overleaf/services/clsi

overleaf/clsi

A web api for compiling LaTeX documents in the cloud

The Common LaTeX Service Interface (CLSI) provides a RESTful interface to traditional LaTeX tools (or, more generally, any command line tool for composing marked-up documents into a display format such as PDF or HTML). The CLSI listens on the following ports by default:

• TCP/3013 - the RESTful interface
• TCP/3048 - reports load information
• TCP/3049 - HTTP interface to control the CLSI service

These defaults can be modified in config/settings.defaults.coffee.

The provided Dockerfile builds a docker image which has the docker command line tools installed. The configuration in docker-compose-config.yml mounts the docker socket, in order that the CLSI container can talk to the docker host it is running in. This allows it to spin up sibling containers running an image with a TeX distribution installed to perform the actual compiles.

The CLSI can be configured through the following environment variables:

• DOCKER_RUNNER - Set to true to use sibling containers
• SYNCTEX_BIN_HOST_PATH - Path to SyncTeX binary
• COMPILES_HOST_DIR - Working directory for LaTeX compiles
• SQLITE_PATH - Path to SQLite database
• TEXLIVE_IMAGE - The TEXLIVE docker image to use for sibling containers, e.g. gcr.io/overleaf-ops/texlive-full:2017.1
• TEXLIVE_IMAGE_USER - When using sibling containers, the user to run as in the TEXLIVE image. Defaults to tex
• TEX_LIVE_IMAGE_NAME_OVERRIDE - The name of the registry for the docker image e.g. gcr.io/overleaf-ops
• FILESTORE_DOMAIN_OVERRIDE - The url for the filestore service e.g.http://$FILESTORE_HOST:3009
• STATSD_HOST - The address of the Statsd service (used by the metrics module)
• LISTEN_ADDRESS - The address for the RESTful service to listen on. Set to 0.0.0.0 to listen on all network interfaces
• SMOKE_TEST - Whether to run smoke tests

Installation

The CLSI can be installed and set up as part of the entire Overleaf stack (complete with front end editor and document storage), or it can be run as a standalone service. To run is as a standalone service, first checkout this repository:

$ git clone git@github.com:overleaf/clsi.git

Then install the require npm modules:

$ npm install

Then build the Docker image:

$ docker build . -t overleaf/clsi

Then pull the TeXLive image:

$ docker pull texlive/texlive

Then start the Docker container:

$ docker run --rm \
    -p 127.0.0.1:3013:3013 \
    -e LISTEN_ADDRESS=0.0.0.0 \
    -e DOCKER_RUNNER=true \
    -e TEXLIVE_IMAGE=texlive/texlive \
    -e TEXLIVE_IMAGE_USER=root \
    -e COMPILES_HOST_DIR="$PWD/compiles" \
    -v "$PWD/compiles:/app/compiles" \
    -v "$PWD/cache:/app/cache" \
    -v /var/run/docker.sock:/var/run/docker.sock \
    overleaf/clsi

Note: if you're running the CLSI in macOS you may need to use -v /var/run/docker.sock.raw:/var/run/docker.sock instead.

The CLSI should then be running at http://localhost:3013

Config

The CLSI will use a SQLite database by default, but you can optionally set up a MySQL database and then fill in the database name, username and password in the config file at config/settings.development.coffee.

API

The CLSI is based on a JSON API.

Example Request

(Note that valid JSON should not contain any comments like the example below).

POST /project/<project-id>/compile

{
    "compile": {
        "options": {
            // Which compiler to use. Can be latex, pdflatex, xelatex or lualatex
            "compiler": "lualatex",
            // How many seconds to wait before killing the process. Default is 60.
            "timeout": 40
        },
        // The main file to run LaTeX on
        "rootResourcePath": "main.tex",
        // An array of files to include in the compilation. May have either the content
        // passed directly, or a URL where it can be downloaded.
        "resources": [
          {
            "path": "main.tex",
            "content": "\\documentclass{article}\n\\begin{document}\nHello World\n\\end{document}"
          }
          // ,{
          //     "path": "image.png",
          //     "url": "www.example.com/image.png",
          //     "modified": 123456789 // Unix time since epoch
          // }
        ]
    }
}

With curl, if you place the above JSON in a file called data.json, the request would look like this:

$ curl -X POST -H 'Content-Type: application/json' -d @data.json http://localhost:3013/project/<id>/compile

You can specify any project-id in the URL, and the files and LaTeX environment will be persisted between requests. URLs will be downloaded and cached until provided with a more recent modified date.

Example Response

{
    "compile": {
        "status": "success",
        "outputFiles": [{
            "type": "pdf",
            "url": "http://localhost:3013/project/<project-id>/output/output.pdf"
        }, {
            "type": "log",
            "url": "http://localhost:3013/project/<project-id>/output/output.log"
        }]
    }
}

License

The code in this repository is released under the GNU AFFERO GENERAL PUBLIC LICENSE, version 3. A copy can be found in the LICENSE file.

Copyright (c) Overleaf, 2014-2021.