path_manifest 0.2.24

Inject a manifest of a directory structure and generate patches against it later.

Introduction

This project allows you to fingerprint a directory by dropping a manifest of relative filepaths and modified-times into it, and then build patches against it later and maintain a history of patching. Inclusions and exclusions can be specified and most of the commands can output JSON-encoded data so that they can be internalized from other tools.

To apply a patch, merely expand it in the directory. Obviously we don’t manage files that have been removed.

Tools

pm_write_manifest

Write a manifest of the complete contents of a given directory to the root of the same directory. The path can be absolute or relative.

Command-Line Help:

usage: pm_write_manifest [-h] [-f] [-mf MANIFEST_FILENAME] [-e REL-PATH]
                         [-ef REL-FILEPATH] [-i REL-PATH] [-j]
                         root_path

Write file-manifest for the contents of the given path.

positional arguments:
  root_path             Root path

optional arguments:
  -h, --help            show this help message and exit
  -f, --force           Force the replacement of an existing manifest
  -mf MANIFEST_FILENAME, --manifest-filename MANIFEST_FILENAME
                        Manifest filename
  -e REL-PATH, --exclude-rel-path REL-PATH
                        Ignore the contents of this child path
  -ef REL-FILEPATH, --exclude-rel-filepath REL-FILEPATH
                        Ignore this filepath
  -i REL-PATH, --include-rel-path REL-PATH
                        Constraint the matched files to one or more
                        directories
  -j, --json            Print result in JSON

Usage:

$ pm_write_manifest /application/root

pm_check_for_changes

Print a list of the changes since the manifest was written.

Command-Line Help:

usage: pm_check_for_changes [-h] [-mf MANIFEST_FILENAME] [-e REL-PATH]
                            [-ef REL-FILEPATH] [-i REL-PATH] [-ir]
                            root_path

Check the given path for changes since the manifest was written.

positional arguments:
  root_path             Root path

optional arguments:
  -h, --help            show this help message and exit
  -mf MANIFEST_FILENAME, --manifest-filename MANIFEST_FILENAME
                        Manifest filename
  -e REL-PATH, --exclude-rel-path REL-PATH
                        Ignore the contents of this child path
  -ef REL-FILEPATH, --exclude-rel-filepath REL-FILEPATH
                        Ignore this filepath
  -i REL-PATH, --include-rel-path REL-PATH
                        Constraint the matched files to one or more
                        directories
  -ir, --ignore-removed
                        Do not show removed files (helpful when we include
                        specific subdirectories)

Usage:

$ pm_check_for_changes /application/root
New
---
new_directory/new_file2
new_file

Updated
-------
updated_file

pm_make_differential_patch

Build a new patch with the difference between the current directory and the state when the manifest was written.

Command-Line Help:

usage: pm_make_differential_patch [-h] [-mf MANIFEST_FILENAME] [-e REL-PATH]
                                  [-i REL-PATH] [-ef REL-FILEPATH] [-j]
                                  [-m COUNT]
                                  root_path patch_name output_path

Create an archive with all differences since the manifest was written.

positional arguments:
  root_path             Root path
  patch_name            Patch name
  output_path           Output path

optional arguments:
  -h, --help            show this help message and exit
  -mf MANIFEST_FILENAME, --manifest-filename MANIFEST_FILENAME
                        Manifest filename
  -e REL-PATH, --exclude-rel-path REL-PATH
                        Ignore the contents of this child path
  -i REL-PATH, --include-rel-path REL-PATH
                        Constraint the matched files to one or more
                        directories
  -ef REL-FILEPATH, --exclude-rel-filepath REL-FILEPATH
                        Ignore this filepath
  -j, --json            Print result in JSON
  -m COUNT, --max-files COUNT
                        A safe maximum for the number of allowed files in the
                        patch (0 for unlimited)

Usage:

$ pm_make_differential_patch /application/root 201507282031 /tmp
Created/Updated Files
---------------------

new_directory/new_file2
updated_file
new_file

Patch file-path:

/tmp/pm-patch-201507282031.tar.bz2

pm_show_applied_patches

Command-Line Help:

usage: pm_show_applied_patches [-h] [-j] root_path

Show the patches that have been applied to the application.

positional arguments:
  root_path   Root path

optional arguments:
  -h, --help  show this help message and exit
  -j, --json  Print result in JSON

Usage:

$ pm_show_applied_patches /application/root
Applied Patches
---------------

201507282031

Affected Files
--------------

new_directory/new_file2
updated_file
new_file

Notes

This is merely a tool of convenience. All patches will deposit a file that looks like “.patch_info.XYZ” into the application root. For example, the patch that we created above deposited a file named “.patch_info.201507282031”. This holds JSON-encoded data that describes the patch.

Example:

$ cat .patch_info.201507282031
{
    "created_timestamp": "2015-07-28 20:31:28",
    "files": {
        "new_directory/new_file2": {
            "filesize_b": 0,
            "mtime_epoch": 1438129768
        },
        "new_file": {
            "filesize_b": 0,
            "mtime_epoch": 1438129731
        },
        "updated_file": {
            "filesize_b": 0,
            "mtime_epoch": 1438129728
        }
    },
    "patch_name": "201507282031"
}

Note that the filesizes were zero merely because we created empty-files for the purpose of these examples.

Patch Application Example

Once you have a patch, simply expand it into the application root in order to apply it:

$ tar xjf /tmp/pm-patch-201507282031.tar.bz2