# Spanner

Kubemq gcp-spanner target connector allows services using kubemq server to access google spanner server.

## Prerequisites

The following are required to run the gcp-spanner target connector:

* kubemq cluster
* gcp-spanner set up
* kubemq-source deployment

## Configuration

spanner target connector configuration properties:

| Properties Key | Required | Description           | Example                                                                               |
| -------------- | -------- | --------------------- | ------------------------------------------------------------------------------------- |
| db             | yes      | gcp spanner db name   | "/mydb"  should conform to pattern "^projects/(?P+)/instances/(?P+)/databases/(?P+)$" |
| credentials    | yes      | gcp credentials files | "\<google json credentials"                                                           |

Example:

```yaml
bindings:
  - name: kubemq-query-gcp-spanner
    source:
      kind: kubemq.query
      name: kubemq-query
      properties:
        address: "kubemq-cluster:50000"
        client_id: "kubemq-query-gcp-spanner-connector"
        auth_token: ""
        channel: "query.gcp.spanner"
        group:   ""
        auto_reconnect: "true"
        reconnect_interval_seconds: "1"
        max_reconnects: "0"
    target:
      kind: gcp.spanner
      name: target-gcp-spanner
      properties:
        db: "id"
        credentials: 'json'
```

## Usage

### Query Request

create query request.

Query metadata setting:

| Metadata Key | Required | Description    | Possible values        |
| ------------ | -------- | -------------- | ---------------------- |
| method       | yes      | type of method | "query"                |
| query        | yes      | the query body | "select \* from table" |

Example:

```javascript
{
  "metadata": {
    "method": "query",
    "query": "select * from table"
  },
  "data": null
}
```

### Read Table Request by columns

read table by table\_name

Read Table metadata setting:

| Metadata Key | Required | Description             | Possible values |
| ------------ | -------- | ----------------------- | --------------- |
| method       | yes      | type of method          | "read"          |
| table\_name  | yes      | table name to read from | ""              |

Example:

```javascript
{
  "metadata": {
    "method": "read",
    "table_name": "<myTable>"
  },
  "data": "W1wiaWRcIixcIm5hbWVcIl0="
}
```

### Insert Or Update Table

insert or update a table

Insert Or Update metadata setting:

| Metadata Key | Required | Description    | Possible values                        |
| ------------ | -------- | -------------- | -------------------------------------- |
| method       | yes      | type of method | "insert","update","insert\_or\_update" |

Example:

```javascript
{
  "metadata": {
    "method": "insert_or_update"
  },
  "data": "W3tcInRhYmxlX25hbWVcIjpcInRlc3QyXCIsXCJjb2x1bW5fbmFtZXNcIjpbXCJpZFwiLFwibmFtZVwiXSxcImNvbHVtbl92YWx1ZXNcIjpbMTcsXCJuYW1lMVwiXSxcImNvbHVtbl90eXBlXCI6W1wiSU5UNjRcIixcIlNUUklOR1wiXX0se1widGFibGVfbmFtZVwiOlwidGVzdDJcIixcImNvbHVtbl9uYW1lc1wiOltcImlkXCIsXCJuYW1lXCJdLFwiY29sdW1uX3ZhbHVlc1wiOlsxOCxcIm5hbWUyXCJdLFwiY29sdW1uX3R5cGVcIjpbXCJJTlQ2NFwiLFwiU1RSSU5HXCJdfV0="
}
```