Would it be helpful if there is an API to allow applications to export/show/output current running configuration?

[zbalkan]

Summary

An application can read configuration from registry, local files, environment variables, command line parameters, an external configuration source, or a database. However there are problems with the running configuration:

• System-wide configurations vs more specific configurations (per user, per app, per instance?)
• Multiple same level configuration resources overriding each other
• "first occurrence wins" vs "last occurrence wins"
• Multiple configuration resources for different use cases
• Environment variables passed through the parent process (Environment variables can be changed but the application needs a restart for the new values)

Would a common API like show-params of click-extra be helpful for devs who uses Microsoft.Extensions.Configuration?

It would be great if it would be possible to have a Cisco network devices show running-config command, which outputs the running config. Although one mostly types just show run and the device implies the rest of the command.

Details

• It all started on the discussion here: https://news.ycombinator.com/item?id=36465886
• Multiple sources of configuration and multiple implementations depending on the software causes havoc
• With Process Monitor/Explorer or strace we can see which files and registry values are accessed. Also, it is possible to access environment variables but it is trickier on Linux.
• Without dumping the memory of a running application, can we not just print out the current configuration values in a structured way -preferable something machine-readably and hopefully human readable?

{
    "configuration": [
        {
            "source": "registry",
            "path": "HKLM/...",
            "values": {
                "key": "value"
            }
        },
        {
            "source": "file",
            "path": "C:\\ProgramData\\...",
            "values": {
                "key": "value"
            }
        },
        {
            "source": "environment",
            "path": "...",
            "values": {
                "APP_SPECIFIC_ENV_VAR": "value"
            }
        }
    ]
}

Also, just providing this would provide an optional way. What does it take to standardize the usage is another issue.

[davidfowl]

Not sure it should be a command like that but there's an API for getting the debug view for a configuration.

@JamesNK also made this change to make it easier to see where configuration comes from in the debugger.