The Swift client
The Python Swift client is a command line tool for using object storage systems such as Allas. If you use Allas on Puhti or Mahti, all required packages and software are already installed.
module load allas
The allas-conf command above asks for your CSC password (the same that you use to login to CSC servers). It lists your projects in Allas and asks you to define the project that will be used. allas-conf generates and authenticates the connection to the selected project in Allas. The authentication information is stored in the shell variables OS_AUTH_TOKEN and OS_STORAGE_URL that are valid for up to eight hours. However, you can refresh the authentication at any time by running allas-conf again. The environment variables are available only for that login session. If you open another session, you need to authenticate again to access Allas.
This chapter includes instructions for the following operations:
|post||Create a bucket|
|upload||Upload an object|
|list||List objects and buckets|
|download||Download objects and buckets|
|delete||Remove objects or bucket|
|download --all||Download whole project|
|delete --all||Remove whole project|
|md5sum||Get the checksum|
|stat --meta||Add metadata|
|tempurl||Create a temporary URL|
|post -r, -w, --read-acl||Manage access rights|
|upload --use-slo||Upload files larger than 5 GB|
You can also install and use Swift outside the CSC computing environment. Make sure that your Swift version is not outdated, since the older Swift versions might not work with Allas.
Create buckets and upload objects
Create a new empty bucket:
swift post <new_bucket_name>
Create a new bucket and add a file to it:
swift upload <new_bucket_name> <file_name>
Add a file to an existing bucket:
swift upload <old_bucket_name> <file_name>
$ swift upload my_fishbucket my_fish.jpg Warning: failed to create container 'my_fishbucket': 409 Conflict: BucketAlreadyExists my_fish.jpg
List objects and buckets
List all buckets belonging to a project:
$ swift list my_fishbucket my_bigfishes
$ swift list my_fishbucket my_fish.jpg salmon.jpg bass.png
Download objects and buckets
Download an object:
swift download <bucket_name> <file_name>
swift download <bucket_name> <file_name> -o <new_name>
swift download <bucket_name>
You can copy data from one bucket to another using the command
swift copy. The command below copies file.txt from bucket1 to bucket2.
swift copy --destination /bucket2 bucket1 file.txt
$ swift copy --destination /other_bucket my_bigfishes bigfish.jpg created container other_bucket my_bigfishes/bigfish.jpg copied to /other_bucket/bigfish.jpg $ swift list other_bucket bigfish.jpg other_file.txt
Rename a file while copying it:
$ swift copy --destination /new_bucket/newname.jpg my_fishbucket my_fish.jpg created container new_bucket my_fishbucket/my_fish.jpg copied to /new_bucket/newname.jpg
For further information about the command swift copy, see the OpenStack documentation.
Remove objects and buckets
Remove objects and buckets using the command
swift delete <bucket_name> <object_name>
$ swift delete my_fishbucket useless_fish.jpg useless_fish.jpg
Unlike with the web client and s3cmd, with Swift, you can delete an entire bucket at once:
swift delete <my_old_bucket>
$ swift delete old_fishbucket old_fish.png useless_salmon.jpg too_tiny_bass.jpg $ swift list old_fishbucket Container u'old_fishbucket' not found
Download or delete projects
Download the entire project:
swift download --all
Delete the entire project:
swift delete --all
Pseudo folders and checksums
In case you want to observe whether an object has changed, use checksum with the command
Pseudo folders can be handled by adding the name of the pseudo folder in front of the file name: my_pseudo_folder_name/my_file
Create a pseudo folder named pictures in the bucket my_bigfishes and add the object bass.png to it:
$ swift upload my_bigfishes/pictures bass.png pictures/bass.png
The example below uploads a file called salmon.jpg to the pseudo folder called fishes inside the bucket my_fishbucket. The file is then downloaded.
$ md5sum salmon.jpg 22e44aa2b856e4df892b43c63d15138a salmon.jpg $ swift upload my_fishbucket/fishes salmon.jpg fishes/salmon.jpg $ swift list my_fishbucket fishes/salmon.jpg my_fish.jpg $ swift download my_fishbucket fishes/salmon.jpg -o my_renamed_salmon.jpg fishes/salmon.jpg [auth 0.664s, headers 0.925s, total 0.969s, 3.605 MB/s] $ md5sum my_renamed_salmon.jpg 22e44aa2b856e4df892b43c63d15138a my_renamed_salmon.jpg
Define metadata for an object:
swift post my_fishbucket my_fish.jpg --meta foo:bar
Display details about a bucket:
$ swift stat my_fishbucket Account: AUTH_$PROJECT_UUID Container: my_fishbucket Objects: 4 Bytes: 2162342 Read ACL: Write ACL: Sync To: Sync Key: Accept-Ranges: bytes X-Trans-Id: txUUID-cpouta-production-kaj X-Storage-Policy: default-placement X-Container-Bytes-Used-Actual: 1167360 X-Timestamp: 1516776076.95812
Set a bucket as read-only to the world (make the content visible at the URL: a3s.fi/bucket_name/object_name) instead of the default (private to the project):
swift post my_fishbucket --read-acl ".r:*"
Find more information about access management in the section Giving another project read and write access to a bucket.
More details about a file:
$ swift stat my_fishbucket fishes/salmon.jpg Account: AUTH_$PROJECT_ID Container: my_fishbucket Object: fishes/salmon.jpg Content Type: image/jpeg Content Length: 63220 Last Modified: Wed, 24 Jan 2018 10:17:03 GMT ETag: a38f8db198e3fea43c83c465ffb0283b Meta S3Cmd-Attrs: atime:1516788402/ctime:1513681753/gid:$LOCALGID/gname:$LOCALGROUP/md5:a38f8db198e3fea43c83c465ffb0283b/mode:33188/mtime:1513681747/uid:$LOCALUID/uname:$LOCALUSER Accept-Ranges: bytes X-Timestamp: 1516789023.84380 X-Trans-Id: tx0000000000000000001d6-q-q-cpouta-production-kaj
Note that the above file was uploaded with the s3cmd client, and therefore there is the additional metadata S3Cmd-Attrs compared to a file uploaded with Swift or S3. ETag is the hash when viewing the file details in the Pouta dashboard.
Giving another project read and write access to a bucket
Give the project project1 read rights to the bucket my_fishbucket:
swift post my_fishbucket -r "project1:*"
Write access can be given similarly by replacing -r (read) with -w (write):
swift post my_fishbucket -w "project1:*"
The character * after the project name defines that all project members in the project gain the rights.
Alternatively, you can give read and write access only to certain members of another project:
swift post my_fishbucket -r "project2:member1" swift post my_fishbucket -w \ "project3:member1,project3:member2,project5:member1,project6:*"
Please note: If you have granted access for specific projects, making the shared project public and private again will remove any previous access permissions.
In case you allow -w access for another project, the members of the other project can upload files to your bucket and remove your files. However, you do not have access to the uploaded files until either you or the sender shares the bucket with your project:
swift post <your_bucket_name> -r "your_project:*"
swift post my_fishbucket -r "project_1234:*,project_4567:*"
Alternatively, you can set the project public and then access the file.
Files larger than 5 GB
Swift has a single-object size limit of 5 GiB. In order to upload files larger than this, you must create a large object that consists of smaller segments. To achieve this, you can use Swift to upload a so-called Static Large Object (SLO).
Try to upload a large file:
$ md5sum /tmp/6GB.zero 9e6a77a2d5650b2e2a710a08e9e61a81 /tmp/6GB.zero $ stat /tmp/6GB.zero File: '/tmp/6GB.zero' Size: 6424625152 Blocks: 12548104 IO Block: 4096 regular file ... $ swift upload my_bigfishes /tmp/6GB.zero Object PUT failed: https://a3s.fi:443/swift/v1/my_bigfishes/tmp/6GB.zero 400 Bad Request EntityTooLarge
It fails with the message
EntityTooLarge, so instead:
$ swift upload my_bigfishes --use-slo --segment-size 1G /tmp/6GB.zero tmp/6GB.zero segment 3 tmp/6GB.zero segment 5 tmp/6GB.zero segment 1 tmp/6GB.zero segment 0 tmp/6GB.zero segment 4 tmp/6GB.zero segment 2 tmp/6GB.zero
This creates a new bucket:
$ swift list |grep my_bigfishes my_bigfishes my_bigfishes_segments
In this case the target bucket (my_bigfishes) contains just a front object that contains information what segments, stored in the segments bucket (my_bigfishes_segments) make the stored file. Operations performed to the front object are automatically reflected to the segments. Normally users don't need to operate with the segments buckets at all and objects inside these buckets should not be deleted or modified.
Download the entire 6GB.zero:
$ swift download my_bigfishes tmp/6GB.zero -o /tmp/6GB.zero tmp/6GB.zero [auth 0.594s, headers 0.881s, total 74.467s, 86.969 MB/s] $ md5sum 6GB.zero 9e6a77a2d5650b2e2a710a08e9e61a81 6GB.zero
Last edited Mon Oct 5 2020