feat: added interval config option to tell the plugin to run periodically

[fransflippo]

This contains the change from #12 to run the plugin continuously and query Salesforce and publish events periodically.

This adds a configuration option interval that indicates the interval at which the plugin should re-run the query and publish events. The interval is from start to start, in other words, the time that the plugin spent actually doing work is subtracted from the interval, and that is how long the plugin will sleep until it starts again.

Important: No functionality is added for "incremental" updates. The same query is run every time and all result records are published as events, regardless of whether they were already retrieved and published before.

[cla-checker-service]

💚 CLA has been signed

[jsvd]

@fransf-wtax failing the CLA check typically means you didn't sign with the email that is shown as the author of this PR's commits: https://patch-diff.githubusercontent.com/raw/logstash-plugins/logstash-input-salesforce/pull/37.patch

[jsvd]

@fransf-wtax we have a different user for you, @fransflippo ?

[fransf-wtax]

@fransf-wtax we have a different user for you, @fransflippo ?

Ugh, I'm juggling work and personal GitHub accounts and e-mail addresses. I pushed using my personal GitHub account, but the commits were originally created from my work account.

Let me try to rewrite the commits so they have my personal e-mail address on them instead and see if that works. Thanks!

[fransf-wtax]

@jsvd I'll also need to update the documentation at https://github.com/elastic/logstash-docs-md/edit/main/docs/lsr/plugins-inputs-salesforce.md with the new configuration option. What's the procedure for that?

[jsvd]

Once the plugin is released we will be updating that. though with 9.0.0 we moved from asciidoc to markdown and are still dealing with some build issues, so it could take a bit longer to show the new plugin version docs.

[fransf-wtax]

Once the plugin is released we will be updating that. though with 9.0.0 we moved from asciidoc to markdown and are still dealing with some build issues, so it could take a bit longer to show the new plugin version docs.

Got it. So for now I should just update doc/index.asciidoc in the plugin project?

[jsvd]

Yes, we periodically monitor for new releases and trigger the jobs to push changes to docs.