refs #2183 #2093

From this comment in #2183: If a "plugins" block appears in metadata.json, it means that a user hasn't migrated over their plugin configuration from metadata.json to datasette.yaml, which is a breaking change in Datasette 1.0.

This PR will ensure that an error is raised whenever that happens.

:books: Documentation preview :books:: https://datasette--2190.org.readthedocs.build/en/2190/

The PR moves the following fields from metadata.yaml to datasette.yaml:

permissions allow allow_sql queries extra_css_urls extra_js_urls

This is a significant breaking change that users will need to upgrade their metadata.yaml files for. But the format/locations are similar to the previous version, so it shouldn't be too difficult to upgrade.

One note: I'm still working on the Configuration docs, specifically the "reference" section. Though it's pretty small, the rest of read to review

Part of #2093

In #2149 , we ported over "settings.json" into the new datasette.yaml config file, with a top-level "settings" key. This PR ports over plugin configuration into top-level "plugins" key, as well as nested database/table plugin config.

From now on, no plugin-related configuration is allowed in metadata.yaml, and must be in datasette.yaml in this new format. This is a pretty significant breaking change. Thankfully, you should be able to copy-paste your legacy plugin key/values into the new datasette.yaml format.

An example of what datasette.yaml would look like with this new plugin config:

```yaml

plugins: datasette-my-plugin: config_key: value

databases: fixtures: plugins: datasette-my-plugin: config_key: fixtures-db-value tables: students: plugins: datasette-my-plugin: config_key: fixtures-students-table-value

```

As an additional benefit, this now works with the new -s flag:

bash datasette --memory -s 'plugins.datasette-my-plugin.config_key' new_value

Marked as a "Draft" right now until I add better documentation. We also should have a plan for the next alpha release to document and publicize this change, especially for plugin authors (since their docs will have to change to say datasette.yaml instead of metadata.yaml

:books: Documentation preview :books:: https://datasette--2183.org.readthedocs.build/en/2183/

refs #2157

This PR adds a new --internal option to datasette serve. If provided, it is the path to a persistent internal database that Datasette core and Datasette plugins can use to store data, as discussed in the proposal issue.

This PR also removes and deprecates the previous in-memory _internal database. Those tables now appear in the internal database, with core_ prefixes (ex tables in _internal is now core_tables in internal).

A note on the new core_ tables

However, one important notes about those new core_ tables: If a --internal DB is passed in, that means those core_ tables will persist across multiple Datasette instances. This wasn't the case before, since _internal was always an in-memory database created from scratch.

I tried to put those core_ tables as TEMP tables - after all, there's always one 1 internal DB connection at a time, so I figured it would work. But, since we use the Database() wrapper for the internal DB, it has two separate connections: a default read-only connection and a write connection that is created when a write operation occurs. Which meant the TEMP tables would be created by the write connection, but not available in the read-only connection.

So I had a brillant idea: Attach an in-memory named database with cache=shared, and create those tables there!

sql ATTACH DATABASE 'file:datasette_internal_core?mode=memory&cache=shared' AS core;

We'd run this on both the read-only connection and the write-only connection. That way, those tables would stay in memory, they'd communicate with the cache=shared feature, and we'd be good to go.

However, I couldn't find an easy way to run a ATTACH DATABASE command on the read-only query.

Using Database() as a wrapper for the internal DB is pretty limiting - it's meant for Datasette "data" databases, where we want multiple readers and possibly 1 write connection at a time. But the internal database doesn't really require that kind of support - I think we could get away with a single read/write connection, but it seemed like too big of a rabbithole to go through now.

:books: Documentation preview :books:: https://datasette--2162.org.readthedocs.build/en/2162/

refs #2093 #2143

This is the first step to implementing the new datasette.yaml/datasette.json configuration file.

• The old --config argument is now back, and is the path to a datasette.yaml file. Acts like the --metadata flag.
• The old settings.json behavior has been removed.
• The "settings" key inside datasette.yaml defines the same --settings flags
• Values passed in --settings will over-write values in datasette.yaml

Docs for the Config file is pretty light, not much to add until we add more config to the file.

:books: Documentation preview :books:: https://datasette--2149.org.readthedocs.build/en/2149/

I'd like there to be a plugin system for sqlite-utils, similar to the datasette/llm plugins. I'd like to make plugins that would do things like:

• Register SQLite extensions for more SQL functions + virtual tables
• Register new subcommands
• Different input file formats for sqlite-utils memory
• Different output file formats (in addition to --csv --tsv --nl etc.

A few real-world use-cases of plugins I'd like to see in sqlite-utils:

• Register many of my sqlite extensions in sqlite-utils (sqlite-http, sqlite-lines, sqlite-regex, etc.)
• New subcommands to work with sqlite-vss vector tables
• Input/ouput Parquet/Avro/Arrow IPC files with sqlite-arrow

Just like the Datasette prepare_connection hook, this PR adds a similar hook for the sqlite-utils plugin system.

The sole argument is conn, since I don't believe a database or datasette argument would be relevant here.

I want to do this so I can release sqlite-utils plugins for my SQLite extensions, similar to the Datasette plugins I've release for them.

An example plugin: https://gist.github.com/asg017/d7cdf0d56e2be87efda28cebee27fa3c

```bash $ sqlite-utils install https://gist.github.com/asg017/d7cdf0d56e2be87efda28cebee27fa3c/archive/5f5ad549a40860787629c69ca120a08c32519e99.zip

$ sqlite-utils memory 'select hello("alex") as response' [{"response": "Hello, alex!"}] ``` Refs: - #574

:books: Documentation preview :books:: https://sqlite-utils--573.org.readthedocs.build/en/573/

Closes #1784

The --load-extension flag can now accept an optional "entrypoint" value, to specify which entrypoint SQLite should load from the given extension.

```bash

would load default entrypoint like before

datasette data.db --load-extension ext

loads the extensions with the "sqlite3_foo_init" entrpoint

datasette data.db --load-extension ext:sqlite3_foo_init

loads the extensions with the "sqlite3_bar_init" entrpoint

datasette data.db --load-extension ext:sqlite3_bar_init ```

For testing, I added a small SQLite extension in C at tests/ext.c. If compiled, then pytest will run the unit tests in test_load_extensions.pyto verify that Datasette loads in extensions correctly (and loads the correct entrypoints). Compiling the extension requires a C compiler, I compiled it on my Mac with:

gcc ext.c -I path/to/sqlite -fPIC -shared -o ext.dylib

Where path/to/sqlite is a directory that contains the SQLite amalgamation header files.

Re documentation: I added a bit to the help text for --load-extension (which I believe should auto-add to documentation?), and the existing extension documentation is spatialite specific. Let me know if a new extensions documentation page would be helpful!

Problem

SQLite extensions have the option to define multiple "entrypoints" in each loadable extension. For example, the upcoming version of sqlite-lines will have 2 entrypoints: the default sqlite3_lines_init (which SQLite will automatically guess for) and sqlite3_lines_noread_init. The sqlite3_lines_noread_init version omits functions that read from the filesystem, which is necessary for security purposes when running untrusted SQL (which Datasette does).

(Similar multiple entrypoints will also be added for sqlite-http).

The --load-extension flag, however, doesn't give the option to specify a different entrypoint, so the default one is always used.

Proposal

I want there to be a new command line option of the --load-extension flag to specify a custom entrypoint like so: datasette my.db \ --load-extension ./lines0 sqlite3_lines0_noread_init

Then, under the hood, this line of code:

https://github.com/simonw/datasette/blob/7af67b54b7d9bca43e948510fc62f6db2b748fa8/datasette/app.py#L562

Would look something like this:

python conn.execute("SELECT load_extension(?, ?)", [extension, entrypoint])

One potential problem: For backward compatibility, I'm not sure if Click allows cli flags to have variable number of options ("arity"). So I guess it could also use a : delimiter like --static:

datasette my.db \ --load-extension ./lines0:sqlite3_lines0_noread_init

Or maybe even a new flag name?

datasette my.db \ --load-extension-entrypoint ./lines0 sqlite3_lines0_noread_init

Personally I prefer the : option... and maybe even --load-extension -> --load? Definitely out of scope for this issue tho

datasette my.db \ --load./lines0:sqlite3_lines0_noread_init