VisiData Cloud Custodian Sidebar

README.md

A Cloud Custodian Output Directory Sidebar Supplement in VisiData

Some experimentation with providing dynamic sidebar help information following discussion in saulpw/visidata#1733

The idea is to conditionally override the help text on a DirSheet only if it looks like we're in a Cloud Custodian output directory.

This is a hack that could be added to ~/.visidatarc... but probably shouldn't yet.

Demo

c7n_output_dir_help.py

import json
import textwrap
from visidata import DirSheet, vd
from functools import cache, wraps

def c7n_help(original_help):
    '''Add Cloud Custodian-specific help to the DirSheet when relevant

    If it looks like we're in a DirSheet for a Cloud Custodian output directory,
    show some high-level details about the policy and output files.
    '''
    c7n_filenames = {'custodian-run.log', 'metadata.json', 'resources.json'}

    @property
    @cache
    @wraps(DirSheet.help)
    def wrapper(self):
        filenames = {row._path.name.removesuffix('.gz') for row in self.rows}
        if not c7n_filenames <= filenames:
            return original_help

        policy_metadata = json.loads(next(row for row in vd.sheet.rows if row._path.name == 'metadata.json').read_text())
        resources = json.loads(next(row for row in vd.sheet.rows if row._path.name == 'resources.json').read_text())
        source_files = '\n'.join(f'''
            - {config}
            '''
            for config in policy_metadata['config']['configs']
        )

        return original_help + textwrap.dedent(f'''
            ## Cloud Custodian

            This looks like a Cloud Custodian output directory!

            [:bold]Policy:[:] {policy_metadata['policy']['name']}
            [:bold]Source Files:[:] {source_files}
            [:bold]Target Resource:[:] {policy_metadata['policy']['resource']}
            [:bold]Account ID:[:] {policy_metadata['config']['account_id']}
            [:bold]Region:[:] {policy_metadata['config']['region']}
            [:bold]Resources Matched:[:] {len(resources)}
            [:bold]Custodian Version:[:] {policy_metadata['version']}

            ## Output File Reference

            - `custodian-run.log`: log messages and errors from the policy run
            - `metadata.json`: the policy body and information about where it ran
            - `resources.json`: a list of all resources that matched the policy
        ''')
    return wrapper

DirSheet.help = c7n_help(DirSheet.help)

I'd call this def help or at least add a @wraps(DirSheet.help).

I think this is computed frequently, so the actual loading should probably be moved out of the actual wrapper function so it's only done once.

I'd call this def help or at least add a @wraps(DirSheet.help).

Good call 👍

I think this is computed frequently, so the actual loading should probably be moved out of the actual wrapper function so it's only done once.

Ah yeah I see that running a bunch. Caching on the property seems to address that and still report the expected dir-specific info. Would be even more noticeable for s3, thanks.