SELinux Security Policy Adjustment

SELinux (Security-Enhanced Linux) is a Linux kernel security module that enforces mandatory access control policies, enhancing security by restricting user and process actions based on predefined rules. It adds an extra layer of protection by limiting the impact of vulnerabilities and attacks.

It is important to properly configure SELinux to ensure that the PostgreSYS Platform services work correctly.

Below are some steps to adjust SELinux security policies for PostgreSQL:

Check SELinux status
Terminal input
```
    sestatus
```
Adjust SELinux policies to allow network connections for PostgreSQL
Terminal input
```
    sudo setsebool -P <BOOLEAN> <VALOR>
```
note
Replace <BOOLEAN> with the name of the SELinux policy boolean to be configured (e.g., postgresql_can_network_connect) and <VALOR> with 1 (enable) or 0 (disable)
Add security contexts to PostgreSQL directories
- Generic command to add a security context (Replace <DIRETORIO> with the directory path and <CONTEXTO> with the desired context)
  Terminal input
```
    sudo semanage fcontext -a -t <CONTEXTO> "<DIRETORIO>"
```
- Apply the security context
  Terminal input
```
    sudo restorecon -Rv <DIRETORIO>
```

Configure SELinux to allow network connections and add security contexts to PostgreSQL directories

Allow network connections for PostgreSQL

Terminal input

    sudo setsebool -P postgresql_can_network_connect 1

Add security context for PostgreSQL directories

Terminal input
    DIRETORIOS=("/var/lib/pgsql" "/var/lib/pgsql/data")
    for DIR in "${DIRETORIOS[@]}"; do
        sudo semanage fcontext -a -t postgresql_db_t "${DIR}(/.*)?"
        sudo restorecon -Rv ${DIR}
    done