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---
- name: process
  reusable:
    top_level: true
    expected:
      - at: process
        as: entry_leader
        short_override: First process from terminal or remote access via SSH, SSM, etc OR a service directly started by the init process.
      - at: process
        as: session_leader
        short_override: Often the same as entry_leader. When it differs, it represents a session started within another session. e.g. using tmux
      - at: process
        as: group_leader
        short_override: Information about the process group leader. In some cases this may be the same as the top level process.
      - at: process.parent
        as: group_leader
        short_override: Information about the parent's process group leader. Only pid, start and entity_id fields are set.
      - at: process.entry_leader
        as: parent
        short_override: Information about the entry leader's parent process. Only pid, start and entity_id fields are set.
      - at: process.session_leader
        as: parent
        short_override: Information about the session leader's parent process. Only pid, start and entity_id fields are set.
      - at: process.entry_leader.parent
        as: session_leader
        short_override: Information about the parent session of the entry leader. Only pid, start and entity_id fields are set.
      - at: process.session_leader.parent
        as: session_leader
        short_override: Information about the parent session of the session leader. Only pid, start and entity_id fields are set.
      - at: process
        as: previous
        short_override: An array of previous executions for the process, including the initial fork. Only executable and args are set.

  fields:
    # Deprecation note: Because we are nesting process.group_leader above, it makes sense to deprecate process.pgid as this information can be accessed via process.group_leader.pid
    # - name: pgid  #to be removed

    - name: interactive
      level: extended
      type: boolean
      example: true
      short: Whether the process is connected to an interactive shell.
      description: >
        Whether the process is connected to an interactive shell.

        Process interactivity is inferred from the processes file descriptors. If the character device for the controlling tty is the same as stdin and stderr for the process, the process is considered interactive.

        Note: A non-interactive process can belong to an interactive session and is simply one that does not have open file descriptors reading the controlling TTY on FD 0 (stdin) or writing to the controlling TTY on FD 2 (stderr). A backgrounded process is still considered interactive if stdin and stderr are connected to the controlling TTY.

    - name: same_as_process
      level: extended
      type: boolean
      example: true
      short: This boolean is used to identify if a leader process is the same as the top level process.
      description: >
        This boolean is used to identify if a leader process is the same as the top level process.

        For example, if process.group_leader.same_as_process = true, it means the process event in question is the leader of its process group. Details under process.* like pid would be the same under process.group_leader.*

        The same applies for both process.session_leader and process.entry_leader.

        This field exists to the benefit of EQL and other rule engines since it's not possible to compare equality between two fields in a single document.

        e.g

        process.entity_id = process.group_leader.entity_id (top level process is the process group leader)

        OR

        process.entity_id = process.entry_leader.entity_id (top level process is the entry session leader)

        Instead these rules could be written like:

        process.group_leader.same_as_process: true

        OR

        process.entry_leader.same_as_process: true

        Note: This field is only set on process.entry_leader, process.session_leader and process.group_leader.

    - name: env_vars
      level: extended
      type: object
      short: Environment variables set at the time of the event.
      description: >
        Environment variables set at the time of the event.

        May be filtered to protect sensitive information.
      example: >
        {
          "USER": "elastic",
          "LANG": "en_US.UTF-8",
          "HOME": "/home/elastic"
        }

    - name: entry_meta.type
      level: extended
      type: keyword
      short: The entry type for the entry session leader.
      description: >
        The entry type for the entry session leader.

        Values include: init(e.g systemd), sshd, ssm, kubelet, teleport, terminal, console

    - name: entry_meta.source
      level: extended
      type: source
      short: Entry point information for a session.
      description: >
        Entry point information for a session.

        Remote client information such as ip, port and geo location.

    - name: tty
      level: extended
      type: object
      short: Information about the controlling TTY device.
      description: >
        Information about the controlling TTY device. If set, the process belongs to an interactive session.

    - name: tty.char_device.major
      level: extended
      type: long
      short: The TTY character device's major number.
      description: >
        The major number identifies the driver associated with the device. The character device's major and minor numbers can be algorithmically combined to produce the more familiar terminal identifiers such as "ttyS0" and "pts/0. For more details see https://www.kernel.org/doc/html/v4.11/admin-guide/devices.html
      example: 1

    - name: tty.char_device.minor
      level: extended
      type: long
      short: The TTY character device's minor number.
      description: >
        The minor number is used only by the driver specified by the major number; other parts of the kernel don’t use it, and merely pass it along to the driver. It is common for a driver to control several devices; the minor number provides a way for the driver to differentiate among them.
      example: 128
