The Problem
The NGINX docker container was started using the below command:
# docker run --detach --name nginx_server nginx 4ffbcd5ee796b8cce3f2c6ed4cce8927d2b13a040af07b36f7a866b2157290e8
But user failed to get connection to the NGINX server. Upon troubleshooting user found below error logs:
# tail -f /var/log/audit/audit.log
type=AVC msg=audit(1565283160.116:316): avc: denied { write } for pid=2387 comm="nginx" name="nginx" dev="dm-0" ino=140648937 scontext=system_u:system_r:container_t:s0:c345,c550 tcontext=system_u:object_r:container_share_t:s0 tclass=dir permissive=0
type=SYSCALL msg=audit(1565283160.116:316): arch=c000003e syscall=83 success=no exit=-13 a0=56247859585f a1=1c0 a2=0 a3=8 items=0 ppid=2371 pid=2387 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="nginx" exe="/usr/sbin/nginx" subj=system_u:system_r:container_t:s0:c345,c550 key=(null)
# docker logs nginx_server 2019/08/08 16:52:40 [emerg] 1#1: mkdir() "/var/cache/nginx/client_temp" failed (13: Permission denied) nginx: [emerg] mkdir() "/var/cache/nginx/client_temp" failed (13: Permission denied)
The Solution
AVC denial messages indicates container_t is not a permissive domain, therefore is not possible to write (13: Permission denied). In order to resolve this issue, add container_t in the SELinux.
# semanage permissive -a container_t # semodule -l | grep permissive permissive_container_t (null) permissivedomains (null)
Try again to run the nginx container using -p option. With -p, it is possible to redirect the port from the docker to the host(ensure firewall is properly configured in the host).
# docker run --detach --name nginx_server -p 8080:80 nginx 2ce7b13f17c8aeaaa0e6f434ce47a16f6ed7bf94affb7f75381636fe7fdf496c
Verify if the docker is running:
# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 2ce7b13f17c8 nginx "nginx -g 'daemon of…" 3 seconds ago Up 3 seconds 0.0.0.0:8080->80/tcp nginx_server
Connect to NGINX container and verify the nginx version.
# docker exec nginx_server nginx -v nginx version: nginx/1.17.2