Integrating Livebook into My Phoenix/Elixir Projects

Lately, I've been using Livebook extensively in my Phoenix/Elixir projects, and I wanted to share how I’ve integrated it into my workflow.

One recent change I made was switching from asdf to mise. While this isn't mandatory, I’ve really come to enjoy mise and find its task system quite convenient.

Project Setup with Mise

At the root of my project, I have a mise.toml file specifying the versions of Erlang and Elixir for this project:

[tools]
erlang = '27.2.1'
elixir = '1.18.2-otp-27'

I also have a mise-tasks folder containing various scripts that I can invoke with:

mise run script_name [arguments]

Connecting to a Production IEx Session

Depending on the deployment setup, I use different scripts to open an IEx session on the production server. I call this script fiex and it live in mise-tasks folder

For Fly.io

#!/usr/bin/env bash
set -e

#MISE description="Run iex on production pod"

fly ssh console --pty -C "/app/bin/app remote"

For Kubernetes (K8s)

#!/usr/bin/env bash
set -e

#MISE description="Run iex on production pod"

if [ -z $KUBECONFIG ]; then
  echo "KUBECONFIG is not set"
  exit 1
fi

pod_name=$(kubectl get pods -l app.kubernetes.io/name=phoenix-app,app=app -o jsonpath='{range .items[?(@.status.phase=="Running")]}{.metadata.name}{end}' )

kubectl exec -it $pod_name -- sh -c "/app/bin/app remote"

Using Livebook in Development and Production

I find Livebook incredibly useful—not just for experimenting with code, but also for executing administrative tasks on production without the need to build a separate admin dashboard.

In my project, I have a livebooks folder where I store all my Livebook notebooks. Here’s the base template I use.

For development, I run the node with:

iex --name app@127.0.0.1 --cookie cookie -S mix phx.server

For production, the node runs with:

RELEASE_DISTRIBUTION="name" and a secure cookie.

Connecting Livebook to Dev/Prod

I have scripts that allow me to quickly attach Livebook to either my dev or prod environment. The script live in mise-tasks folder and I call it livebook-connect

For Fly.io

#!/usr/bin/env bash
set -e

#MISE description="Run livebook on dev / prod"

# Usage:
#
# Development:  ./connect-live.sh
# Production:   ./connect-live.sh prod

fly_app="app"
fly_cookie=$RELEASE_COOKIE
dev_app="app"
dev_cookie="cookie"

export LIVEBOOK_HOME="$PWD/livebooks"

case "$1" in
  "prod")
    echo "[PROD] Starting Livebook..."
    fly_ip=$(fly ips private --app $fly_app | cut -f 3 | sed -n 2p)
    fly_node="$fly_app@$fly_ip"
    export LIVEBOOK_DEFAULT_RUNTIME="attached:$fly_node:$fly_cookie"
    export LIVEBOOK_NODE="livebook@127.0.0.1"
    export LIVEBOOK_DISTRIBUTION="name"
    export ERL_AFLAGS="-proto_dist inet6_tcp"
    ;;
  *)
    echo "[DEV] Starting Livebook..."
    dev_node="$dev_app@127.0.0.1"
    export LIVEBOOK_DEFAULT_RUNTIME="attached:$dev_node:$dev_cookie"
    ;;
esac

livebook server

For Kubernetes (K8s)

#!/usr/bin/env bash
set -xe

#MISE description="Run livebook on dev / prod"

function show_help {
  echo "Usage: livebook-connect <env>"
  echo "Development:  ./livebook-connect dev"
  echo "Production:   ./livebook-connect prod"
}

if [[ "$1" == "" ]]; then
  show_help
  exit 1
fi

app="app"
cookie=$RELEASE_COOKIE
dev_app="app"
dev_cookie="cookie"
epmd_port=4369

export LIVEBOOK_HOME="$(pwd)/livebooks"

case "$1" in
  "prod")
    if [ -z $KUBECONFIG ]; then
      echo "KUBECONFIG is not set"
      exit 1
    fi

    if [ -z $RELEASE_COOKIE ]; then
      echo "RELEASE_COOKIE is not set"
      exit 1
    fi

    echo "[PROD] Starting Livebook..."
    pod_name=$(kubectl get pods -l app.kubernetes.io/name=phoenix-app,app=app -o jsonpath='{range .items[?(@.status.phase=="Running")]}{.metadata.name}{end}' )
    # Kill local epmd
    killall epmd || true
    # Forward remote epmd
    kubectl port-forward $pod_name $epmd_port &
    epmd_tunnel_pid=$!
    sleep 3

    epmd=$(epmd -names)
    # Ports
    port=$(echo "$epmd" | tail -n +2 | cut -d' ' -f 5)
    # Finding the node name
    name=$(echo "$epmd" | tail -n +2 | cut -d' ' -f 2)

    # Forward remote node
    kubectl port-forward $pod_name $port &
    node_tunnel_pid=$!
    sleep 3

    pod_ip=$(kubectl get pod $pod_name -o jsonpath='{.status.podIP}')
    host=$(echo $pod_ip | sed 's/\./-/g').default.pod.cluster.local

    node="app@$host"

    export ERL_INETRC=/tmp/erl_inetrc
    echo "{host, {127,0,0,1}, [\"$host\", \"$node\"]}." >$ERL_INETRC
    echo "{edns,0}." >>$ERL_INETRC
    echo "{lookup, [file, dns]}." >>$ERL_INETRC

    export LIVEBOOK_DEFAULT_RUNTIME="attached:$node:$cookie"
    export LIVEBOOK_NODE="livebook@127.0.0.1"
    export LIVEBOOK_DISTRIBUTION="name"
    ;;
  "dev")
    echo "[DEV] Starting Livebook..."
    dev_node="$dev_app@127.0.0.1"
    export LIVEBOOK_DEFAULT_RUNTIME="attached:$dev_node:$dev_cookie"
    ;;
esac

livebook server && echo "cleanup"

Livebook has been a big improvement for my workflow, allowing me to:

Experiment with Elixir in a structured and reproducible manner.
Perform admin tasks on production without needing a dedicated admin panel.
Quickly attach to dev or prod nodes, keeping everything organized.

If you’re working with Phoenix/Elixir, I highly recommend integrating Livebook into your project. 🚀

Project Setup with Mise

Connecting to a Production IEx Session

For Fly.io

For Kubernetes (K8s)

Using Livebook in Development and Production

Connecting Livebook to Dev/Prod

For Fly.io

For Kubernetes (K8s)

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