Feature discussion: Retry HTTP request in cases of bad response from esplora

[vincenzopalazzo]

Hi,

Before all, I want say if this issue contains some stupid affirmation, please close it :)

Today I pass several time to test esplora on my "server" and I received an error descrived inside this issue #15.

before to open the issue I made some test on my branch and I make some consideration, such as:

• esplora plugin is designed to fetch all data from esplora, it mean that it should make a lot of http connection. In most of the cases and at this moment this plugin is very useful to permit to run c-lightning on small devices, such as raspberry (without some special configuration) or Android devices. With this introduction, I list the possible problem that I can happenend:
  • Small devices can be connected to not good connections, this event can cause some errors such as connection error (i.e. switch network on devices, lost connection on devices for few seconds). Wiht this problem and c-lightning marked some plugin such as important plugin with this PR Important plugin ElementsProject/lightning#3890.
    At this point some error inside the http request can bring the lightningd to crash. This is not a big problem because you can restart it but this can be frustrating in some cases.

The solution that I want propose, is the same that bcli has inside the code when the bitcoind is not ready. It wait a few second and retries the connection. I think is good to have this function also in esplora plugin?

What do you think?