The TestDrive has been replaced by the OpenFaaS workshop which is a set of self-paced labs developed by the community to teach you the basics of building Serverless Functions with OpenFaaS.
Please start Lab 1 here
OpenFaaS (or Functions as a Service) is a framework for building serverless functions on Docker Swarm and Kubernetes with first class metrics. Any UNIX process can be packaged as a function in FaaS enabling you to consume a range of web events without repetitive boiler-plate coding.
Please support the project and put a Star on the repo.
We have provided several sample functions which are built-into the Docker Stack file we deploy during the test drive. You'll be up and running in a few minutes and invoking functions via the Web UI or curl. When you're ready to deploy your own function click "Deploy Function" in the UI or head over to the CLI tutorial:
The guide makes use of a cloud playground service called play-with-docker.com that provides free Docker hosts for around 5 hours. If you want to try this on your own laptop just follow along.
Background info:
- There is also a blog post that goes into the background of the project.
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So let's head over to https://play-with-docker.com/ and start a new session. You will probably have to fill out a Captcha.
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Click "Add New Instance" to create a single Docker host (more can be added later)
This one-shot script clones the code, sets up a Docker Swarm master node then deploys OpenFaaS with the sample stack:
# docker swarm init --advertise-addr eth0 && \
git clone https://github.com/openfaas/faas && \
cd faas && \
git checkout 0.8.0 && \
./deploy_stack.sh && \
docker service ls
The shell script makes use of a v3 docker-compose.yml file - read the deploy_stack.sh file for more details.
If you are not testing on play-with-docker then remove
--advertise-addr eth0from first line of the script.
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Now that everything's deployed take note of the two ports at the top of the screen:
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8080 - the API Gateway and OpenFaaS UI
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9090 - the Prometheus metrics endpoint
We have packaged some simple starter functions in the Docker stack, so as soon as you open the OpenFaaS UI you will see them listed down the left-hand side.
Here are a few of the functions:
- Markdown to HTML renderer (markdownrender) - takes .MD input and produces HTML (Golang)
- Docker Hub Stats function (hubstats) - queries the count of images for a user on the Docker Hub (Golang)
- Node Info (nodeinfo) function - gives you the OS architecture and detailled info about the CPUS (Node.js)
- Webhook stasher function (webhookstash) - saves webhook body into container's filesystem - even binaries (Golang)
We will also install the OpenFaaS CLI which can be used to create, list, invoke and remove functions.
$ curl -sL cli.openfaas.com | shOn your own machine change | sh to | sudo sh, for MacOS you can just use brew install faas-cli.
- Find out what you can do
$ faas-cli --helpHead over to the Github and Star the project, or read on to see the input/output from the sample functions.
You can access the sample functions via the command line with a HTTP POST request, the FaaS-CLI or by using the built-in UI portal.
- Invoke the markdown function with the CLI:
$ echo "# Test *Drive*"| faas-cli invoke func_markdown
<h1>Test <em>Drive</em></h1>
- List your functions
$ faas-cli list
Function Invocations Replicas
func_echoit 0 1
func_base64 0 1
func_decodebase64 0 1
func_markdown 3 1
func_nodeinfo 0 1
func_wordcount 0 1
func_hubstats 0 1
func_webhookstash 0 1
UI portal:
The UI portal is accessible on: http://127.0.0.1:8080/ - it show a list of functions deployed on your swarm and allows you to test them out.
View screenshot:
You can find out which services are deployed like this:
# docker stack ls
NAME SERVICES
func 3
# docker stack ps func
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE
rhzej73haufd func_gateway.1 alexellis2/faas-gateway:latest moby Running Running 26 minutes ago
fssz6unq3e74 func_hubstats.1 alexellis2/faas-dockerhubstats:latest moby Running Running 27 minutes ago
nnlzo6u3pilg func_prometheus.1 quay.io/prometheus/prometheus:latest moby Running Running 27 minutes ago
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Head over to http://127.0.0.1:9090 for your Prometheus metrics
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A saved Prometheus view is available here: metrics overview
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Your functions can be accessed via the gateway UI or read on for
curl
The following guides show how to use the CLI and code templates to build functions.
Using a template means you only have to write a handler file in your chosen programming language such as:
- Ruby
- Node.js
- Python
- CSharp
- Or propose a template for another programming languae
Guides:
Read the developer guide:
The original blog post also walks through creating a function:
Option 1: via the FaaS CLI
The FaaS CLI can be used to build functions very quickly though the use of templates. See more details on the FaaS CLI here.
Option 2: via FaaS UI portal
To attach a function at runtime you can use the "Create New Function" button on the portal UI at http://127.0.0.1:8080/
Creating a function via the UI:
| Option | Usage |
|---|---|
Image |
The name of the image you want to use for the function. A good starting point is functions/alpine |
Service Name |
Describe the name of your service. The Service Name format is: [a-zA-Z_0-9] |
fProcess |
The process to invoke for each function call. This must be a UNIX binary and accept input via STDIN and output via STDOUT. |
Network |
The network func_functions is the default network. |
Once the create button is clicked, faas will provision a new Docker Swarm service. The newly created function will shortly be available in the list of functions on the left hand side of the UI.
Option 3: Through docker-compose.yml stack file
Edit the docker-compose stack file, then run ./deploy_stack.sh - this will only update changed/added services, not existing ones.
Option 4: Programatically through a HTTP POST to the API Gateway
A HTTP post can also be sent via curl etc to the endpoint used by the UI (HTTP post to /system/functions)
// CreateFunctionRequest create a function in the swarm.
type CreateFunctionRequest struct {
Service string `json:"service"`
Image string `json:"image"`
Network string `json:"network"`
EnvProcess string `json:"envProcess"`
}
Example:
For a quote-of-the-day type of application:
curl 127.0.0.1:8080/system/functions -d '
{"service": "oblique", "image": "vielmetti/faas-oblique", "envProcess": "/usr/bin/oblique", "network": "func_functions"}'
For a hashing algorithm:
curl 127.0.0.1:8080/system/functions -d '
{"service": "stronghash", "image": "functions/alpine", "envProcess": "sha512sum", "network": "func_functions"}'
You can delete a function through the FaaS-CLI or with the Docker CLI
$ docker service rm func_echoit
Sample function: Docker Hub Stats (hubstats)
# curl -X POST http://127.0.0.1:8080/function/func_hubstats -d "alexellis2"
The organisation or user alexellis2 has 99 repositories on the Docker hub.
The -d value passes in the argument for your function. This is read via STDIN and used to query the Docker Hub to see how many images you've created/pushed.
You can also invoke functions using the OpenFaaS CLI:
# echo -n "library" | faas-cli invoke func_hubstats
The organisation or user library has 128 repositories on the Docker hub.
Sample function: Node OS Info (nodeinfo)
Grab OS, CPU and other info via a Node.js container using the os module.
If you invoke this method in a while loop or with a load-generator tool then it will auto-scale to 5, 10, 15 and finally 20 replicas due to the load. You will then be able to see the various Docker containers responding with a different Hostname for each request as the work is distributed evenly.
Here is a loop that can be used to invoke the function in a loop to trigger auto-scaling.
while [ true ] ; do curl -X POST http://127.0.0.1:8080/function/func_nodeinfo -d ''; done
Example:
# curl -X POST http://127.0.0.1:8080/function/func_nodeinfo -d ''
Hostname: 9b077a81a489
Platform: linux
Arch: arm
CPU count: 1
Uptime: 776839
To control scaling behaviour you can set a min/max scale value with a label when deploying your function via the CLI or the API:
labels:
"com.openfaas.scale.min": "5"
"com.openfaas.scale.max": "15"
Sample function: webhook stasher (webhookstash)
Another cool sample function is the Webhook Stasher which saves the body of any data posted to the service to the container's filesystem. Each file is written with the filename of the UNIX time.
# curl -X POST http://127.0.0.1:8080/function/func_webhookstash -d '{"event": "fork", "repo": "alexellis2/faas"}'
Webhook stashed
# docker ps|grep stash
d769ca70729d alexellis2/faas-webhookstash@sha256:b378f1a144202baa8fb008f2c8896f5a8
# docker exec d769ca70729d find .
.
./1483999546817280727.txt
./1483999702130689245.txt
./1483999702533419188.txt
./1483999702978454621.txt
./1483999703284879767.txt
./1483999719981227578.txt
./1483999720296180414.txt
./1483999720666705381.txt
./1483999720961054638.txt
Why not start the code on play-with-docker.com and then configure a Github repository to send webhooks to the API Gateway?