Improving currencyrate plugin

[enaples]

Important

26.04 FREEZE March 11th: Non-bugfix PRs not ready by this date will wait for 26.06.

RC1 is scheduled on March 23rd

The final release is scheduled for April 15th.

Checklist

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• The changelog has been updated in the relevant commit(s) according to the guidelines.
• Tests have been added or modified to reflect the changes.
• Documentation has been reviewed and updated as needed.
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• Important All PRs must consider how to reverse any persistent changes for tools/lightning-downgrade

Currencyrate plugin changes

As mentioned in #9010,

1. Check on RPC argument number added
2. Show max three decimal digits
3. Added source argument to the currencyrate RPC call
4. Added "Example" on RPC documentation

Info Needed

I would personally suggest to add a README.md file in the currencyrate plugin folder reporting how to configure new sources in the config file, plus some best practice using reckless to add and disable sources without restarting the node.

[daywalker90]

I would personally suggest to add a README.md file in the currencyrate plugin folder reporting how to configure new sources in the config file

We can do that, but personally i go to https://docs.corelightning.org/reference/lightningd-config first to see documentation on config options and we have the currencyrate options with instructions on how they need to be written included there.

, plus some best practice using reckless to add and disable sources without restarting the node.

No sure if it can be done with reckless but it can be done with just the plugin command e.g.:

lightning-cli plugin stop cln-currencyrate

then to add a source:

lightning-cli plugin -k subcommand=start plugin=/media/addonssd/dev/lightning/plugins/cln-currencyrate currencyrate-add-source="test,https://test.com/{currency},rate"

But keep in mind that afaik any events happening while the plugin is stopped will have their currencyrate missing.

[daywalker90]

We should then also do the same check for object based queries here aswell.

[daywalker90]

We should then also do the same check for object based queries here aswell.

[daywalker90]

We do allow sources to be named as numbers only and this would then cause currencyrate to silently ignore the sourrce and return a median result. I suggest changing this to:

let source = values.get(1).and_then(|v| {
                v.as_str()
                    .map(str::to_owned)
                    .or_else(|| v.as_number().map(std::string::ToString::to_string))
            });

[daywalker90]

Same as above:

let source = map.get("source").and_then(|v| {
                v.as_str()
                    .map(str::to_owned)
                    .or_else(|| v.as_number().map(std::string::ToString::to_string))
            });

[daywalker90]

Usually we would use setconfig to change options dynamically but since here we have multi options it's not possible until something like #8751. Then we could change sources without restarting the plugin or node or extra rpc methods(yikes).