206aa3c203
* update vendor directory, add go.opencensus.io * update imports * oops * s/opentracing/opencensus/ & remove prometheus / zipkin stuff & remove old stats * the dep train rides again * fix gin build * deps from last guy * start in on the agent metrics * she builds * remove tags for now, cardinality error is fussing. subscribe instead of register * update to patched version of opencensus to proceed for now TODO switch to a release * meh fix imports * println debug the bad boys * lace it with the tags * update deps again * fix all inconsistent cardinality errors * add our own logger * fix init * fix oom measure * remove bugged removal code * fix s3 measures * fix prom handler nil
Function Examples
The goal of the fdk's are to make it just as easy to write a hot function as
it is a cold one. The best way to showcase this is with an example.
This is an example of a hot function using the fdk-go bindings. The hot function
documentation
contains an analysis of how this example works under the hood. With any of the
examples provided here, you may use any format to configure your functions in
fn itself. Here we add instructions to set up functions with a 'hot' format.
How to run the example
Install the CLI tool, start a Fn server and run docker login to login to
DockerHub. See the front page for
instructions.
Initialize the example with an image name you can access:
fn init --runtime docker --format http --name <DOCKERHUB_USER/image_name>
--format json will also work here, or if your functions already use json
then adding the fdk will be seamless.
Build and deploy the function to the Fn server (default localhost:8080)
fn deploy --app hot-app
Now call your function (may take a sec to pull image):
curl -X POST -d '{"name":"Clarice"}' http://localhost:8080/r/hot-app/hello
Note that this expects you were in a directory named 'hello' (where this
example lives), if this doesn't work, replace 'hello' with your $PWD from
the deploy command.
Then call it again to see how fast hot functions are!
Details
If you poke around in the Dockerfile you'll see that we're simply adding the
file found in this directory, getting the fdk-go package to our workspace
and then building a binary and building an image with that binary. That then
gets deployed to dockerhub and fn.
For more robust projects, it's recommended to use a tool like dep or
glide to get dependencies such as the fdk-go into your functions.
Scoping out func.go you can see that the handler code only deals with input
and output, and doesn't have to deal with decoding the formatting from
functions (i.e. i/o is presented through io.Writer and io.Reader). This
makes it much easier to write hot functions.