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Getting data from an S3 bucket

Connecting to an S3 bucket

Section titled “Connecting to an S3 bucket”

To get data from an S3 bucket, you need to execute connect get s3 with following mandatory parameters:

  • --bucket then the S3 bucket name
  • --region then the region where the bucket is located

Depending on the type of authentication you need to either use --access-key and --secret-access-key for key based authentication or use the IAM Role Assigned to the Instance (if the server is running on AWS).

To use the Access Key and Secret Access Key authentication you need to provide:

  • --access-key then the Access Key
  • --secret-access-key then the Secret Access Key

You can use aws configure. This command prompts you to enter the Access Key ID and Secret Access Key, which are then stored in your AWS CLI configuration file ~/.aws/credentials. Then you can omit providing the credentials as they will be obtained from the configuration.

If your instance is running in AWS the temporary credentials will be automatically retrieved from the instance metadata (unless you have overridden it with aws configure). You don’t have to specify the credentials then.

To connect to an S3-compatible service like Minio you need to provide the URL using:

  • --custom-url and then the S3 instance URL

Getting single file from an S3 bucket

Section titled “Getting single file from an S3 bucket”

To get a single file from an S3 bucket you should use

  • --file followed by the file name to be downloaded

Following command will get file1.zip file from an S3 bucket my-s3-bucket bucket in eu-central-1 region using Access Key and Secret Access Key authentication.

Terminal window
$ connect get s3 --file file1.zip --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/05 10:39:09 INFO Getting files from s3://my-s3-bucket/
[file1.zip] 10.00 MiB / 10.00 MiB done

Getting multiple files from an S3 bucket

Section titled “Getting multiple files from an S3 bucket”

If you’d like to get multiple files from an S3 bucket you need to specify either file mask or file regular expression for the files.

  • --file-mask a file mask
  • --file-regex regular expression

This will download all files that match a certain mask or pattern. You can also provide an optional source folder that contains the files to be downloaded:

  • -s, --src-folder folder containing the files to download

If you don’t provide the source folder files will be downloaded from “root folder” of the S3 bucket.

Following command will get all .zip files from data folder of S3 bucket my-s3-bucket in eu-central-1 region using Access Key and Secret Access Key authentication.

Terminal window
$ connect get s3 --file-mask "*.zip" -s data --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/05 10:40:44 INFO Getting files from s3://my-s3-bucket/data/
[file1.zip] 10.00 MiB / 10.00 MiB done
[file2.zip] 10.00 MiB / 10.00 MiB done
[file3.zip] 10.00 MiB / 10.00 MiB done

You can also provide an optional destination folder where the files will be downloaded to:

  • -d, --dst-folder target folder where to download files

If you don’t provide the destination folder files will be downloaded to the current folder.

In below example all .zip files from data folder of S3 bucket my-s3-bucket in eu-central-1 region will be downloaded to local folder using Access Key and Secret Access Key authentication.

Terminal window
$ connect get s3 --file-mask "*.zip" -s data -d local --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/05 10:41:58 INFO Getting files from s3://my-s3-bucket/data/
[file1.zip] 10.00 MiB / 10.00 MiB done
[file2.zip] 10.00 MiB / 10.00 MiB done
[file3.zip] 10.00 MiB / 10.00 MiB done

Getting files from an S3 bucket in batch mode

Section titled “Getting files from an S3 bucket in batch mode”

When using the application in batch or non-interactive mode, such as in a script or scheduler, you should disable the progress bar by using

  • --batch to get files in batch mode

Following command will get all .zip files from the data folder of S3 bucket my-s3-bucket in eu-central-1 region and place them in the local folder, using batch mode and Access Key and Secret Access Key authentication.

Terminal window
$ connect get s3 --file-mask "*.zip" -s data -d local --batch --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/05 10:45:23 INFO Getting files from s3://my-s3-bucket/data/
2025/06/05 10:45:23 INFO Files to get: count=3
2025/06/05 10:45:23 INFO Transferring file=data/file1.zip targetFolder=local
2025/06/05 10:45:23 INFO File transferred successfully bytesTransferred=10485760 duration=157ms transferRate=63.53MB/s file=data/file1.zip targetFolder=local
2025/06/05 10:45:23 INFO Transferring file=data/file2.zip targetFolder=local
2025/06/05 10:45:23 INFO File transferred successfully bytesTransferred=10485760 duration=102ms transferRate=97.90MB/s file=data/file2.zip targetFolder=local
2025/06/05 10:45:23 INFO Transferring file=data/file3.zip targetFolder=local
2025/06/05 10:45:23 INFO File transferred successfully bytesTransferred=10485760 duration=99ms transferRate=100.83MB/s file=data/file3.zip targetFolder=local

Getting files from an S3 bucket using scheduler

Section titled “Getting files from an S3 bucket using scheduler”

When running the application from a scheduler, it’s recommended to ensure only one instance operates on a specific folder. It’s possible to configure the application to create a flag file at startup and delete it upon completion. If another instance tries to start while one is already running, it will detect the flag file and exit. This approach ensures that only one instance of the application runs at any given time. To do that use

  • --flag path to the flag file

Following command will get all .zip files from the data folder of S3 bucket my-s3-bucket in eu-central-1 region and place them in the local folder using /tmp/flag1 as a flag file and Access Key and Secret Access Key authentication. Mind that we are using batch mode as it’s required for the application to run correctly from script or scheduler.

Terminal window
$ connect get s3 --flag /tmp/flag1 --batch --file-mask "*.zip" -s data -d local --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/05 10:49:40 INFO Using flag file: /tmp/flag1
2025/06/05 10:49:40 INFO Getting files from s3://my-s3-bucket/data/
2025/06/05 10:49:40 INFO Files to get: count=3
2025/06/05 10:49:40 INFO Transferring file=data/file1.zip targetFolder=local
2025/06/05 10:49:40 INFO File transferred successfully bytesTransferred=10485760 duration=138ms transferRate=72.01MB/s file=data/file1.zip targetFolder=local
2025/06/05 10:49:40 INFO Transferring file=data/file2.zip targetFolder=local
2025/06/05 10:49:40 INFO File transferred successfully bytesTransferred=10485760 duration=117ms transferRate=85.34MB/s file=data/file2.zip targetFolder=local
2025/06/05 10:49:40 INFO Transferring file=data/file3.zip targetFolder=local
2025/06/05 10:49:40 INFO File transferred successfully bytesTransferred=10485760 duration=98ms transferRate=101.84MB/s file=data/file3.zip targetFolder=local
2025/06/05 10:49:40 INFO Removing flag file: /tmp/flag1

Getting files from an S3 bucket in parallel

Section titled “Getting files from an S3 bucket in parallel”

To speed up file download you can fetch files simultaneously. Application will then get files using multiple sessions. To specify number of concurrent S3 sessions use:

  • --parallel number of S3 sessions

Following command will get all .zip files from data folder of S3 bucket my-s3-bucket in eu-central-1 region using 3 parallel sessions.

Terminal window
$ connect get s3 --file-mask "*.zip" -s data --batch --parallel 3 --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/05 11:29:35 INFO Getting files from s3://my-s3-bucket/data/
2025/06/05 11:29:35 INFO Files to get: count=3
2025/06/05 11:29:35 INFO Transferring file=data/file3.zip targetFolder=
2025/06/05 11:29:35 INFO Transferring file=data/file2.zip targetFolder=
2025/06/05 11:29:35 INFO Transferring file=data/file1.zip targetFolder=
2025/06/05 11:29:35 INFO File transferred successfully bytesTransferred=10485760 duration=194ms transferRate=51.48MB/s file=data/file3.zip targetFolder=
2025/06/05 11:29:35 INFO File transferred successfully bytesTransferred=10485760 duration=256ms transferRate=39.03MB/s file=data/file1.zip targetFolder=
2025/06/05 11:29:35 INFO File transferred successfully bytesTransferred=10485760 duration=278ms transferRate=35.86MB/s file=data/file2.zip targetFolder=

Getting files from an S3 bucket in sequence

Section titled “Getting files from an S3 bucket in sequence”

If you don’t specify the --parallel option then files will be downloaded using single S3 session in the same order as they showed up on S3 bucket (oldest files first).

Action after file is downloaded from an S3 bucket

Section titled “Action after file is downloaded from an S3 bucket”

After file is successfully downloaded to local system it’s possible to remove it from source or move it to a different folder at the source system.

  • --delete delete a file after it’s downloaded
  • --move-folder target folder to move the file after it’s downloaded

Following command will get all .zip files from data folder of S3 bucket my-s3-bucket in eu-central-1 region using 3 parallel sessions and store them in local folder. Then files will be moved to archive folder at in the S3 bucket.

Terminal window
$ connect get s3 --file-mask "*.zip" -s data -d local --batch --parallel 3 --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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 --move-folder archive
2025/06/05 11:31:11 INFO Getting files from s3://my-s3-bucket/data/
2025/06/05 11:31:11 INFO Files to get: count=3
2025/06/05 11:31:11 INFO Transferring file=data/file1.zip targetFolder=local
2025/06/05 11:31:11 INFO File moved to folder folder=archive file=data/file1.zip
2025/06/05 11:31:11 INFO File transferred successfully bytesTransferred=10485760 duration=169ms transferRate=58.86MB/s file=data/file1.zip targetFolder=local
2025/06/05 11:31:11 INFO Transferring file=data/file2.zip targetFolder=local
2025/06/05 11:31:11 INFO File moved to folder folder=archive file=data/file2.zip
2025/06/05 11:31:11 INFO File transferred successfully bytesTransferred=10485760 duration=99ms transferRate=100.21MB/s file=data/file2.zip targetFolder=local
2025/06/05 11:31:11 INFO Transferring file=data/file3.zip targetFolder=local
2025/06/05 11:31:12 INFO File moved to folder folder=archive file=data/file3.zip
2025/06/05 11:31:12 INFO File transferred successfully bytesTransferred=10485760 duration=94ms transferRate=105.49MB/s file=data/file3.zip targetFolder=local

Following command will get all .zip files from data folder of S3 bucket my-s3-bucket in eu-central-1 region using 3 parallel sessions and then remove the files from the S3 bucket.

Terminal window
$ connect get s3 --file-mask "*.zip" -s data --batch --parallel 3 --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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 --delete
2025/06/05 11:33:41 INFO Getting files from s3://my-s3-bucket/data/
2025/06/05 11:33:41 INFO Files to get: count=3
2025/06/05 11:33:41 INFO Transferring file=data/file2.zip targetFolder=
2025/06/05 11:33:41 INFO File deleted file=data/file2.zip
2025/06/05 11:33:41 INFO File transferred successfully bytesTransferred=10485760 duration=116ms transferRate=86.06MB/s file=data/file2.zip targetFolder=
2025/06/05 11:33:41 INFO Transferring file=data/file3.zip targetFolder=
2025/06/05 11:33:41 INFO File deleted file=data/file3.zip
2025/06/05 11:33:41 INFO File transferred successfully bytesTransferred=10485760 duration=96ms transferRate=104.14MB/s file=data/file3.zip targetFolder=
2025/06/05 11:33:41 INFO Transferring file=data/file1.zip targetFolder=
2025/06/05 11:33:41 INFO File deleted file=data/file1.zip
2025/06/05 11:33:41 INFO File transferred successfully bytesTransferred=10485760 duration=98ms transferRate=101.88MB/s file=data/file1.zip targetFolder=

All S3 Get Options

Section titled “All S3 Get Options”
Terminal window
Usage:
  connect get s3 [command] [flags]


Flags:
      --access-key string          S3 access key
      --bucket string              S3 bucket
      --custom-url string          S3 custom URL
      --region string              S3 region
      --secret-access-key string   S3 secret access key


Global Flags:
      --batch                     No progress bars
      --delete                    Try to delete files after successful get
  -d, --dst-folder string         Destination folder for retrieved files
      --file string               File name to be get
      --file-mask string          File mask to filter files
      --file-regex string         File regex to filter files
      --flag string               Flag file name
      --from-mail string          From mail used to send notifications (only in batch mode)
      --godebug                   Turns on debug mode
      --help                      Prints help for the command
      --log-format string         Log output format: text|json (default "text")
      --mail-format string        Mail format [text|html] (only in batch mode) (default "plain")
      --move-folder string        Folder to move files after successful get
      --no-color                  Do not use colors in logs
      --parallel uint             Number of sessions used to get files (default 1)
      --quiet                     Makes no output
  -s, --src-folder string         Folder to look for files
      --to-mail-failure strings   Email list to send failure notification (only in batch mode)
      --to-mail-success strings   Email list to send success notification (only in batch mode)

Errors

Section titled “Errors”

Please check here for information on the possible errors.