Setup Azure Blob Storage Docs (#714)

* Setup Azure Blob Storage Docs

* Add link in read me of how to setup state store

howto/setup-state-store/README.md

@@ -61,5 +61,6 @@ kubectl apply -f statestore.yaml
 * [Setup Azure CosmosDB](./setup-azure-cosmosdb.md)
 * [Setup Azure SQL Server](./setup-sqlserver.md)
 * [Setup Azure Table Storage](./setup-azure-tablestorage.md)
+* [Setup Azure Blob Storage](./setup-azure-blobstorage.md)
 * [Setup Google Cloud Firestore (Datastore mode)](./setup-firestore.md)
 * [Supported State Stores](./supported-state-stores.md)

howto/setup-state-store/setup-azure-blobstorage.md

@@ -0,0 +1,95 @@
+# Setup Azure Blob Storage 
+
+## Creating Azure Storage account
+
+[Follow the instructions](https://docs.microsoft.com/en-us/azure/storage/common/storage-account-create?tabs=azure-portal) from the Azure documentation on how to create an Azure Storage Account. 
+
+If you wish to create a container for Dapr to use, you can do so beforehand. However, Blob Storage state provider will create one for you automatically if it doesn't exist.
+
+In order to setup Azure Blob Storage as a state store, you will need the following properties:
+
+* **AccountName**: The storage account name. For example: **mystorageaccount**. 
+* **AccountKey**: Primary or secondary storage key.
+* **ContainerName**: The name of the container to be used for Dapr state. The container will be created for you if it doesn't exist.
+
+## Create a Dapr component
+
+The next step is to create a Dapr component for Azure Blob Storage.
+
+Create the following YAML file named `azureblob.yaml`:
+
+```yaml
+apiVersion: dapr.io/v1alpha1
+kind: Component
+metadata:
+  name: <NAME>
+  namespace: <NAMESPACE>
+spec:
+  type: state.azure.blobstorage
+  metadata:
+  - name: accountName
+    value: <REPLACE-WITH-ACCOUNT-NAME>
+  - name: accountKey
+    value: <REPLACE-WITH-ACCOUNT-KEY>
+  - name: containerName
+    value: <REPLACE-WITH-CONTAINER-NAME>
+```
+
+The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described [here](../../concepts/secrets/README.md).
+
+The following example uses the Kubernetes secret store to retrieve the secrets:
+
+```yaml
+apiVersion: dapr.io/v1alpha1
+kind: Component
+metadata:
+  name: <NAME>
+  namespace: <NAMESPACE>
+spec:
+  type: state.azure.blobstorage
+  metadata:
+  - name: accountName
+    value: <REPLACE-WITH-ACCOUNT-NAME>
+  - name: accountKey
+    secretKeyRef:
+      name: <KUBERNETES-SECRET-NAME>
+      key: <KUBERNETES-SECRET-KEY>
+  - name: containerName
+    value: <REPLACE-WITH-CONTAINER-NAME>
+```
+
+## Apply the configuration
+
+### In Kubernetes
+
+To apply Azure Blob Storage state store to Kubernetes, use the `kubectl` CLI:
+
+```
+kubectl apply -f azureblob.yaml
+```
+
+### Running locally
+
+To run locally, create a `components` dir containing the YAML file and provide the path to the `dapr run` command with the flag `--components-path`.
+
+This state store creates a blob file in the container and puts raw state inside it.
+
+For example, the following operation coming from service called `myservice`
+
+```shell
+curl -X POST http://localhost:3500/v1.0/state \
+  -H "Content-Type: application/json"
+  -d '[
+        {
+          "key": "nihilus",
+          "value": "darth"
+        }
+      ]'
+```
+
+will create the blob file in the containter with key as filename and value as the contents of file.
+
+## Concurrency
+
+Azure Blob Storage state concurrency is achieved by using `ETag`s according to [the official documenation](https://docs.microsoft.com/en-us/azure/storage/common/storage-concurrency#managing-concurrency-in-blob-storage).
+

howto/setup-state-store/supported-state-stores.md

@@ -17,4 +17,6 @@
 | Azure CosmosDB | :white_check_mark: | :white_check_mark: |
 | Azure SQL Server  | :white_check_mark:  | :white_check_mark: |
 | Azure Table Storage  | :white_check_mark:  | :x: |
+| Azure Blob Storage | :white_check_mark: | :x: |
 | Google Cloud Firestore | :white_check_mark: | :x: |
+