dlt-init-openapi 0.1.0a1

Generate dlt Python clients from OpenAPI

dlt-init-openapi

dlt-init-openapi generates dlt pipelines from OpenAPI 3.x documents/specs using the dlt rest_api verified source. If you do not know dlt or our verified sources, please read:

• Getting started to learn the dlt basics
• dlt rest_api to learn how our rest_api source works

This generator does not support OpenAPI 2.x FKA Swagger. If you need to use an older document, try upgrading it to version 3 first with one of many available converters.

Prior work

This project started as a fork of openapi-python-client. Pretty much all parts are heavily changed or completely replaced, but some lines of code still exist and we like to acknowledge the many good ideas we got from the original project :)

Support

If you need support for this tool, join our slack community and ask for help on the technical help channel. We're usually around to help you out or discuss features :)

Features

The dlt-init-openapi generates code from an OpenAPI spec that you can use to extract data from a rest_api into any destination (e.g. Postgres, BigQuery, Redshift...) dlt supports.

Features include

• Pagination discovery for each endpoint
• Primary key discovery for each entity
• Endpoint relationship mapping into dlt transformers (e.g. /users/ -> /user/{id})
• Payload JSON path data selector discovery for results nested in the returned json
• Authentication discovery for an API

Setup

You will need Python 3.9 or higher installed, as well as pip.

# 1. install this tool locally
$ pip install dlt-init-openapi

# 2. Show the version of the installed package to verify it worked
$ dlt-init-openapi --version

Basic Usage

Let's create an example pipeline from the PokeAPI spec. You can point to any other OpenAPI Spec instead if you like.

# 1.a. Run the generator with an url:
$ dlt-init-openapi pokemon --url https://raw.githubusercontent.com/cliffano/pokeapi-clients/ec9a2707ef2a85f41b747d8df013e272ef650ec5/specification/pokeapi.yml

# 1.b. If you have a local file, you can use the --path flag:
$ dlt-init-openapi pokemon --path ./my_specs/pokeapi.yml

# 2. You can now pick the endpoints you need from the popup

# 3. After selecting your pokemon endpoints and hitting Enter, your pipeline will be rendered

# 4. If you have any kind of authentication on your pipeline (this example has not), open the `.dlt/secrets.toml` and provide the credentials. You can find further settings in the `.dlt/config.toml`.

# 5. Go to the created pipeline folder and run your pipeline
$ cd pokemon-pipeline
$ PROGRESS=enlighten python pipeline.py # we use enlighten for a nice progress bar :)

# 6. Print the pipeline info to console to see what got loaded
$ dlt pipeline pokemon_pipeline info

# 7. You can now also install streamlit to see a preview of the data
$ pip install pandas streamlit
$ dlt pipeline pokemon_pipeline show

# 8. You can go to our docs at https://dlthub.com/docs to learn how modify the generated pipeline to load to many destinations, place schema contracts on your pipeline and many other things.

What will be created?

When you run the init command above, the following files will be generated:

• ./pokemon-pipeline - a folder containing the full project.
• ./pokemon-pipeline/pipeline.py - a file which you can execute to run your pipeline.
• ./pokemon-pipeline/pokemon/__init__.py - a file that contains the generated code to connect to the PokeApi, you can inspect this file and manually change it to your liking or to fix incorrectly generated results.
• ./pokemon-pipeline/.dlt - a folder with the config.toml. You can add your secrets.toml with credentials here.
• ./pokemon-pipeline/rest_api - a folder that contains the rest_api source from our verified sources.

If you re-generate your pipeline, you will be prompted to continue if this folder exists. If you select yes, all generated files will be overwritten. All other files you may have created will remain in this folder.

CLI commands

$ dlt-init-openapi [OPTIONS] <source_name> [ARGS]
# example:
$ dlt-init-openapi pokemon --path ./path/to/my_spec.yml

Options:

• --version: Print the version and exit
• --help: Show this message and exit.

Commands:

• init: Generate a new dlt rest_api source

dlt-init-openapi

Generate a new dlt rest_api source

Usage:

$ dlt-init-openapi pokemon --path ./path/to/my_spec.yml

Options:

• --url URL: A url to read the OpenAPI JSON or YAML file from
• --path PATH: A path to read the OpenAPI JSON or YAML file from locally
• --output-path PATH: A path to render the output to
• --config PATH: Path to the config file to use (see below)
• --no-interactive: Skip endpoint selection and render all paths of the OpenAPI spec.
• --log-level: Set logging level for stdout output, defaults to 20 (INFO).
• --global-limit: Set a global limit on the generated source.
• --update-rest-api-source: Update the locally cached rest_api verified source.
• --allow-openapi-2: Allow to use OpenAPI v2. specs. Migration of the spec to 3.0 is recommended though.
• --version: Show installed version of the generator.
• --help: Show this message and exit.

Config options

You can pass a path to a config file with the --config PATH argument. To see available config values, go to https://github.com/dlt-hub/dlt-init-openapi/blob/devel/dlt_init_openapi/config.py and read the information below each field on the Config class.

The config file can be supplied as json or yaml dictionary. For example to change the package name, you can create a yaml file:

# config.yml
package_name: "other_package_name"

And use it with the config argument:

$ dlt-init-openapi pokemon --url ... --config config.yml

Telemetry

We track your usage of this tool similar to how we track other commands in the dlt core library. Read more about this and how to disable it here: https://dlthub.com/docs/reference/telemetry.

Implementation notes

• OAuth Authentication currently is not natively supported, you can supply your own
• Per endpoint authentication currently is not supported by the generator, only the first globally set securityScheme will be applied. You can add your own per endpoint if you need to.