一、简介
在微服务架构应用中,众多组件在集群中动态地创建、伸缩、更新。在如此动态和大规模的分布式系统上,管理和分发密码、证书等敏感信息将会是非常具有挑战性的工作。对于容器应用,传统的秘密分发方式,如将秘钥存放在容器镜像中,或是利用环境变量,volume动态挂载方式动态传入都存在着潜在的安全风险。
为了应对这个问题,在Docker 1.13及更高版本中,Docker推出了Secrets管理,可以在Swarm mode集群中安全地管理密码、密钥证书等敏感信息,并允许在多个Docker容器实例之间共享访问指定的秘密信息。
二、基本功能和应用
注: docker secret
只能从Docker Swarm模式的manager节点调用,如果你在本机进行试验,请先执行 docker swarm init
命令
Docker命令行工具提供了docker secret
命令来管理敏感信息
# docker secret --helpUsage: docker secret COMMANDManage Docker secretsOptions:Commands: create Create a secret from a file or STDIN as content inspect Display detailed information on one or more secrets ls List secrets rm Remove one or more secrets
其中 docker secret create
支持从标准输入读取信息,并且存入指定的secret
(1)创建两个secrets
# echo "Password4DB" | docker secret create db_password -anyyxxynb6r9ra9698f38c86x# echo "Password4Root" | docker secret create root_password -8ipun85hi89ibsg5ftp3l3uda
# docker secret lsID NAME DRIVER CREATED UPDATEDanyyxxynb6r9ra9698f38c86x db_password 3 minutes ago 3 minutes ago8ipun85hi89ibsg5ftp3l3uda root_password 3 minutes ago 3 minutes ago
(2)创建一个db服务,并引用secret作为数据库和root密码
# docker service create \--name my-db \--publish 3306:3306 \--secret db_password \--secret root_password \-e MYSQL_ROOT_PASSWORD_FILE=/run/secrets/root_password \-e MYSQL_USER=dbtest \-e MYSQL_DATABASE=dbtest \-e MYSQL_PASSWORD_FILE=/run/secrets/db_password \mysql
(3)检查服务状态
# docker service lsID NAME MODE REPLICAS IMAGE PORTSb9rvq5wwln5p my-db replicated 1/1 mysql:latest *:3306->3306/tcp# docker service ps my-dbID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS7hezr6rtkp0k my-db.1 mysql:latest node-03 Running Running 4 minutes ago
(4)查看挂在到容器中的密码文件
# docker exec -it 56d5845c6741 ls /run/secrets/db_password root_password# docker exec -it 56d5845c6741 cat /run/secrets/db_passwordPassword4DB# docker exec -it 56d5845c6741 cat /run/secrets/root_passwordPassword4Root
(5)登入验证
# mysql -h host_ip -uroot -pEnter password: Welcome to the MariaDB monitor. Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.21 MySQL Community Server (GPL)Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.MySQL [(none)]> show databases;+--------------------+| Database |+--------------------+| information_schema || dbtest || mysql || performance_schema || sys |+--------------------+5 rows in set (0.00 sec)
三、容器编排中使用 docker secret
从 Docker Compose V3.1开始,支持在容器编排文件中使用 secret,这可以方便地在不同容器中分享所需的敏感信息。下面将使用 Compose 模板来构建一个Wordpress应用,通过 secret 实现 “wordpress”服务容器和“db”服务容器中共享数据库密码。
(1)secret_stack.yml
version: "3.3"services: wordpress: image: wordpress:latest secrets: - wp_db_password ports: - "8080:80" environment: - WORDPRESS_DB_USER=wordpress - WORDPRESS_DB_NAME=wordpress - WORDPRESS_DB_PASSWORD_FILE=/run/secrets/wp_db_password - WORDPRESS_DB_HOST=mysql deploy: replicas: 3 update_config: parallelism: 2 delay: 10s restart_policy: condition: on-failure mysql: image: mysql:latest secrets: - wp_db_password - root_db_password environment: - MYSQL_USER=wordpress - MYSQL_DATABASE=wordpress - MYSQL_PASSWORD_FILE=/run/secrets/wp_db_password - MYSQL_ROOT_PASSWORD_FILE=/run/secrets/root_db_password deploy: replicas: 1 restart_policy: condition: on-failuresecrets: wp_db_password: external: true root_db_password: external: true
(2)生成密码
[root@manager stack_compose]# echo "Password4DB" | docker secret create wp_db_password -xtkut0zoe7u774aymwremncpj[root@manager stack_compose]# echo "Password4Root" | docker secret create root_db_password -nx22on48v96qdph2k3s7hs6mv
(3)部署服务
# docker stack deploy -c secret_stack.yml wordpress
(4)查看部署情况
[root@manager ~]# docker service lsID NAME MODE REPLICAS IMAGE PORTSxa450wyt625o wordpress_mysql replicated 1/1 mysql:latest otpkb5li30vx wordpress_wordpress replicated 3/3 wordpress:latest *:8080->80/tcp
(5)配置WordPress
访问host_ip:8080