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.
This change adds `access` format support for notifications to a
Elasticsearch server, and it refactors `namespace` format support.
In the case of `access` format, for each event in Minio, a JSON
document is inserted into Elasticsearch with its timestamp set to the
event's timestamp, and with the ID generated automatically by
elasticsearch. No events are modified or deleted in this mode.
In the case of `namespace` format, for each event in Minio, a JSON
document is keyed together by the bucket and object name is updated in
Elasticsearch. In the case of an object being created or over-written
in Minio, a new document or an existing document is inserted into the
Elasticsearch index. If an object is deleted in Minio, the
corresponding document is deleted from the Elasticsearch index.
Additionally, this change upgrades Elasticsearch support to the 5.x
series. This is a breaking change, and users of previous elasticsearch
versions should upgrade.
Also updates documentation on Elasticsearch notification target usage
and has a link to an elasticsearch upgrade guide.
This is the last patch that finally resolves#3928.
This change adds `access` format support for notifications to a Redis
server, and it refactors `namespace` format support.
In the case of `access` format, a list is used to store Minio
operations in Redis. Each entry in the list is a JSON encoded list of
two items - the first is the Minio server timestamp of the event, and
the second is an object describing the operation that created/replaced
the object in the server.
In the case of `namespace` format, a hash is used. Entries in the hash
may be updated or removed if objects in Minio are updated or deleted
respectively. The field values in the Redis hash are JSON encoded.
Also updates documentation on Redis notification target usage.
Towards resolving #3928
* Add configuration parameter "format" for db targets and perform
configuration migration.
* Add PostgreSQL `access` format: This causes Minio to append all events
to the configured table. Prefix, suffix and event filters continue
to be supported for this mode too.
* Update documentation for PostgreSQL notification target.
* Add MySQL `access` format: It is very similar to the same format for
PostgreSQL.
* Update MySQL notification documentation.
As a new configuration parameter is added, configuration version is
bumped up from 14 to 15.
The MySQL target's behaviour is identical to the PostgreSQL: rows are
deleted from the MySQL table on delete-object events, and are
created/updated on create/over-write events.
