faas-cli: A Go repository from justinfx

faas-cli

This is a CLI for use with OpenFaaS - a serverless functions framework for Docker & Kubernetes.

Before using this tool please setup OpenFaaS by following instructions over on the main repo.

The CLI can be used to build and deploy functions to OpenFaaS. You can build OpenFaaS functions from a set of supported language templates (such as Node.js, Python, CSharp and Ruby). That means you just write a handler file such as (handler.py/handler.js) and the CLI does the rest to create a Docker image.

Demo: ASCII cinema

TL;DR - Introductory tutorial

Blog: Coffee with the FaaS-CLI

Get started: Install the CLI

You can install the CLI with a curl utility script, brew or by downloading the binary from the releases page. Once installed you'll get the faas-cli command and faas alias.

Utility script with curl:

$ curl -sSL https://cli.openfaas.com | sudo sh

Non-root with curl (requires further actions as advised after downloading):

$ curl -sSL https://cli.openfaas.com | sh

Via brew:

$ brew install faas-cli

Note: The brew release may not run the latest minor release but is updated regularly.

Via npm (coming soon):

$ npm install --global @openfaas/faas-cli

Note: See npm specific installation instructions and usage in the npm README.md

Windows

To install the faas-cli on Windows go to Releases and download the latest faas-cli.exe.

Or in PowerShell:

$version = (Invoke-WebRequest "https://api.github.com/repos/openfaas/faas-cli/releases/latest" | ConvertFrom-Json)[0].tag_name
(New-Object System.Net.WebClient).DownloadFile("https://github.com/openfaas/faas-cli/releases/download/$version/faas-cli.exe", "faas-cli.exe")

Build from source

The contributing guide has instructions for building from source and for configuring a Golang development environment.

Run the CLI

The main commands supported by the CLI are:

faas-cli new - creates a new function via a template in the current directory
faas-cli login - stores basic auth credentials for OpenFaaS gateway (supports multiple gateways)
faas-cli logout - removes basic auth credentials for a given gateway
faas-cli up - a combination of build/push and deploy
faas-cli build - builds Docker images from the supported language types
faas-cli push - pushes Docker images into a registry
faas-cli deploy - deploys the functions into a local or remote OpenFaaS gateway
faas-cli remove - removes the functions from a local or remote OpenFaaS gateway
faas-cli invoke - invokes the functions and reads from STDIN for the body of the request
faas-cli store - allows browsing and deploying OpenFaaS store functions
faas-cli secret - manage secrets for your functions
faas-cli auth - (alpha) initiates an OAuth2 authorization flow to obtain a cookie

The default gateway URL of 127.0.0.1:8080 can be overridden in three places including an environmental variable.

1st priority --gateway flag
2nd priority --yaml / -f flag or stack.yml if in current directory
3rd priority OPENFAAS_URL environmental variable

For Kubernetes users you may want to set this in your .bash_rc file:

export OPENFAAS_URL=http://127.0.0.1:31112

Advanced commands:

faas-cli template pull - pull in templates from a remote git repository Detailed Documentation

The default template URL of https://github.com/openfaas/templates.git can be overridden in two places including an environmental variable

1st priority CLI input
2nd priority OPENFAAS_TEMPLATE_URL environmental variable

Help for all of the commands supported by the CLI can be found by running:

faas-cli help or faas-cli [command] --help

You can chose between using a programming language template where you only need to provide a handler file, or a Docker that you can build yourself.

`faas-cli auth`

The auth command is currently available for alpha testing. Use the auth command to obtain a JWT to use as a Bearer token.

Two flow-types are supported in the CLI.

`code` grant - default

Use this flow to obtain a token.

At this time the token cannot be saved or retained in your OpenFaaS config file. You can pass the token using a CLI flag of --token=$TOKEN.

Example:

faas-cli auth \
  --auth-url https://tenant0.eu.auth0.com/authorize \
  --audience http://gw.example.com \
  --client-id "${OAUTH_CLIENT_ID}"

`client_credentials` grant

Use this flow for machine to machine communication such as when you want to deploy a function to a gateway that uses OAuth2 / OIDC.

Example:

faas-cli auth \
  --grant client_credentials \
  --auth-url https://tenant0.eu.auth0.com/oauth/token \
  --client-id "${OAUTH_CLIENT_ID}" \
  --client-secret "${OAUTH_CLIENT_SECRET}"\
  --audience http://gw.example.com

Environment variable substitution

The CLI supports the use of envsubst-style templates. This means that you can have a single file with multiple configuration options such as for different user accounts, versions or environments.

Here is an example use-case, in your project there is an official and a development Docker Hub username/account. For the CI server images are always pushed to exampleco, but in development you may want to push to your own account such as alexellis2.

functions:
  url-ping:
    lang: python
    handler: ./sample/url-ping
    image: ${DOCKER_USER:-exampleco}/faas-url-ping:0.2

Use the default:

$ faas-cli build
$ DOCKER_USER="" faas-cli build

Override with "alexellis2":

$ DOCKER_USER="alexellis2" faas-cli build

Build templates

Command: faas-cli new FUNCTION_NAME --lang python/node/go/ruby/Dockerfile/etc

In your YAML you can also specify lang: node/python/go/csharp/ruby

Supports common languages
Quick and easy - just write one file
Specify dependencies on Gemfile / requirements.txt or package.json etc
Customise the provided templates

Perhaps you need to have gcc or another dependency in your Python template? That's not a problem.

You can customise the Dockerfile or code for any of the templates. Just create a new directory and copy in the templates folder from this repository. The templates in your current working directory are always used for builds.

HMAC

It is possible to sign a faas-cli invoke request using a sha1 HMAC. To do this, the name of a header to hold the code during transmission should be specified using the --sign flag, and the shared secret used to hash the message should be provided through --key. E.g.

$ echo -n OpenFaaS | faas-cli invoke env --sign X-Hub-Signature --key yoursecret

Results in the following header being added:

Http_X_Hub_Signature=sha1=2fc4758f8755f57f6e1a59799b56f8a6cf33b13f

Docker image as a function

Specify lang: Dockerfile if you want the faas-cli to execute a build or skip_build: true for pre-built images.

Ultimate versatility and control
Package anything
If you are using a stack file add the skip_build: true attribute
Use one of the samples as a basis

Read the blog post/tutorial: Turn Any CLI into a Function with OpenFaaS

Private registries

For Kubernetes

Create a named image pull secret and add the secret name to the secrets section of your YAML file or your deployment arguments with --secret.

Alternatively you can assign a secret to the node to allow it to pull from your private registry. In this case you do not need to assign the secret to your function.

For Docker Swarm

For Docker Swarm use the --send-registry-auth flag or its shorthand -a which will look up your registry credentials in your local credentials store and then transmit them over the wire to the deploy command on the API Gateway. Make sure HTTPS/TLS is enabled before attempting this.

Use a YAML stack file

Read the YAML reference guide in the OpenFaaS docs.

Quick guide

A YAML stack file groups functions together and also saves on typing.

You can define individual functions or a set of them within a YAML file. This makes the CLI easier to use and means you can use this file to deploy to your OpenFaaS instance. By default the faas-cli will attempt to load stack.yaml from the current directory.

Here is an example file using the stack.yml file included in the repository.

provider:
  name: openfaas
  gateway: http://127.0.0.1:8080

functions:
  url-ping:
    lang: python
    handler: ./sample/url-ping
    image: alexellis2/faas-urlping

This url-ping function is defined in the sample/url-ping folder makes use of Python. All we had to do was to write a handler.py file and then to list off any Python modules in requirements.txt.

Build the files in the .yml file:

$ faas-cli build

-f specifies the file or URL to download your YAML file from. The long version of the -f flag is: --yaml.

You can also download over HTTP(s):

$ faas-cli build -f https://raw.githubusercontent.com/openfaas/faas-cli/master/stack.yml

Docker along with a Python template will be used to build an image named alexellis2/faas-urlping.

Deploy your function

Now you can use the following command to deploy your function(s):

$ faas-cli deploy

Access functions with `curl`

You can initiate a HTTP POST via curl:

with the -d flag i.e. -d "my data here"
or with --data-binary @filename.txt to send a whole file including newlines
if you want to pass input from STDIN then use --data-binary @-

$ curl -d '{"hello": "world"}' http://127.0.0.1:8080/function/nodejs-echo
{ nodeVersion: 'v6.9.1', input: '{"hello": "world"}' }

$ curl --data-binary @README.md http://127.0.0.1:8080/function/nodejs-echo

$ uname -a | curl http://127.0.0.1:8080/function/nodejs-echo--data-binary @-

For further instructions on the manual CLI flags (without using a YAML file) read manual_cli.md

OpenFaaS Cloud (extensions)

OpenFaaS Cloud provides a GitOps experience for functions on Kubernetes.

Commands:

seal

You can use the CLI to seal a secret for usage on public Git repo. The pre-requisite is that you have installed SealedSecrets and exported your public key from your cluster as pub-cert.pem.

Install kubeseal using faas-cli or the SealedSecrets docs:

$ faas-cli cloud seal --download

You can also download a specific version:

$ faas-cli cloud seal --download --download-version v0.8.0

Now grab your pub-cert.pem file from your cluster, or use the official OpenFaaS Cloud certificate.

$ kubeseal --fetch-cert --controller-name ofc-sealedsecrets-sealed-secrets > pub-cert.pem

Then seal a secret using the OpenFaaS CLI:

$ faas-cli cloud seal --name alexellis-github \
  --literal hmac-secret=1234 --cert=pub-cert.pem

You can then place the secrets.yml file in any public Git repo without others being able to read the contents.

When SealedSecrets is installed by ofc-bootstrap

The scripts/export-sealed-secret-pubcert.sh does everything automatically.

Environment variable overrides

OPENFAAS_TEMPLATE_URL - to set the default URL to pull templates from
OPENFAAS_PREFIX - for use with faas-cli new - this can act in place of --prefix
OPENFAAS_URL - to override the default gateway URL

FaaS-CLI Developers / Contributors

See contributing guide.

License

This project is part of OpenFaaS and is licensed under the MIT License.

justinfx/faas-cli