store.wit

interface store {
    /// An error type that encapsulates the different errors that can occur fetching configuration values.
    variant error {
        /// This indicates an error from an "upstream" config source. 
        /// As this could be almost _anything_ (such as Vault, Kubernetes ConfigMaps, KeyValue buckets, etc), 
        /// the error message is a string.
        upstream(string),
        /// This indicates an error from an I/O operation. 
        /// As this could be almost _anything_ (such as a file read, network connection, etc), 
        /// the error message is a string. 
        /// Depending on how this ends up being consumed, 
        /// we may consider moving this to use the `wasi:io/error` type instead. 
        /// For simplicity right now in supporting multiple implementations, it is being left as a string.
        io(string),
    }

    /// Gets a configuration value of type `string` associated with the `key`. 
    /// 
    /// The value is returned as an `option<string>`. If the key is not found,
    /// `Ok(none)` is returned. If an error occurs, an `Err(error)` is returned.
    get: func(
        /// A string key to fetch
        key: string
    ) -> result<option<string>, error>;

    /// Gets a list of configuration key-value pairs of type `string`.
    /// 
    /// If an error occurs, an `Err(error)` is returned.
    get-all: func() -> result<list<tuple<string, string>>, error>;
}