Jean Paul Start

L'enfer, c'est les .bats

Jean-Paul Start is verbose about plugin loading, batch loading and parsing, task execution, ...

Be sure to set your logging level to INFO if needed

Usage as a CLI

python -m jeanpaulstart -f path/to/a/batch.yml

Usage from the API

Basic batch run

import jeanpaulstart

jeanpaulstart.run_from_filepath('path/to/a/batch.yml')

Batch run inside a GUI

Tasks can be run step by step, so progress can be forwarded to the user

Here, ui stands for any class that represents a window or dialog

import jeanpaulstart

executor = jeanpaulstart.executor_from_filepath('path/to/a/batch.yml')

while not executor.has_stopped:
    ui.set_status_message(executor.next_task.name)

    status, messages = executor.step()
    if status != jeanpaulstart.OK:
        ui.set_status_message(' '.join([messages[-1], status]))
    
    ui.set_progress(executor.progress)

if executor.success:
    ui.set_status_message('Execution OK !')
    ui.set_progress(0.0)

Batch Redaction

Batch are redacted in YAML or JSON, in a way similar to Ansible playbooks

A batch describes

• a name
• an icon path
• tags
• an environment (through variables, can be omitted)
• tasks to perform

---
name: Jean Bauchefort
icon_path: $ENVIRONMENT/_config/jeanpaulstart/icons/jean-bauchefort.png
tags:
  - production
environment:
  PYTHONPATH:
    - C:\cube\python\Lib\site-packages
    - R:\deploy\cube
tasks:
  - name: Running application
    raw:
      command: python -m jeanbauchefortui
...

For a complete example please read example-batch.yml

User Tags

A YAML file represents how usernames (based on os.getpass.getuser()) are associated with batch tags

Example

---
production:
  - jp.sartre
  - p.deproges

graphist_base:
  - y.montand
  - j.hallyday

rigging:
  - s.weaver
  - j.rochefort
...

Batches with 'production' tag will show for jp.sartre

• Special character $ allows to reference a group withing another group

everyone:
  - $production
  - $graphist_base
  - $rigging
  - m.polnareff
...

Tasks

Each task is identified by a command name

Tasks are written as plugins, in the package jeanpaulstart.tasks, they must conform to what the plugin loader expects

Copy

Copies a file

If destination exists and force: no, nothing will happen

- name: Name of task
  copy:
    src: /path/to/source.ext
    dest: /path/to/destination.ext
    force: [yes|no]

File

Creates a file

Use state: directory if you want to create a directory

Use state: absent if you want to remove a file, or a directory and its subdirectories

- name: Name of task
  file:
    path: /path/to/file
    state: [directory|absent]

Include Tasks

Runs another batch file

Current environment is passed to executed batch, modifications made by that batch to the environment are not kept

- name: Name
  include_tasks:
    file: path/to/batch/file.yml

Ini File

Modifies a config file (.ini)

- name: Task Name
  ini_file:
    src: /path/to/ini/file.ini
    state: [present|absent]
    section: sectionName
    option: optionName
    value: valueValue

Pip / Pip3

Runs pip install / pip3 install

Please make sure that pip / pip3 is in your $PATH

Parameter state is not mandatory, defaults to present

- name: Task Name
  pip:
      name: PySide
      state: [present|forcereinstall]

- name: Task Name
  pip3:
      name: PySide
      state: [present|forcereinstall]

- name: Task Name
  pip:
      name: git+http://some/url.git

Raw

Run a command in the terminal

Parameter async spawns a new process (Popen()) Parameter open_terminal opns a new terminal window

async defaults to True open_terminal defaults to False

If the exit code of the command is 0, jeanpaulstart.OK is return, else the exit code is returned

If async: yes, jeanpaulstart.OK is immediately returned

- name: Launch djv_view
  raw: 
    command: "\"C:\\Program Files\\djv-1.1.0-Windows-64\\bin\\djv_view.exe\""
    async:[yes|no]
    open_terminal:[yes|no]

Template

Copy a file and applies Jinja2 templating, based on environment variables

Parameter force: yes will overwrite destination if it already exists

- name: Task Name
  template:
    src: /path/to/source.ext.j2
    dest: /path/to/dest.ext
    force: [yes|no]

Url

Opens the given url in the default browser

- name: Task Name
  url: http://some.url/

Datetime

Registers the current datetime, formatted, to an environment variable

- name: Register Timestamp
  datetime:
    variable: LOG_TIMESTAMP
    format: "%y%m%d-%H%M%S"

Win_err_reporting_dialog

Enable or disable the windows error reporting dialog when the application crashs

- name: Task Name
  win_err_reporting_dialog:
    state: [present|absent]

Tasks flags

All tasks have 4 flags that can be set besides the command and its arguements.

• register_status defaults to False or no
• catch_exception defaults to False or no
• exit_if_not_ok defaults to True or yes
• when defaults to "True"

'Register status'

register_status memorises the status returned by the task, and stores this status in the environment variable $JPS_REGISTERED_STATUS, immediately available for the next task

The executor returns the last registered status

'Catch exception' and 'exit if not ok'

All tasks must return OK, maybe something else if something went wrong.

Most tasks should not raise any exception (exception should be dealt with when writing the task plugin), but it can happen (e.g when a socket is busy, a file missing, ...)

Those two flags are used to control batch execution, when task execution doesn't return OK, or when an Exception is raised.

If catch_exception is set to True or yes, exit_if_not_ok is forced to False or no

Here is a table of what happens on different cases

Task return	catch_exception=True exit_if_not_ok=False	catch_exception=False exit_if_not_ok=True
OK	execution continues	execution continues
not OK but no Exception is raised	execution continues	batch is exited status is returned
Exception raised	exception is catched TASK_ERROR_IGNORED is returned execution continues	exception is raised

When

The when clause allows to specify a python expression that will be evaluated

If that expression doesn't evaluates to True, task is skipped

Environment variables can be used. For example

tasks:
  - name: Render Image Sequence
    raw:
      command: $BLENDER_BIN --enable-autoexec ...
      async: False
      open_terminal: True
    register_status: True
    

  - name: Make mov
    raw:
      command: python -m preview ....
    when: $JPS_REGISTERED_STATUS == 'OK'
    register_status: True

The "Make mov" task will be run only if the task "Render Image Sequence" returns OK

If the when clause evaluates to False and register_status is on, no status will be registered