VishalandSoam Vasani
da820186f0
This change adds a layer of abstraction over poolmgr. Poolmgr is now just one of the ways to turn a function into a service; other implementations will be added. The executor abstraction is a uniform API over all these implementations. * Executor layer added on top of pool manager * Removed the external server for executor * Minor changes to keep existing semantics as much possible * Separating the executor vs. poolmgr backend functionality and associated data members * Executor logic separated from Poolmgr backend completely, placeholder for new backend * Changed references to poolmgr in tests * Moved poolmgr to it's package, as a side effect moved Cache to its's package (was causing cyclical dependency) and had to make some data structures exposed outside package * Rebased from master and changed references to tpr -> crd * Executor layer added on top of pool manager * Executor logic separated from Poolmgr backend completely, placeholder for new backend * Changed podName to a generic objectReference in fscache (#391) Changed podName to a generic objectReference in function service cache implementation. * Moved poolmgr to it's package, as a side effect moved Cache to its's package (was causing cyclical dependency) and had to make some data structures exposed outside package * Rebased from master and changed references to tpr -> crd * Merged from master with latest changes * Removed stale executor service & deployment from previous merge * Addressed review comments, still testing some areas
Fission: Serverless Functions for Kubernetes
Fission is a fast serverless framework for Kubernetes with a focus on developer productivity and high performance.
Fission operates on just the code: Docker and Kubernetes are abstracted away under normal operation, though you can use both to extend Fission if you want to.
Fission is extensible to any language; the core is written in Go, and language-specific parts are isolated in something called environments (more below). Fission currently supports NodeJS, Python, Ruby, Go, PHP, Bash, and any Linux executable, with more languages coming soon.
Performance: 100msec cold start
Fission maintains a pool of "warm" containers that each contain a small dynamic loader. When a function is first called, i.e. "cold-started", a running container is chosen and the function is loaded. This pool is what makes Fission fast: cold-start latencies are typically about 100msec.
Kubernetes is the right place for Serverless
We're built on Kubernetes because we think any non-trivial app will use a combination of serverless functions and more conventional microservices, and Kubernetes is a great framework to bring these together seamlessly.
Building on Kubernetes also means that anything you do for operations on your Kubernetes cluster — such as monitoring or log aggregation — also helps with ops on your Fission deployment.
Fission Concepts
A function is a piece of code that follows the fission function interface.
An environment contains the language- and runtime-specific parts of running a function.
The following environments are currently available:
| Environment | Image |
|---|---|
| Binary (for executables or scripts) | fission/binary-env |
| Go | fission/go-env |
| .NET | fission/dotnet-env |
| .NET 2.0 | fission/dotnet20-env |
| NodeJS (Alpine) | fission/node-env |
| NodeJS (Debian) | fission/node-env-debian |
| Perl | fission/perl-env |
| PHP 7 | fission/php-env |
| Python 3 | fission/python-env |
| Ruby | fission/ruby-env |
You can also extend environments or create entirely new ones if you want. (An environment is essentially just a container with a webserver and dynamic loader.)
A trigger is something that maps an event to a function; Fission supports HTTP routes as triggers today, with upcoming support for other types of event triggers, such as timers and Kubernetes events.
Usage
# Add the stock NodeJS env to your Fission deployment
$ fission env create --name nodejs --image fission/node-env
# A javascript one-liner that prints "hello world"
$ curl https://raw.githubusercontent.com/fission/fission/master/examples/nodejs/hello.js > hello.js
# Upload your function code to fission
$ fission function create --name hello --env nodejs --code hello.js
# Map GET /hello to your new function
$ fission route create --method GET --url /hello --function hello
# Run the function. This takes about 100msec the first time.
$ curl http://$FISSION_ROUTER/hello
Hello, world!
See the examples directory for more.
Running Fission on your Cluster
See the installation guide.
Compiling Fission
See the compilation guide.
Status
Fission is in early alpha. It's not suitable for production use just yet.
Fission is a project by Platform9 Systems and many contributors.