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Perl on Miren

Perl isn't auto-detected, so you deploy it with a Dockerfile.miren. This guide uses Mojolicious, which ships its own production web server — no separate PSGI wiring needed. The same pattern works for Dancer2 or any PSGI app run under Plack.

Let your agent do this

Ask your AI coding agent to "set up this Perl app on Miren" after installing the Miren agent skills. It adds the Dockerfile.miren, points the server at 0.0.0.0:$PORT, and deploys — using this page as its reference.

Do you need a Dockerfile?​

Yes. Miren doesn't auto-detect Perl, so add a Dockerfile.miren to your project root. Miren builds from it instead of guessing the stack — see Using Dockerfile.miren.

Want native support?

Miren auto-detects and builds common stacks (Python, Node, Bun, Go, Ruby, Rust) without a Dockerfile. This language isn't one of them yet — if you'd like first-class support, request it.

Bind to the injected port​

Miren injects PORT and routes traffic to it. Mojolicious's daemon command takes a listen URL — use http://*:$PORT to bind all interfaces:

use Mojolicious::Lite -signatures;

get '/' => sub ($c) {
  $c->render(text => "Hello from Perl on Miren!\n");
};

app->start;

The Dockerfile​

Create Dockerfile.miren in your project root. Install dependencies with cpanm:

FROM perl:5.40

WORKDIR /app
RUN cpanm --notest Mojolicious
COPY . /app

EXPOSE 8080

For an app with a cpanfile, install from it instead: RUN cpanm --notest --installdeps .

.dockerignore​

.git

Set up the app​

Even with a Dockerfile.miren, Miren needs at least one service defined — it doesn't use the image's CMD as the start command. Add a Procfile that starts the Mojolicious daemon on the injected port:

web: perl /app/app.pl daemon -l "http://*:$PORT"

Then create .miren/app.toml naming your app and deploy from your project root:

name = "perl-bench"
miren deploy
Deploying without a service fails

If no service is defined, the build succeeds but the deploy stops with no services defined: please define at least one service in a Procfile or .miren/app.toml.

For a PSGI app (Dancer2, Catalyst), run it under a Plack server instead: web: plackup -s Starman --host 0.0.0.0 --port $PORT app.psgi.

Environment variables​

Set variables with miren env set — -e for plain values, -s for secrets (masked in output and logs). Read them with $ENV{KEY}:

miren env set -e MOJO_MODE=production
miren env set -s DATABASE_URL

You can also declare variables in .miren/app.toml:

[[env]]
key = "DATABASE_URL"
value = ""
required = true
sensitive = true

See App Configuration — Environment Variables.

Agent quick reference​

  • Detection: none — requires Dockerfile.miren
  • Base image: perl:5.40; cpanm --notest Mojolicious (or --installdeps . with a cpanfile)
  • Service is required: Procfile web: perl /app/app.pl daemon -l "http://*:$PORT" — the image CMD is not used
  • Port: Mojolicious daemon -l http://*:$PORT; PSGI apps use plackup --host 0.0.0.0 --port $PORT
  • Env vars: miren env set -e/-s; read with $ENV{KEY}

Next steps​