Skip to content
Connect

Sending data to an S3 bucket

Connecting to an S3 bucket

Section titled “Connecting to an S3 bucket”

To send data to an S3 bucket, you need to execute connect send 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

Sending single file to an S3 bucket

Section titled “Sending single file to an S3 bucket”

To send a single file to an S3 bucket you should use

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

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

Terminal window
$ connect send s3 --file file1.zip --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/03 11:05:15 INFO Sending files to s3://my-s3-bucket/
2025/06/03 11:05:15 INFO Files to send: count=1
[file1.zip] 10.00 MiB / 10.00 MiB done

Sending multiple files to an S3 bucket

Section titled “Sending multiple files to an S3 bucket”

If you’d like to send multiple files to 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 cause all files that match a certain mask or pattern to be sent. You can also provide an optional source folder that contain the files to be sent:

  • -s, --src-folder

If you don’t provide the source folder files will be sent from the current folder.

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

Terminal window
$ connect send s3 --file-mask "*.zip" -s /data --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/03 11:06:15 INFO Sending files to s3://my-s3-bucket/
2025/06/03 11:06:15 INFO Files to send: count=3
[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 on S3 bucket:

  • -d, --dst-folder

If you don’t provide the destination folder files will be sent to the “root folder” of the S3 bucket (top-level of the S3 bucket).

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

Terminal window
$ connect send s3 --file-regex ".+\.zip" -s /data -d remote --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/03 11:07:04 INFO Sending files to s3://my-s3-bucket/
2025/06/03 11:07:04 INFO Files to send: count=3
[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

Sending files in batch mode to an S3 bucket

Section titled “Sending files in batch mode to an S3 bucket”

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 send files in batch mode

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

Terminal window
$ connect send s3 --file-mask "*.zip" -s /data -d remote --batch --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/03 11:07:51 INFO Sending files to s3://my-s3-bucket/remote
2025/06/03 11:07:51 INFO Files to send: count=3
2025/06/03 11:07:51 INFO Transferring file=file1.zip targetFolder=remote
2025/06/03 11:07:52 INFO File transferred successfully bytesTransferred=10485760 duration=173ms transferRate=57.80MB/s file=file1.zip targetFolder=remote
2025/06/03 11:07:52 INFO Transferring file=file2.zip targetFolder=remote
2025/06/03 11:07:52 INFO File transferred successfully bytesTransferred=10485760 duration=128ms transferRate=78.10MB/s file=file2.zip targetFolder=remote
2025/06/03 11:07:52 INFO Transferring file=file3.zip targetFolder=remote
2025/06/03 11:07:52 INFO File transferred successfully bytesTransferred=10485760 duration=126ms transferRate=78.81MB/s file=file3.zip targetFolder=remote

Sending files from scheduler to an S3 bucket

Section titled “Sending files from scheduler to an S3 bucket”

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

Terminal window
$ connect send s3 --flag /tmp/flag1 --batch --file-mask "*.zip" -s /data -d remote --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/03 11:09:49 INFO Using flag file: /tmp/flag1
2025/06/03 11:09:49 INFO Sending files to s3://my-s3-bucket/remote
2025/06/03 11:09:49 INFO Files to send: count=3
2025/06/03 11:09:49 INFO Transferring file=file1.zip targetFolder=remote
2025/06/03 11:09:50 INFO File transferred successfully bytesTransferred=10485760 duration=194ms transferRate=51.32MB/s file=file1.zip targetFolder=remote
2025/06/03 11:09:50 INFO Transferring file=file2.zip targetFolder=remote
2025/06/03 11:09:50 INFO File transferred successfully bytesTransferred=10485760 duration=139ms transferRate=71.70MB/s file=file2.zip targetFolder=remote
2025/06/03 11:09:50 INFO Transferring file=file3.zip targetFolder=remote
2025/06/03 11:09:50 INFO File transferred successfully bytesTransferred=10485760 duration=129ms transferRate=76.98MB/s file=file3.zip targetFolder=remote
2025/06/03 11:09:50 INFO Removing flag file: /tmp/flag1

Sending files in parallel to an S3 bucket

Section titled “Sending files in parallel to an S3 bucket”

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

  • --parallel number of S3 sessions

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

Terminal window
$ connect send s3 --file-mask "*.zip" -s /data -d remote --batch --parallel 3 --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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
2025/06/03 11:10:53 INFO Sending files to s3://my-s3-bucket/remote
2025/06/03 11:10:53 INFO Files to send: count=3
2025/06/03 11:10:53 INFO Transferring file=file1.zip targetFolder=remote
2025/06/03 11:10:53 INFO Transferring file=file3.zip targetFolder=remote
2025/06/03 11:10:53 INFO Transferring file=file2.zip targetFolder=remote
2025/06/03 11:10:53 INFO File transferred successfully bytesTransferred=10485760 duration=321ms transferRate=31.07MB/s file=file2.zip targetFolder=remote
2025/06/03 11:10:53 INFO File transferred successfully bytesTransferred=10485760 duration=322ms transferRate=30.98MB/s file=file3.zip targetFolder=remote
2025/06/03 11:10:53 INFO File transferred successfully bytesTransferred=10485760 duration=323ms transferRate=30.92MB/s file=file1.zip targetFolder=remote

Sending files in sequence to an S3 bucket

Section titled “Sending files in sequence to an S3 bucket”

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

Action after file is delivered to an S3 bucket

Section titled “Action after file is delivered to an S3 bucket”

After file is successfully delivered to remote location 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 delivered
  • --move-folder target folder to move the file after it’s delivered

Following command will send all .zip files from the /data folder to the remote folder of S3 bucket my-s3-bucket in eu-central-1 region using 3 parallel sessions and then move the files to /archive at the source system.

Terminal window
$ connect send s3 --file-mask "*.zip" -s /data -d remote --batch --parallel 3 --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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 --move-folder /archive
2025/06/03 11:20:30 INFO Sending files to s3://my-s3-bucket/remote
2025/06/03 11:20:30 INFO Creating folder to move files after successful send
2025/06/03 11:20:30 INFO Files to send: count=3
2025/06/03 11:20:30 INFO Transferring file=file3.zip targetFolder=remote
2025/06/03 11:20:30 INFO Transferring file=file2.zip targetFolder=remote
2025/06/03 11:20:30 INFO Transferring file=file1.zip targetFolder=remote
2025/06/03 11:20:30 INFO File moved to folder folder=/archive file=file1.zip
2025/06/03 11:20:30 INFO File transferred successfully bytesTransferred=10485760 duration=344ms transferRate=29.02MB/s file=file1.zip targetFolder=remote
2025/06/03 11:20:30 INFO File moved to folder folder=/archive file=file2.zip
2025/06/03 11:20:30 INFO File transferred successfully bytesTransferred=10485760 duration=345ms transferRate=28.95MB/s file=file2.zip targetFolder=remote
2025/06/03 11:20:30 INFO File moved to folder folder=/archive file=file3.zip
2025/06/03 11:20:30 INFO File transferred successfully bytesTransferred=10485760 duration=346ms transferRate=28.89MB/s file=file3.zip targetFolder=remote

Following command will send all .zip files from the /data folder to the remote folder of S3 bucket my-s3-bucket in eu-central-1 region using 3 parallel sessions and then removes the files from source.

Terminal window
$ connect send s3 --file-mask "*.zip" -s /data -d remote --batch --parallel 3 --bucket my-s3-bucket --region eu-central-1 --access-key AKIA4YINCR26KRN42IDA --secret-access-key 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 --delete
2025/06/03 11:22:10 INFO Sending files to s3://my-s3-bucket/remote
2025/06/03 11:22:10 INFO Files to send: count=3
2025/06/03 11:22:10 INFO Transferring file=file3.zip targetFolder=remote
2025/06/03 11:22:10 INFO Transferring file=file2.zip targetFolder=remote
2025/06/03 11:22:10 INFO Transferring file=file1.zip targetFolder=remote
2025/06/03 11:22:10 INFO File deleted file=file2.zip
2025/06/03 11:22:10 INFO File transferred successfully bytesTransferred=10485760 duration=327ms transferRate=30.52MB/s file=file2.zip targetFolder=remote
2025/06/03 11:22:10 INFO File deleted file=file1.zip
2025/06/03 11:22:10 INFO File transferred successfully bytesTransferred=10485760 duration=335ms transferRate=29.83MB/s file=file1.zip targetFolder=remote
2025/06/03 11:22:10 INFO File deleted file=file3.zip
2025/06/03 11:22:10 INFO File transferred successfully bytesTransferred=10485760 duration=335ms transferRate=29.83MB/s file=file3.zip targetFolder=remote

All S3 Send Options

Section titled “All S3 Send Options”
Terminal window
Usage:
  connect send 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                    Delete files after successful send
  -d, --dst-folder string         Folder where files should be sent
      --file string               File name to be sent
      --file-mask string          File mask to filter files for sending
      --file-regex string         File regex to filter files for sending
      --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 send
      --no-color                  Do not use colors in logs
      --parallel uint             Number of sessions used to send files (default 1)
      --quiet                     Makes no output
  -s, --src-folder string         Folder containing files to be sent (default "./")
      --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.