如何在Go中管理文件内的状态？

Question

Hard to admit it but I struggle to manage state in my cli go app. What I basically want is to manage a list of objects with their properties in a file on disk. I want to be able to add objects with their properties, update objects and/or their properties and remove them if needed.

I thought it would be easy to just have a yml or json file and edit it with some kind of library but it seems harder than it should for a go beginner like me.

An example would be the following json structure.

{
  "servers":
    [
      { "hostname": "gandalf", "ip": "192.168.1.10", "color": "red" },
      { "hostname": "bilbo", "ip": "192.168.1.11", "color": "blue" },
      { "hostname": "frodo", "ip": "192.168.1.12", "color": "yellow" }
    ]
}

Now I want to be able to add, remove and edit servers. It doesn't have to be json, yaml is fine as well.

Do you girls and guys have any suggestions (libs and an example) on how to do it? I already tried Viper but adding new objects or even editing the existing ones seems to be impossible.

Answer 1

For settings that need to be human readable and will primarily be edited by a human a yaml or json file seems fine.

If the state is both written and read by the program itself and a full fledged database seems overkill then I would use a file based database. Probably a simple key/value store like boltdb or sqlite if the data needs more structure.

I personally use boltdb in such a case, because it is very lightweight, superfast and I like its simplicity.

-- edit --

With json as a file structure the problem is that you need to write and read the entire file every single time. A edit would be a read of the entire file, unmarshalling the json, changing something in the unmarshalled object, marshalling it back to json and writing the entire file again.

Thats why I would only use this for settings that the program reads once on startup and that's it.