Re-configuration possibilities for Synology DSM

[mib1185]

Proposed change

With this when adding a new configuration, it is checked if there is an already existing configuration entry (identified by serial number) than this will be proper updated with new given configuration and reloaded, instead of creating a new entry.
Furthermore, when via SSDP an as new supposed NAS is detected, but an corresponding configuration entry (again identified by serial number) is found, than the existing entry will be updated (only host field)

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes Synology_DSM integration does not allow changing essential configs like the username and password #51352
• This PR is related to issue:
• Link to documentation pull request:

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[probot-home-assistant]

Hey there @hacf-fr, @Quentame, mind taking a look at this pull request as its been labeled with an integration (synology_dsm) you are listed as a codeowner for? Thanks!
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[bdraco]

Please see comment above

[mib1185]

will have a look until end of this week 👍

[bdraco]

I did some testing and this works as expected 👍

This seems like an existing issue, but from a security perspective, I don't think we should send back the existing password to the UI when reconfiguring. The password field should start off as blank. That's probably better addressed in #54298