Azure Blob Storage connector

Azure Blob Storage connector

The Azure Blob connector writes one blob for each rule result. It signs each request with the storage account shared key.

Use it when cold storage must keep telemetry files in Azure. You get one blob under the container and blob name that the action names.

flowchart LR
    Rule["rule engine"] -- "action parameters" --> Action["azure_blob action"]
    Action -- "container and blob template" --> Sink["azure_blob sink"]
    Sink -- "Put Blob SharedKey" --> Blob["storage account blob"]

Before you start

• Create a storage account and a container.
• Note the account name and the account key.
• For a full build, enable --features azure_blob. The default build answers 400 and names the feature.

Settings

The connector holds the account. The action holds the container and blob name.

Connector setting	Required	Meaning
account_name	yes	Storage account name.
account_key	yes	Base64 storage account key.
endpoint	no	Custom endpoint, for example a local emulator.

Action setting	Required	Meaning
container	yes	Target container.
blob	yes	Blob name template.
content	no	Only the documented default ${.} is supported.

Example action:

{
  "name": "azure-cold",
  "type": "azure_blob_storage",
  "connector": "azure-account",
  "parameters": {"container": "telemetry", "blob": "event/${topic}/${timestamp}.json"}
}

Limits

• A missing account, key, container or blob answers 400 and names the field.
• A custom content, headers or ACL value is refused. The driver writes the projected event body.
• The data path keeps the action key, the container and the blob from the action. It invents no target.

Next steps

• Feed the connector from a rule in Actions.
• See every kind in Connectors.

Check that it works

Create the connector. The broker answers 201 with the kind when the build holds the feature, else 400 names it. Both answers print ok.

[node]
id = "docs-connector-azure-blob"

[listeners.tcp]
bind = "0.0.0.0:1883"

[listeners.api]
bind = "0.0.0.0:18083"

[logging]
level = "warn"

[auth]
allow_anonymous = true

python3 - <<'PY'
import json, os, urllib.request
port = os.environ.get("API_PORT", "18083")
key = os.environ["API_KEY"]
body = json.dumps({"name": "docs-azure-1", "type": "azure_blob",
                   "account_name": "mydeviceblobs", "account_key": "YUtJRA=="}).encode()
req = urllib.request.Request(
    f"http://127.0.0.1:{port}/api/v5/connectors", data=body, method="POST",
    headers={"Authorization": f"Bearer {key}", "Content-Type": "application/json"})
try:
    with urllib.request.urlopen(req, timeout=5) as res:
        status, created = res.status, json.load(res)
except urllib.error.HTTPError as err:
    status, created = err.code, json.load(err)
assert status in (201, 400), (status, created)
if status == 201:
    assert created["type"] == "azure_blob", created
else:
    assert "azure" in created["message"], created
print("ok")
PY

ok