Ansible-Playbook通过role角色部署Lnmp架构

一、配置Nginx的Roles角色

1.1编写files/default.conf

1.2编写files/nginx.repo

1.3编写handlers/main.yml

1.4编写tasks/main.yml文件

1.5编写vars/main.yml文件

1.6测试运行结果，并不是真的执行任务

二、配置Mysql的Roles角色

2.1编写tasks/main.yml文件

2.2编写tasks/init.yml文件

2.3编写vars/main.yml定义变量

2.4测试运行结果，并不是真的执行任务

三、配置php的Roles角色

3.1编写files/index.php文件

3.2编写files/www.conf文件

3.3编写handlers/main.yml

3.4编写tasks/main.yml

3.5编写vars/main.yml文件

四、编写启动文件

五、启动并测试

六、浏览器访问

环境准备

服务器类型	IP地址	需要安装的组件
Ansible管理服务器	192.168.246.7	Ansible
被管理客户端	192.168.246.8	LNMP

被管理节点（192.168.246.7）

yum install epel-release -y
yum install -y ansible

密钥认证

ssh-keygen -t rsa
sshpass -p '123' ssh-copy-id root@192.168.246.8

所有节点

systemctl stop firewalld.service
setenforce 0

准备角色、目录准备每个角色的子目录、准备main.yaml文件

mkdir /etc/ansible/roles/nginx/{files,templates,tasks,handlers,vars,defaults,meta} -p
mkdir /etc/ansible/roles/mysql/{files,templates,tasks,handlers,vars,defaults,meta} -p
mkdir /etc/ansible/roles/php/{files,templates,tasks,handlers,vars,defaults,meta} -p
touch /etc/ansible/roles/nginx/{defaults,vars,tasks,meta,handlers}/main.yml
touch /etc/ansible/roles/mysql/{defaults,vars,tasks,meta,handlers}/main.yml
touch /etc/ansible/roles/php/{defaults,vars,tasks,meta,handlers}/main.yml

一、配置Nginx的Roles角色

files：用来存放由 copy 模块或 script 模块调用的文件。

1.1编写files/default.conf

编写Nginx配置文件

vim /etc/ansible/roles/nginx/files/default.conf

server {
    listen      80;
    server_name  www.kgc.com;
    
    #access_log  /var/log/nginx/host.access.log  main;
    
    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;
    }
    
    #error_page  404              /404.html;
    
    # redirect server error pages to the static page /50x.html
    #
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }
    
    # proxy the PHP scripts to Apache listening on 127.0.0.1:80
    #
    #location ~ \.php$ {
    #    proxy_pass   http://127.0.0.1;
    #}
    
    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
# 
    location ~ \.php$ {
        root           /www;
        fastcgi_pass   192.168.246.8:9000;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        include        fastcgi_params;  
    }   
    
    # deny access to .htaccess files, if Apache's document root
    # concurs with nginx's one 
    # 
    #location ~ /\.ht {
    #    deny  all;
    #}   
}

1.2编写files/nginx.repo

编写Nginx安装文件

vim /etc/ansible/roles/nginx/files/nginx.repo
[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/centos/7/$basearch/
gpgcheck=0
enabled=1

1.3编写handlers/main.yml

编写Nginx控制器文件

vim /etc/ansible/roles/nginx/handlers/main.yml
- name: restart nginx
  service: name={{svc}} state=restarted

1.4编写tasks/main.yml文件

编写Nginx任务文件

vim /etc/ansible/roles/nginx/tasks/main.yml

- name: disable selinux
  command: '/usr/sbin/setenforce 0'
  ignore_errors: true
- name: disable firewalld
  service: name=firewalld state=stopped enabled=no
- name: upload nginx repo
  copy: src=nginx.repo dest=/etc/yum.repos.d/nginx.repo
- name: install nginx
  yum: name={{app}} state=latest
- name: prepare nginx configuration file
  copy: src=default.conf dest=/etc/nginx/conf.d/default.conf
- name: start nginx
  service: name={{svc}} state=started enabled=yes

ignore_errors: true 这个设置通常用于在执行Ansible playbook时忽略特定任务的错误，即使任务失败也不会导致整个playbook的失败。这在某些情况下可能很有用，例如当某些任务失败但不希望影响整体执行时。设置ignore_errors: true后，Ansible会继续执行其他任务，而不会因为特定任务的失败而停止整个过程。

1.5编写vars/main.yml文件

编写Nginx变量文件

vim /etc/ansible/roles/nginx/vars/main.yml

1.6测试运行结果，并不是真的执行任务

---
- name: lnmp nginx
  hosts: webservers
  remote_user: root
  roles:
   - nginx

ansible-playbook role_lnmp.yml -C

二、配置Mysql的Roles角色

2.1编写tasks/main.yml文件

编写Mysql任务文件

vim /etc/ansible/roles/mysql/tasks/main.yml

---
- include: init.yml

- name: install mysql repo first
  yum: name={{repo}}

- name: install mysql repo second
  shell: "sed -i 's#gpgcheck=1#gpgcheck=0#' /etc/yum.repos.d/mysql-community.repo"
- name: install mysql app
  yum: name={{app}}

- name: mysql start
  service: name=mysqld state=started enabled=1

- name: first password
  shell: mysql -uroot -p"{{passwd}}" --connect-expired-password -e "ALTER USER 'root'@'localhost' IDENTIFIED B
Y 'Admin@123';"

- name: sudo login
  shell: mysql -uroot -pAdmin@123 -e "grant all privileges on *.* to root@'%' identified by 'Admin@123' with g
rant option;"

2.2编写tasks/init.yml文件

编写Mysql启动文件

[root@zz1 roles]#vim /etc/ansible/roles/mysql/tasks/init.yml

- name: disable selinux
  command: '/usr/sbin/setenforce 0'
  ignore_errors: true

- name: disable firewalld
  service: name=firewalld state=stopped enabled=no

2.3编写vars/main.yml定义变量

编写Mysql变量文件

vim /etc/ansible/roles/mysql/vars/main.yml

repo: https://repo.mysql.com/mysql57-community-release-el7-11.noarch.rpm

passwd: $(grep "password" /var/log/mysqld.log | awk '{print $NF}')

app: mysql-server

从/var/log/mysqld.log文件中提取包含"password"关键词的行，并使用awk命令打印该行的最后一个字段

2.4测试运行结果，并不是真的执行任务

[root@zz1 ansible]#vim role_lnmp.yml 
---
- name: lnmp mysql
  hosts: webservers
  remote_user: root
  roles:
   - mysql

三、配置php的Roles角色

3.1编写files/index.php文件

编写Php的页面文件

vim /etc/ansible/roles/php/files/index.php

<?php
$link=mysqli_connect('192.168.246.8','root','Admin@123');
if($link) echo "<h1>Success!!</h1>";
else echo "Fail!!";
?>

3.2编写files/www.conf文件

; Start a new pool named 'www'.
[www]
 
; Unix user/group of processes
; Note: The user is mandatory. If the group is not set, the default user's group
;       will be used.
; RPM: apache Choosed to be able to access some dir as httpd
user = php
; RPM: Keep a group allowed to write in log dir.
group = php
; The address on which to accept FastCGI requests.
; Valid syntaxes are:
;   'ip.add.re.ss:port'    - to listen on a TCP socket to a specific IPv4 address on
;                            a specific port;
;   '[ip:6:addr:ess]:port' - to listen on a TCP socket to a specific IPv6 address on
;                            a specific port;
;   'port'                 - to listen on a TCP socket to all addresses
;                            (IPv6 and IPv4-mapped) on a specific port;
;   '/path/to/unix/socket' - to listen on a unix socket.
; Note: This value is mandatory.
listen = 192.168.246.8:9000
; Set listen(2) backlog.
; Default Value: 511 (-1 on FreeBSD and OpenBSD)
;listen.backlog = 511
; Set permissions for unix socket, if one is used. In Linux, read/write
; permissions must be set in order to allow connections from a web server. Many
; BSD-derived systems allow connections regardless of permissions.
; Default Values: user and group are set as the running user
;                 mode is set to 0660
;listen.owner = nobody
;listen.group = nobody
;listen.mode = 0660
; When POSIX Access Control Lists are supported you can set them using
; these options, value is a comma separated list of user/group names.
; When set, listen.owner and listen.group are ignored
;listen.acl_users =
;listen.acl_groups =
; List of addresses (IPv4/IPv6) of FastCGI clients which are allowed to connect.
; Equivalent to the FCGI_WEB_SERVER_ADDRS environment variable in the original
; PHP FCGI (5.2.2+). Makes sense only with a tcp listening socket. Each address
; must be separated by a comma. If this value is left blank, connections will be
; accepted from any ip address.
; Default Value: any
listen.allowed_clients = 192.168.246.8
; Specify the nice(2) priority to apply to the pool processes (only if set)
; The value can vary from -19 (highest priority) to 20 (lower priority)
; Note: - It will only work if the FPM master process is launched as root
;       - The pool processes will inherit the master process priority
;         unless it specified otherwise
; Default Value: no set
; process.priority = -19
; Choose how the process manager will control the number of child processes.
; Possible Values:
;   static  - a fixed number (pm.max_children) of child processes;
;   dynamic - the number of child processes are set dynamically based on the
;             following directives. With this process management, there will be
;             always at least 1 children.
;             pm.max_children      - the maximum number of children that can
;                                    be alive at the same time.
;             pm.start_servers     - the number of children created on startup.
;             pm.min_spare_servers - the minimum number of children in 'idle'
;                                    state (waiting to process). If the number
;                                    of 'idle' processes is less than this
;                                    number then some children will be created.
;             pm.max_spare_servers - the maximum number of children in 'idle'
;                                    state (waiting to process). If the number
;                                    of 'idle' processes is greater than this
;                                    number then some children will be killed.
;  ondemand - no children are created at startup. Children will be forked when
;             new requests will connect. The following parameter are used:
;             pm.max_children           - the maximum number of children that
;                                         can be alive at the same time.
;             pm.process_idle_timeout   - The number of seconds after which
;                                         an idle process will be killed.
; Note: This value is mandatory.
pm = dynamic
; The number of child processes to be created when pm is set to 'static' and the
; maximum number of child processes when pm is set to 'dynamic' or 'ondemand'.
; This value sets the limit on the number of simultaneous requests that will be
; served. Equivalent to the ApacheMaxClients directive with mpm_prefork.
; Equivalent to the PHP_FCGI_CHILDREN environment variable in the original PHP
; CGI.
; Note: Used when pm is set to 'static', 'dynamic' or 'ondemand'
; Note: This value is mandatory.
pm.max_children = 50
; The number of child processes created on startup.
; Note: Used only when pm is set to 'dynamic'
; Default Value: min_spare_servers + (max_spare_servers - min_spare_servers) / 2
pm.start_servers = 5
; The desired minimum number of idle server processes.
; Note: Used only when pm is set to 'dynamic'
; Note: Mandatory when pm is set to 'dynamic'
pm.min_spare_servers = 5
; The desired maximum number of idle server processes.
; Note: Used only when pm is set to 'dynamic'
; Note: Mandatory when pm is set to 'dynamic'
pm.max_spare_servers = 35
; The number of seconds after which an idle process will be killed.
; Note: Used only when pm is set to 'ondemand'
; Default Value: 10s
;pm.process_idle_timeout = 10s;
; The number of requests each child process should execute before respawning.
; This can be useful to work around memory leaks in 3rd party libraries. For
; endless request processing specify '0'. Equivalent to PHP_FCGI_MAX_REQUESTS.
; Default Value: 0
;pm.max_requests = 500
; The URI to view the FPM status page. If this value is not set, no URI will be
; recognized as a status page. It shows the following informations:
;   pool                 - the name of the pool;
;   process manager      - static, dynamic or ondemand;
;   start time           - the date and time FPM has started;
;   start since          - number of seconds since FPM has started;
;   accepted conn        - the number of request accepted by the pool;
;   listen queue         - the number of request in the queue of pending
;                          connections (see backlog in listen(2));
;   max listen queue     - the maximum number of requests in the queue
;                          of pending connections since FPM has started;
;   listen queue len     - the size of the socket queue of pending connections;
;   idle processes       - the number of idle processes;
;   active processes     - the number of active processes;
;   total processes      - the number of idle + active processes;
;   max active processes - the maximum number of active processes since FPM
;                          has started;
;   max children reached - number of times, the process limit has been reached,
;                          when pm tries to start more children (works only for
;                          pm 'dynamic' and 'ondemand');
; Value are updated in real time.
; Example output:
;   pool:                 www
;   process manager:      static
;   start time:           01/Jul/2011:17:53:49 +0200
;   start since:          62636
;   accepted conn:        190460
;   listen queue:         0
;   max listen queue:     1
;   listen queue len:     42
;   idle processes:       4
;   active processes:     11
;   total processes:      15
;   max active processes: 12
;   max children reached: 0
;
; By default the status page output is formatted as text/plain. Passing either
; 'html', 'xml' or 'json' in the query string will return the corresponding
; output syntax. Example:
;   http://www.foo.bar/status
;   http://www.foo.bar/status?json
;   http://www.foo.bar/status?html
;   http://www.foo.bar/status?xml
;
; By default the status page only outputs short status. Passing 'full' in the
; query string will also return status for each pool process.
; Example:
;   http://www.foo.bar/status?full
;   http://www.foo.bar/status?json&full
;   http://www.foo.bar/status?html&full
;   http://www.foo.bar/status?xml&full
; The Full status returns for each process:
;   pid                  - the PID of the process;
;   state                - the state of the process (Idle, Running, ...);
;   start time           - the date and time the process has started;
;   start since          - the number of seconds since the process has started;
;   requests             - the number of requests the process has served;
;   request duration     - the duration in µs of the requests;
;   request method       - the request method (GET, POST, ...);
;   request URI          - the request URI with the query string;
;   content length       - the content length of the request (only with POST);
;   user                 - the user (PHP_AUTH_USER) (or '-' if not set);
;   script               - the main script called (or '-' if not set);
;   last request cpu     - the %cpu the last request consumed
;                          it's always 0 if the process is not in Idle state
;                          because CPU calculation is done when the request
;                          processing has terminated;
;   last request memory  - the max amount of memory the last request consumed
;                          it's always 0 if the process is not in Idle state
;                          because memory calculation is done when the request
;                          processing has terminated;
; If the process is in Idle state, then informations are related to the
; last request the process has served. Otherwise informations are related to
; the current request being served.
; Example output:
;   ************************
;   pid:                  31330
;   state:                Running
;   start time:           01/Jul/2011:17:53:49 +0200
;   start since:          63087
;   requests:             12808
;   request duration:     1250261
;   request method:       GET
;   request URI:          /test_mem.php?N=10000
;   content length:       0
;   user:                 -
;   script:               /home/fat/web/docs/php/test_mem.php
;   last request cpu:     0.00
;   last request memory:  0
;
; Note: There is a real-time FPM status monitoring sample web page available
;       It's available in: @EXPANDED_DATADIR@/fpm/status.html
;
; Note: The value must start with a leading slash (/). The value can be
;       anything, but it may not be a good idea to use the .php extension or it
;       may conflict with a real PHP file.
; Default Value: not set
;pm.status_path = /status
 
; The ping URI to call the monitoring page of FPM. If this value is not set, no
; URI will be recognized as a ping page. This could be used to test from outside
; that FPM is alive and responding, or to
; - create a graph of FPM availability (rrd or such);
; - remove a server from a group if it is not responding (load balancing);
; - trigger alerts for the operating team (24/7).
; Note: The value must start with a leading slash (/). The value can be
;       anything, but it may not be a good idea to use the .php extension or it
;       may conflict with a real PHP file.
; Default Value: not set
;ping.path = /ping
 
; This directive may be used to customize the response of a ping request. The
; response is formatted as text/plain with a 200 response code.
; Default Value: pong
;ping.response = pong
 
; The access log file
; Default: not set
;access.log = log/$pool.access.log
 
; The access log format.
; The following syntax is allowed
;  %%: the '%' character
;  %C: %CPU used by the request
;      it can accept the following format:
;      - %{user}C for user CPU only
;      - %{system}C for system CPU only
;      - %{total}C  for user + system CPU (default)
;  %d: time taken to serve the request
;      it can accept the following format:
;      - %{seconds}d (default)
;      - %{miliseconds}d
;      - %{mili}d
;      - %{microseconds}d
;      - %{micro}d
;  %e: an environment variable (same as $_ENV or $_SERVER)
;      it must be associated with embraces to specify the name of the env
;      variable. Some exemples:
;      - server specifics like: %{REQUEST_METHOD}e or %{SERVER_PROTOCOL}e
;      - HTTP headers like: %{HTTP_HOST}e or %{HTTP_USER_AGENT}e
;  %f: script filename
;  %l: content-length of the request (for POST request only)
;  %m: request method
;  %M: peak of memory allocated by PHP
;      it can accept the following format:
;      - %{bytes}M (default)
;      - %{kilobytes}M
;      - %{kilo}M
;      - %{megabytes}M
;      - %{mega}M
;  %n: pool name
;  %o: output header
;      it must be associated with embraces to specify the name of the header:
;      - %{Content-Type}o
;      - %{X-Powered-By}o
;      - %{Transfert-Encoding}o
;      - ....
;  %p: PID of the child that serviced the request
;  %P: PID of the parent of the child that serviced the request
;  %q: the query string
;  %Q: the '?' character if query string exists
;  %r: the request URI (without the query string, see %q and %Q)
;  %R: remote IP address
;  %s: status (response code)
;  %t: server time the request was received
;      it can accept a strftime(3) format:
;      %d/%b/%Y:%H:%M:%S %z (default)
;      The strftime(3) format must be encapsuled in a %{<strftime_format>}t tag
;      e.g. for a ISO8601 formatted timestring, use: %{%Y-%m-%dT%H:%M:%S%z}t
;  %T: time the log has been written (the request has finished)
;      it can accept a strftime(3) format:
;      %d/%b/%Y:%H:%M:%S %z (default)
;      The strftime(3) format must be encapsuled in a %{<strftime_format>}t tag
;      e.g. for a ISO8601 formatted timestring, use: %{%Y-%m-%dT%H:%M:%S%z}t
;  %u: remote user
;
; Default: "%R - %u %t \"%m %r\" %s"
;access.format = "%R - %u %t \"%m %r%Q%q\" %s %f %{mili}d %{kilo}M %C%%"
 
; The log file for slow requests
; Default Value: not set
; Note: slowlog is mandatory if request_slowlog_timeout is set
slowlog = /var/log/php-fpm/www-slow.log
 
; The timeout for serving a single request after which a PHP backtrace will be
; dumped to the 'slowlog' file. A value of '0s' means 'off'.
; Available units: s(econds)(default), m(inutes), h(ours), or d(ays)
; Default Value: 0
;request_slowlog_timeout = 0
 
; The timeout for serving a single request after which the worker process will
; be killed. This option should be used when the 'max_execution_time' ini option
; does not stop script execution for some reason. A value of '0' means 'off'.
; Available units: s(econds)(default), m(inutes), h(ours), or d(ays)
; Default Value: 0
;request_terminate_timeout = 0
 
; Set open file descriptor rlimit.
; Default Value: system defined value
;rlimit_files = 1024
 
; Set max core size rlimit.
; Possible Values: 'unlimited' or an integer greater or equal to 0
; Default Value: system defined value
;rlimit_core = 0
 
; Chroot to this directory at the start. This value must be defined as an
; absolute path. When this value is not set, chroot is not used.
; Note: chrooting is a great security feature and should be used whenever
;       possible. However, all PHP paths will be relative to the chroot
;       (error_log, sessions.save_path, ...).
; Default Value: not set
;chroot =
 
; Chdir to this directory at the start.
; Note: relative path can be used.
; Default Value: current directory or / when chroot
;chdir = /var/www
 
; Redirect worker stdout and stderr into main error log. If not set, stdout and
; stderr will be redirected to /dev/null according to FastCGI specs.
; Note: on highloaded environement, this can cause some delay in the page
; process time (several ms).
; Default Value: no
;catch_workers_output = yes
 
; Clear environment in FPM workers
; Prevents arbitrary environment variables from reaching FPM worker processes
; by clearing the environment in workers before env vars specified in this
; pool configuration are added.
; Setting to "no" will make all environment variables available to PHP code
; via getenv(), $_ENV and $_SERVER.
; Default Value: yes
;clear_env = no
 
; Limits the extensions of the main script FPM will allow to parse. This can
; prevent configuration mistakes on the web server side. You should only limit
; FPM to .php extensions to prevent malicious users to use other extensions to
; exectute php code.
; Note: set an empty value to allow all extensions.
; Default Value: .php
;security.limit_extensions = .php .php3 .php4 .php5 .php7
 
; Pass environment variables like LD_LIBRARY_PATH. All $VARIABLEs are taken from
; the current environment.
; Default Value: clean env
;env[HOSTNAME] = $HOSTNAME
;env[PATH] = /usr/local/bin:/usr/bin:/bin
;env[TMP] = /tmp
;env[TMPDIR] = /tmp
;env[TEMP] = /tmp
 
; Additional php.ini defines, specific to this pool of workers. These settings
; overwrite the values previously defined in the php.ini. The directives are the
; same as the PHP SAPI:
;   php_value/php_flag             - you can set classic ini defines which can
;                                    be overwritten from PHP call 'ini_set'.
;   php_admin_value/php_admin_flag - these directives won't be overwritten by
;                                     PHP call 'ini_set'
; For php_*flag, valid values are on, off, 1, 0, true, false, yes or no.
; Defining 'extension' will load the corresponding shared extension from
; extension_dir. Defining 'disable_functions' or 'disable_classes' will not
; overwrite previously defined php.ini values, but will append the new value
; instead.
; Default Value: nothing is defined by default except the values in php.ini and
;                specified at startup with the -d argument
;php_admin_value[sendmail_path] = /usr/sbin/sendmail -t -i -f www@my.domain.com
;php_flag[display_errors] = off
php_admin_value[error_log] = /var/log/php-fpm/www-error.log
php_admin_flag[log_errors] = on
;php_admin_value[memory_limit] = 128M
; Set session path to a directory owned by process user
php_value[session.save_handler] = files
php_value[session.save_path]    = /var/lib/php/session
php_value[soap.wsdl_cache_dir]  = /var/lib/php/wsdlcache

编写Php的配置文件

3.3编写handlers/main.yml

编写Php的控制器文件

---
- name: reload php-fpm
  service: name={{svc}} state=restarted

3.4编写tasks/main.yml

编写Php的任务文件

vim /etc/ansible/roles/php/tasks/main.yml

---
- name: disable selinux
  command: '/usr/sbin/setenforce 0'
  ignore_errors: true

- name: disable firewalld
  service: name=firewalld state=stopped enabled=no

- name: install php repo
  yum: name={{repo}}

- name: install php app
  yum: name={{app}}
  ignore_errors: true

- name: add php user
  user: name=php shell=/sbin/nologin

- name: create /www dir
  file: path=/www state=directory

- name: copy index.php
  copy: src=index.php dest=/www/index.php

- name: copy configuration file
  copy: src=www.conf dest=/etc/php-fpm.d/www.conf
  notify: reload php-fpm

- name: modify php.ini
  shell: "sed -i 's#;date.timezone =#date.timezone = Asia/shanghai#' /etc/php.ini"

- name: start php-fpm
  service: name={{svc}} state=started enabled=yes

这个命令是用来通过sed命令在/etc/php.ini文件中设置PHP的时区为"Asia/Shanghai"。具体来说：

sed是一个流编辑器，用来处理文本流。
-i参数表示直接修改文件内容，而不是输出到标准输出。
's#;date.timezone =#date.timezone = Asia/shanghai#'是sed的替换命令，用来将;date.timezone =替换为date.timezone = Asia/shanghai。
/etc/php.ini是被修改的目标文件，即PHP的配置文件。

3.5编写vars/main.yml文件

编写Php的变量文件

[root@zz1 php]#vim /etc/ansible/roles/php/vars/main.yml
 
app:
- php72w
- php72w-cli
- php72w-common
- php72w-devel
- php72w-embedded
- php72w-gd
- php72w-mbstring
- php72w-pdo
- php72w-xml
- php72w-fpm
- php72w-mysqlnd
- php72w-opcache
 
svc: php-fpm
 
repo:
- http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
- http://mirror.webtatic.com/yum/el7/webtatic-release.rpm

四、编写启动文件

---
- hosts: webservers
  remote_user: root
  roles:
     - nginx
- hosts: webservers
  remote_user: root
  roles:
     - mysql
- hosts: webservers
  remote_user: root
  roles:
     - php