ryanray/template-renderer

Basic handlebars template renderer for Kubernetes / Docker

Basic Template Renderer Based on Fastify

Minimal template rendering with simple environment variable based interpolation.

GitHub Repo: https://github.com/ryanray/template-renderer

DockerHub Repo https://hub.docker.com/r/ryanray/template-renderer

Fastify: https://www.fastify.io/

Example

// ./my-templates/hello.hbs
<h1>Hello, from {{TMPL_SERVER_NAME}}!</h1>

version: "3.8"
services:
  my-basic-renderer:
    container_name: my-basic-renderer
    image: ryanray/template-renderer:latest
    ports:
      - "8080:3000"
    environment:
      - TMPL_SERVER_NAME="my-basic-renderer"
    volumes:
    # mount your own templates directory
    - ./my-templates:/usr/src/app/templates

docker-compose up
curl http://localhost:8080/hello
<h1>Hello, from my-basic-renderer!</h1>

Configuration

Custom Templates

When starting with Docker, docker-compose, or Kubernetes you just need to mount your own template directory in the container at /usr/src/app/templates

docker run -it -v ./my-template-dir:/usr/src/app/templates -p 3000:3000 ryanray/template-renderer:latest

Template Context

Template context is the data that gets passed to the template. The only way to modify that context at the moment is by setting environment variables for the container. Any variable that starts with TMPL_ will be added to the context object.

Template Resolution

BTR will take the path of the request and try to resolve the template first by looking for a directory by that name with an index.hbs and if there isn't a directory by that name it will look for the path with hbs on the end.

Examples: http://localhost:3000/dashboard -> /templates/dashboard/index.hbs

http://localhost:3000/dashboard/statistics -> /templates/dashboard/statistics/index.hbs

http://localhost:3000/about -> /templates/about.hbs

http://localhost:3000/ -> /templates/index.hbs

Limitations / Nice to haves

There are A LOT of limitations. Keep in mind I threw this together pretty quickly for testing purposes.

• only supports handlebars at the moment(should be easy to add more support)
• environment variables regex is hardcoded - has to start with TMPL_
• Context is the same across all templates - would be nice to be able to configure context per template
• Would be nice to configure context via JSON or YAML instead of env variables
• I almost spent more time on the documentation than the code - and look how bad the docs are 😬

Why?

I needed a quick and easy way to drop some templates into a docker container and then pass some data into them to have them rendered - mostly to demo other Kubernetes functionality. So I published the image to DockerHub and here we are.