S3 credentials added squash

UPD documentation for S3

gui/README.md

@@ -260,3 +260,62 @@ resources:
 ```
 
 You can find more information here [https://wiki.openstack.org/wiki/Heat](https://wiki.openstack.org/wiki/Heat).
+
+##Object storage management
+
+OpenStack supports object storage based on [OpenStack Swift](https://docs.openstack.org/swift/latest/api/object_api_v1_overview.html). Creation of object storage container (database) is done by clicking on `+Container` on [Object storage containers page](https://dashboard.cloud.muni.cz/project/containers).
+
+Every object typically contains data along with metadata and unique global identifier to access it. OpenStack allows you to upload your files via HTTPs protocol. There are two ways managing created object storage container:
+
+1. Use OpenStack component [Swift](https://docs.openstack.org/swift/train/admin/index.html)
+
+2. Use [S3 API](https://docs.aws.amazon.com/AmazonS3/latest/userguide/Welcome.html)
+
+In both cases you will need application credentials to be able to manage your data.
+
+
+### Swift credentials
+
+The easiest way to generate **Swift** storage credentials is through [MetaCentrum cloud dashboard](https://dashboard.cloud.muni.cz). You can generate application credentials as described [here](/cli/#getting-credentials). You must have role **heat_stack_owner**.
+
+### S3 credentials
+
+If you want to use **S3 API** you will need to generate ec2 credentials for access. Note that to generate ec2 credentials you will also need credentials containing role of **heat_stack_owner**. Once you sourced your credentials for CLI you can generate ec2 credentials by following command:
+
+```
+$ openstack ec2 credentials create          
++------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| Field      | Value                                                                                                                                                                    |
++------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| access     | 896**************************651                                                                                                                                         |
+| project_id | f0c**************************508                                                                                                                                         |
+| secret     | 336**************************49c                                                                                                                                         |
+...
+| user_id    | e65***********************************************************6a                                                                                                         |
++------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+
+```
+Then you will obtain S3 credentials. There is also a possibility that you can encouter following problem while working with S3:
+
+Then you may use one of the s3 clients (minio client mc, s3cmd, ...)
+Running minio client against created object storage container is very easy:
+
+```
+$ MC config host add swift-s3 https://object-store.cloud.muni.cz  896**************************651 336**************************49c --api S3v2
+Added `swift-s3` successfully.
+
+$ MC ls swift-s3
+[2021-04-19 15:13:45 CEST]     0B freznicek-test/
+```
+s3cmd client requires configuration file which looks like:
+In this case please open your file with credentials which will look like this:
+```
+default]
+access_key = 896**************************651
+secret_key = 336**************************49c
+host_base = object-store.cloud.muni.cz
+host_bucket = object-store.cloud.muni.cz
+use_https = True
+```
+
+For more info please refer to [https://docs.openstack.org/swift/latest/s3_compat.html](https://docs.openstack.org/swift/latest/s3_compat.html) and [https://docs.openstack.org/train/config-reference/object-storage/configure-s3.html](https://docs.openstack.org/train/config-reference/object-storage/configure-s3.html).