Tehnix / playground-ServHs

Fun with serverless-haskell!

ServHs - Fun with serverless-haskell!

To get it running, first install the various dependencies,

$ yarn

And then test it locally with,

$ yarn sls invoke local --function entry

Here, entry is the name of our function (under functions) in serverless.yml, which points to the ServHs package and then the entry executable. The format of the handlers, when using serverless-haskell, goes Package.Executable, as defined in your .cabal/package.yaml file.

If you want to use the API Gateway, serverless-haskell also supports serverless-offline. You can try it out by running,

$ yarn sls offline start

and then hit the endpoint with,

$ curl localhost:3000/hello/john

Note that serverless-haskell will take care of building your project with stack everytime you invoke any of the above functions.

Finally, to deploy your serverless setup, you run,

$ yarn sls deploy

And yarn sls remove to tear it down again, if you are just testing.

FAQ

Q: yarn sls invoke local -f entry and yarn sls offline start crashes after some time, with Error: socket hang up.

A: This is caused by some issues with Node version 10.7.0 and there about. You should set your node version to 8.10.0, via e.g. something like nodenv (there's a .node-version file that does this automatically for you, if you have nodenv). See seek-oss/serverless-haskell#62 for more.