kwkhtmltopdf

A wkhtmlpdf server with drop-in client.

Why?

• avoid deploying wkhtmltopdf and it's dependencies in your application image
• keep the memory requirement of your application pods low while delegating memory hungry wkhtmltopdf jobs to dedicated pods
• easily select the wkhtmltopdf version to use at runtime

WARNING

The server is not meant to be exposed to untrusted clients.

Several attack vectors exist (local file access being the most obvious). Mitigating them is not a priority, since the main use case is to use it as a private service.

kwkhtmltopdf_server

A web server accepting wkhtmlpdf options and files to convert as multipart form data.

It is written in go.

kwkhtmltopdf_client

A drop-in replacement for wkhtmlpdf which invokes the above server defined in the KWKHTMLTOPDF_SERVER_URL environment variable.

There are two clients:

• a go client (preferred)
• a python client, which only depends on the requests library. It should work with any python version supported by requests.

Quick start

Run the server

$ docker run --rm -p 8080:8080 ghcr.io/acsone/kwkhtmltopdf:0.12.6.1-latest

or

$ go run server/kwkhtmltopdf_server.go

The server should now listen on http://localhost:8080.

Note for Apple Silicon users

The docker image is built for amd64. If you are on Apple Silicon, you can use it by disabling the Use Rosetta for x86_64/amd64 emulation on Apple Silicon option in the Docker Desktop general settings first.

Run the client

Any of the following should generate a printout of the wkhtmltopdf home page to /tmp/test.pdf.

Using the built binary

$ go build -o client/go/kwkhtmltopdf_client client/go/kwkhtmltopdf_client.go
$ env KWKHTMLTOPDF_SERVER_URL=http://localhost:8080 \
    client/go/kwkhtmltopdf_client https://wkhtmltopdf.org /tmp/test.pdf

Using the Go client

$ env KWKHTMLTOPDF_SERVER_URL=http://localhost:8080 \
    go run client/go/kwkhtmltopdf_client.go https://wkhtmltopdf.org /tmp/test.pdf

Using the Python client

$ env KWKHTMLTOPDF_SERVER_URL=http://localhost:8080 \
    client/python/kwkhtmltopdf_client.py https://wkhtmltopdf.org /tmp/test.pdf

Run tests

1. Start the server.
2. Set and export KWKHTMLTOPDF_SERVER_URL environment variable.
3. Run tox.

This will run the same tests against the the native wkhtmltopdf executable, as well as against the server using the python and go clients.

Roadmap

See issues on GitHub as well as some TODO's in the source code.

Releasing

Push the master branch and ensure tests pass on GitHub.

Build the go client and server as explained above. Create and tag a release on GitHub and attach the client and server you just built to it.

Images are built and pushed to ghcr.io by a GitHub action.

Credits

Author: [email protected].

Contributors are visible on GitHub.

License

MIT