# Blob

Kubemq blob target connector allows services using kubemq server to access blob messaging services.

## Prerequisites

The following are required to run the blob target connector:

* kubemq cluster
* Azure active storage account
* Azure active with storage enable - with access account
* kubemq-targets deployment

## Configuration

blob target connector configuration properties:

| Properties Key       | Required | Description                                           | Example                                                                         |
| -------------------- | -------- | ----------------------------------------------------- | ------------------------------------------------------------------------------- |
| storage\_account     | yes      | azure storage account name                            | "my\_account"                                                                   |
| storage\_access\_key | yes      | azure storage access key                              | "abcd1234"                                                                      |
| policy               | no       | azure blob retry policy                               | "retry\_policy\_exponential",retry\_policy\_fixed(default retry\_policy\_fixed) |
| max\_tries           | no       | try at most x times to perform the operation          | "3" default (1)                                                                 |
| try\_timeout         | no       | Maximum time allowed for any single try (Millisecond) | "600"default (1000)                                                             |
| retry\_delay         | no       | Backoff amount for each retry (Millisecond)           | "60" default (60)                                                               |
| max\_retry\_delay    | no       | Max delay between retries (Millisecond)               | "180"default (180                                                               |

Example:

```yaml
bindings:
  - name: kubemq-query-azure-blob
    source:
      kind: kubemq.query
      name: kubemq-query
      properties:
        address: "kubemq-cluster:50000"
        client_id: "kubemq-query-azure-blob-connector"
        auth_token: ""
        channel: "azure.storage.blob"
        group:   ""
        concurrency: "1"
        auto_reconnect: "true"
        reconnect_interval_seconds: "1"
        max_reconnects: "0"
    target:
      kind: azure.storage.blob
      name: azure-storage-blob
      properties:
        storage_account: "id"
        storage_access_key: "key"
```

## Usage

### Upload

Upload metadata setting:

| Metadata Key   | Required | Description                                    | Possible values                                  |
| -------------- | -------- | ---------------------------------------------- | ------------------------------------------------ |
| method         | yes      | type of method                                 | "upload"                                         |
| file\_name     | yes      | the name to upload the file under              | "myfile.txt"                                     |
| service\_url   | yes      | service url path                               | "<https://test.blob.core.windows.net/test>"      |
| data           | yes      | file data (byte array)                         | "bXktZmlsZS1kYXRh"                               |
| block\_size    | no       | specifies the block size to use                | "0" ,default(azblob.BlockBlobMaxStageBlockBytes) |
| parallelism    | no       | maximum number of blocks to upload in parallel | "upload",default(0)                              |
| blob\_metadata | no       | Key value string string of blob\_metadata      | "{"tag":"test","name":"myname"}"                 |

Example:

```javascript
{
  "metadata": {
    "method": "upload",
    "file_name": "myfile.txt",
    "service_url": "https://test.end.point.test.net/test"
  },
  "data": "bXktZmlsZS1kYXRh"
}
```

### Delete

Delete metadata setting:

| Metadata Key                    | Required | Description                    | Possible values                             |
| ------------------------------- | -------- | ------------------------------ | ------------------------------------------- |
| method                          | yes      | type of method                 | "delete"                                    |
| file\_name                      | yes      | the name of the file to delete | "myfile.txt"                                |
| service\_url                    | yes      | service url path               | "<https://test.blob.core.windows.net/test>" |
| delete\_snapshots\_option\_type | no       | type of method                 | "only","include","" (default "")            |

Example:

```javascript
{
  "metadata": {
    "method": "delete",
    "file_name": "myfile.txt",
    "service_url": "https://test.end.point.test.net/test"
  },
  "data": null
}
```

### get

For more information, see <https://docs.microsoft.com/rest/api/storageservices/get-blob> get metadata setting:

| Metadata Key        | Required | Description                    | Possible values                               |
| ------------------- | -------- | ------------------------------ | --------------------------------------------- |
| method              | yes      | type of method                 | "get"                                         |
| file\_name          | yes      | the name of the file to get    | "myfile.txt"                                  |
| service\_url        | yes      | service url path               | "<https://test.blob.core.windows.net/test>"   |
| max\_retry\_request | no       | type of method                 | "20" (default "1")                            |
| count               | no       | number of files to get         | "20" (will get all from offset)               |
| offset              | no       | start reading blob from offset | "20" (will start from the first byte in blob) |

Example:

```javascript
{
  "metadata": {
    "method": "get",
    "file_name": "myfile.txt",
    "service_url": "https://test.end.point.test.net/test"
  },
  "data": null
}
```