This implementation is similar to AMQP notifications:
* Notifications are published on a single topic as a JSON feed
* Topic is configurable, as is the QoS. Uses the paho.mqtt.golang
library for the mqtt connection, and supports connections over tcp
and websockets, with optional secure tls support.
* Additionally the minio server configuration has been bumped up
so mqtt configuration can be added.
* Configuration migration code is added with tests.
MQTT is an ISO standard M2M/IoT messaging protocol and was
originally designed for applications for limited bandwidth
networks. Today it's use is growing in the IoT space.
xl.storageDisks is sometimes passed to some low-level XL functions. Some disks in
xl.storageDisks are set to nil when they encounter some errors. This means all
elements in xl.storageDisks will be nil after some time which lead to an unusable XL.
Looks like if we follow pattern such as
```
_ = rlk
```
Go can potentially kick in GC and close the fd when
the reference is lost, only speculation is that
the cause here is `SetFinalizer` which is set on
`os.close()` internally in `os` stdlib.
This is unexpected and unsual endeavour for Go, but
we have to make sure the reference is never lost
and always dies with the server.
Fixes#4530
This patch also reverts previous changes which were
merged for migration to the newer disk format. We will
be bringing these changes in subsequent releases. But
we wish to add protection in this release such that
future release migrations are protected.
Revert "fs: Migration should handle bucketConfigs as regular objects. (#4482)"
This reverts commit 976870a391.
Revert "fs: Migrate object metadata to objects directory. (#4195)"
This reverts commit 76f4f20609.
isDocker was currently reading from `/proc/cgroup` file. But
this file alone is rather not conclusive evidence. Docker
internally has `.dockerenv` as a special file which we should
use instead.
Fixes#4456
Current code failed to anticipate the existence of files
which could have been created to corrupt the namespace such
as `policy.json` file created at the bucket top level.
In the current release creating such as file conflicts
with the namespace for future bucket policy operations.
We implemented migration of backend format to avoid situations
such as these.
This PR handles this situation, makes sure that the
erroneous files should have been moved properly.
Fixes#4478
Krishna Srinivas