PostgrSQL binding spec

Detailed documentation on the PostgrSQL binding component

Setup Dapr component

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
  namespace: <NAMESPACE>
spec:
  type: bindings.postgres
  metadata:
  - name: url # Required
    value: <CONNECTION_STRING>

The PostgrSQL binding uses pgx connection pool internally so the url parameter can be any valid connection string, either in a DSN or URL format:

Example DSN

user=dapr password=secret host=dapr.example.com port=5432 dbname=dapr sslmode=verify-ca

Example URL

postgres://dapr:secret@dapr.example.com:5432/dapr?sslmode=verify-ca

Both methods also support connection pool configuration variables:

  • pool_min_conns: integer 0 or greater
  • pool_max_conns: integer greater than 0
  • pool_max_conn_lifetime: duration string
  • pool_max_conn_idle_time: duration string
  • pool_health_check_period: duration string

Output Binding Supported Operations

  • exec
  • query
  • close

exec

The exec operation can be used for DDL operations (like table creation), as well as INSERT, UPDATE, DELETE operations which return only metadata (e.g. number of affected rows).

Request

{
  "operation": "exec",
  "metadata": {
    "sql": "INSERT INTO foo (id, c1, ts) VALUES (1, 'demo', '2020-09-24T11:45:05Z07:00')"
  }
}

Response

{
  "metadata": {
    "operation": "exec",
    "duration": "294µs", 
    "start-time": "2020-09-24T11:13:46.405097Z",
    "end-time": "2020-09-24T11:13:46.414519Z",
    "rows-affected": "1",
    "sql": "INSERT INTO foo (id, c1, ts) VALUES (1, 'demo', '2020-09-24T11:45:05Z07:00')"
  }
}

query

The query operation is used for SELECT statements, which returns the metadata along with data in a form of an array of row values.

Request

{
  "operation": "query",
  "metadata": {
    "sql": "SELECT * FROM foo WHERE id < 3"
  }
}

Response

{
  "metadata": {
    "operation": "query",
    "duration": "432µs", 
    "start-time": "2020-09-24T11:13:46.405097Z",
    "end-time": "2020-09-24T11:13:46.420566Z",
    "sql": "SELECT * FROM foo WHERE id < 3"
  },
  "data": "[
    [0,\"test-0\",\"2020-09-24T04:13:46Z\"],
    [1,\"test-1\",\"2020-09-24T04:13:46Z\"],
    [2,\"test-2\",\"2020-09-24T04:13:46Z\"]
  ]"
}

close

Finally, the close operation can be used to explicitly close the DB connection and return it to the pool. This operation doesn’t have any response.

Request

{
  "operation": "close"
}

Note, the PostgreSql binding itself doesn’t prevent SQL injection, like with any database application, validate the input before executing query.

Last modified November 20, 2020: Revert commands for 0.11 (#947) (904c3d3)