主機使用ansible指令，控制多臺從機安裝nginx軟件並自動化運行，在主機的位置運行最後出現報錯：
TASK [Start nginx] *************************************************************************************************************************************************************************************************************
fatal: [192.168.0.108]: FAILED! => {"changed": false, "msg": "Unable to start service nginx: Job for nginx.service failed because the control process exited with error code. See \"systemctl status nginx.service\" and \"journalctl -xe\" for details.\n"}
fatal: [192.168.0.110]: FAILED! => {"changed": false, "msg": "Unable to start service nginx: Job for nginx.service failed because the control process exited with error code. See \"systemctl status nginx.service\" and \"journalctl -xe\" for details.\n"}
PLAY RECAP *********************************************************************************************************************************************************************************************************************
192.168.0.108 : ok=4 changed=1 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0
192.168.0.110 : ok=4 changed=1 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0
[root@localhost ansible-demo]# ansible-playbook nginx.yml
PLAY [group1] ******************************************************************************************************************************************************************************************************************
TASK [Gathering Facts] *********************************************************************************************************************************************************************************************************
ok: [192.168.0.110]
ok: [192.168.0.108]
TASK [Add repo] ****************************************************************************************************************************************************************************************************************
ok: [192.168.0.110]
ok: [192.168.0.108]
TASK [Install nginx] ***********************************************************************************************************************************************************************************************************
changed: [192.168.0.110]
changed: [192.168.0.108]
TASK [Copy nginx configuration file] *******************************************************************************************************************************************************************************************
ok: [192.168.0.110]
ok: [192.168.0.108]
TASK [Start nginx] *************************************************************************************************************************************************************************************************************
fatal: [192.168.0.108]: FAILED! => {"changed": false, "msg": "Unable to start service nginx: Job for nginx.service failed because the control process exited with error code. See \"systemctl status nginx.service\" and \"journalctl -xe\" for details.\n"}
fatal: [192.168.0.110]: FAILED! => {"changed": false, "msg": "Unable to start service nginx: Job for nginx.service failed because the control process exited with error code. See \"systemctl status nginx.service\" and \"journalctl -xe\" for details.\n"}
PLAY RECAP *********************************************************************************************************************************************************************************************************************
192.168.0.108 : ok=4 changed=1 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0
192.168.0.110 : ok=4 changed=1 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0
然而我在從機的位置啓動NGINX卻出現報錯：
[root@agent1 ~]# systemctl start nginx
Job for nginx.service failed because the control process exited with error code. See "systemctl status nginx.service" and "journalctl -xe" for details.
[root@agent1 ~]# systemctl status nginx
● nginx.service - nginx - high performance web server
Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Wed 2020-05-20 14:40:30 UTC; 6s ago
Docs: http://nginx.org/en/docs/
Process: 2226 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=1/FAILURE)
May 20 14:40:30 agent1.cluster.com systemd[1]: Starting nginx - high performance web server...
May 20 14:40:30 agent1.cluster.com nginx[2226]: nginx: [emerg] bind() to 0.0.0.0:90 failed (13: Permission denied)
May 20 14:40:30 agent1.cluster.com systemd[1]: nginx.service: control process exited, code=exited status=1
May 20 14:40:30 agent1.cluster.com systemd[1]: Failed to start nginx - high performance web server.
May 20 14:40:30 agent1.cluster.com systemd[1]: Unit nginx.service entered failed state.
May 20 14:40:30 agent1.cluster.com systemd[1]: nginx.service failed.
這個原因可能有兩種，我建議你都試一下：
第一個原因就是你的NGINX端口衝突了，你改一下NGINX的默認端口吧！！
解決方案是：
vim /etc/nginx/conf.d/default.conf
- 注意：更改listen的端口，因爲原來的端口被佔用（ Address already in use）
第二個原因就是你的centos7系統有些默認配置使用問題的，你需要改一下！（selinux引起nginx啓動失敗）
解決方法：
發現是因爲selinux狀態是enforcing，關閉了selinux再啓動nginx就好了
[root@test101 nginx]# vim /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing - SELinux security policy is enforced.
# permissive - SELinux prints warnings instead of enforcing.
# disabled - No SELinux policy is loaded.
SELINUX=enforcing #改成disabled就OK了
# SELINUXTYPE= can take one of three two values:
# targeted - Targeted processes are protected,
# minimum - Modification of targeted policy. Only selected processes are protected.
# mls - Multi Level Security protection.
SELINUXTYPE=targeted