chore: postgresql ping schema

Author: ddebrunner

dbquery/pings/postgresql/README.md

@@ -0,0 +1,64 @@
+# Ping PostgreSQL
+
+Simple schema that when deployed provides an easy way to check that a
+PostgreSQL database can be connected to from a GraphQL endpoint.
+
+## Setup
+
+Either set an environment variable or an `.env` file containing the URI of the PostgreSQL instance.
+
+Replace `<<xxx>>` values with the correct connection information.
+
+If a port number is required then add it to the host as `:1234`.
+
+If the password contains special characters then must be URL escaped.
+
+### Environment variable
+```
+export STEPZEN_PG_DB_URI=postgresql://<<host>>/<<database>>?user=<<user>>&password=<<password>>
+```
+
+### `.env` contents
+
+```
+STEPZEN_PG_DB_URI=postgresql://<<host>>/<<database>>?user=<<user>>&password=<<password>>
+```
+
+## Deploy
+
+```
+stepzen deploy
+```
+
+## Test
+
+```
+stepzen request '{ping{status}}'
+```
+
+## Example
+
+```
+>stepzen deploy 
+Deploying dbping/postgresql to StepZen... done in 443ms 🚀
+  ✓ 🔐 https://danville.us-east-a.ibm.stepzen.net/dbping/postgresql/__graphql
+  ✓ 🔐 wss://danville.us-east-a.ibm.stepzen.net/stepzen-subscriptions/dbping/postgresql/__graphql (subscriptions)
+
+You can test your hosted API with curl:
+
+curl https://danville.us-east-a.ibm.stepzen.net/dbping/postgresql/__graphql \
+   --header "Authorization: Apikey $(stepzen whoami --apikey)" \
+   --header "Content-Type: application/json" \
+   --data-raw '{
+     "query": "query SampleQuery { __schema { description queryType { fields {name} } } }"
+   }'
+
+stepzen request '{ping{status}}'
+{
+  "data": {
+    "ping": {
+      "status": "ok"
+    }
+  }
+}
+```

dbquery/pings/postgresql/config.yaml

@@ -0,0 +1,4 @@
+configurationset:
+  - configuration:
+      name: pgdb
+      uri: STEPZEN_PG_DB_URI

dbquery/pings/postgresql/index.graphql

@@ -0,0 +1,15 @@
+type Query {
+  """
+  Pings the configured database by running a SQL statement
+  that does not access any user tables or schema.
+  """
+  ping: Ping
+    @dbquery(
+      type: "postgresql"
+      query: "SELECT 'ok' AS status"
+      configuration: "pgdb"
+    )
+}
+type Ping {
+  status: String
+}

dbquery/pings/postgresql/stepzen.config.json

@@ -0,0 +1,3 @@
+{
+  "endpoint": "dbping/postgresql"
+}