Install

% pip3 install bg-helper

Usage

import bg_helper as bh

Helper functions in bg_helper that can be used to:

• run shell commands in a variety of ways

  run(cmd, stderr_to_stdout=False, debug=False, timeout=None, exception=False, show=False)
      Run a shell command and return the exit status
  
      - cmd: string with shell command
      - stderr_to_stdout: if True, redirect stderr to stdout
      - debug: if True, insert breakpoint right before subprocess.call
      - timeout: number of seconds to wait before stopping cmd
      - exception: if True, raise Exception if non-zero exit status or TimeoutExpired
      - show: if True, show the command before executing
  
  run_output(cmd, strip=True, debug=False, timeout=None, exception=False, show=False)
      Run a shell command and return output or error
  
      - cmd: string with shell command
      - strip: if True, strip trailing and leading whitespace from output
      - debug: if True, insert breakpoint right before subprocess.call
      - timeout: number of seconds to wait before stopping cmd
      - exception: if True, raise Exception if non-zero exit status or TimeoutExpired
      - show: if True, show the command before executing
  
  run_or_die(cmd, stderr_to_stdout=False, debug=False, timeout=None, exception=False, show=False)
      Run a shell command; if non-success, raise Exception or exit the system
  
      - cmd: string with shell command
      - stderr_to_stdout: if True, redirect stderr to stdout
      - debug: if True, insert breakpoint right before subprocess.call
      - timeout: number of seconds to wait before stopping cmd
      - exception: if True, raise Exception if non-zero exit status or TimeoutExpired
      - show: if True, show the command before executing
  

• call a Python function & capture the value or any uncaught exceptions

  call_func(func, *args, **kwargs)
      Call a func with arbitrary args/kwargs and capture uncaught exceptions
  
      The following kwargs will be popped and used internally:
  
      - logger: logger object to use
      - verbose: if True (default), print line separator & tracebacks when caught
  
      The returned dict will always have at least the following keys:
  
      - `func_name`
      - `args`
      - `kwargs`
      - `status` (ok/error)
  
      If the function call was successful, there will also be a `value` key. If
      there was an uncaught exception, the following additional keys will be
      provided in the return dict
  
      - `error_type`
      - `error_value`
      - `fqdn`
      - `func_doc`
      - `func_module`
      - `time_epoch`
      - `time_string`
      - `traceback_string`
  

• start a long-running shell command or Python function in the background (like vlc media player)

  SimpleBackgroundTask(func, *args, **kwargs)
      Run a single command in a background thread and log any exceptions
  
      You can pass a callable object, or a string representing a shell command
  
      - if passing a callable, you may also pass in the args and kwargs
          - since the callable will be executed by the `call_func` function,
              the `logger` and `verbose` keyword arguments (if passed in) will be
              used by `call_func`
  

Helper functions in bg_helper.tools

git

• ctx_repo_path_root
• git_repo_path_root
• git_clone
• git_fetch
• git_origin_url
• git_do
• git_current_branch
• git_current_tracking_branch
• git_last_tag
• git_tag_message
• git_last_tag_message
• git_tags
• git_first_commit_id
• git_last_commit_id
• git_commits_since_last_tag
• git_unpushed_commits
• git_untracked_files
• git_stashlist
• git_status
• git_info_dict
• git_info_string
• git_branch_date
• git_remote_branches
• git_local_branches
• git_remote_branches_merged_with
• git_local_branches_merged_with

grep

• grep_output

pip

• pip_freeze
• pip_install_editable

ps

• ps_output

ssh

• ssh_to_server
• ssh_pem_files
• ssh_private_key_files
• ssh_configured_hosts
• ssh_determine_aws_user_for_server

docker

• docker_ok
• docker_stop
• docker_start_or_run
• docker_container_id
• docker_container_inspect
• docker_container_config
• docker_container_env_vars
• docker_logs
• docker_exec
• docker_exec_wait
• docker_shell
• docker_cleanup_volumes
• docker_redis_start
• docker_redis_cli
• docker_mongo_start
• docker_mongo_cli
• docker_postgres_start
• docker_postgres_cli
• docker_postgres_wait
• docker_mysql_start
• docker_mysql_cli
• docker_mysql_wait
• docker_alpine_start
• docker_ubuntu_start
• docker_fedora_start

Examples

% ipython
...

In [1]: import bg_helper as bh

In [2]: def lame():
   ...:     return 1/0

In [3]: def blah(*args, **kwargs):
   ...:     return locals()

In [4]: bh.call_func(blah)
Out[4]: 
{'args': '()',
 'func_name': 'blah',
 'kwargs': '{}',
 'status': 'ok',
 'value': {'args': (), 'kwargs': {}}}

In [5]: bh.call_func(blah, 'cats', 'dogs')
Out[5]: 
{'args': "('cats', 'dogs')",
 'func_name': 'blah',
 'kwargs': '{}',
 'status': 'ok',
 'value': {'args': ('cats', 'dogs'), 'kwargs': {}}}

In [6]: bh.call_func(blah, 'cats', 'dogs', meh=[1, 2, 3, 4, 5])
Out[6]: 
{'args': "('cats', 'dogs')",
 'func_name': 'blah',
 'kwargs': "{'meh': [1, 2, 3, 4, 5]}",
 'status': 'ok',
 'value': {'args': ('cats', 'dogs'), 'kwargs': {'meh': [1, 2, 3, 4, 5]}}}

In [7]: bh.call_func(lame)
======================================================================
2017-04-01 12:32:35,107: func=lame args=() kwargs={}
Traceback (most recent call last):
  File "/tmp/here/venv/lib/python3.5/site-packages/bg_helper/__init__.py", line 70, in call_func
    value = func(*args, **kwargs)
  File "<ipython-input-2-ac0fa5de647a>", line 2, in lame
    return 1/0
ZeroDivisionError: division by zero

Out[7]: 
{'args': '()',
 'error_type': "<class 'ZeroDivisionError'>",
 'error_value': "ZeroDivisionError('division by zero',)",
 'fqdn': 'x200-purple',
 'func_doc': None,
 'func_module': '__main__',
 'func_name': 'lame',
 'kwargs': '{}',
 'status': 'error',
 'time_epoch': 1491067955.1004958,
 'time_string': '2017_0401-Sat-123235',
 'traceback_string': 'Traceback (most recent call last):\n  File "/tmp/here/venv/lib/python3.5/site-packages/bg_helper/__init__.py", line 70, in call_func\n    value = func(*args, **kwargs)\n  File "<ipython-input-2-ac0fa5de647a>", line 2, in lame\n    return 1/0\nZeroDivisionError: division by zero\n'}

In [8]: cat log--bg-helper.log
2017-04-01 12:32:35,107 - ERROR - call_func: func=lame args=() kwargs={}
Traceback (most recent call last):
  File "/tmp/here/venv/lib/python3.5/site-packages/bg_helper/__init__.py", line 70, in call_func
    value = func(*args, **kwargs)
  File "<ipython-input-2-ac0fa5de647a>", line 2, in lame
    return 1/0
ZeroDivisionError: division by zero

In [9]: bh.SimpleBackgroundTask('echo "hello from console" > /tmp/blahblah.txt')
Out[9]: <bg_helper.SimpleBackgroundTask at 0x7ff112229c18>

In [10]: ls /tmp/blahblah.txt
/tmp/blahblah.txt

In [11]: cat /tmp/blahblah.txt
hello from console

In [12]: bh.SimpleBackgroundTask('echo "$(date)" >> /tmp/blahblah.txt')
Out[12]: <bg_helper.SimpleBackgroundTask at 0x7ff110057cf8>

In [13]: cat /tmp/blahblah.txt
hello from console
Sat Apr  1 12:33:23 CDT 2017