"NOAUTH Authentication required" Gitlab error with Azure cache for Redis - azure

Question

I have created an Azure cache for Redis and I am trying to use it as external redis for Gitlab.
My gitlab.rb is this:
#external_url "https://ci.example.com"
nginx['redirect_http_to_https'] = true
nginx['ssl_certificate'] = "/etc/gitlab/ssl/ci.example.com.crt"
nginx['ssl_certificate_key'] = "/etc/gitlab/ssl/ci.example.com.key"
### The duration in seconds to keep backups before they are allowed to be deleted
gitlab_rails['backup_keep_time'] = 604800
### External postgres settings
postgresql['enable'] = false
gitlab_rails['db_adapter'] = "postgresql"
gitlab_rails['db_encoding'] = "unicode"
gitlab_rails['db_database'] = "cisomething"
# username string for AWS
# gitlab_rails['db_username'] = "gitlab"
# username string for Azure
gitlab_rails['db_username'] = "gitlab#ci-something.postgres.database.azure.com"
gitlab_rails['db_password'] = "really long password"
gitlab_rails['db_host'] = "ci-something.postgres.database.azure.com"
gitlab_rails['db_port'] = 5432
gitlab_rails['auto_migrate'] = false
### External redis settings
redis['enable'] = false
gitlab_rails['redis_host'] = "ci.redis.cache.windows.net"
gitlab_rails['redis_port'] = 6379
gitlab_rails['redis_password'] = "azure-redis-primary-access-key"
### Whitelist VPC cidr for access to health checks
gitlab_rails['monitoring_whitelist'] = ['XX.XXX.X.X/24']
### Default Theme
gitlab_rails['gitlab_default_theme'] = 2
### Enable or disable automatic database migrations
gitlab_rails['auto_migrate'] = false
### GitLab email server settings
... other settings here
I can connect to Redis with redis-cli
redis-cli -h ci.redis.cache.windows.net -p 6379 -a azure-redis-primary-access-key
and execute commands.
When I execute gitlab-ctl tail I see this error:
==> /var/log/gitlab/gitlab-workhorse/current <==
{"error":"keywatcher: pubsub receive: NOAUTH Authentication required.","level":"error","msg":"unknown error","time":"2020-02-21T10:26:08Z"}
{"address":"ci.redis.cache.windows.net","level":"info","msg":"redis: dialing","scheme":"redis","time":"2020-02-21T10:26:08Z"}
{"error":"keywatcher: pubsub receive: NOAUTH Authentication required.","level":"error","msg":"unknown error","time":"2020-02-21T10:26:08Z"}
{"address":"ci.redis.cache.windows.net","level":"info","msg":"redis: dialing","scheme":"redis","time":"2020-02-21T10:26:08Z"}
{"error":"keywatcher: pubsub receive: NOAUTH Authentication required.","level":"error","msg":"unknown error","time":"2020-02-21T10:26:08Z"}
{"address":"ci.redis.cache.windows.net","level":"info","msg":"redis: dialing","scheme":"redis","time":"2020-02-21T10:26:08Z"}
{"error":"keywatcher: pubsub receive: NOAUTH Authentication required.","level":"error","msg":"unknown error","time":"2020-02-21T10:26:08Z"}
{"address":"ci.redis.cache.windows.net","level":"info","msg":"redis: dialing","scheme":"redis","time":"2020-02-21T10:26:08Z"}
I searched the internet but I cannot find something to resolve this.
System information
System: Ubuntu 16.04
Current User: git
Using RVM: no
Ruby Version: 2.6.5p114
Gem Version: 2.7.10
Bundler Version:1.17.3
Rake Version: 12.3.3
Redis Version: 5.0.7
Git Version: 2.24.1
Sidekiq Version:5.2.7
GitLab information
Version: 12.7.6
Revision: 61654d25b20
Directory: /opt/gitlab/embedded/service/gitlab-rails
DB Adapter: PostgreSQL
DB Version: 9.5.20,

Answer 1

So, I figured it out.
For future reference here it goes.
gitlab.rb
### External redis settings
redis['enable'] = false
gitlab_rails['redis_host'] = "ci.redis.cache.windows.net"
gitlab_rails['redis_port'] = 6380
gitlab_rails['redis_password'] = "azure-primary-access-key"
gitlab_rails['redis_ssl'] = true
Azure Cache for Redis configuration [Azure portal]
Final note:
When deploying the Gitlab VM, check the logs with gitlab-ctl tail. If you see the redis default port to be 6379 means that Sidekiq has old configuration, which as I observed is not updated with gitlab-ctl reconfigure. Delete the VM and redeploy it.