datasette-block-robots

Datasette plugin that blocks robots and crawlers using robots.txt

Installation

Install this plugin in the same environment as Datasette.

$ pip install datasette-block-robots

Usage

Having installed the plugin, /robots.txt on your Datasette instance will return the following:

User-agent: *
Disallow: /

This will request all robots and crawlers not to visit any of the pages on your site.

Here's a demo of the plugin in action: https://sqlite-generate-demo.datasette.io/robots.txt

Configuration

By default the plugin will block all access to the site, using Disallow: /.

If you want the index page to be indexed by search engines without crawling the database, table or row pages themselves, you can use the following:

{
    "plugins": {
        "datasette-block-robots": {
            "allow_only_index": true
        }
    }
}

This will return a /robots.txt like so:

User-agent: *
Disallow: /db1
Disallow: /db2

With a Disallow line for every attached database.

To block access to specific areas of the site using custom paths, add this to your metadata.json configuration file:

{
    "plugins": {
        "datasette-block-robots": {
            "disallow": ["/mydatabase/mytable"]
        }
    }
}

This will result in a /robots.txt that looks like this:

User-agent: *
Disallow: /mydatabase/mytable

Alternatively you can set the full contents of the robots.txt file using the literal configuration option. Here's how to do that if you are using YAML rather than JSON and have a metadata.yml file:

plugins:
    datasette-block-robots:
        literal: |-
            User-agent: *
            Disallow: /
            User-agent: Bingbot
            User-agent: Googlebot
            Disallow:

This example would block all crawlers with the exception of Googlebot and Bingbot, which are allowed to crawl the entire site.

Extending this with other plugins

This plugin adds a new plugin hook to Datasete called block_robots_extra_lines() which can be used by other plugins to add their own additional lines to the robots.txt file.

The hook can optionally accept these parameters:

• datasette: The current Datasette instance. You can use this to execute SQL queries or read plugin configuration settings.
• request: The Request object representing the incoming request to /robots.txt.

The hook should return a list of strings, each representing a line to be added to the robots.txt file.

It can also return an async def function, which will be awaited and used to generate a list of lines. Use this option if you need to make await calls inside you hook implementation.

This example uses the hook to add a Sitemap: http://example.com/sitemap.xml line to the robots.txt file:

from datasette import hookimpl

@hookimpl
def block_robots_extra_lines(datasette, request):
    return [
        "Sitemap: {}".format(datasette.absolute_url(request, "/sitemap.xml")),
    ]

This example blocks access to paths based on a database query:

@hookimpl
def block_robots_extra_lines(datasette):
    async def inner():
        db = datasette.get_database()
        result = await db.execute("select path from mytable")
        return [
            "Disallow: /{}".format(row["path"]) for row in result
        ]
    return inner

datasette-sitemap is an example of a plugin that uses this hook.

Development

To set up this plugin locally, first checkout the code. Then create a new virtual environment:

cd datasette-block-robots
python3 -mvenv venv
source venv/bin/activate

Or if you are using pipenv:

pipenv shell

Now install the dependencies and tests:

pip install -e '.[test]'

To run the tests:

pytest