Update details about logs retention

docs/operations.md

@@ -59,11 +59,14 @@ For more information about mixins, take a look at the [mixins project docs](http
 
 ## Retention/Deleting old data
 
-A retention policy and API to delete ingested logs is still under development.
+Retention in Loki can be done by configuring Table Manager. You need to set a retention period and enable deletes for retention using yaml config as seen [here](https://github.com/grafana/loki/blob/39bbd733be4a0d430986d9513476a91334485e9f/production/ksonnet/loki/config.libsonnet#L128-L129) or using `table-manager.retention-period` and `table-manager.retention-deletes-enabled` command line args. Retention period needs to be a duration in string format that can be parsed using [time.Duration](https://golang.org/pkg/time/#ParseDuration).
+
+In the case of chunks retention when using S3 or GCS, you need to set the expiry policy on the bucket that is configured for storing chunks. For more details check [this](https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lifecycle-mgmt.html) for S3 and [this](https://cloud.google.com/storage/docs/managing-lifecycles) for GCS.
+
+Currently we only support global retention policy. A per user retention policy and API to delete ingested logs is still under development.
 Feel free to add your use case to this [GitHub issue](https://github.com/grafana/loki/issues/162).
 
 A design goal of Loki is that storing logs should be cheap, hence a volume-based deletion API was deprioritized.
-But we realize that time-based retention could be a compliance issue.
 
 Until this feature is released: If you suddenly must delete ingested logs, you can delete old chunks in your object store.
 Note that this will only delete the log content while keeping the label index intact.
@@ -185,3 +188,4 @@ create the table manually you cannot easily erase old data and your index just g
 If you set your DynamoDB table manually, ensure you set the primary index key to `h`
 (string) and use `r` (binary) as the sort key. Also set the "period" attribute in the yaml to zero.
 Make sure adjust your throughput base on your usage.
+