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Azure Blob Storage

Availability:
Available Airbyte CloudAvailable Airbyte OSSAvailable PyAirbyte
Support Level:
certified
Connector Version:
0.4.4

This page contains the setup guide and reference information for the Azure Blob Storage source connector.

info

Cloud storage may incur egress costs. Egress refers to data that is transferred out of the cloud storage system, such as when you download files or access them from a different location. For more information, see the Azure Blob Storage pricing guide.

Prerequisites​

Minimum permissions (role Storage Blob Data Reader ):

[
   {
      "actions": [
         "Microsoft.Storage/storageAccounts/blobServices/containers/read",
         "Microsoft.Storage/storageAccounts/blobServices/generateUserDelegationKey/action"
      ],
      "notActions": [],
      "dataActions": [
         "Microsoft.Storage/storageAccounts/blobServices/containers/blobs/read"
      ],
      "notDataActions": []
   }
]

Setup guide​

Step 1: Set up Azure Blob Storage​

  • Create a storage account with the permissions details
warning

To use Oauth 2.0 Authentication method, Access Control (IAM) should be setup. It is recommended to use role Storage Blob Data Reader

Follow these steps to set up an IAM role:

  1. Go to Azure portal, select the Storage (or Container) you'd like to sync from and get to Access Control(IAM) -> Role Assignment Access Control (IAM)
  2. Click on Add and select Add role assignment from the dropdown list Add role assignment
  3. Search by role name Storage Blob Data Reader in search box, Select role from the list and click Next Search Role
  4. Select User, Group, or service principal, click on members and select member(s) so they appear in table and click Next Add Members
  5. (Optional) Add Conditions to restrict the role assignments a user can create.
  6. Click Review + Assign

Step 2: Set up the Azure Blob Storage connector in Airbyte​

  1. Log in to your Airbyte Cloud account, or navigate to your Airbyte Open Source dashboard.
  2. In the left navigation bar, click Sources. In the top-right corner, click + New source.
  3. Find and select Azure Blob Storage from the list of available sources.
  4. Enter the name of your Azure Account.
  5. Enter your Tenant ID and Click Authenticate your Azure Blob Storage account.
  6. Log in and authorize the Azure Blob Storage account.
  7. Enter the name of the Container containing your files to replicate.
  8. Add a stream
    1. Write the File Type
    2. In the Format box, use the dropdown menu to select the format of the files you'd like to replicate. The supported formats are CSV, Parquet, Avro and JSONL. Toggling the Optional fields button within the Format box will allow you to enter additional configurations based on the selected format. For a detailed breakdown of these settings, refer to the File Format section below.
    3. Give a Name to the stream
    4. (Optional)—If you want to enforce a specific schema, you can enter a Input schema. By default, this value is set to {} and will automatically infer the schema from the file(s) you are replicating. For details on providing a custom schema, refer to the User Schema section.
    5. Optionally, enter the Globs which dictates which files to be synced. This is a regular expression that allows Airbyte to pattern match the specific files to replicate. If you are replicating all the files within your bucket, use ** as the pattern. For more precise pattern matching options, refer to the Path Patterns section below.
  9. (Optional) Enter the endpoint to use for the data replication.
  10. (Optional) Enter the desired start date from which to begin replicating data.

Supported Streams​

The Azure Blob Storage source connector supports the following sync modes:

FeatureSupported?
Full Refresh SyncYes
Incremental SyncYes
Replicate Incremental DeletesNo
Replicate Multiple Files (pattern matching)Yes
Replicate Multiple Streams (distinct tables)Yes
NamespacesNo

File Compressions​

CompressionSupported?
GzipYes
ZipNo
Bzip2Yes
LzmaNo
XzNo
SnappyNo

Please let us know any specific compressions you'd like to see support for next!

Path Patterns​

(tl;dr -> path pattern syntax using wcmatch.glob. GLOBSTAR and SPLIT flags are enabled.)

This connector can sync multiple files by using glob-style patterns, rather than requiring a specific path for every file. This enables:

  • Referencing many files with just one pattern, e.g. ** would indicate every file in the bucket.
  • Referencing future files that don't exist yet (and therefore don't have a specific path).

You must provide a path pattern. You can also provide many patterns split with | for more complex directory layouts.

Each path pattern is a reference from the root of the bucket, so don't include the bucket name in the pattern(s).

Some example patterns:

  • ** : match everything.
  • **/*.csv : match all files with specific extension.
  • myFolder/**/*.csv : match all csv files anywhere under myFolder.
  • */** : match everything at least one folder deep.
  • */*/*/** : match everything at least three folders deep.
  • **/file.*|**/file : match every file called "file" with any extension (or no extension).
  • x/*/y/* : match all files that sit in folder x -> any folder -> folder y.
  • **/prefix*.csv : match all csv files with specific prefix.
  • **/prefix*.parquet : match all parquet files with specific prefix.

Let's look at a specific example, matching the following bucket layout:

myBucket
    -> log_files
    -> some_table_files
        -> part1.csv
        -> part2.csv
    -> images
    -> more_table_files
        -> part3.csv
    -> extras
        -> misc
            -> another_part1.csv

We want to pick up part1.csv, part2.csv and part3.csv (excluding another_part1.csv for now). We could do this a few different ways:

  • We could pick up every csv file called "partX" with the single pattern **/part*.csv.
  • To be a bit more robust, we could use the dual pattern some_table_files/*.csv|more_table_files/*.csv to pick up relevant files only from those exact folders.
  • We could achieve the above in a single pattern by using the pattern *table_files/*.csv. This could however cause problems in the future if new unexpected folders started being created.
  • We can also recursively wildcard, so adding the pattern extras/**/*.csv would pick up any csv files nested in folders below "extras", such as "extras/misc/another_part1.csv".

As you can probably tell, there are many ways to achieve the same goal with path patterns. We recommend using a pattern that ensures clarity and is robust against future additions to the directory structure.

User Schema​

Providing a schema allows for more control over the output of this stream. Without a provided schema, columns and datatypes will be inferred from the first created file in the bucket matching your path pattern and suffix. This will probably be fine in most cases but there may be situations you want to enforce a schema instead, e.g.:

  • You only care about a specific known subset of the columns. The other columns would all still be included, but packed into the _ab_additional_properties map.
  • Your initial dataset is quite small (in terms of number of records), and you think the automatic type inference from this sample might not be representative of the data in the future.
  • You want to purposely define types for every column.
  • You know the names of columns that will be added to future data and want to include these in the core schema as columns rather than have them appear in the _ab_additional_properties map.

Or any other reason! The schema must be provided as valid JSON as a map of {"column": "datatype"} where each datatype is one of:

  • string
  • number
  • integer
  • object
  • array
  • boolean
  • null

For example:

  • {"id": "integer", "location": "string", "longitude": "number", "latitude": "number"}
  • {"username": "string", "friends": "array", "information": "object"}

File Format Settings​

CSV​

Since CSV files are effectively plain text, providing specific reader options is often required for correct parsing of the files. These settings are applied when a CSV is created or exported so please ensure that this process happens consistently over time.

  • Header Definition: How headers will be defined. User Provided assumes the CSV does not have a header row and uses the headers provided and Autogenerated assumes the CSV does not have a header row and the CDK will generate headers using for f{i} where i is the index starting from 0. Else, the default behavior is to use the header from the CSV file. If a user wants to autogenerate or provide column names for a CSV having headers, they can set a value for the "Skip rows before header" option to ignore the header row.
  • Delimiter: Even though CSV is an acronym for Comma Separated Values, it is used more generally as a term for flat file data that may or may not be comma separated. The delimiter field lets you specify which character acts as the separator. To use tab-delimiters, you can set this value to \t. By default, this value is set to ,.
  • Double Quote: This option determines whether two quotes in a quoted CSV value denote a single quote in the data. Set to True by default.
  • Encoding: Some data may use a different character set (typically when different alphabets are involved). See the list of allowable encodings here. By default, this is set to utf8.
  • Escape Character: An escape character can be used to prefix a reserved character and ensure correct parsing. A commonly used character is the backslash (\). For example, given the following data:
Product,Description,Price
Jeans,"Navy Blue, Bootcut, 34\"",49.99

The backslash (\) is used directly before the second double quote (") to indicate that it is not the closing quote for the field, but rather a literal double quote character that should be included in the value (in this example, denoting the size of the jeans in inches: 34" ).

Leaving this field blank (default option) will disallow escaping.

  • False Values: A set of case-sensitive strings that should be interpreted as false values.
  • Null Values: A set of case-sensitive strings that should be interpreted as null values. For example, if the value 'NA' should be interpreted as null, enter 'NA' in this field.
  • Quote Character: In some cases, data values may contain instances of reserved characters (like a comma, if that's the delimiter). CSVs can handle this by wrapping a value in defined quote characters so that on read it can parse it correctly. By default, this is set to ".
  • Skip Rows After Header: The number of rows to skip after the header row.
  • Skip Rows Before Header: The number of rows to skip before the header row.
  • Strings Can Be Null: Whether strings can be interpreted as null values. If true, strings that match the null_values set will be interpreted as null. If false, strings that match the null_values set will be interpreted as the string itself.
  • True Values: A set of case-sensitive strings that should be interpreted as true values.

Parquet​

Apache Parquet is a column-oriented data storage format of the Apache Hadoop ecosystem. It provides efficient data compression and encoding schemes with enhanced performance to handle complex data in bulk. At the moment, partitioned parquet datasets are unsupported. The following settings are available:

  • Convert Decimal Fields to Floats: Whether to convert decimal fields to floats. There is a loss of precision when converting decimals to floats, so this is not recommended.

Avro​

The Avro parser uses the Fastavro library. The following settings are available:

  • Convert Double Fields to Strings: Whether to convert double fields to strings. This is recommended if you have decimal numbers with a high degree of precision because there can be a loss precision when handling floating point numbers.

JSONL​

There are currently no options for JSONL parsing.

Document File Type Format (Experimental)​

warning

The Document File Type Format is currently an experimental feature and not subject to SLAs. Use at your own risk.

The Document File Type Format is a special format that allows you to extract text from Markdown, TXT, PDF, Word and Powerpoint documents. If selected, the connector will extract text from the documents and output it as a single field named content. The document_key field will hold a unique identifier for the processed file which can be used as a primary key. The content of the document will contain markdown formatting converted from the original file format. Each file matching the defined glob pattern needs to either be a markdown (md), PDF (pdf), Word (docx) or Powerpoint (.pptx) file.

One record will be emitted for each document. Keep in mind that large files can emit large records that might not fit into every destination as each destination has different limitations for string fields.

Parsing via Unstructured.io Python Library​

This connector utilizes the open source Unstructured library to perform OCR and text extraction from PDFs and MS Word files, as well as from embedded tables and images. You can read more about the parsing logic in the Unstructured docs and you can learn about other Unstructured tools and services at www.unstructured.io.

Performance considerations​

The Azure Blob Storage connector should not encounter any Microsoft API limitations under normal usage.

Reference​

Config fields reference

Field
Type
Property name
array<object>
streams
object
credentials
string
azure_blob_storage_account_name
string
azure_blob_storage_container_name
string
start_date
string
azure_blob_storage_endpoint

Changelog​

Expand to review
VersionDatePull RequestSubject
0.4.32024-05-2938701Avoid error on empty stream when running discover
0.4.22024-04-2337504Update specification
0.4.12024-04-2237467Fix start date filter
0.4.02024-04-0536825Add oauth 2.0 support
0.3.62024-04-0336542Use Latest CDK; add integration tests
0.3.52024-03-2636487Manage dependencies with Poetry.
0.3.42024-02-0634936Bump CDK version to avoid missing SyncMode errors
0.3.32024-01-3034681Unpin CDK version to make compatible with the Concurrent CDK
0.3.22024-01-3034661Pin CDK version until upgrade for compatibility with the Concurrent CDK
0.3.12024-01-1034084Fix bug for running check with document file format
0.3.02023-12-1433411Bump CDK version to auto-set primary key for document file streams and support raw txt files
0.2.52023-12-0633187Bump CDK version to hide source-defined primary key
0.2.42023-11-1632608Improve document file type parser
0.2.32023-11-1332357Improve spec schema
0.2.22023-10-3031904Update CDK to support document file types
0.2.12023-10-1831543Base image migration: remove Dockerfile and use the python-connector-base image
0.2.02023-10-1031336Migrate to File-based CDK. Add support of CSV, Parquet and Avro files
0.1.02023-02-1723222Initial release with full-refresh and incremental sync with JSONL files
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