157 lines
5.3 KiB
Markdown
157 lines
5.3 KiB
Markdown
# Picasso
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Functions-as-a-Service (FaaS) on OpenStack
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## Mission
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Picasso aims to provide an API abstraction layer for Functions-as-a-Service (FaaS) on OpenStack.
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## What is FaaS?
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Functions as a service is a new paradigm in computing that enables simplicity, efficiency and scalability for both developers
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and operators. It's important to distinguish the two, because the benefits differ:
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### Benefits for developers
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The main benefits that most people refer to are on the developer side and they include:
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* No servers to manage -- you just upload your code and the platform deals with the infrastructure
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* Super simple coding -- no more monoliths! Just simple little bits of code
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* Pay by the milliseconds your code is executing -- unlike a typical application that runs 24/7, and you're paying
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24/7, functions only run when needed
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Since you'll be running IronFunctions yourself, the paying part may not apply, but it does apply to
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cost savings on your infrastructure bills as you'll read below.
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### Benefits for operators
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If you will be operating IronFunctions, then the benefits are different, but related.
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* Extremely efficient use of resources
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* Unlike an app/API/microservice that consumes resources 24/7 whether they
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are in use or not, functions are time sliced across your infrastructure and only consume resources while they are
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actually doing something
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* Easy to manage and scale
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* Single system for code written in any language or any technology
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* Single system to monitor
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* Scaling is the same for all functions, you don't scale each app independently
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* Scaling is simply adding more IronFunctions nodes
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## System requirements
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* Operating system: Linux/MacOS
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* Python version: 3.5 or greater
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* Database: MySQL 5.7 or greater
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## Quick-start guide
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* Install DevStack with [IronFunctions enabled](https://github.com/openstack/picasso/blob/master/devstack/README.md)
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* Clone the [Picasso source](https://github.com/openstack/picasso)
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Create a Python3.5 virtualenv
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$ virtualenv -p python3.5 .venv
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$ source .venv/bin/activate
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Install Picasso dependencies
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$ pip install -r requirements.txt -r test-requirements.txt
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Install Picasso
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$ pip install -e .
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Install MySQL if you haven't already, and create a new database for functions
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$ mysql -uroot -p -e "CREATE DATABASE functions"
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### Migrations
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Once all dependencies are installed it is necessary to run database migrations. First,
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set the following environment variable:
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export PICASSO_MIGRATIONS_DB=mysql+pymysql://root:root@localhost/functions
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Then use `alembic` to apply the migrations
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$ alembic upgrade head
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### Starting the Picasso API server
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$ picasso-api --help
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Usage: picasso-api [OPTIONS]
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Starts Picasso API service
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Options:
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--host TEXT API service bind host.
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--port INTEGER API service bind port.
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--db-uri TEXT Picasso persistence storage URI.
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--keystone-endpoint TEXT OpenStack Identity service endpoint.
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--functions-url TEXT IronFunctions API URL
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--log-level TEXT Logging file
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--log-file TEXT Log file path
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--help Show this message and exit.
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The following are the minimum required options to start the Picasso API service:
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--db-uri mysql://root:root@192.168.0.112/functions
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--keystone-endpoint http://192.168.0.112:5000/v3
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--functions-url http://192.168.0.112:8080/v1
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--log-level INFO
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### Building and Running Picasso in Docker
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Install [Docker engine](https://docs.docker.com/engine/installation/) if you haven't already.
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From the Picasso repo, build a Docker image using the following commands:
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export DOCKER_HOST=tcp://<docker-host>:<docker-port>
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docker build -t picasso-api -f Dockerfile .
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To start the container, pass in the required env vars with `--env-file` or by entering all required
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values in `-e <KEY>=<VALUE>` format to the `docker run` command.
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Example [Dockerfile.env](Dockerfile.env.example)
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docker run -d -p 10001:10001 --env-file Dockerfile.env picasso-api
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Once the container is started, check if the service in running. In your web browser navigate to:
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<docker-host>:10001/api
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or using the CLI:
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curl -X GET http://<docker-host>:10001/api/swagger.json | python -mjson.tool
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### API docs
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API docs are discoverable via Swagger. Just launch the Picasso API and browse to:
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http://<picasso-host>:<picasso-port>/api
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### Picasso provides private and public functions
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Using the Picasso API, it is possible to create two type of functions - private and public.
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* Private functions are defined as functions that belong to a specific OpenStack project,
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and the execution of the function requires passing in authorization headers.
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* Public functions belong to a specific OpenStack project ID, but do not require any authorization
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headers to execute, allowing the function to be shared with anyone.
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Private and public functions are handled by different URL handlers:
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<picasso-api-host>:<picasso-api-port>/r/{project}/{app}/{route} for private functions
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<picasso-api-host>:<picasso-api-port>/r/{app}/{route} for public functions
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See [OpenStack alarming example](examples/openstack-alarms/README.md) for more details.
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### Testing Picasso
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See [Testing.md](TESTING.md)
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### Support
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Join us on [Slack](https://open-iron.slack.com/)!
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