Pdf-Service

A standalone service to generate PDF documents from templates.

It uses HTML templates to generate HTML documents and HTML to PDF engines to convert HTML to PDF.

Templates

All templates are stored in the templates directory.

Each template is also a directory, which contains template files and configurations.

On start-up, the service will go through all directories under the templates directory and load them as templates if they contain a templaterc.json configuration file.

It uses structured go html templates and JSON configuration files.

See examples in code/templates.

Template Configuration File

Each template directory should contain a templaterc.json configuration file.

The content of the configuration file is the following:

{
  "name": "{{template-name}}",
  "cover": "{{cover-html-template-file}}",
  "templates": ["{{doc-template-files}}"],
  "style": "{{styles-css}}",
  "header": "{{header-html}}",
  "footer": "{{footer-html}}"
}

Some of these fields can be omitted.

HTML to PDF Engines

There are two engines currently integrated into the service: wkhtmltopdf and chromedp.

Wkhtmltopdf

This engine uses wkhtmltopdf library to convert HTML to PDF.

This is the official links to the library: wkhtmltopdf.org, github

Chromedb

This engine uses a headless chrome session to visualize the generated HTML document, which is then printed as a PDF.

Official links: go package, github

Env Valiables

There are some environment variables that can be used to configure the service.

• PDF_SERVICE_ROOT - the root directory where can be found service assets (configs and templates). Default is the current direcotry
• PDF_SERVICE_CONCURRENCY - Max number of cuncurrent workers which can be spawned to generate the pdf docs. Default is 4
• REPORT_SERVICE_ENGINE - HTML to PDF engine which will be used to generate the docs (chromedp or wkhtmltopdf). Default is chromedp
• PDF_SERVICE_HTTP_ENABLED - Enable/disable generation of doc over HTTP(S) service. Default is true
• PDF_SERVICE_HTTP_PORT - HTTP(S) service port. Default is 3000
• PDF_SERVICE_HTTPS - Use TLS layer for HTTP service. Default is false
• PDF_SERVICE_KEY_FILE - the key file path when HTTPS is enabled
• PDF_SERVICE_CERT_FILE - the certificate file path when HTTPS is enabled
• PDF_SERVICE_KAFKA_ENABLED - Enable/disable generation over kafka. Default is true
• PDF_SERVICE_KAFKA_HOST - Kafka host. Default kafka:9092
• PDF_SERVICE_CREATE_CONSUMER_TOPICS - Create consumer topics if they are not exist. Default is false
• PDF_SERVICE_KAFKA_REQUESTS_TOPIC - The name of the requests topic. Default is PdfRequests
• PDF_SERVICE_KAFKA_RESPONSES_TOPIC - The name of the responses topic. Default is PdfResponses