Coding for Entrepreneurs

HTTPs on localhost with Caddy

By Justin

HTTPs on localhost with Caddy
Using HTTPs on localhost as well as custom domain names is made incredibly simple using Caddy. If you can run on localhost, you can use Caddy.
For example, if you have a web app that runs on:
localhost:8080
You can map Caddy to this address (as a reverse proxy) to enable local TLS/HTTPs such as https://myapp.localhost
You can use this with nearly any type of application such as:
  • Django
  • FastAPI
  • Docker
  • Express.js
  • Ruby on Rails
  • Static Websites
  • Next.js
  • Nginx
  • Whatever
Pretty neat right? Let's get started.

Install Caddy

Install Caddy on macOS

Using homebrew, run:
Install caddy
brew install caddy
  • In some tests, Java was required in order for caddy to work with Homebrew (brew install java nss)

Install Caddy on Windows

  1. Go to Caddy's website
  2. Download the correct platform
  3. Move the downloaded binary to a user folder
  4. Run .\path\to\my\binary\caddy_download version

Install Caddy on Linux

Open terminal and run:
sudo apt-get update && sudo apt-get install caddy -y
You may need to install Java in order for this to run correctly.

Verify Installation

In you command line, run:
caddy version
Which should respond with:
v2.6.2 <version-hash>

Run an App Locally

For this, we'll run a Docker-based Nginx app:
docker run -p 8181:80 nginx
In this command I am binding my localhost port 8181 to the internal container port of 80 (the nginx default)

Create Caddyfile

Create a Caddyfile with the contents:
caddyfile

my-nginx.localhost {
    reverse_proxy localhost:8181
}
In this case, my-nginx.localhost will become https://my-nginx.localhost and map directly to our localhost:8181 server. Pretty neat huh?
Since I'm using Docker, you can create the Caddyfile file anywhere. I recommend keeping the Caddyfile in the same directory as your project whenever possible.

Run Caddy Server

If you're in the same working directory as the Caddyfile you can run:
caddy run
Or just specify the path
caddy run --config path/to/Caddyfile
To stop the caddy server, just hit CTRL + C to cancel the program.

Open Caddy-served Endpoint

In your command line type:
open http://my-nginx.localhost
Notice that when your webbrowser opens you should see the url being https://my-nginx.localhost with no security issue warnings!!
Pretty neat huh?
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HTTPs on localhost with Caddy