Use unique combination of hostname/bucket/key for external storages

[juliusknorr]

Avoid conflicts with the storage id of external s3 storages when the bucket name is the same for different mountpoints.

[icewind1991]

Unfortunately this will need some kind of migration script.

Changing the storage id of an existing external storage will cause all fileids for the storage to change with all the effects that has

[juliusknorr]

Right, so my attempt for that would be to just iterate over all configured external mounts and if we match the old pattern for an entry in oc_storages update that with the new format. Doing it during storage setup sounds a bit too risky to me and we can actually do this during upgrade since s3 only has key/secret auth and does not require any user session.

[juliusknorr]

Added a migration step to rename the storage ids for all external storages using the "amazons3" backend, please have another look

[AndyScherzinger]

@icewind1991 can you re-review with latest changes from @juliushaertl so we can provide it to the customer :) Thanks ❤️

[CarlSchwan]

After enabling the app and applying this patch I get

An exception occurred while executing a query: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'nextcloud.oc_external_mounts' doesn't exist

[CarlSchwan]

After enabling the app and applying this patch I get

An exception occurred while executing a query: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'nextcloud.oc_external_mounts' doesn't exist

Found a fix, if apps/files_external/lib/Migration/Version1011Date20200630192246.php::changeSchema return null. The schema will be written immediately to the database, if it returns $schema, it will only write it in the next MigrationStep that returns null (or the last one).

[CarlSchwan]

Tested under this two scenarios and the migration worked now:

1. Setup Nextcloud with master branch => setup external storage with s3 => switch to this branch => migrations work
2. Setup Nextcloud with this branch, activating the files_external app works now and I can add an external storage

[PVince81]

👍 please see comment about some thing to test

[juliusknorr]

Also gave that another test run 👍

Thanks for helping out here @CarlSchwan

[icewind1991]

Did some basic testing for the migration

[CarlSchwan]

/backport to stable22

[CarlSchwan]

/backport to stable21

[CarlSchwan]

/backport to stable20