f:

        f.write(file_data)

 

dict=os.environ

filenames = dict['__config_location']

filenames = filenames.split(',')

for filename in filenames:

    print(filename)

    alter(filename)

time.sleep(60)  #测试添加入env_docker.py脚本

shell处理脚本（ubuntu /bin/sh不支持数组功能，要用/bin/bash)

#!/bin/bash

deal(){

   key=($(env|awk -F= '{print $1}'))

   value=($(env|awk -F= '{print $2}'))

   num=$(env|wc -l)

   for ((i=0;i<$num;i++))

   do

         key1=${key[$i]}

         keya="{{"$key1"}}"

         value1=${value[$i]}

         grep $keya $file >/dev/null

         if [ $? -eq 0 ];

         then

             sed -i "s/$keya/$value1/g" $file

         fi

   done

}

for file in `echo ${__config_location}|awk -F, '{for(i=1;i<=NF;i++){print $i;}}'`

do

   deal

done