Process Manager

This small PHP dashboard is created to solve this problem:

We have a script that runs in the background continuously. It also logs some stuff in a file. We need a web panel to be able to start and stop the process. And see it's logs. Simple as that.

(Note: This only works in UNIX based operating systems, not Windows)

Setup

To set this thing up, first clone the project, then:

Copy settings.example.php to settings.php and edit the settings in it.

Then:

$ php -S localhost:8000

And go to http://localhost:8000/index.php and use the app!

Configuration

Totally we have 2 elements in the configuration file (settings.example.php): Users and Commands

Users

You can implement different users in the config file. Each user has username and password and they can login to the dashboard using them.

Also you can change permissions of each user and restrict their access to different actions.

And also all of the actions of the users will be logged into a file.

// You can set the users here. Put the username in array key, in in each you can set password and permissions
// there are 4 permissions: PERMISSION_READ_LOG, PERMISSION_READ_STATS, PERMISSION_START, PERMISSION_STOP
// You can set permissions of the user to each command like this:
// You can put them in an array like this:
// 'permissions_for_commands' => [
//    'Main' => [PERMISSION_READ_LOG, PERMISSION_READ_STATS],
// ],
// Also if you want to give someone all of the permissions, you don't need to write them all.
// You can write it this way: 'Main' => PERMISSION_ALL
const USERS = [
    'admin' => [
        'password' => 'admin',
        'permissions_for_commands' => [
            'Main' => PERMISSION_ALL,
            'Second' => [
                PERMISSION_READ_LOG,
            ],
        ],
    ],
];

As you can see above, there are some signs of Commands. We'll learn about them in the next section.

Also there is another variable to set the log file for user actions:

// The user logs will be saved into this file
// The logs include datetime, username and the action happened
// For example it says user Admin has started the process at datetime X
const USER_LOGS_FILE = 'user-logs.txt';

An example of user-logs.txt content:

[2022-12-21 21:47:41] [User admin] Stopped the process
[2022-12-21 21:47:41] [User admin] Started the process
[2022-12-21 21:47:41] [User admin] Read the process logs
...

There is also another scenario that you don't want to implement any user and want anyone to be able to open the dashboard. In that case, just leave the USERS array empty. Simple as that. Then everyone can open the dashboard without having to enter any username or password. And they would probably have full permission on everything.

Commands

You can implement multiple commands (scripts, processes or whatever you call them) in the system. They will appear in a dropdown in the main dashboard. User can select them and start/stop them or see their logs, etc.

// You can implement multiple commands here
// User can select which command to manage in a dropdown in the main page of the app
const COMMANDS = [
    'Main' => [
        'command' => 'python3 test-script.py', // the command to run
        'working_dir' => __DIR__, // working directory of the command
        'stdin_file' => __DIR__ . '/stdin-file.txt', // a file that will be used to handle sending inputs to the process
        'log_file' => __DIR__ . '/log-file.txt', // a file to log command output to it
        'log_tail_maximum_lines' => 20, // number of the lines for the log file tail when we show the logs
        'process_id_file' => 'process-id.txt', // a file to store the process id for the command
        'kill_signal' => S_TERM, // the signal you want to be sent to the command when the stop button gets pressed
        'description' => 'This is a description for the first command', // a description for the command
    ],
    'Second' => [
        'command' => 'python3 test-script.py',
        'working_dir' => __DIR__,
        'stdin_file' => __DIR__ . '/stdin-file-2.txt',
        'log_file' => __DIR__ . '/log-file-2.txt',
        'log_tail_maximum_lines' => 20,
        'process_id_file' => 'process-id-2.txt',
        'kill_signal' => S_KILL, // these options are available: S_HUP, S_INT, S_QUIT, S_ILL, S_TRAP, S_IOT, S_BUS, S_FPE, S_KILL, S_USR1, S_SEGV, S_USR2, S_PIPE, S_ALRM, S_TERM, S_STKFLT, S_CHLD, S_CONT, S_STOP, S_TSTP, S_TTIN, S_TTOU, S_URG, S_XCPU, S_XFSZ, S_VTALRM, S_PROF, S_WINCH, S_POLL, S_PWR, S_SYS
        'description' => 'This is a description for the second command. You can leave this field as a blank "" string',
    ],
];

As you saw in the Users section, we can give access of different commands to different users, with different permissions.

const USERS = [
    'admin' => [
        'password' => 'admin',
        'permissions_for_commands' => [
            'Main' => PERMISSION_ALL,
            'Second' => [
                PERMISSION_READ_LOG,
            ],
        ],
    ],
];

In the permissions_for_commands, we use names of the commands in array keys, and permissions for them in the array value.

API

This app also has an API system. There are 5 actions available:

• status: Get status of the process
• logs: Get logs of the process
• stats: Get stats of the process
• start: Start the process
• stop: Stop the process

$ curl http://localhost:8000/api.php?username=admin&password=123&command=Main

As you can see above, username, password and command arguments should always be passed to the APIs.

If there is no user configured, you can ignore username and password. You can also ignore the command too, if you do the first command will be selected by default.

Then you can use action argument to do what you want:

$ curl http://localhost:8000/api.php?username=admin&password=123&command=Main&action=status
$ curl http://localhost:8000/api.php?username=admin&password=123&command=Main&action=logs
$ curl http://localhost:8000/api.php?username=admin&password=123&command=Main&action=stats
$ curl http://localhost:8000/api.php?username=admin&password=123&command=Main&action=start
$ curl http://localhost:8000/api.php?username=admin&password=123&command=Main&action=stop

The APIs check the permissions, and if you don't have a permission to do something, they will return 403 response code. And a JSON like this:

{
    "ok": false,
    "message": "You don't have permission to ..."
}

The ok field is in all of the responses. If it's true it means there is no error. But if it's false the error message will be written in message.

There is also another action that you can get list of the commands with it:

$ curl http://localhost:8000/api.php?username=admin&password=123&action=commands_list

Custom actions

We have 2 actions for processes by default: Start and Stop.

But you may want to add more than that. You can use Custom actions system.

You can define this in your config file:

$GLOBALS['CUSTOM_ACTIONS'] = [
    'force_kill' => [ // the key should be a unique name for the action
        'title' => 'Force kill', // title of the button
        'description' => 'Kills the process forcefully', // a description for action. you can leave it blank
        'button_color' => 'yellow', // color of the button. it can be "red", "green", "blue" and "yellow"
        'is_visible' => (function () { // in this closure you should return a boolean which determines if the current user has permission to run this action
            return user_has_permission(123); // if user doesn't have permission for this action, disable it
        }),
        'is_enabled' => (function ($processID) { // in this closure you should return a boolean which determines if the action is enabled or not
            return $processID !== false; // only enable if process is running
        }),
        'handle' => (function ($processID) { // and in this closure, you will handle running the action
            exec('kill -KILL ' . $processID);
            // You can do lots of things in here
            // For example you can send a string to process STDIN:
            $stdin_file = fopen(get_current_selected_command()['stdin_file'], 'a'); // open process stdin file in "append" mode
            fwrite($stdin_file, "Hello!".PHP_EOL); // send the input
            fclose($stdin_file);
        }),
        'parameters' => [], // you can define parameters for your action
    ],
    'another_action' => [
        // ...
    ],
];

Then in the commands section, you can enable different actions for different commands:

const COMMANDS = [
    'command1' => [
        // ...
        'custom_actions' => ['force_kill'],
        // ...
    ],
];

Also you can put your custom permissions for users to check them for custom actions (we used 123 in the example above):

const USERS = [
    // ...
    'permissions_for_commands' => [
        // ...
        'command1' => [
            // ...
            123,
            // ...
        ],
        // ...
    ],
    // ...
];

And another thing to mention is that you can use all of the available functions in source code of this project in your closures for custom commands (is_visible, is_enable, handle). Like the example above that we've used user_has_permission.

Action parameters

There is another feature that gives you the ability to add "parameters" for your action.

Then when user attempts to run your custom action, the parameters will be asked from user.

'parameters' => [
    'name' => 'Please enter your name',
],
// ...
// then you can access then in `handle`:
'handle' => (function ($processID, $params) {
    $params['name']; // do something with it...
}),

This is a good example:

$GLOBALS['CUSTOM_ACTIONS']['enter_input'] = [
    'title' => 'Enter input',
    'description' => 'Enters an input into process STDIN',
    'button_color' => 'blue',
    'is_visible' => (function () {
        return user_has_permission(PERMISSION_BUILTIN_ACTION_ENTER_INPUT);
    }),
    'is_enabled' => (function ($processID) {
        return $processID !== false;
    }),
    'parameters' => [
        'input' => 'Enter the input',
    ],
    'handle' => (function ($processID, $params) {
        $input = $params['input'];
        $stdin_file = fopen(get_current_selected_command()['stdin_file'], 'a');
        fwrite($stdin_file, $input.PHP_EOL);
        fclose($stdin_file);
    }),
];

Also if you wanna call your action using API, you can pass the parameters this way:

/api.php?command=Something&action=enter_input&param_enter_input_input=something

The param name would be param_<action-name>_<param-name>.

Builtin actions

There are also some builtin actions implemented in process manager.

To register them, you have to add this line in the end of your settings.php:

// ...
register_builtin_custom_actions();
// ...

1. enter_input: Gives you the ability to send an input to process stdin.

// ...
"custom_actions" => ["enter_input"],
// ...

Permission for this action is PERMISSION_BUILTIN_ACTION_ENTER_INPUT.

Then it will receive the input from user and then sends it to the process stdin.

More builtin actions will be added in future...

License

This project is created and maintained by Parsa and licensed under MIT License.