OpenSlides/caddy/entrypoint

#!/bin/sh

set -e

if [[ -z "$EXTERNAL_HTTP_PORT" ]] && [[ -z "$EXTERNAL_HTTPS_PORT" ]]; then
    echo "EXTERNAL_HTTP_PORT and EXTERNAL_HTTPS_PORT are not set. Aborting."
    exit 1
fi

if [[ -f "/certs/key.pem" ]] && [[ -f "/certs/cert.pem" ]]; then
    certs_exists=1
fi

if [[ -n "$EXTERNAL_HTTPS_PORT" ]] && [[ -z "$certs_exists" ]]; then
    echo "Configured https, but no certificates found. Aborting"
    exit 1
fi

# config: https
if [[ -n "$EXTERNAL_HTTPS_PORT" ]] ; then
    cat <<EOF > /etc/caddy/endpoint
https://:8001 {
    tls /certs/cert.pem /certs/key.pem
EOF
    echo "Configured https"
fi

# config: http and no https
if [[ -n "$EXTERNAL_HTTP_PORT" ]] && [[ -z "$EXTERNAL_HTTPS_PORT" ]] ; then
    echo "http://:8000 {" > /etc/caddy/endpoint
    echo "Configured http only"
fi

# config: https and additionally http -> create redirect-file
if [[ -n "$EXTERNAL_HTTP_PORT" ]] && [[ -n "$EXTERNAL_HTTPS_PORT" ]] ; then
    cat <<EOF > /etc/caddy/redirect
http://:8000 {
    redir https://$INSTANCE_DOMAIN{uri}
}
EOF
    echo "Configured http to https redirect"
fi

# Add allowed hosts from $ALLOWED_HOSTS
# If the variable is empty, all hosts are allowed.
# The hosts are ORed, so the request is valid, if one host matches.
# Example: ALLOWED_HOSTS="localhost:8000 127.0.0.1:8000"
#
# @invalid-host {
#     not {
#         header Host localhost:8000
#         header Host 127.0.0.1:8000
#     }
# }
# respond @invalid-host "Misdirected Request" 421 {
#     close
# }
if [[ ! -z "$ALLOWED_HOSTS" ]]; then
    cat <<EOF > /etc/caddy/invalid_host
    @invalid-host {
        not {
EOF
    for host in $ALLOWED_HOSTS; do
        echo "            host $host" >> /etc/caddy/invalid_host
    done
    cat <<EOF >> /etc/caddy/invalid_host
        }
    }
    respond @invalid-host "Misdirected Request" 421 {
        close
    }
EOF
    echo "Configured allowed hosts: $ALLOWED_HOSTS"
else
    echo "All hosts allowed"
fi

exec "$@"