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Azure Blob Storage

Cribl Stream supports collecting data, and replaying specific events, both from Azure Blob Storage, and from Azure Data Lake Storage Gen2, which implements a hierarchical namespace over blob data. This page covers how to configure the Collector.

Configuring an Azure Blob Storage Collector
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From the top nav, click Manage, then select a Worker Group to configure. Next, select Data > Sources, then select Collectors > Azure Blob from the Manage Sources page’s tiles or left nav. Click Add Collector to open the Azure Blob > New Collector modal, which provides the following options and fields.

The sections described below are spread across several tabs. Click the tab links at left to navigate among tabs. Click Save when you’ve configured your Collector.

Collector Sources currently cannot be selected or enabled in the QuickConnect UI.

Cribl Stream supports data collection and replay from Azure’s hot and cool access tiers, but not from the archive tier – whose stated retrieval lag, up to several hours, cannot guarantee data availability.

Collector Settings
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The Collector Settings determine how data is collected before processing.

Collector ID: Unique ID for this Collector. E.g., azure_42-a.

Auto-populate from: Optionally, select a predefined Destination that will be used to auto-populate Collector settings. Useful when replaying data.

Container name: Container to collect from. This value can be a constant, or a JavaScript expression that can be evaluated only at init time. E.g., referencing a Global Variable: myBucket-${C.vars.myVar}.

Container names can include only lowercase letters, numbers, and/or hyphens (-). This restriction is imposed by Azure.

Authentication
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Use the Authentication method buttons to select one of these options:

  • Manual: Use this default option to enter your Azure Storage connection string directly. Exposes a Connection string field for this purpose. (If left blank, Cribl Stream will fall back to env.AZURE_STORAGE_CONNECTION_STRING.)

  • Secret: This option exposes a Connection string (text secret) drop-down, in which you can select a stored secret that references an Azure Storage connection string. The secret can reside in Cribl Stream’s internal secrets manager or (if enabled) in an external KMS. A Create link is available if you need to generate a new secret.

Using Shared Access Signature
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You can authenticate for Azure Blob Storage using a shared access signature token as connection string.

To employ it successfully, go to your storage account’s Shared access signature settings and make sure that Allowed blob index permissions enables both Read/Write and Filter.

If you are using Azure Premium storage, you can’t set blob index permissions. In such a case, in your collector’s setting, enable the Include Metadata option. This will allow you to use shared access signature, but as side effect will strip defined tags for downloaded blobs.

Optional Settings
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Path: The directory from which to collect data. Templating is supported (e.g., myDir/${datacenter}/${host}/${app}/). Time-based tokens are also supported (e.g., myOtherDir/${_time:%Y}/${_time:%m}/${_time:%d}/). More on templates and Filters.

Path extractors: Extractors allow using template tokens as context for expressions that enrich discovery results.

Click Add Extractor to add each extractor as a key-value pair, mapping a Token name on the left (of the form /<path>/${<token>}) to a custom JavaScript Extractor expression on the right (e.g., {host: value.toLowerCase()}).

Each expression accesses its corresponding <token> through the value variable, and evaluates the token to populate event fields. Here is a complete example:

TokenExpressionMatched ValueExtracted Result
/var/log/${foobar}{program: value.split('.')[0]}/var/log/syslog.1{program: syslog, foobar: syslog.1}

Recursive: If set to Yes (the default), data collection will recurse through subdirectories.

Include metadata: With the default Yes setting, Cribl Stream will include Azure Blob metadata in collected events (at __collectible.metadata).

Include tags: With the default Yes setting, Cribl Stream will include Azure Blob tags in collected events (at __collectible.tags). To prevent errors, toggle this to No when using a Shared Access Signature connection string, especially on storage accounts that do not support Azure Blob index tags.

Max batch size (objects): Maximum number of metadata objects to batch before recording as results. Defaults to 10. To override this limit in the Collector’s Schedule/Run modal, use Advanced Settings > Upper task bundle size.

Tags: Optionally, add tags that you can use to filter and group Sources in Cribl Stream’s Manage Sources page. These tags aren’t added to processed events. Use a tab or hard return between (arbitrary) tag names.

Connection String Format
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Either authentication method uses an Azure Storage connection string in this format: DefaultEndpointsProtocol=[http|https];AccountName=<your‑account‑name>;AccountKey=<your‑account‑key>

A fictitious example, using Microsoft’s recommended HTTPS option, is: DefaultEndpointsProtocol=https;AccountName=storagesample;AccountKey=12345678...32

Result Settings
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The Result Settings determine how Cribl Stream transforms and routes the collected data.

Custom Command
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In this section, you can pass the data from this input to an external command for processing, before the data continues downstream.

Enabled: Defaults to No. Toggle to Yes to enable the custom command.

Command: Enter the command that will consume the data (via stdin) and will process its output (via stdout).

Arguments: Click Add Argument to add each argument to the command. You can drag arguments vertically to resequence them.

Event Breakers
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In this section, you can apply event breaking rules to convert data streams to discrete events.

Event Breaker rulesets: A list of event breaking rulesets that will be applied, in order, to the input data stream. Defaults to System Default Rule.

Event Breaker buffer timeout: How long (in milliseconds) the Event Breaker will wait for new data to be sent to a specific channel, before flushing out the data stream, as-is, to the Routes. Minimum 10 ms, default 10000 (10 sec), maximum 43200000 (12 hours).

Fields
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In this section, you can add Fields to each event, using Eval-like functionality.

Name: Field name.

Value: JavaScript expression to compute the field’s value (can be a constant).

Result Routing
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Send to Routes: If set to Yes (the default), Cribl Stream will send events to normal routing and event processing. Toggle to No to select a specific Pipeline/Destination combination. The No setting exposes these two additional fields:

  • Pipeline: Select a Pipeline to process results.
  • Destination: Select a Destination to receive results.

The default Yes setting instead exposes this field:

  • Pre-processing Pipeline: Pipeline to process results before sending to Routes. Optional.

This field is always exposed:

  • Throttling: Rate (in bytes per second) to throttle while writing to an output. Also takes values with multiple-byte units, such as KB, MB, GB, etc. (Example: 42 MB.) Default value of 0 indicates no throttling.

You might disable Send to Routes when configuring a Collector that will connect data from a specific Source to a specific Pipeline and Destination. This keeps the Collector’s configuration self‑contained and separate from Cribl Stream’s routing table for live data – potentially simplifying the Routes structure.

Advanced Settings
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Advanced Settings enable you to customize post-processing and administrative options.

Environment: If you’re using GitOps, optionally use this field to specify a single Git branch on which to enable this configuration. If empty, the config will be enabled everywhere.

Time to live: How long to keep the job’s artifacts on disk after job completion. This also affects how long a job is listed in Job Inspector. Defaults to 4h.

Remove Discover fields: List of fields to remove from the Discover results. This is useful when discovery returns sensitive fields that should not be exposed in the Jobs user interface. You can specify wildcards (such as aws*).

Resume job on boot: Toggle to Yes to resume ad hoc collection jobs if Cribl Stream restarts during the jobs’ execution.

Replay
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See these resources that demonstrate how to replay data from object storage. Both are written around Amazon S3-compatible stores, but the general principles apply to Azure blobs as well:

How the Collector Pulls Data
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In the Discover phase, the first available Worker returns the list of files to the Leader Node. In the Collect phase, Cribl Stream spreads the list of files to process spread across 1..N Workers, based on file size, with the goal of distributing tasks as evenly as possible across Workers. These Workers then stream in their assigned files from the remote Azure Blob Storage location.

Proxying Requests
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If you need to proxy HTTP/S requests, see System Proxy Configuration.

Troubleshooting
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When permissions are correct on the object store, and events are reaching the Collector, the Preview pane will show events and the Job Inspector will show an Events collected count.

However, if previewing returns no events and throws no error, first check your Filter expression by previewing without it (e.g., simplify the Filter expression to true). Then check the Job Inspector: If the Total size is greater than 0, and the Received size is NA or 0, make sure you have list and read permissions on the object store.