jdswinbank/jdsnap

Automatic Tarsnap Backups

Quick & dirty package to maintain a rolling set of Tarsnap backups. Tested on Python 3.7 & 3.8.

Installation

For the author's (macOS 10.15) system. We're going to:

• Use my default Python (installed by Macports);
• Install into a virtualenv;
• Run from launchd.

We'll start by setting up the virtualenv:

$ python -m venv ~/sw/venv/jdsnap
$ . ~/sw/venv/jdsnap/bin/activate

Now install jdsnap into the new environment. Note that it's pulling in its dependencies:

$ python setup.py install

At this point, it should be possible to run jdsnap without setting up the virtualenv:

$ ~/sw/venv/jdsnap/bin/jdsnap  # ... and away we go.

And so at this point we can drop the following into ~/Library/LaunchAgentes/org.jdswinbank.jdsnap:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>ProgramArguments</key>
    <array>
        <string>/Users/jds/sw/venv/jdsnap/bin/jdsnap</string>
        <string>--tarsnap</string>
        <string>/opt/local/bin/tarsnap</string>
        <string>--config</string>
        <string>/Users/jds/.jdsnap.json</string>
    </array>
    <key>Label</key>
    <string>org.swinbank.jdsnap</string>
    <key>KeepAlive</key>
    <false/>
    <key>StartCalendarInterval</key>
    <dict>
        <key>Minute</key>
        <integer>0</integer>
        <key>Hour</key>
        <integer>11</integer>
    </dict>
    <key>StandardOutPath</key>
    <string>/Users/jds/sw/log/jdsnap.log</string>
    <key>StandardErrorPath</key>
    <string>/Users/jds/sw/log/jdsnap.err</string>
</dict>
</plist>

Note that it seems tempting to use the system Python 3 (/usr/bin/python3), but that doesn't have access to read the ~/Documents folder I'm trying to back up, and there's no easy way to give it that access. See, for example, this Stack Overflow discussion, and note that /usr/bin/python3 is just failing rather than prompting for access.