本篇文章给大家分享的是有关如何进行docker CE on Linux中的服务编排,小编觉得挺实用的,因此分享给大家学习,希望大家阅读完这篇文章后可以有所收获,话不多说,跟着小编一起来看看吧。
容器部署
资源控制
健康检查
应用配置
规模伸缩
位置迁移
docker-ce原生提供了compose与stack两种方式,通过定义在配置文件中的容器运行参数对服务进行编排,配置文件的格式可以为yaml或json。本文以前端代理(nginx) + web程序(tomcat)为例,简述这两种方式的应用。
宿主机2台:dock_host_0(192.168.9.168/24),dock_host_1(192.168.9.169/24),系统与软件环境一致,均为全新最小化安装,单物理网卡,操作系统版本CentOS Linux release 7.6.1810 (Core),内核版本3.10.0-957.12.2.el7.x86_64,关闭selinux与防火墙。
docker为默认安装,版本18.09.6,无其他额外设置。
基础镜像为最新版CentOS 7官方镜像。
tomcat与jdk环境,以及nginx的配置文件与日志,均以目录的方式挂载至容器。
源码包jdk-8u212-linux-x64.tar.gz与apache-tomcat-8.5.40.tar.gz,位于宿主机的/opt/目录。
nginx为tengine,通过源码编译安装。
安装docker-compose
https://github.com/docker/compose/releases/ 中包含docker-compose的所有版本,本文以1.24.0为例。
下载源文件:
[root@docker_host_0 ~]# ip addr show eth0 | sed -n '/inet /p' | awk '{print $2}'
192.168.9.168/24
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# uname -r
3.10.0-957.12.2.el7.x86_64
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# docker -v
Docker version 18.09.6, build 481bc77156
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# curl -L "https://github.com/docker/compose/releases/download/1.24.0/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 617 0 617 0 0 540 0 --:--:-- 0:00:01 --:--:-- 541
100 15.4M 100 15.4M 0 0 261k 0 0:01:00 0:01:00 --:--:-- 836k
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# ll /usr/local/bin/docker-compose
-rw-r--r-- 1 root root 16154160 May 30 23:23 /usr/local/bin/docker-compose
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# chmod u+x /usr/local/bin/docker-compose
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# which docker-compose
/usr/local/bin/docker-compose
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# docker-compose version
docker-compose version 1.24.0, build 0aa59064
docker-py version: 3.7.2
CPython version: 3.6.8
OpenSSL version: OpenSSL 1.1.0j 20 Nov 2018
[root@docker_host_0 ~]#
添加docker-compose的命令行补全功能:
[root@docker_host_0 ~]# curl -L https://raw.githubusercontent.com/docker/compose/1.24.0/contrib/completion/bash/docker-compose -o /etc/bash_completion.d/docker-compose
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 13258 100 13258 0 0 14985 0 --:--:-- --:--:-- --:--:-- 14980
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# source /etc/bash_completion.d/docker-compose
[root@docker_host_0 ~]#
[root@docker_host_0 ~]# docker-compose
build create exec kill port push run stop up
bundle down help logs ps restart scale top version
config events images pause pull rm start unpause
[root@docker_host_0 ~]#
部署服务
创建目录挂载的源路径:
本例中,tomcat与jdk环境对应的源挂载路径分别为/opt/apps/app_0/source与/opt/jdks。
server.xml中的pattern字段用于设置默认的访问日志格式,更改为%A:%{local}p %a:%{remote}p,表示本端IP:端口 对端IP:端口,用于区分访问来源。
[root@docker_host_0 ~]# cd /opt/
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# ls
apache-tomcat-8.5.40.tar.gz containerd jdk-8u212-linux-x64.tar.gz
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# mkdir -p /opt/{apps/app_0/source,jdks}
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# tar axf apache-tomcat-8.5.40.tar.gz --strip-components=1 -C apps/app_0/source/
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# sed -i 's/pattern="%h %l %u %t/pattern="%A:%{local}p %a:%{remote}p %t/' apps/app_0/source/conf/server.xml
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# tar axf jdk-8u212-linux-x64.tar.gz -C jdks/
[root@docker_host_0 opt]#
编辑dockerfile:
[root@docker_host_0 opt]# vi dockerfile-for-nginx
FROM centos:latest
ARG tmp_dir='/tmp'
ARG repo_key='http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7'
ARG repo_src='http://mirrors.163.com/.help/CentOS7-Base-163.repo'
ARG repo_dst='/etc/yum.repos.d/CentOS-Base.repo'
ARG tengine_ver='2.3.0'
ARG tengine_src="http://tengine.taobao.org/download/tengine-${tengine_ver}.tar.gz"
ARG tengine_dst="tengine-${tengine_ver}.tar.gz"
ARG tengine_cfg_opts='--prefix=/usr/local/nginx \
--with-http_gzip_static_module \
--with-http_stub_status_module \
--with-http_ssl_module \
--with-http_slice_module \
--with-pcre'
ARG depend_rpms='gcc make openssl-devel pcre-devel'
RUN cd ${tmp_dir} \
&& cp -a ${repo_dst} ${repo_dst}.ori \
&& curl -L ${repo_src} -o ${repo_dst} \
&& curl -L ${tengine_src} -o ${tengine_dst} \
&& rpm --import ${repo_key} \
&& yum -y update --downloadonly --downloaddir=. \
&& yum -y install ${depend_rpms} --downloadonly --downloaddir=. \
&& yum -y install ./*.rpm \
&& useradd www -s /sbin/nologin \
&& tar axf ${tengine_dst} \
&& cd tengine-${tengine_ver} \
&& ./configure ${tengine_cfg_opts} \
&& make \
&& make install \
&& cd \
&& yum -y remove gcc make cpp \
&& yum clean all \
&& rm -rf ${tmp_dir}/*
EXPOSE 80/tcp 443/tcp
ENV PATH ${PATH}:/usr/local/nginx/sbin
CMD nginx -g "daemon off;"
编辑服务编排配置文件:
docker中的yaml格式配置文件通常以yml或yaml作为后缀(惯例,非强制)。
本例定义了2个服务,名称分别为webapp与proxy:
webapp服务运行centos:latest镜像(image),挂载数据卷/目录(volumes),并指定环境变量(environment),工作目录(working_dir),容器内运行的命令(command),以及重启策略(restart)为命令运行失败时(on-failure)。
proxy服务运行tengine_nginx:2.3.0镜像,依赖于webapp服务内的容器启动(depends_on)。编译(build)镜像时使用的dockerfile文件名为dockerfile-for-nginx,容器的80端口开放为外部的80端口(ports)。
配置文件内可以通过顶级的networks指令设置网络相关的参数,未指定则按默认设置。对于连接至同一网络驱动下的所有容器,相互之间开放所有端口,本例使用默认网络设置,tomcat默认的8080端口对nginx开放,web服务的访问通过nginx进行转发,因此端口的开放与映射(expose/ports)可选。
[root@docker_host_0 opt]# vi tomcat-with-nginx-compose.yml
version: '3.7'
services:
webapp:
image: centos:latest
volumes:
- /opt/jdks/jdk1.8.0_212:/opt/jdks/jdk1.8.0_212:ro
- /opt/apps/app_0/source:/opt/apps/app_0
environment:
JAVA_HOME: /opt/jdks/jdk1.8.0_212
working_dir: /opt/apps/app_0
command: bin/catalina.sh run
restart: on-failure
proxy:
build:
context: .
dockerfile: dockerfile-for-nginx
depends_on:
- webapp
image: tengine_nginx:2.3.0
volumes:
- /opt/apps/app_0/nginx/conf:/usr/local/nginx/conf:ro
- /opt/apps/app_0/nginx/logs:/usr/local/nginx/logs
restart: on-failure
ports:
- '80:80/tcp'
检查编排配置文件:
docker-compose config命令用于检查配置文件的语法与指令,并输出配置文件的所有内容,若指定-q/--quiet参数则仅执行检查而不输出。
docker-compose默认的配置文件名称为docker-compose.yml或docker-compose.yaml,-f参数用于指定自定义的配置文件。
[root@docker_host_0 opt]# docker-compose -f tomcat-with-nginx-compose.yml config -q
[root@docker_host_0 opt]#
编译镜像:
docker-compose build命令根据配置文件中services.服务名.build定义的参数编译镜像,若配置文件中未指定build指令,则不执行该步骤。
[root@docker_host_0 opt]# docker-compose -f tomcat-with-nginx-compose.yml build
...
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
tengine_nginx 2.3.0 9404e1b71b70 32 seconds ago 340MB
centos latest 9f38484d220f 2 months ago 202MB
[root@docker_host_0 opt]#
以非守护进程模式(nginx -g "daemon off;")运行nginx 60秒,复制nginx所需文件:
[root@docker_host_0 opt]# docker run -dit --rm --name t_nginx tengine_nginx:2.3.0 bash -c 'timeout 60 nginx -g "daemon off;"'
3cc8de88de3fe295657fde08552165e69514c368689e2078ec89771e23cb16e8
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3cc8de88de3f tengine_nginx:2.3.0 "bash -c 'timeout 60…" 7 seconds ago Up 6 seconds 80/tcp, 443/tcp t_nginx
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker exec -it t_nginx ls -l /usr/local/nginx
total 0
drwx------ 2 nobody root 6 May 30 23:39 client_body_temp
drwxr-xr-x 2 root root 333 May 30 23:37 conf
drwx------ 2 nobody root 6 May 30 23:39 fastcgi_temp
drwxr-xr-x 2 root root 40 May 30 23:37 html
drwxr-xr-x 1 root root 58 May 30 23:39 logs
drwx------ 2 nobody root 6 May 30 23:39 proxy_temp
drwxr-xr-x 2 root root 19 May 30 23:37 sbin
drwx------ 2 nobody root 6 May 30 23:39 scgi_temp
drwx------ 2 nobody root 6 May 30 23:39 uwsgi_temp
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker cp t_nginx:/usr/local/nginx/ /opt/apps/app_0/
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# ll /opt/apps/app_0/nginx/
total 0
drwx------ 2 root root 6 May 30 23:39 client_body_temp
drwxr-xr-x 2 root root 333 May 30 23:37 conf
drwx------ 2 root root 6 May 30 23:39 fastcgi_temp
drwxr-xr-x 2 root root 40 May 30 23:37 html
drwxr-xr-x 2 root root 58 May 30 23:39 logs
drwx------ 2 root root 6 May 30 23:39 proxy_temp
drwxr-xr-x 2 root root 19 May 30 23:37 sbin
drwx------ 2 root root 6 May 30 23:39 scgi_temp
drwx------ 2 root root 6 May 30 23:39 uwsgi_temp
[root@docker_host_0 opt]#
编辑nginx配置文件:
docker内部实现了服务发现(service discovery)功能,对连接至同一网络驱动下的容器自动提供名称解析。本例中,webapp服务成功启动后,可以被proxy服务的nginx识别,因此服务名称或别名均可以作为nginx中proxy_pass或upstream的参数。
user www www;
worker_processes auto;
pid logs/nginx.pid;
error_log logs/error.log warn;
worker_rlimit_nofile 51200;
events {
use epoll;
worker_connections 4096;
}
http {
include mime.types;
default_type application/octet-stream;
server_names_hash_bucket_size 128;
client_header_buffer_size 16k;
large_client_header_buffers 4 32k;
client_max_body_size 8m;
access_log off;
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 30;
proxy_cache_methods POST GET HEAD;
open_file_cache max=655350 inactive=20s;
open_file_cache_valid 30s;
open_file_cache_min_uses 2;
gzip on;
gzip_min_length 1k;
gzip_buffers 8 8k;
gzip_http_version 1.0;
gzip_comp_level 4;
gzip_types text/plain application/x-javascript text/css application/xml text/javascript application/x-httpd-php;
gzip_vary on;
server_tokens off;
log_format main '$remote_addr\t$upstream_addr\t[$time_local]\t$request\t'
'$status\t$body_bytes_sent\t$http_user_agent\t$http_referer\t'
'$http_x_forwarded_for\t$request_time\t$upstream_response_time\t$remote_user\t'
'$request_body';
map $http_upgrade $connection_upgrade {
default upgrade;
'' close;
}
upstream tomcat-app-0 {
server webapp:8080;
}
server {
listen 80;
server_name 127.0.0.1;
charset utf-8;
client_max_body_size 75M;
location / {
proxy_pass http://tomcat-app-0;
}
access_log logs/webapp-access.log main;
}
}
测试nginx配置文件:
[root@docker_host_0 opt]# docker run -it --rm --mount type=bind,src=/opt/apps/app_0/nginx/conf,dst=/usr/local/nginx/conf,ro --add-host webapp:127.0.0.1 tengine_nginx:2.3.0 bash -c 'nginx -t'
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful
[root@docker_host_0 opt]#
启动服务:
docker-compose up命令用于启动服务:
默认启动配置文件内定义的所有服务,可以显式指定服务名,以启动特定的服务。若配置文件中指定的镜像名称不存在,则默认首先执行编译(build)。
-d/--detach用于指定容器后台运行,等同于docker run命令的-d/--detach选项。
--scale用于指定相应服务的容器数量,格式为服务名=数量。
[root@docker_host_0 opt]# docker-compose -f tomcat-with-nginx-compose.yml up -d --scale webapp=3
Creating network "opt_default" with the default driver
Creating opt_webapp_1 ... done
Creating opt_webapp_2 ... done
Creating opt_webapp_3 ... done
Creating opt_proxy_1 ... done
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
6b55fe98a99c tengine_nginx:2.3.0 "/bin/sh -c 'nginx -…" 10 seconds ago Up 9 seconds 0.0.0.0:80->80/tcp, 443/tcp opt_proxy_1
0617d640c60a centos:latest "bin/catalina.sh run" 11 seconds ago Up 9 seconds opt_webapp_2
c85f2de181cd centos:latest "bin/catalina.sh run" 11 seconds ago Up 10 seconds opt_webapp_3
2517e03f11c9 centos:latest "bin/catalina.sh run" 11 seconds ago Up 10 seconds opt_webapp_1
[root@docker_host_0 opt]#
docker-compose默认创建bridge模式的网络:
[root@docker_host_0 opt]# docker network ls
NETWORK ID NAME DRIVER SCOPE
cb90714e47b3 bridge bridge local
a019d8b63640 host host local
bb7095896ade none null local
80ce8533b964 opt_default bridge local
[root@docker_host_0 opt]#
查看容器内的进程运行情况:
docker-compose top可以指定服务名称,以查看特定服务内的进程运行情况。
[root@docker_host_0 opt]# docker-compose -f tomcat-with-nginx-compose.yml top
opt_proxy_1
UID PID PPID C STIME TTY TIME CMD
----------------------------------------------------------------------------------------------
root 13674 13657 0 00:28 ? 00:00:00 nginx: master process nginx -g daemon off;
1000 13738 13674 0 00:28 ? 00:00:00 nginx: worker process
1000 13739 13674 0 00:28 ? 00:00:00 nginx: worker process
opt_webapp_1
UID PID PPID C STIME TTY TIME CMD
-------------------------------------------------------------------------------------------------
root 13367 13342 1 00:28 ? 00:00:02 /opt/jdks/jdk1.8.0_212/bin/java -Djava.util.l
ogging.config.file=/opt/apps/app_0/conf/loggi
ng.properties -Djava.util.logging.manager=org
.apache.juli.ClassLoaderLogManager
-Djdk.tls.ephemeralDHKeySize=2048 -Djava.prot
ocol.handler.pkgs=org.apache.catalina.webreso
urces -Dorg.apache.catalina.security.Security
Listener.UMASK=0027 -Dignore.endorsed.dirs=
-classpath /opt/apps/app_0/bin/bootstrap.jar:
/opt/apps/app_0/bin/tomcat-juli.jar
-Dcatalina.base=/opt/apps/app_0
-Dcatalina.home=/opt/apps/app_0
-Djava.io.tmpdir=/opt/apps/app_0/temp
org.apache.catalina.startup.Bootstrap start
opt_webapp_2
UID PID PPID C STIME TTY TIME CMD
-------------------------------------------------------------------------------------------------
root 13436 13388 1 00:28 ? 00:00:02 /opt/jdks/jdk1.8.0_212/bin/java -Djava.util.l
ogging.config.file=/opt/apps/app_0/conf/loggi
ng.properties -Djava.util.logging.manager=org
.apache.juli.ClassLoaderLogManager
-Djdk.tls.ephemeralDHKeySize=2048 -Djava.prot
ocol.handler.pkgs=org.apache.catalina.webreso
urces -Dorg.apache.catalina.security.Security
Listener.UMASK=0027 -Dignore.endorsed.dirs=
-classpath /opt/apps/app_0/bin/bootstrap.jar:
/opt/apps/app_0/bin/tomcat-juli.jar
-Dcatalina.base=/opt/apps/app_0
-Dcatalina.home=/opt/apps/app_0
-Djava.io.tmpdir=/opt/apps/app_0/temp
org.apache.catalina.startup.Bootstrap start
opt_webapp_3
UID PID PPID C STIME TTY TIME CMD
-------------------------------------------------------------------------------------------------
root 13425 13397 1 00:28 ? 00:00:02 /opt/jdks/jdk1.8.0_212/bin/java -Djava.util.l
ogging.config.file=/opt/apps/app_0/conf/loggi
ng.properties -Djava.util.logging.manager=org
.apache.juli.ClassLoaderLogManager
-Djdk.tls.ephemeralDHKeySize=2048 -Djava.prot
ocol.handler.pkgs=org.apache.catalina.webreso
urces -Dorg.apache.catalina.security.Security
Listener.UMASK=0027 -Dignore.endorsed.dirs=
-classpath /opt/apps/app_0/bin/bootstrap.jar:
/opt/apps/app_0/bin/tomcat-juli.jar
-Dcatalina.base=/opt/apps/app_0
-Dcatalina.home=/opt/apps/app_0
-Djava.io.tmpdir=/opt/apps/app_0/temp
org.apache.catalina.startup.Bootstrap start
[root@docker_host_0 opt]#
访问web服务,请求被调度至服务内的每个容器:
[root@docker_host_0 opt]# ss -atn | grep 80
LISTEN 0 128 :::80 :::*
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# for i in $(seq 6); do curl -s 127.0.0.1 -o /dev/null; done
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# cat /opt/apps/app_0/source/logs/localhost_access_log.$(date +%F).txt
172.20.0.3:80 172.20.0.5:42430 [31/May/2019:00:32:16 +0000] "GET / HTTP/1.0" 200 11184
172.20.0.3:80 172.20.0.5:42436 [31/May/2019:00:32:16 +0000] "GET / HTTP/1.0" 200 11184
172.20.0.4:80 172.20.0.5:45098 [31/May/2019:00:32:16 +0000] "GET / HTTP/1.0" 200 11184
172.20.0.4:80 172.20.0.5:45122 [31/May/2019:00:32:16 +0000] "GET / HTTP/1.0" 200 11184
172.20.0.2:80 172.20.0.5:59294 [31/May/2019:00:32:16 +0000] "GET / HTTP/1.0" 200 11184
172.20.0.2:80 172.20.0.5:59306 [31/May/2019:00:32:16 +0000] "GET / HTTP/1.0" 200 11184
[root@docker_host_0 opt]#
扩充服务内的容器数量:
对运行中的服务再次执行docker-compose up命令时,--scale用于在现有基础上动态增加或减小服务内的容器数量。
[root@docker_host_0 opt]# docker-compose -f tomcat-with-nginx-compose.yml up -d --scale webapp=6
Starting opt_webapp_1 ... done
Starting opt_webapp_2 ... done
Starting opt_webapp_3 ... done
Creating opt_webapp_4 ... done
Creating opt_webapp_5 ... done
Creating opt_webapp_6 ... done
opt_proxy_1 is up-to-date
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b9fc74985a13 centos:latest "bin/catalina.sh run" 9 seconds ago Up 7 seconds opt_webapp_4
29e9837c7b4d centos:latest "bin/catalina.sh run" 9 seconds ago Up 7 seconds opt_webapp_5
5e0a0611bb2f centos:latest "bin/catalina.sh run" 9 seconds ago Up 8 seconds opt_webapp_6
6b55fe98a99c tengine_nginx:2.3.0 "/bin/sh -c 'nginx -…" 3 minutes ago Up 3 minutes 0.0.0.0:80->80/tcp, 443/tcp opt_proxy_1
0617d640c60a centos:latest "bin/catalina.sh run" 3 minutes ago Up 3 minutes opt_webapp_2
c85f2de181cd centos:latest "bin/catalina.sh run" 3 minutes ago Up 3 minutes opt_webapp_3
2517e03f11c9 centos:latest "bin/catalina.sh run" 3 minutes ago Up 3 minutes opt_webapp_1
[root@docker_host_0 opt]#
移除服务:
docker-compose down命令用于移除服务,包括停止与移除与服务相关联的容器与网络,另可指定--rmi与-v/--volumes选项移除相关联的数据卷与镜像。
[root@docker_host_0 opt]# docker-compose -f tomcat-with-nginx-compose.yml down
Stopping opt_webapp_4 ... done
Stopping opt_webapp_5 ... done
Stopping opt_webapp_6 ... done
Stopping opt_proxy_1 ... done
Stopping opt_webapp_2 ... done
Stopping opt_webapp_3 ... done
Stopping opt_webapp_1 ... done
Removing opt_webapp_4 ... done
Removing opt_webapp_5 ... done
Removing opt_webapp_6 ... done
Removing opt_proxy_1 ... done
Removing opt_webapp_2 ... done
Removing opt_webapp_3 ... done
Removing opt_webapp_1 ... done
Removing network opt_default
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@docker_host_0 opt]#
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# ss -atn | grep 80
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker network ls
NETWORK ID NAME DRIVER SCOPE
cb90714e47b3 bridge bridge local
a019d8b63640 host host local
bb7095896ade none null local
[root@docker_host_0 opt]#
宿主机docker_host_0创建群集,docker_host_1以管理角色加入群集:
[root@docker_host_0 opt]# docker swarm init
Swarm initialized: current node (u9siv3gxc4px3xa85t5tybv68) is now a manager.
To add a worker to this swarm, run the following command:
docker swarm join --token SWMTKN-1-5icsimlouv1ppt09fxovvlvn9pp3prevlu2vus6wvtdilv6w86-3y28uwlmc5hcb61hw42oxe4j2 192.168.9.168:2377
To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker swarm join-token manager
To add a manager to this swarm, run the following command:
docker swarm join --token SWMTKN-1-5icsimlouv1ppt09fxovvlvn9pp3prevlu2vus6wvtdilv6w86-elvhukieu148f22dmimq914ki 192.168.9.168:2377
[root@docker_host_0 opt]#
[root@docker_host_1 ~]# ip addr show eth0 | sed -n '/inet /p' | awk '{print $2}'
192.168.9.169/24
[root@docker_host_1 ~]#
[root@docker_host_1 ~]# uname -r
3.10.0-957.12.2.el7.x86_64
[root@docker_host_1 ~]#
[root@docker_host_1 ~]# docker -v
Docker version 18.09.6, build 481bc77156
[root@docker_host_1 ~]#
[root@docker_host_1 ~]# docker swarm join --token SWMTKN-1-5icsimlouv1ppt09fxovvlvn9pp3prevlu2vus6wvtdilv6w86-elvhukieu148f22dmimq914ki 192.168.9.168:2377
This node joined a swarm as a manager.
[root@docker_host_1 ~]#
[root@docker_host_1 ~]# docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
u9siv3gxc4px3xa85t5tybv68 docker_host_0 Ready Active Leader 18.09.6
qhgpqw9n5wwow1zfzji69eac0 * docker_host_1 Ready Active Reachable 18.09.6
[root@docker_host_1 ~]#
在docker_host_0节点上导出tengine_nginx:2.3.0镜像,并传输至docker_host_1节点:
[root@docker_host_0 opt]# docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
tengine_nginx 2.3.0 9404e1b71b70 About an hour ago 340MB
centos latest 9f38484d220f 2 months ago 202MB
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker image save tengine_nginx:2.3.0 -o nginx.tar
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# ll -h nginx.tar
-rw------- 1 root root 338M May 31 00:56 nginx.tar
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# scp nginx.tar root@192.168.9.169:/opt
nginx.tar 100% 337MB 83.1MB/s 00:04
[root@docker_host_0 opt]#
在docker_host_1节点上导入tengine_nginx:2.3.0镜像,并设置与docker_host_0节点相同的挂载源路径:
[root@docker_host_1 ~]# cd /opt/
[root@docker_host_1 opt]#
[root@docker_host_1 opt]# ls
apache-tomcat-8.5.40.tar.gz containerd jdk-8u212-linux-x64.tar.gz nginx.tar
[root@docker_host_1 opt]#
[root@docker_host_1 opt]# docker image load -i nginx.tar
d69483a6face: Loading layer 209.5MB/209.5MB
717661697400: Loading layer 144.3MB/144.3MB
Loaded image: tengine_nginx:2.3.0
[root@docker_host_1 opt]#
[root@docker_host_1 opt]# docker image ls -a
REPOSITORY TAG IMAGE ID CREATED SIZE
tengine_nginx 2.3.0 9404e1b71b70 About an hour ago 340MB
[root@docker_host_1 opt]#
[root@docker_host_1 opt]# mkdir -p /opt/{apps/app_0/source,jdks}
[root@docker_host_1 opt]#
[root@docker_host_1 opt]# tar axf apache-tomcat-8.5.40.tar.gz --strip-components=1 -C apps/app_0/source/
[root@docker_host_1 opt]#
[root@docker_host_1 opt]# sed -i 's/pattern="%h %l %u %t/pattern="%A:%{local}p %a:%{remote}p %t/' apps/app_0/source/conf/server.xml
[root@docker_host_1 opt]#
[root@docker_host_1 opt]# tar axf jdk-8u212-linux-x64.tar.gz -C jdks/
[root@docker_host_1 opt]#
在docker_host_0节点上编辑服务编排配置文件:
volumes与port使用长语法(long syntax)格式指定挂载点与端口。
services.服务名.deploy指定服务的运行模式(mode),副本数量(replicas),重启策略(restart_policy),服务所在节点(placement)。
[root@docker_host_0 opt]# vi tomcat-with-nginx-stack.yml
version: "3.7"
services:
webapp:
image: centos:latest
volumes:
- type: bind
source: /opt/jdks/jdk1.8.0_212
target: /opt/jdks/jdk1.8.0_212
read_only: true
- type: bind
source: /opt/apps/app_0/source
target: /opt/apps/app_0
environment:
JAVA_HOME: /opt/jdks/jdk1.8.0_212
working_dir: /opt/apps/app_0
command: bin/catalina.sh run
deploy:
mode: replicated
replicas: 3
restart_policy:
condition: on-failure
proxy:
image: tengine_nginx:2.3.0
volumes:
- type: bind
source: /opt/apps/app_0/nginx/conf
target: /usr/local/nginx/conf
read_only: true
- type: bind
source: /opt/apps/app_0/nginx/logs
target: /usr/local/nginx/logs
deploy:
placement:
constraints:
- node.hostname == docker_host_0
mode: global
restart_policy:
condition: on-failure
ports:
- target: 80
published: 80
protocol: tcp
mode: ingress
部署服务,名称为web-cluster:
[root@docker_host_0 opt]# docker stack deploy -c tomcat-with-nginx-stack.yml web-cluster
Creating network web-cluster_default
Creating service web-cluster_webapp
Creating service web-cluster_proxy
[root@docker_host_0 opt]#
副本服务webapp被分配至2个节点,全局服务proxy按约束条件(constraints)被分配至docker_host_0节点:
[root@docker_host_0 opt]# docker stack ls
NAME SERVICES ORCHESTRATOR
web-cluster 2 Swarm
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
njg5ngjjp9gi web-cluster_proxy global 1/1 tengine_nginx:2.3.0 *:80->80/tcp
wc2uv0zllneo web-cluster_webapp replicated 3/3 centos:latest
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker service ps web-cluster_webapp
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
nh0pei38ikf7 web-cluster_webapp.1 centos:latest docker_host_1 Running Running about a minute ago
otzusftmorjr web-cluster_webapp.2 centos:latest docker_host_1 Running Running about a minute ago
tmjkmrmtbx9g web-cluster_webapp.3 centos:latest docker_host_0 Running Running about a minute ago
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker service ps web-cluster_proxy
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
tal0jywnmukv web-cluster_proxy.u9siv3gxc4px3xa85t5tybv68 tengine_nginx:2.3.0 docker_host_0 Running Running 53 seconds ago
[root@docker_host_0 opt]#
stack默认使用swarm模式创建的overlay网络:
[root@docker_host_0 opt]# docker network ls
NETWORK ID NAME DRIVER SCOPE
b728df2e4b85 bridge bridge local
dfe3ba6e0df5 docker_gwbridge bridge local
a019d8b63640 host host local
mxcmpb9uzjy2 ingress overlay swarm
bb7095896ade none null local
xxl3uk5r7s7v web-cluster_default overlay swarm
[root@docker_host_0 opt]#
通过docker_host_0与docker_host_1节点均可访问被代理的web服务:
[root@docker_host_1 ~]# ss -atn | grep :80
LISTEN 0 128 :::80 :::*
[root@docker_host_1 ~]#
[root@docker_host_1 ~]# curl -I -o /dev/null -s -w %{http_code} 192.168.9.168
200
[root@docker_host_1 ~]# curl -I -o /dev/null -s -w %{http_code} 192.168.9.169
200
[root@docker_host_1 ~]#
[root@docker_host_0 opt]# ss -atn | grep :80
LISTEN 0 128 :::80 :::*
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# curl -I -o /dev/null -s -w %{http_code} 192.168.9.168
200
[root@docker_host_0 opt]# curl -I -o /dev/null -s -w %{http_code} 192.168.9.169
200
[root@docker_host_0 opt]#
移除服务:
对于通过swarm stack方式编排的服务,部署操作为docker stack deploy 服务名,移除操作为docker stack rm 服务名。移除服务后,与之相关联的网络驱动也随之被移除。
[root@docker_host_0 opt]# docker stack ls
NAME SERVICES ORCHESTRATOR
web-cluster 2 Swarm
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker stack rm web-cluster
Removing service web-cluster_proxy
Removing service web-cluster_webapp
Removing network web-cluster_default
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker stack ls
NAME SERVICES ORCHESTRATOR
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
[root@docker_host_0 opt]#
[root@docker_host_0 opt]# docker network ls
NETWORK ID NAME DRIVER SCOPE
b728df2e4b85 bridge bridge local
dfe3ba6e0df5 docker_gwbridge bridge local
a019d8b63640 host host local
mxcmpb9uzjy2 ingress overlay swarm
bb7095896ade none null local
[root@docker_host_0 opt]#
depends_on指令仅可用于docker-compose方式指定镜像的构建顺序,以及容器的启动与停止顺序。若需要解决容器内应用程序间的依赖关系,则需手动实现容器内命令的慢启动(如在容器的脚本内执行目标端口存活或url的可用性检测,以决定是否开启本端服务),或借助于诸如dockerize之类的第三方工具。
stack与compose均通过yaml或json格式的配置文件进行服务的编排,区别主要包括:
某些指令在两种方式下不兼容,如build,deploy,depends_on,restart_policy等。
stack由docker引擎内置,须开启swarm模式,组成同一服务的多个容器可能跨越多个宿主机,因此要求相应的镜像必须存在于宿主机本地或可访问的仓库中;compose需要额外安装,无须开启swarm模式,所有容器均位于当前单个宿主机。
stack仅可根据预先已编译的镜像部署服务;compose支持镜像的编译与服务的部署,二者可同时执行,或单独执行。
以上就是如何进行docker CE on Linux中的服务编排,小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注亿速云行业资讯频道。
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原文链接:https://my.oschina.net/superwjc/blog/3056296