forked from mystiq/dex
42 lines
1.9 KiB
Markdown
42 lines
1.9 KiB
Markdown
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genconfig
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====
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The genconfig tool generates boilerplate code for registering and deserializing configuration objects.
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## Usage - Go source
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Let's say you have an interface called `Foo` with several concrete implmentations, and you'd like to be able to instantiate these implementations by reading JSON configuration files.
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The first thing you do is create a new interface called `FooConfig` and add a `go:generate` directive to it like so:
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//go:generate genconfig -o config.go foo Foo
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type FooConfig interface {
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FooID() string
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Foo()
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...
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The first argument is the name of the file to create. The second (`foo`) is the name of the package. The third is the object that is to be configurable.
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## Usage - Go Generate
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To generate (or re-generate) your config file, issue the following command in your shell:
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```
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go generate github.com/coreos/dex/foo
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```
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## Usage - Generated Code API
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Every time you make a new `Foo` implementation, you should create a new `FooConfig` which configures it, and can return a `Foo`. You should tag `FooConfig` so that it can be serialized/de-serialized as you plesae.
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After creating the `Config` object, you can register it with the the generated `RegisterFooConfigType`. This allows you to create `NewFooFromType(fooType string)` and also `newFooConfigFromMap`.
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In practice you will do something like: deserialize a JSON object into a `map[string]interface{}`, pass that map into `newFooConfigFromMap` which gives you your `FooConfig` and then call whatever you've implemented to get a `Foo` from a `FooConfig`
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## The Future?
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There's still a lot of boilerplate that needs to be generated to use this API. It would be nice to generate even more code, with more `go:generate` directives. For example, partial implementations of the XXXConfig objects could be generated, along with functions for deserializing the Config objects (or slices of them) from an io.Reader.
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