How to Install and Test Apache OpenWhisk on Ubuntu: A Step‑by‑Step Guide

Introduction

Apache OpenWhisk is an open‑source, serverless FaaS platform that runs actions in containers in response to events. The article provides a practical, end‑to‑end tutorial for installing OpenWhisk on Ubuntu 18.04 Desktop.

Prerequisites

Ubuntu 18.04 Desktop

Git installed ( apt install git)

Clone the Repository

git clone https://github.com/apache/incubator-openwhisk.git openwhisk

After cloning, the repository structure is shown in the accompanying image.

Initial Setup

Navigate to the tools directory and run the Ubuntu setup script, which installs Java and other required packages.

cd openwhisk && cd tools/ubuntu-setup && ./all.sh

Configure Limits

Edit ansible/environments/group_vars/all to adjust limits such as invocationsPerMinute, concurrentInvocations, and sequenceMaxLength. Example snippet:

limits:
  invocationsPerMinute: "{{ limit_invocations_per_minute | default(60) }}"
  concurrentInvocations: "{{ limit_invocations_concurrent | default(30) }}"
  concurrentInvocationsSystem: "{{ limit_invocations_concurrent_system | default(5000) }}"
  firesPerMinute: "{{ limit_fires_per_minute | default(60) }}"
  sequenceMaxLength: "{{ limit_sequence_max_length | default(50) }}"

Configure Persistent Storage

Set environment variables for CouchDB (or Cloudant). Example:

export OW_DB=CouchDB
export OW_DB_USERNAME=root
export OW_DB_PASSWORD=PASSWORD
export OW_DB_PROTOCOL=http
export OW_DB_HOST=172.17.0.1
export OW_DB_PORT=5984

Deploy with Ansible

Run the series of Ansible playbooks from the openwhisk/ansible directory:

ansible-playbook -i environments/local/ setup.yml
ansible-playbook -i environments/local/ couchdb.yml
ansible-playbook -i environments/local/ initdb.yml
ansible-playbook -i environments/local/ wipe.yml
ansible-playbook -i environments/local/ apigateway.yml
ansible-playbook -i environments/local/ openwhisk.yml
ansible-playbook -i environments/local/ postdeploy.yml

Verify Docker Containers

After a successful deployment, OpenWhisk runs several Docker containers. List them with:

docker ps --format "{{.Image}} 	 {{.Names }}"

Configure the wsk CLI

The CLI binary is located in openwhisk/bin. Set the API host and authentication key:

./bin/wsk property set --apihost '172.17.0.1'
./bin/wsk property set --auth `cat ansible/files/auth.guest`

Test an Action

Create a simple Python action that computes Fibonacci numbers:

# test.py
def main(args):
    num = args.get("number", "30")
    return {"fibonacci": F(int(num))}

def F(n):
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return F(n - 1) + F(n - 2)

Create the action and invoke it:

/bin/wsk action create myfunction ./test.py --insecure
./bin/wsk -i action invoke myfunction --result --blocking --param number 20

Conclusion

The article demonstrates a complete workflow: from preparing the Ubuntu environment, cloning and configuring OpenWhisk, deploying with Ansible, setting up the CLI, to creating and invoking a sample action, confirming that the serverless platform is operational.