我有一个Ansible剧本部署Java应用程序作为init。
d守护进程。作为Ansible和Linux的初学者，我在根据主机状态有条件地执行主机上的任务时遇到了麻烦。
也就是说，我有一些主机已经提供了服务并正在运行，我想在做其他事情之前停止它。然后可能会有新的主机，它们还没有这项服务。所以我不能简单地使用service: name={{service_name}} state=stopped，因为这将在新主机上失败。
我怎样才能做到这一点?以下是目前为止的内容:
- name: Check if Service Exists
shell: "if chkconfig --list | grep -q my_service; then echo true; else echo false; fi;"
register: service_exists
# This should only execute on hosts where the service is present
- name: Stop Service
service: name={{service_name}} state=stopped
when: service_exists
register: service_stopped
# This too
- name: Remove Old App Folder
command: rm -rf {{app_target_folder}}
when: service_exists
# This should be executed on all hosts, but only after the service has stopped, if it was present
- name: Unpack App Archive
unarchive: src=../target/{{app_tar_name}} dest=/opt
参见Ansible 2.5中新增的service_facts模块。
- name: Populate service facts
service_facts:
- debug:
msg: Docker installed!
when: "'docker' in services"
当然我也可以检查包装器脚本是否存在于/etc/init.d中这就是我最后写的:
- name: Check if Service Exists
stat: path=/etc/init.d/{{service_name}}
register: service_status
- name: Stop Service
service: name={{service_name}} state=stopped
when: service_status.stat.exists
register: service_stopped
我修改了Florian的答案，只使用service命令的返回代码(这在Mint 18.2上有效)
- name: Check if Logstash service exist
shell: service logstash status
register: logstash_status
failed_when: not(logstash_status.rc == 3 or logstash_status.rc == 0)
- name: Check if Logstash service exist
service:
name: logstash
state: stopped
when: logstash_status.rc == 0
如果"service"模块能处理"unrecognized service"错误就好了。
这是我的方法，使用service命令而不是检查初始化脚本:
- name: check for apache
shell: "service apache2 status"
register: _svc_apache
failed_when: >
_svc_apache.rc != 0 and ("unrecognized service" not in _svc_apache.stderr)
- name: disable apache
service: name=apache2 state=stopped enabled=no
when: "_svc_apache.rc == 0"
- 检查"服务状态"退出码，当输出包含"无法识别的服务"时接受退出码0
- 如果退出代码为0，该服务已安装(已停止或正在运行)
以@Maciej对RedHat 8的回答为基础，并结合对它的评论。
这是我如何设法停止芹菜只有当它已经安装:
- name: Populate service facts
service_facts:
- debug:
msg: httpd installed!
when: ansible_facts.services['httpd.service'] is defined
- name: Stop celery.service
service:
name: celery.service
state: stopped
enabled: true
when: ansible_facts.services['celery.service'] is defined
您可以删除调试语句——它只是用来确认ansible_facts正在工作。
systemd的另一种方法(来自Jakuje):
- name: Check if cups-browsed service exists
command: systemctl cat cups-browsed
check_mode: no
register: cups_browsed_exists
changed_when: False
failed_when: cups_browsed_exists.rc not in [0, 1]
- name: Stop cups-browsed service
systemd:
name: cups-browsed
state: stopped
when: cups_browsed_exists.rc == 0
这样只使用service模块就可以了:
- name: Disable *service_name*
service:
name: *service_name*
enabled: no
state: stopped
register: service_command_output
failed_when: >
service_command_output|failed
and 'unrecognized service' not in service_command_output.msg
and 'Could not find the requested service' not in service_command_output.msg
我的几分钱。与上面相同的方法，但用于kubernetes
检查kublete服务是否正在运行
- name: "Obtain state of kublet service"
command: systemctl status kubelet.service
register: kubelet_status
failed_when: kubelet_status.rc > 3
如果kublet服务没有运行，显示调试信息
- debug:
msg: "{{ kubelet_status.stdout }}"
when: "'running' not in kubelet_status.stdout"
从Ansible 2.5开始你就可以使用service_facts模块了。但是您需要知道输出是服务的真实名称，如docker.service或somthing@.service。所以你有不同的选项，比如:
- name: Populate service facts
service_facts:
- debug:
msg: Docker installed!
when: "'docker.service' in services"
或者您可以搜索以服务名称开头的字符串;这样更可靠，因为不同发行版之间的服务名称是不同的:
- name: Populate service facts
service_facts:
- debug:
msg: Docker installed!
when: "services.keys()|list|select('search', '^docker')|length >0"