50de0f34bb
**What** - Use the compose-go library to read the service definitions from an external compose file instead of building them in Go - Add default compose file and copy during `faasd install` - Add test for load and parse of compose file - Make testing easier by sorting the env keys - Allow append to instantiate the slices so that we can more easily test for proper parsing (e.g. nil is still nil etc) - Add the arch suffix to the compose file and set this as part of the env when we parse the compose file. This allows faasd to dynamically set the arch suffix used for the basic auth and the gateway images. Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>
mapstructure 
mapstructure is a Go library for decoding generic map values to structures and vice versa, while providing helpful error handling.
This library is most useful when decoding values from some data stream (JSON,
Gob, etc.) where you don't quite know the structure of the underlying data
until you read a part of it. You can therefore read a map[string]interface{}
and use this library to decode it into the proper underlying native Go
structure.
Installation
Standard go get:
$ go get github.com/mitchellh/mapstructure
Usage & Example
For usage and examples see the Godoc.
The Decode function has examples associated with it there.
But Why?!
Go offers fantastic standard libraries for decoding formats such as JSON. The standard method is to have a struct pre-created, and populate that struct from the bytes of the encoded format. This is great, but the problem is if you have configuration or an encoding that changes slightly depending on specific fields. For example, consider this JSON:
{
"type": "person",
"name": "Mitchell"
}
Perhaps we can't populate a specific structure without first reading
the "type" field from the JSON. We could always do two passes over the
decoding of the JSON (reading the "type" first, and the rest later).
However, it is much simpler to just decode this into a map[string]interface{}
structure, read the "type" key, then use something like this library
to decode it into the proper structure.