[8.x] Fix flushDb (cache:clear) for redis clusters

[willbrowningme]

When running php artisan cache:clear with a redis cluster as the cache driver, the flushDb() function is currently unable to run on each master if you are using a password or TLS scheme - #35180

For redis clusters an empty $config array is passed through to the constructor of vendor\laravel\framework\src\Illuminate\Redis\Connections\PhpRedisConnection.php causing authentication to fail.

However, even if you update vendor\laravel\framework\src\Illuminate\Redis\Connectors\PhpRedisConnector.php to pass through the cluster password it still fails because the current $redis = tap(new Redis)->connect($host, $port); does not connect to each master node using the correct TLS scheme or any stream context such as local_cert, local_pk, cafile or verify_peer_name.

This pull request fixes the issue by using directed node commands as described here - https://github.com/phpredis/phpredis/blob/develop/cluster.markdown#directed-node-commands

It uses the already authenticated RedisCluster connection with correct scheme and context to direct the flushdb command to each master node to succesfully clear the entire cache.

[taylorotwell]

I will probably need someone actually using Redis Cluster to confirm this.

[taylorotwell]

Are you using any particular Docker setup to test Redis Cluster?

[taylorotwell]

Got a cluster up and running with Docker and this does indeed seem to not break anything at least.

[willbrowningme]

I've tested on Homestead running 6 instances 3 masters, each with 1 replica (slave).

I've also tested on an Ubuntu staging server running 20.04, using self signed certs and TLSv1.2.

Thanks for the merge!

[J5Dev]

Sorry to comment on an old MR, but I have found this after we have come across the same issue when using PHPRedis, however we are on laravel/framework v6.20.19.

I have verified that the issue is the exact same, and changing the PhpRedisConnection@flushdb to the above submitted code, does indeed fix the issue.

@taylor or @willbrowningme ... Can this fix be back-ported into the V6, given it is still LTS and receiving support fixes?
If not, is there an alternative that can be suggested?

Thank you.

[driesvints]

@J5Dev maybe try a PR to see if Taylor would accept it?

[J5Dev]

@J5Dev maybe try a PR to see if Taylor would accept it?

No problems, will put one together now.

[JasonXup6]

@J5Dev maybe try a PR to see if Taylor would accept it?

No problems, will put one together now.

Could you make PR to laravel:7.x , we also facing this isssue.
It's wold be helpful a lot, thanks in advance.

[driesvints]

Laravel 7 isn't maintained anymore