August 16, 2023

tS3List – Docs for ESB 6.x

tS3List

Lists the files on Amazon S3 based on the bucket/file prefix settings.

tS3List Standard properties

These properties are used to configure tS3List running in the Standard Job framework.

The Standard
tS3List component belongs to the Cloud family.

The component in this framework is generally available.

Basic settings

Use existing connection

Select this check box and in the Component
List
click the relevant connection component to reuse the connection
details you already defined.

Access Key

The Access Key ID that uniquely identifies an AWS Account. For how to
get your Access Key and Access Secret, visit Getting Your AWS Access Keys.

Secret Key

The Secret Access Key, constituting the security credentials in
combination with the access Key.

To enter the secret key, click the […] button next to
the secret key field, and then in the pop-up dialog box enter the password between double
quotes and click OK to save the settings.

Inherit credentials from AWS role

Select this check box to obtain AWS security credentials from Amazon EC2
instance metadata. To use this option, the Amazon EC2 instance must be started and
your Job must be running on Amazon EC2. For more information, see Using an IAM Role to Grant
Permissions to Applications Running on Amazon EC2 Instances
.

Assume role

Select this check box and specify the values for the following parameters used to
create a new assumed role session.

  • Role ARN: the Amazon Resource Name (ARN) of the
    role to assume.

  • Role session name: an identifier for the
    assumed role session.

  • Session duration (minutes): the duration (in
    minutes) for which we want to have the assumed role session to be active.

For more information about assuming roles, see AssumeRole.

Region

Specify the AWS region by selecting a region name from the list or entering
a region between double quotation marks (e.g. “us-east-1”) in the
list. For more information about the AWS Region, see Regions and Endpoints.

List all bucket objects

Select this check box to list all the files on the S3 server.

Key prefix: enter the prefix of files
to be listed. This way, only files with that prefix will be
listed.

Bucket

Click the [+] button to add one or
more lines for defining the buckets and file prefixes.

Bucket name: name of the bucket,
namely the top level folder, whose files will be listed.

Key prefix: prefix of files to be
listed.

Not available when List all bucket
objects
is selected.

Die on error

This check box is cleared by default, meaning to skip the row on error
and to complete the process for error-free rows.

Advanced settings

Config client

Select this check box to configure client parameters.

Client parameter: select client
parameters from the list.

Value: enter the parameter
value.

Not available when Use existing
connection
is selected.

STS Endpoint

Select this check box and in the field displayed, specify the AWS Security Token
Service endpoint where session credentials are retrieved from.

This check box is available only when the Assume
role
check box is selected.

tStatCatcher Statistics

Select this check box to collect log data at the component
level.

Global Variables

Global Variables

CURRENT_BUCKET: the current bucket name. This is a Flow
variable and it returns a string.

CURRENT_KEY: the current key. This is a Flow variable and
it returns a string.

NB_BUCKET: the number of buckets. This is an After
variable and it returns an integer.

NB_BUCKET_OBJECT: the number of objects in all the
buckets. This is an After variable and it returns an integer.

ERROR_MESSAGE: the error message generated by the
component when an error occurs. This is an After variable and it returns a string. This
variable functions only if the Die on error check box is
cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable
functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl +
Space
to access the variable list and choose the variable to use from it.

For further information about variables, see
Talend Studio

User Guide.

Usage

Usage rule

This component can be used alone or with other S3 components, e.g.
tS3Delete.

Dynamic settings

Click the [+] button to add a
row in the table and fill the Code field
with a context variable to choose your database connection dynamically from
multiple connections planned in your Job. This feature is useful when you
need to access database tables having the same data structure but in
different databases, especially when you are working in an environment where
you cannot change your Job settings, for example, when your Job has to be
deployed and executed independent of
Talend Studio
.

Once a dynamic parameter is defined, the Component List box in the Basic
settings
view becomes unusable.

For examples on using dynamic parameters, see Scenario: Reading data from databases through context-based dynamic connections and Scenario: Reading data from different MySQL databases using dynamically loaded connection parameters. For more information on Dynamic
settings
and context variables, see
Talend Studio User Guide
.

Limitation

Due to license incompatibility, one or more JARs required to use this component are not
provided. You can install the missing JARs for this particular component by clicking the
Install button on the Component tab view. You can also find out and add all missing JARs easily on the
Modules tab in the
Integration
perspective of your
studio. You can find more details about how to install external modules in Talend Help Center (https://help.talend.com).

Scenario: Listing files with the same prefix from a bucket

In this scenario, tS3List is used to list all the
files in a bucket which have the same prefix.

There are such files in this bucket:

use_case_ts3list_1.png

For how to create a bucket and put files into it, see Scenario: Verifing the absence of a bucket, creating it and listing all the S3 buckets and Scenario: File exchanges with Amazon S3.

Linking the components

  1. Drop tS3Connection, tS3List, tIterateToFlow,
    tLogRow and tS3Close onto the workspace.
  2. Link tS3Connection to tS3List using the OnSubjobOk trigger.
  3. Link tS3List to tIterateToFlow using the Row >
    Iterate
    connection.
  4. Link tIterateToFlow to tLogRow using the Row >
    Main
    connection.
  5. Link tS3List to tS3Close using the OnSubjobOk trigger.

    use_case_ts3list_2.png

Configuring the components

  1. Double-click tS3Connection to open its
    Basic settings view.

    use_case_ts3list_3.png

  2. In the Access Key and Secret Key fields, enter the authentication
    credentials.
  3. Double-click tS3List to open its
    Basic settings view.

    use_case_ts3list_4.png

  4. Select the Use existing connection check
    box to reuse the connection.
  5. In the Bucket area, click the [+] button to add one line.
  6. In the Bucket name and Key prefix fields, enter the bucket name and file
    prefix.

    This way, only files with the specified prefix will be listed.
  7. Double-click tIterateToFlow to open its
    Basic settings view.

    use_case_ts3list_5.png

  8. Click Edit schema to open the schema
    editor.

    use_case_ts3list_6.png

    Click the [+] button to add one column,
    namely file_list of the String
    type.
    Click Ok to validate the setup and close
    the schema editor.
  9. In the Mapping area, press Ctrl + Space in the Value field to choose the variable tS3List_1_CURRENT_KEY.
  10. Double-click tLogRow to open its
    Basic settings view.

    use_case_ts3list_7.png

    Select Table (print values in cells of a
    table)
    for a better display of the results.
  11. Double-click tS3Close to open its
    Basic settings view.

    use_case_ts3list_8.png

    There is no need to select a connection component as the only one is
    selected by default.

Executing the Job

  1. Press Ctrl + S to save the Job.
  2. Press F6 to run the Job.

    use_case_ts3list_9.png

    As shown above, only the files with the prefix “in” are listed.

Document get from Talend https://help.talend.com
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