SELinux provides a flexible Mandatory Access Control (MAC) system built into the Linux kernel. Under standard Linux Discretionary Access Control (DAC), an application or process running as a user (UID or SUID) has the user's permissions to objects such as files, sockets, and other processes. Running a MAC kernel protects the system from malicious or flawed applications that can damage or destroy the system.
SELinux defines the access and transition rights of every user, application, process, and file on the system. SELinux then governs the interactions of these entities using a security policy that specifies how strict or lenient a given Red Hat Enterprise Linux installation should be. (Reference)
SELinux by default does not allow the Docker process to access the required files and folders from a container context. To allow the appropriate files and folders to be accessed, run the following commands:
chcon -Rt svirt_sandbox_file_t /var/virtru/vg/queue
chcon -Rt svirt_sandbox_file_t /var/virtru/vg/tls
chcon -Rt svirt_sandbox_file_t /var/virtru/vg/dkim/