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azure_cosmosdb input

Executes a SQL query against Azure CosmosDB and creates a batch of messages from each page of items.

# Common config fields, showing default values
input:
  label: ""
  azure_cosmosdb:
    endpoint: "" # No default (optional)
    account_key: "" # No default (optional)
    connection_string: "" # No default (optional)
    database: "" # No default (required)
    container: "" # No default (required)
    partition_keys_map: "" # No default (required)
    query: "" # No default (required)
    args_mapping: "" # No default (optional)
    auto_replay_nacks: true

Cross-partition queries​

Cross-partition queries are currently not supported by the underlying driver. For every query, the PartitionKey values must be known in advance and specified in the config. See details.

Credentials​

You can use one of the following authentication mechanisms:

  • Set the endpoint field and the account_key field
  • Set only the endpoint field to use DefaultAzureCredential
  • Set the connection_string field

Metadata​

This component adds the following metadata fields to each message:

- activity_id
- request_charge

You can access these metadata fields using function interpolation.

Examples​

Query container​

Execute a parametrized SQL query to select documents from a container.

input:
  azure_cosmosdb:
    endpoint: http://localhost:8080
    account_key: C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==
    database: blobbase
    container: blobfish
    partition_keys_map: root = "AbyssalPlain"
    query: SELECT * FROM blobfish AS b WHERE b.species = @species
    args_mapping: |
      root = [
          { "Name": "@species", "Value": "smooth-head" },
      ]

Fields​

endpoint​

CosmosDB endpoint.

Type: string

account_key​

Account key.

Secret

This field contains sensitive information. Use a secret reference rather than a literal value.

Type: string

connection_string​

Connection string.

Secret

This field contains sensitive information. Use a secret reference rather than a literal value.

Type: string

database​

Database.

Type: string

container​

Container.

Type: string

partition_keys_map​

A Bloblang mapping which should evaluate to a single partition key value or an array of partition key values of type string, integer or boolean. Currently, hierarchical partition keys are not supported so only one value may be provided.

Type: string

query​

The query to execute

Type: string

args_mapping​

A Bloblang mapping that, for each message, creates a list of arguments to use with the query.

Type: string

batch_count​

The maximum number of messages that should be accumulated into each batch. Use '-1' specify dynamic page size.

Type: int
Default: -1

auto_replay_nacks​

Whether messages that are rejected (nacked) at the output level should be automatically replayed indefinitely, eventually resulting in back pressure if the cause of the rejections is persistent. If set to false these messages will instead be deleted. Disabling auto replays can greatly improve memory efficiency of high throughput streams as the original shape of the data can be discarded immediately upon consumption and mutation.

Type: bool
Default: true

CosmosDB emulator​

If you wish to run the CosmosDB emulator that is referenced in the documentation here, the following Docker command should do the trick:

> docker run --rm -it -p 8081:8081 --name=cosmosdb -e AZURE_COSMOS_EMULATOR_PARTITION_COUNT=10 -e AZURE_COSMOS_EMULATOR_ENABLE_DATA_PERSISTENCE=false mcr.microsoft.com/cosmosdb/linux/azure-cosmos-emulator

Note: AZURE_COSMOS_EMULATOR_PARTITION_COUNT controls the number of partitions that will be supported by the emulator. The bigger the value, the longer it takes for the container to start up.

Additionally, instead of installing the container self-signed certificate which is exposed via https://localhost:8081/_explorer/emulator.pem, you can run mitmproxy like so:

> mitmproxy -k --mode "reverse:https://localhost:8081"

Then you can access the CosmosDB UI via http://localhost:8080/_explorer/index.html and use http://localhost:8080 as the CosmosDB endpoint.