issue_comments

Just spotted this: https://github.com/simonw/datasette/blob/17ec309e14f9c2e90035ba33f2f38ecc5afba2fa/datasette/app.py#L328-L332

https://github.com/simonw/datasette/blob/17ec309e14f9c2e90035ba33f2f38ecc5afba2fa/datasette/app.py#L359-L360

Looks to me like that second bit of code doesn't yet handle datasette.yml

This code does though:

https://github.com/simonw/datasette/blob/17ec309e14f9c2e90035ba33f2f38ecc5afba2fa/datasette/app.py#L333-L335

parse_metadata() is clearly a bad name for this function:

https://github.com/simonw/datasette/blob/d97e82df3c8a3f2e97038d7080167be9bb74a68d/datasette/utils/init.py#L980-L990

That @documented decorator indicates that it's part of the documented API used by plugin authors: https://docs.datasette.io/en/1.0a4/internals.html#parse-metadata-content

So we should rename it to something better like parse_json_or_yaml() but keep parse_metadata as an undocumented alias for that to avoid any unnecessary plugin breaks.

The other thing that could work is something like this: bash export AUTH_TOKENS_DB="tokens" datasette \ -s settings.sql_time_limit_ms 1000 \ -s plugins.datasette-auth-tokens.manage_tokens true \ -e plugins.datasette-auth-tokens.manage_tokens_database AUTH_TOKENS_DB So -e is an alternative version of -s which reads from the named environment variable instead of having the value provided directly as the second value in the pair.

I quite like this, because it could replace the really ugly $ENV pattern we have in plugin configuration at the moment: https://docs.datasette.io/en/1.0a4/plugins.html#secret-configuration-values yaml plugins: datasette-auth-github: client_secret: $env: GITHUB_CLIENT_SECRET

That's a really good call, thanks @rclement - environment variable configuration totally makes sense here.

Need to figure out the right syntax for that. Something like this perhaps:

bash DATASETTE_CONFIG_PLUGINS='{"datasette-ripgrep": ...}' Hard to know how to make this nestable though. I considered this: bash DATASETTE_CONFIG_PLUGINS_DATASETTE_RIPGREP_PATH='/path/to/code/' But that doesn't work, because how does the processing code know that it should split on _ for most of the tokens but NOT split DATASETTE_RIPGREP, instead treating that as datasette-ripgrep?

I checked and - is not a valid character in an environment variable, at least in zsh on macOS: % export FOO_BAR-BAZ=1 export: not valid in this context: FOO_BAR-BAZ

Something notable about this design is that, because the values in the key-value pairs are treated as JSON first and then strings only if they don't parse cleanly as JSON, it's possible to represent any structure (including nesting structures) using this syntax. You can do things like this if you need to (settings for an imaginary plugin):

bash datasette data.db \ -s plugins.datasette-complex-plugin.configs '{"foo": [1,2,3], "bar": "baz"}' Which would be equivalent to: yaml plugins: datasette-complex-plugin: configs: foo: - 1 - 2 - 3 bar: baz This is a bit different from a previous attempt I made at the same problem: https://github.com/simonw/json-flatten - that used syntax like foo.bar.[0]$int = 1 to specify an integer as the first item of an array, which is much more complex.

That previous design was meant to support round-trips, so you could take any nested JSON object and turn it into an HTMl form or query string where every value can have its own form field, then turn the result back again.

For the datasette -s key value feature we don't need round-tripping with individual values each editable on their own, so we can go with something much simpler.

@simonw, FWIW, I do exactly the same thing for one of my projects (both to allow multiple configuration files to be passed on the command line and setting individual values) and it works quite well for me and my users. I even use the same parameter name for both (https://studio.zerobrane.com/doc-configuration#configuration-via-command-line), but I understand why you may want to use different ones for files and individual values. There is one small difference that I accept code snippets, but I don't think it matters much in this case.

That's a neat example thanks!

I've been thinking about what it might look like to allow command-line arguments to be used to define any of the configuration options in datasette.yml, as alternative and more convenient syntax.

Here's what I've come up with: datasette \ -s settings.sql_time_limit_ms 1000 \ -s plugins.datasette-auth-tokens.manage_tokens true \ -s plugins.datasette-auth-tokens.manage_tokens_database tokens \ -s plugins.datasette-ripgrep.path "/home/simon/code-to-search" \ -s databases.mydatabase.tables.example_table.sort created \ mydatabase.db tokens.db Which would be equivalent to datasette.yml containing this: yaml plugins: datasette-auth-tokens: manage_tokens: true manage_tokens_database: tokens datasette-ripgrep: path: /home/simon/code-to-search databases: mydatabase: tables: example_table: sort: created settings: sql_time_limit_ms: 1000 Here's a prototype implementation of this: ```python import json from typing import Any, List, Tuple

def _handle_pair(key: str, value: str) -> dict: """ Turn a key-value pair into a nested dictionary. foo, bar => {'foo': 'bar'} foo.bar, baz => {'foo': {'bar': 'baz'}} foo.bar, [1, 2, 3] => {'foo': {'bar': [1, 2, 3]}} foo.bar, "baz" => {'foo': {'bar': 'baz'}} foo.bar, '{"baz": "qux"}' => {'foo': {'bar': "{'baz': 'qux'}"}} """ try: value = json.loads(value) except json.JSONDecodeError: # If it doesn't parse as JSON, treat it as a string pass

keys = key.split('.')
result = current_dict = {}

for k in keys[:-1]:
    current_dict[k] = {}
    current_dict = current_dict[k]

current_dict[keys[-1]] = value
return result

def _combine(base: dict, update: dict) -> dict: """ Recursively merge two dictionaries. """ for key, value in update.items(): if isinstance(value, dict) and key in base and isinstance(base[key], dict): base[key] = _combine(base[key], value) else: base[key] = value return base

def handle_pairs(pairs: List[Tuple[str, Any]]) -> dict: """ Parse a list of key-value pairs into a nested dictionary. """ result = {} for key, value in pairs: parsed_pair = _handle_pair(key, value) result = _combine(result, parsed_pair) return result Exercised like this:python print(json.dumps(handle_pairs([ ("settings.sql_time_limit_ms", "1000"), ("plugins.datasette-auth-tokens.manage_tokens", "true"), ("plugins.datasette-auth-tokens.manage_tokens_database", "tokens"), ("plugins.datasette-ripgrep.path", "/home/simon/code-to-search"), ("databases.mydatabase.tables.example_table.sort", "created"), ]), indent=4)) Output:json { "settings": { "sql_time_limit_ms": 1000 }, "plugins": { "datasette-auth-tokens": { "manage_tokens": true, "manage_tokens_database": "tokens" }, "datasette-ripgrep": { "path": "/home/simon/code-to-search" } }, "databases": { "mydatabase": { "tables": { "example_table": { "sort": "created" } } } } } `` Note that-sisn't currently an option fordatasette serve`.

--setting key value IS an existing option, but it isn't completely compatible with this because it maps directly just to settings.

Although... we could keep compatibility by saying that if you call --setting known_setting value and that known_setting is in this list then we treat it as if you said -s settings.known_setting value instead:

https://github.com/simonw/datasette/blob/bdf59eb7db42559e538a637bacfe86d39e5d17ca/datasette/app.py#L114-L204

This also makes it simple to separate out secrets.

datasette --config settings.yaml --config secrets.yaml --config db-docs.yaml --config db-fixtures.yaml

Having multiple configs that combine in that way is a really interesting direction.

To chime in from a poweruser perspective: I'm worried that this is an overengineering trap. Yes, the current solution is somewhat messy. But there are datasette-wide settings, there are database-scope settings, there are table-scope settings etc, but then there are database-scope metadata and table-scope metadata. Trying to cleanly separate "settings" from "configuration" is, I believe, an uphill fight.

I'm very keen on separating out the "metadata" - where metadata is the slimmest possible set of things, effectively the data license and the source and the column and table descriptions - from everything else, mainly because I want metadata to be able to travel with the data.

One idea that's been discussed before is having an optional mechanism for storing metadata in the SQLite database file itself - potentially in a _datasette_metadata table. That way you could distribute a DB file and anyone who opened it in Datasette would also see the correct metadata about it.

That's why I'm so keen on splitting out metadata from all of the other stuff - settings and plugin configuration and authentication rules.

So really it becomes "true metadata" v.s. "all of the other junk that's accumulated in metadata and settings.json".

Another option would be, instead of flat datasette.json/datasette.yaml files, we could instead use a Python file, like datasette_config.py. That way one could dynamically generate config (ex dev vs prod, auto-discover credentials, etc.). Kinda like Django settings.

Another option would be, instead of flat datasette.json/datasette.yaml files, we could instead use a Python file, like datasette_config.py. That way one could dynamically generate config (ex dev vs prod, auto-discover credentials, etc.). Kinda like Django settings.

I'm not a fan of that. I feel like software history is full of examples of projects that implemented configuration-as-code and then later regretted it - the most recent example is setup.py in Python turning into pyproject.yaml, but I feel like I've seen that pattern play out elsewhere too.

I don't think having people dynamically generate JSON/YAML for their configuration is a big burden. I'd have to see some very compelling use-cases to convince me otherwise.

That said, I do really like a bias towards settings that can be changed at runtime. Datasette has suffered a bit from some settings that can't be easily changed at runtime already - hence my gnarly https://github.com/simonw/datasette-remote-metadata plugin.

For things like Datasette Cloud for example the more people can configure without rebooting their container the better!

I don't think live reconfiguration at runtime is incompatible with JSON/YAML configuration though. Caddy is one of my favourite examples of software that can be entirely re-configured at runtime by POSTING a big blob of JSON to it: https://caddyserver.com/docs/quick-starts/api

Actually there is one thing that I'm not comfortable about with respect to the existing design: the way the database / tables stuff is nested.

They assume that the user will attach the database to Datasette using a fixed name - docs.db or whatever.

But what if we want to support users downloading databases from each other and attaching them to Datasette where those DBs might carry some of their own configuration?

Moving metadata into the databases makes sense there, but what about database-specific settings like the default sort order for a table, or configured canned queries?

Having those tied to the filename of the database itself feels unpleasant to me. But how else could we handle this?

Yeah, I'm convinced by that. There's not point in having both settings.json and datasette.json.

I like datasette.json ( / datasette.yml) as a name. That can be the file that lives in your config directory too, so if you run datasette . in a folder containing datasette.yml all of those settings get picked up.

Here's a thought for how it could look - I'll go with the YAML format because I expect that to be the default most people use, just because it supports multi-line strings better.

I based this on the big example at https://docs.datasette.io/en/1.0a3/metadata.html#using-yaml-for-metadata - and combined some bits from https://docs.datasette.io/en/1.0a3/authentication.html as well.

```yaml title: Demonstrating Metadata from YAML description_html: |-

This description includes a long HTML string

• YAML is better for embedding HTML strings than JSON!

settings: default_page_size: 10 max_returned_rows: 3000 sql_time_limit_ms": 8000

databases: docs: permissions: create-table: id: editor fixtures: tables: no_primary_key: hidden: true queries: neighborhood_search: sql: |- select neighborhood, facet_cities.name, state from facetable join facet_cities on facetable.city_id = facet_cities.id where neighborhood like '%' || :text || '%' order by neighborhood; title: Search neighborhoods description_html: |-

This demonstrates basic LIKE search

permissions: debug-menu: id: '*'

plugins: datasette-ripgrep: path: /usr/local/lib/python3.11/site-packages `` I'm inclined to say we try to be a super-set of the existingmetadata.yml` format, at least where it makes sense to do so. That way the upgrade path is smooth for people. Also, I don't think the format itself is terrible - it's the name that's the big problem.

In this example I've mixed in one extra concept: that settings: block with a bunch of settings in it.

There are some things in there that look a little bit like metadata - the title and description_html fields.

But are they metadata? The title and description of the overall instance feels like it could be described as general configuration. The stuff for the query should live where the query itself is defined.

Note that queries can be defined by a plugin hook too: https://docs.datasette.io/en/1.0a3/plugin_hooks.html#canned-queries-datasette-database-actor

What do you think? Is this the right direction, or are you thinking there's a more radical redesign that would make sense here?

The single biggest design challenge I've had with metadata relates to how it should or should not be inherited.

If you apply a license to a Datasette instance, it feels like that should flow down to cover all of the databases and all of the tables within those databases.

If the license is at the database level, it should cover all tables.

But... should source do the same thing? I made it behave the same way as license, but it's presumably common for one database to have a single license but multiple different sources of data.

Then there's title - should that inherit? It feels like title should apply to only one level - you may want a title that applies to the instance, then a different custom title for databases and tables.

Here's the current state of play for metadata: https://docs.datasette.io/en/1.0a3/metadata.html

So there's title and description - and I'll be honest, I'm not 100% sure even I understand how those should be inherited down by tables/etc.

There's description_html which over-rides the description if it is set. It's a useful customization hack, but a bit surprising.

Then there are these six:

• license
• license_url
• source
• source_url
• about
• about_url

I added about later than the others, because I realized that plenty of my own projects needed a link to an article explaining them somewhere - e.g. https://scotrail.datasette.io/

Tables can also have column descriptions - just a string for each column. There's a demo of those here: https://latest.datasette.io/fixtures/roadside_attractions

And then there's all of the other stuff, most of which feels much more like "settings" than "metadata":

• sort: created - the custom sort order
• size: 10 for a custom page size for a specific table
• sortable_columns to set which columns can be used to sort
• hidden: true to hide a table
• label_column: title is an interesting one - it lets you hint to Datasette which column should be displayed when there is a foreign key relationship. It's sort-of-metadata and sort-of-a-setting.
• facets sets default facets, see https://docs.datasette.io/en/1.0a3/facets.html#facets-in-metadata
• facet_size sets the number of facets to display
• fts_table and fts_pk can be used to configure FTS, especially for views: https://docs.datasette.io/en/1.0a3/full_text_search.html

And the authentication stuff! allow and allow_sql blocks: https://docs.datasette.io/en/1.0a3/authentication.html#defining-permissions-with-allow-blocks

And the new permissions key in the 1.0 alphas: https://docs.datasette.io/en/1.0a3/authentication.html#other-permissions-in-metadata

I think that might be everything (excluding the plugins settings stuff, which is also a bad fit for metadata.)

And to make things even more confusing... I believe you can add arbitrary key/value pairs to your metadata and then use them in your templates! I think I've heard from at least one person who uses that ability.

I completely agree: metadata is a mess, and it deserves our attention.

1. Metadata cannot be updated without re-starting the entire Datasette instance.

That's not completely true - there are hacks around that. I have a plugin that applies one set of gnarly hacks for that here: https://github.com/simonw/datasette-remote-metadata - it's pretty grim though!

1. The metadata.json/metadata.yaml has become a kitchen sink of unrelated (imo) features like plugin config, authentication config, canned queries

100% this: it's a complete mess.

Datasette used to have a datasette --config foo:bar mechanism, which I deprecated in favour of datasette --setting foo bar partly because I wanted to free up --config for pointing at a real config file, so we could stop dropping everything in --metadata metadata.yml.

1. The Python APIs for defining extra metadata are a bit awkward (the datasette.metadata() class, get_metadata() hook, etc.)

Yes, they're not pretty at all.

Hah, that --plugin-secret thing was a messy solution I came up with to the problem that all metadata is visible at /-/metadata - so if you need to stash a secret you need a way to keep it not-visible in there!

Hence the whole $env mess: https://docs.datasette.io/en/stable/plugins.html#secret-configuration-values

json { "plugins": { "datasette-auth-github": { "client_secret": { "$env": "GITHUB_CLIENT_SECRET" } } } }

If configuration and metadata were separate we could ditch that whole messy situation - configuration can stay hidden, metadata can stay public.

Though I have been thinking that Datasette might benefit from a "secrets" mechanism that's separate from configuration and metadata... kind of like what LLM has: https://llm.datasette.io/en/stable/help.html#llm-keys-help

A related point that I've been considering a lot recently: it turns out that sometimes I really want to define settings on the CLI instead of in a file, purely for convenience.

It's pretty annoying when I want to try out a new plugin but I have to create a dedicated metadata.yml file for it just to setup a single option - I'd love to have the option to be able to run this instead:

bash datasette data.db --plugin-setting datasette-upload-csvs default-database data

So maybe there's a world in which all of the settings can be applied in a datasette.yml file OR with command-line options.

That gets trickier when you need to pass a nested structure or similar, but we could always support those as JSON:

bash datasette data.db --plugin-setting datasette-emoji-reactions emoji '["😼", "🐺"]' Note that we kind of have precedent for this in datasette publish: https://docs.datasette.io/en/stable/publish.html#custom-metadata-and-plugins

bash datasette publish heroku my_database.db \ --name my-heroku-app-demo \ --install=datasette-auth-github \ --plugin-secret datasette-auth-github client_id your_client_id \ --plugin-secret datasette-auth-github client_secret your_client_secret

My ideal situation then would be something like this:

• Metadata itself is VERY clearly described, including sensible rules for metadata inheritance where it makes sense. There is a datasette.X method for accessing it which is much more intuitive than datasette.metadata().
• It's possible that method should be an async method, because that would support things like plugins that lookup metadata in database tables better.
• All templates etc switch to the new, clean, intuitive metadata mechanism before 1.0.
• I'm interested in the option of metadata being able to live in a _datasette_metadata table in the databases themselves - either as a plugin or as a core feature. I think it makes a lot of sense for metadata to optionally live with the data that it describes.
• Configuration gets split from metadata. The stuff that configures Datasette no longer lives in the metadata.yml file - it lives in config.yml (or even datasette.yml).

Currently we have three types of things:

• Metadata - information about the data
• Configuration - stuff like "these columns should be sortable" and "this is configured as fts_table" and suchlike
• Settings - the stuff that you pass to datasette --setting x y on server start.

Should settings and configuration be separate? I'm not 100% sure that they should - maybe those two concepts should be combined somehow.

Configuration directory mode needs to be considered too: https://docs.datasette.io/en/stable/settings.html#configuration-directory-mode - interestingly it already has a thing where it can pick up settings from a settings.json file - where settings are things like datasette --setting sql_time_limit_ms 4000.