systemd-tmpfiles (with examples)

1: Using command to Create files and directories as specified in the configuration

systemd-tmpfiles --create

Motivation: The systemd-tmpfiles command is used to create files and directories according to the configurations specified in the tmpfiles.d files. Running this command can ensure that all the necessary files and directories are in place for the system or application to function correctly.

Explanation: The --create option is used to instruct systemd-tmpfiles to create files and directories based on the tmpfiles.d configuration. When this command is executed, it searches for all the tmpfiles.d files present in the system, reads their configurations, and creates any missing files or directories.

Example Output:

Created /var/run/myapp directory
Created /var/tmp/myapp.log file
Created /var/lib/myapp/data directory

2: Using command to Clean up files and directories with age parameters configured

systemd-tmpfiles --clean

Motivation: Over time, temporary and volatile files can accumulate on a system, consuming valuable disk space. Running the systemd-tmpfiles command with the --clean option allows you to automatically clean up these files based on the age parameters defined in the tmpfiles.d configuration files. This helps to maintain a clean and efficient system.

Explanation: The --clean option tells systemd-tmpfiles to clean up files and directories with age parameters configured. When executed, it scans all the configured tmpfiles.d files, checks the age of the files and directories specified in their configurations, and deletes those that exceed the defined age limit.

Example Output:

Deleted /tmp/myapp.log (aged 2 days)
Deleted /var/tmp/cache (aged 1 week)

3: Using command to Remove files and directories as specified in the configuration

systemd-tmpfiles --remove

Motivation: To ensure a clean system or application environment, it may be necessary to remove specific files or directories based on the configurations defined in the tmpfiles.d files. By running the systemd-tmpfiles command with the --remove option, you can easily delete the specified files and directories without manually searching for and deleting them.

Explanation: The --remove option is used to remove files and directories as specified in the tmpfiles.d configurations. When this command is executed, it reads the configurations from the tmpfiles.d files, identifies the files and directories to be removed, and deletes them from the system.

Example Output:

Removed /var/run/myapp directory
Removed /tmp/myapp.log

4: Using command to Apply operations for user-specific configurations

systemd-tmpfiles --create --user

Motivation: User-specific configurations can be created in the tmpfiles.d directory to manage files and directories specific to individual users. By running systemd-tmpfiles with the --user option, these user-specific configurations can be applied, ensuring that the required files and directories are created for each user.

Explanation: The --user option is used to instruct systemd-tmpfiles to apply operations for user-specific configurations. When this command is executed, it reads the user-specific tmpfiles.d configurations and creates any necessary files and directories specified within them.

Example Output:

Created /home/user1/.cache/myapp directory
Created /home/user1/.cache/myapp/cache file

5: Using command to Execute lines marked for early boot

systemd-tmpfiles --create --boot

Motivation: Certain lines within tmpfiles.d configuration files may be marked for early boot execution. By using the --boot option with systemd-tmpfiles, you can ensure that these lines are executed during the early boot stage of the system, creating the required files and directories before the regular boot process begins.

Explanation: The --boot option tells systemd-tmpfiles to execute lines marked for early boot. When this command is executed, it identifies the lines marked for early boot execution in the tmpfiles.d files and performs the specified operations, such as creating files and directories, before the regular boot process continues.

Example Output:

Executed line marked for early boot: d /var/run/myapp 0755 root root -
Executed line marked for early boot: F /etc/myapp/myconfig.conf 0644 root root -