TLS Certificates

Trusting the Authority

With a standard installation, the authority used to sign certificates generated in the Caddy container is not trusted by your local machine. You must add the authority to the trust store of the host :

# Mac
$ docker cp $(docker compose ps -q php):/data/caddy/pki/authorities/local/root.crt /tmp/root.crt && sudo security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain /tmp/root.crt
# Linux
$ docker cp $(docker compose ps -q php):/data/caddy/pki/authorities/local/root.crt /usr/local/share/ca-certificates/root.crt && sudo update-ca-certificates
# Windows
$ docker compose cp php:/data/caddy/pki/authorities/local/root.crt %TEMP%/root.crt && certutil -addstore -f "ROOT" %TEMP%/root.crt

Using Custom TLS Certificates

By default, Caddy will automatically generate TLS certificates using Let's Encrypt or ZeroSSL. But sometimes you may prefer using custom certificates.

For instance, to use self-signed certificates created with mkcert do as follows:

Locally install mkcert
Create the folder storing the certs: mkdir -p frankenphp/certs
Generate the certificates for your local host (example: "server-name.localhost"): mkcert -cert-file frankenphp/certs/tls.pem -key-file frankenphp/certs/tls.key "server-name.localhost"

Add these lines to the ./compose.override.yaml file about CADDY_SERVER_EXTRA_DIRECTIVES environment and volume for the php service :

php:
  environment:
+    CADDY_EXTRA_CONFIG: |
+      https:// {
+          tls /etc/caddy/certs/tls.pem /etc/caddy/certs/tls.key
+      }
    # ...
  volumes:
+    - ./frankenphp/certs:/etc/caddy/certs:ro
    - ./public:/app/public:ro

Restart your php service

Disabling HTTPS for Local Development

To disable HTTPS, configure your environment to use HTTP by setting the following variables and starting the project with this command:

SERVER_NAME=http://localhost \
MERCURE_PUBLIC_URL=http://localhost/.well-known/mercure \
docker compose up --pull always -d --wait

Ensure your application is accessible over HTTP by visiting http://localhost in your web browser.