syspol - System Policy

by Pedro Ivan Lopez

System policy. Inspired by the Rule of Separation.

Syspol extends standard Linux/Unix practice including the File Hierarchy Standard.

Private Syspol

Define/maintain a private Syspol project that extends the public one; if publishing a policy doesn’t create serious security risks, consider sharing it by integrating it into the public Syspol (see this blog post).

Time based directory structure

A time base directory structure with resolution X is a simple hierarchy for storing files in a predictable and manageable way. X can be one of year, month, day, minute or second. It's not necessary for the structure to have node directories for every time unit.

Examples

The root of a time based directory structure with resolution year

$ tree -d .
.
├── 2014
└── 2015

2 directories

The root of a time based directory structure with resolution month

$ tree -d .
.
├── 2014
│   ├── 01
│   └── 09
└── 2015
    ├── 01
    ├── 09
    ├── 10
    └── 11

8 directories

Logging

Let APPROOT be the root directory of application/environment data, log files are stored in time based directory structure with resolution month in $APPROOT/var/log. For example:

$APPROOT
  /var
    /log
      /2015
        /01
        /02
        /03
        /04

Each month directory stores the log files.

Application locks

Lock resources with files stored at $APPROOT/var/lock.

Single application instances

Sometimes you need to be sure that at all times only one instance of an application or script is running. Let APPROOT be the application root path of an application named xyz that is currently running, then the lock files exists $APPROOT/var/lock/LCK..xyz.

When xyz starts, it checks if the lock file exists. If the lock exists then xyz fails and exits with an error code. Otherwise it creates the lock file and executes normally. When finished xyz deletes the lock file.

Sound alarms

The following environment variables hold filepaths of sound files used for alarms with severity of different types.

• SYSPOL_SOUND_ALARM_CRITICAL_FP
• SYSPOL_SOUND_ALARM_ERROR_FP
• SYSPOL_SOUND_ALARM_WARNING_FP
• SYSPOL_SOUND_ALARM_INFO_FP
• SYSPOL_SOUND_ALARM_DEBUG_FP