PostgreSQL binding spec
Detailed documentation on the PostgreSQL binding component
Component format
To setup PostgreSQL binding create a component of type bindings.postgres
. See this guide on how to create and apply a binding configuration.
apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
name: <NAME>
namespace: <NAMESPACE>
spec:
type: bindings.postgres
version: v1
metadata:
- name: url # Required
value: <CONNECTION_STRING>
Warning
The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described here.
Spec metadata fields
Field | Required | Binding support | Details | Example |
---|---|---|---|---|
url | Y | Output | Postgres connection string See here for more details | “user=dapr password=secret host=dapr.example.com port=5432 dbname=dapr sslmode=verify-ca” |
URL format
The PostgreSQL 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 greaterpool_max_conns
: integer greater than 0pool_max_conn_lifetime
: duration stringpool_max_conn_idle_time
: duration stringpool_health_check_period
: duration string
Binding support
This component supports output binding with the following 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.
Related links
- Basic schema for a Dapr component
- Bindings building block
- How-To: Trigger application with input binding
- How-To: Use bindings to interface with external resources
- Bindings API reference
Last modified March 18, 2021: Merge pull request #1321 from dapr/aacrawfi/logos (9a399d5)