探索云原生技术之基石-Docker容器入门篇(4)【与云原生的故事】

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探索云原生技术之基石-Docker容器入门篇(4)

本博文一共有7篇，如下

• 探索云原生技术之基石-Docker容器入门篇(1)
• 探索云原生技术之基石-Docker容器入门篇(2)
• 探索云原生技术之基石-Docker容器入门篇(3)
• 探索云原生技术之基石-Docker容器入门篇(4)，=>由于篇幅过长，所以另起一篇

等你对Docker有一定理解的时候可以看高级篇，不过不太建议。

• 探索云原生技术之基石-Docker容器高级篇(1)
• 探索云原生技术之基石-Docker容器高级篇(2)
• 探索云原生技术之基石-Docker容器高级篇(3）-视情况而定

剧透：未来将出云原生技术-Kubernetes（k8s），此时的你可以对Docker进行统一管理、动态扩缩容等等。

看完之后你会对Docker有一定的理解，并能熟练的使用Docker进行容器化开发、以及Docker部署微服务、Docker网络等等。干起来！

什么是云原生

Pivotal公司的Matt Stine于2013年首次提出云原生（Cloud-Native）的概念；2015年，云原生刚推广时，Matt Stine在《迁移到云原生架构》一书中定义了符合云原生架构的几个特征：12因素、微服务、自敏捷架构、基于API协作、扛脆弱性；到了2017年，Matt Stine在接受InfoQ采访时又改了口风，将云原生架构归纳为模块化、可观察、可部署、可测试、可替换、可处理6特质；而Pivotal最新官网对云原生概括为4个要点：DevOps+持续交付+微服务+容器。

总而言之，符合云原生架构的应用程序应该是：采用开源堆栈（K8S+Docker）进行容器化，基于微服务架构提高灵活性和可维护性，借助敏捷方法、DevOps支持持续迭代和运维自动化，利用云平台设施实现弹性伸缩、动态调度、优化资源利用率。

（此处摘选自《知乎-华为云官方帐号》）

什么是Docker

• Docker 是一个开源的应用容器引擎，基于Go语言开发。
• Docker 可以让开发者打包他们的应用以及依赖包到一个轻量级、可移植的容器中，然后发布到任何流行的 Linux 机器上，也可以实现虚拟化。
• 容器是完全使用沙箱机制（容器实例相互隔离），容器性能开销极低（高性能）。

总而言之：

Docker是一个高性能的容器引擎；

可以把本地源代码、配置文件、依赖、环境通通打包成一个容器即可以到处运行；

使用Docker安装软件十分方便，而且安装的软件十分精简，方便扩展。

Docker安装常用的软件

Ubuntu安装

• 拉取Ubuntu镜像

$ docker pull ubuntu

• 运行Ubuntu

$ docker run -it --name MyUbuntu ubuntu

[root@aubin ~]# docker run -it --name MyUbuntu ubuntu
root@9cb5882e5c7d:/# ls
bin   dev  home  lib32  libx32  mnt  proc  run   srv  tmp  var
boot  etc  lib   lib64  media   opt  root  sbin  sys  usr

FastDFS安装

$ docker search fastdfs
$ docker pull delron/fastdfs
$ docker images
$ docker run -dti --network=host --name tracker -v /var/fdfs/tracker:/var/fdfs -v /etc/localtime:/etc/localtime delron/fastdfs tracker
   docker run -dti  --network=host --name storage -e TRACKER_SERVER=192.168.184.132:22122 -v /var/fdfs/storage:/var/fdfs  -v /etc/localtime:/etc/localtime  delron/fastdfs storage
$ docker ps #查看容器id
$ docker exec -it 容器id /bin/bash
#下面这两行命令可以不写，就默认配置
$ vi /etc/fdfs/storage.conf
$ vi /usr/local/nginx/conf/nginx.conf
   
$ firewall-cmd --zone=public  --permanent --add-port=8888/tcp
$ firewall-cmd --zone=public  --permanent --add-port=22122/tcp
$ firewall-cmd --zone=public  --permanent --add-port=23000/tcp
   
#重启防火墙
$ systemctl restart firewalld

#自启动
$ docker update --restart=always tracker
$ docker update --restart=always storage

RabbitMQ安装

$ docker pull rabbitmq    #从Docker仓库拉取最新的RabbitMQ镜像
$ docker run -d --hostname my-rabbit --name yblog-rabbit -p 15672:15672 -p 5672:5672 rabbitmq  #运行RabbitMQ镜像
$ docker exec -it yblog-rabbit /bin/bash   #进入RabbitMQ容器
$ rabbitmq-plugins enable rabbitmq_management   #安装RabbitMQ的插件

MySQL5.7安装（生产环境）

拉取MySQL镜像

$ docker pull mysql:5.7

启动mysql并挂载容器数据卷

    $ docker run -d -p 3306:3306 --privileged=true -v /bf/mysql/log:/var/log/mysql -v /bf/mysql/data:/var/lib/mysql -v /bf/mysql/conf:/etc/mysql/conf.d -e MYSQL_ROOT_PASSWORD=123456 --name mysql mysql:5.7

在宿主机所在conf目录新建my.cnf文件

• 如果不指定配置文件会导致编码问题（就如下面那样）

查看MySQL编码

mysql> show variables like 'character%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | latin1                     |
| character_set_connection | latin1                     |
| character_set_database   | latin1                     |
| character_set_filesystem | binary                     |
| character_set_results    | latin1                     |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.01 sec)

• 可以看出默认的mysql编码格式是：latin1，这样对我们明显是不行的

• 我们要修改成UTF-8或者utf-8mb4

my.cnf 文件：

[client]
default_character_set=utf8
[mysqld]
collation_server=utf8_general_ci
character_set_server=utf8

利用my.cnf文件，解决编码问题

[root@aubin ~]# cd /bf/mysql/conf
[root@aubin conf]# vim my.cnf

• 然后把上面的my.cnf内容复制进去。

重启容器

$ docker restart mysql 

登录MySQL

mysql -u root -p

再次查看编码

mysql> show variables like 'character%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | utf8                       |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | utf8                       |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.01 sec)

• 大功告成了

进入MySQL客户端，查看MySQL编码

show variables like 'character%';

进入MySQL客户端

$ docker exec -it mysql /bin/bash

登录

mysql -u 你的MySQL帐号 -p

• 然后回车。
• 输入密码即可。

Redis6.2.6安装（生产环境）

• 拉取redis镜像

$ docker pull redis6.2.6

• 创建宿主机redis配置文件夹

$ mkdir /home/redis

$ mkdir /home/redis/data

$ vim redis.conf

• 再次目录创建redis.conf，内容如下：

bind 0.0.0.0

protected-mode no

# Accept connections on the specified port, default is 6379 (IANA #815344).
# If port 0 is specified Redis will not listen on a TCP socket.
port 6379

tcp-backlog 511

# Close the connection after a client is idle for N seconds (0 to disable)
timeout 0

tcp-keepalive 300

daemonize no

supervised no

pidfile /var/run/redis_6379.pid

loglevel notice

logfile "/data/redis.log"

databases 16

always-show-logo yes

save 900 1
save 300 10
save 60 10000

stop-writes-on-bgsave-error yes

rdbcompression yes

rdbchecksum yes

# The filename where to dump the DB
dbfilename dump.rdb

dir /data

replica-serve-stale-data yes

replica-read-only yes

repl-diskless-sync no

repl-diskless-sync-delay 5

repl-disable-tcp-nodelay no

replica-priority 100

# A Redis master is able to list the address and port of the attached
# replicas in different ways. For example the "INFO replication" section
# offers this information, which is used, among other tools, by
# Redis Sentinel in order to discover replica instances.
# Another place where this info is available is in the output of the
# "ROLE" command of a master.
#
# The listed IP and address normally reported by a replica is obtained
# in the following way:
#
#   IP: The address is auto detected by checking the peer address
#   of the socket used by the replica to connect with the master.
#
#   Port: The port is communicated by the replica during the replication
#   handshake, and is normally the port that the replica is using to
#   listen for connections.
#
# However when port forwarding or Network Address Translation (NAT) is
# used, the replica may be actually reachable via different IP and port
# pairs. The following two options can be used by a replica in order to
# report to its master a specific set of IP and port, so that both INFO
# and ROLE will report those values.
#
# There is no need to use both the options if you need to override just
# the port or the IP address.
#
# replica-announce-ip 5.5.5.5
# replica-announce-port 1234

################################## SECURITY ###################################

# Require clients to issue AUTH <PASSWORD> before processing any other
# commands.  This might be useful in environments in which you do not trust
# others with access to the host running redis-server.
#
# This should stay commented out for backward compatibility and because most
# people do not need auth (e.g. they run their own servers).
#
# Warning: since Redis is pretty fast an outside user can try up to
# 150k passwords per second against a good box. This means that you should
# use a very strong password otherwise it will be very easy to break.
#
requirepass

# Command renaming.
#
# It is possible to change the name of dangerous commands in a shared
# environment. For instance the CONFIG command may be renamed into something
# hard to guess so that it will still be available for internal-use tools
# but not available for general clients.
#
# Example:
#
# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
#
# It is also possible to completely kill a command by renaming it into
# an empty string:
#
# rename-command CONFIG ""
#
# Please note that changing the name of commands that are logged into the
# AOF file or transmitted to replicas may cause problems.

################################### CLIENTS ####################################

# Set the max number of connected clients at the same time. By default
# this limit is set to 10000 clients, however if the Redis server is not
# able to configure the process file limit to allow for the specified limit
# the max number of allowed clients is set to the current file limit
# minus 32 (as Redis reserves a few file descriptors for internal uses).
#
# Once the limit is reached Redis will close all the new connections sending
# an error 'max number of clients reached'.
#
# maxclients 10000

############################## MEMORY MANAGEMENT ################################

# Set a memory usage limit to the specified amount of bytes.
# When the memory limit is reached Redis will try to remove keys
# according to the eviction policy selected (see maxmemory-policy).
#
# If Redis can't remove keys according to the policy, or if the policy is
# set to 'noeviction', Redis will start to reply with errors to commands
# that would use more memory, like SET, LPUSH, and so on, and will continue
# to reply to read-only commands like GET.
#
# This option is usually useful when using Redis as an LRU or LFU cache, or to
# set a hard memory limit for an instance (using the 'noeviction' policy).
#
# WARNING: If you have replicas attached to an instance with maxmemory on,
# the size of the output buffers needed to feed the replicas are subtracted
# from the used memory count, so that network problems / resyncs will
# not trigger a loop where keys are evicted, and in turn the output
# buffer of replicas is full with DELs of keys evicted triggering the deletion
# of more keys, and so forth until the database is completely emptied.
#
# In short... if you have replicas attached it is suggested that you set a lower
# limit for maxmemory so that there is some free RAM on the system for replica
# output buffers (but this is not needed if the policy is 'noeviction').
#
# maxmemory <bytes>

# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
# is reached. You can select among five behaviors:
#
# volatile-lru -> Evict using approximated LRU among the keys with an expire set.
# allkeys-lru -> Evict any key using approximated LRU.
# volatile-lfu -> Evict using approximated LFU among the keys with an expire set.
# allkeys-lfu -> Evict any key using approximated LFU.
# volatile-random -> Remove a random key among the ones with an expire set.
# allkeys-random -> Remove a random key, any key.
# volatile-ttl -> Remove the key with the nearest expire time (minor TTL)
# noeviction -> Don't evict anything, just return an error on write operations.
#
# LRU means Least Recently Used
# LFU means Least Frequently Used
#
# Both LRU, LFU and volatile-ttl are implemented using approximated
# randomized algorithms.
#
# Note: with any of the above policies, Redis will return an error on write
#       operations, when there are no suitable keys for eviction.
#
#       At the date of writing these commands are: set setnx setex append
#       incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
#       sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
#       zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
#       getset mset msetnx exec sort
#
# The default is:
#
# maxmemory-policy noeviction

lazyfree-lazy-eviction no
lazyfree-lazy-expire no
lazyfree-lazy-server-del no
replica-lazy-flush no

appendonly yes

# The name of the append only file (default: "appendonly.aof")

appendfilename "appendonly.aof"

appendfsync everysec

no-appendfsync-on-rewrite no

auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 64mb

aof-load-truncated yes

aof-use-rdb-preamble yes

lua-time-limit 5000

slowlog-log-slower-than 10000

# There is no limit to this length. Just be aware that it will consume memory.
# You can reclaim memory used by the slow log with SLOWLOG RESET.
slowlog-max-len 128

latency-monitor-threshold 0

notify-keyspace-events ""

hash-max-ziplist-entries 512
hash-max-ziplist-value 64

list-max-ziplist-size -2

list-compress-depth 0

set-max-intset-entries 512

zset-max-ziplist-entries 128
zset-max-ziplist-value 64

hll-sparse-max-bytes 3000

stream-node-max-bytes 4096
stream-node-max-entries 100

activerehashing yes

client-output-buffer-limit normal 0 0 0
client-output-buffer-limit replica 256mb 64mb 60
client-output-buffer-limit pubsub 32mb 8mb 60


hz 10

dynamic-hz yes

# When a child rewrites the AOF file, if the following option is enabled
# the file will be fsync-ed every 32 MB of data generated. This is useful
# in order to commit the file to the disk more incrementally and avoid
# big latency spikes.
aof-rewrite-incremental-fsync yes

# When redis saves RDB file, if the following option is enabled
# the file will be fsync-ed every 32 MB of data generated. This is useful
# in order to commit the file to the disk more incrementally and avoid
# big latency spikes.
rdb-save-incremental-fsync yes

• 运行Redis

$ docker run --restart always -d -v /home/redis/redis.conf:/usr/local/etc/redis/redis.conf -v /home/redis/data:/data --name redis -p 6379:6379 redis:6.2.6 redis-server /usr/local/etc/redis/redis.conf

• 进入redis容器

$ docker exec -it redis /bin/bash

• 进入redis-cli

root@5d9912d20e4a:/data# redis-cli
127.0.0.1:6379> set k1 v1
OK

查看Redis版本

root@5d9912d20e4a:/data# redis-server -v
Redis server v=6.2.6 sha=00000000:0 malloc=jemalloc-5.1.0 bits=64 build=b61f37314a089f19

Nginx最新版安装

• 拉取镜像

$ docker pull nginx

• 运行容器

docker run --name mynginx -p 80:80 -d nginx

• 使用浏览器访问nginx：虚拟机的ip:80

Tomcat服务器安装

• 拉取最新的Tomcat

$ docker pull tomcat

• 运行容器

[root@aubin ~]# docker run --name mytomcat -p 8080:8080 -v $PWD/test:/usr/local/tomcat/webapps/test -d tomcat
a956f63b4aa08014e8584e2f8f9b04cf2603c0e7144f917bb146b947492f2419

docker安装最新版Tomcat无法访问

此时我们会发现访问不了这个Tomcat，那是因为webapps目录没有任何东西，此时我们要这样做。

• 把webapps.dist目录的内容复制到webapps目录中（因为webapps.dist包含了Tomcat的首页html）

使用pwd命令检查一下当前目录

root@a956f63b4aa0:/usr/local/tomcat# pwd
/usr/local/tomcat

开始复制（重点）

cp -r webapps.dist/* ./webapps

• 最后把webapps.dist删除即可，反正也没用了。

rm -rf webapps.dist

• OK，执行完上述命令之后就完成了！

MongoDB安装

• 拉取镜像

$ docker pull mongo:latest

• 运行MongoDB容器

$ docker run -itd --name mongo -p 27017:27017 mongo --auth

• –auth：意思是需要密码才能访问容器服务。

$ docker exec -it mongo mongo admin
# 创建一个名为 admin，密码为 123456 的用户。
> db.createUser({ user:'admin',pwd:'123456',roles:[ { role:'userAdminAnyDatabase', db: 'admin'},"readWriteAnyDatabase"]});
# 尝试使用上面创建的用户信息进行连接。
> db.auth('admin', '123456')

❤️💛🧡本章结束，我们下一章（高级篇）见❤️💛🧡

【与云原生的故事】有奖征文火热进行中：https://bbs.huaweicloud.com/blogs/345260