postgres: add --json body example to create-role help

cmd/workspace/postgres/overrides.go

@@ -0,0 +1,93 @@
+package postgres
+
+import (
+	"encoding/json"
+	"errors"
+	"strings"
+
+	"github.com/databricks/cli/libs/flags"
+	"github.com/databricks/databricks-sdk-go/service/postgres"
+	"github.com/spf13/cobra"
+)
+
+// createRoleOverride appends an example body to the auto-generated help and
+// rejects wrapped {"role": ...} bodies with a clear client-side error.
+// The --json flag binds to the inner Role object (CreateRoleRequest.Role,
+// JSON-tagged "role"), so users supply spec/name/etc. directly. Without an
+// example, the auto-generated `// TODO: complex arg: spec` flags leave no
+// hint about the body shape and the API's "Field 'role' is required" error
+// is unhelpful when the request body is wrong.
+func createRoleOverride(createRoleCmd *cobra.Command, _ *postgres.CreateRoleRequest) {
+	prevPreRunE := createRoleCmd.PreRunE
+	createRoleCmd.PreRunE = func(cmd *cobra.Command, args []string) error {
+		if err := rejectWrappedRoleJSON(cmd); err != nil {
+			return err
+		}
+		if prevPreRunE != nil {
+			return prevPreRunE(cmd, args)
+		}
+		return nil
+	}
+
+	createRoleCmd.Long += `
+
+  Body shape (passed via --json): fields go directly on the Role object.
+  Do not wrap them in '{"role": ...}' — the CLI rejects wrapped bodies
+  client-side with a hint pointing to the right shape.
+
+  Example — create a service-principal-backed role:
+
+    databricks postgres create-role projects/<PROJECT_ID>/branches/<BRANCH_ID> \
+      --role-id <SP_CLIENT_ID> \
+      --json '{"spec": {"identity_type": "SERVICE_PRINCIPAL", "postgres_role": "<SP_CLIENT_ID>", "auth_method": "LAKEBASE_OAUTH_V1"}}'
+
+  The example omits 'membership_roles' so the role starts with default
+  privileges only — grant database/schema/table access separately via
+  SQL, following least privilege. Set 'membership_roles' (e.g.
+  ["DATABRICKS_SUPERUSER"]) only when broad administrative access is
+  intentional.
+
+  See databricks-sdk-go/service/postgres.RoleRoleSpec for the full set of
+  spec fields.`
+}
+
+// rejectWrappedRoleJSON returns a clear error when --json is a top-level
+// object containing a "role" key. Without this guard the generated unmarshal
+// strips the unknown outer "role" field with a warning and ships an empty
+// body, and the server rejects with a confusing "Field 'role' is required"
+// message.
+func rejectWrappedRoleJSON(cmd *cobra.Command) error {
+	flag := cmd.Flags().Lookup("json")
+	if flag == nil {
+		return nil
+	}
+	jf, ok := flag.Value.(*flags.JsonFlag)
+	if !ok {
+		return nil
+	}
+	raw := jf.Raw()
+	if len(raw) == 0 {
+		return nil
+	}
+	var top map[string]json.RawMessage
+	if err := json.Unmarshal(raw, &top); err != nil {
+		return nil //nolint:nilerr // defer non-object inputs to the generated unmarshal so its diagnostics render
+	}
+	if _, hasRole := top["role"]; hasRole {
+		return errors.New(strings.TrimSpace(`
+--json should NOT be wrapped in '{"role": ...}'.
+
+The flag binds to the inner Role object — supply 'spec'/'name'/etc.
+directly. Example:
+
+  databricks postgres create-role projects/<PROJECT_ID>/branches/<BRANCH_ID> \
+    --role-id <SP_CLIENT_ID> \
+    --json '{"spec": {"identity_type": "SERVICE_PRINCIPAL", "postgres_role": "<SP_CLIENT_ID>", "auth_method": "LAKEBASE_OAUTH_V1"}}'
+`))
+	}
+	return nil
+}
+
+func init() {
+	createRoleOverrides = append(createRoleOverrides, createRoleOverride)
+}

cmd/workspace/postgres/overrides_test.go

@@ -0,0 +1,50 @@
+package postgres
+
+import (
+	"testing"
+
+	"github.com/databricks/cli/libs/flags"
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func cmdWithJSON(t *testing.T, raw string) *cobra.Command {
+	t.Helper()
+	cmd := &cobra.Command{}
+	var jf flags.JsonFlag
+	cmd.Flags().Var(&jf, "json", "JSON body")
+	if raw != "" {
+		require.NoError(t, jf.Set(raw))
+	}
+	return cmd
+}
+
+func TestRejectWrappedRoleJSON(t *testing.T) {
+	t.Run("rejects wrapped {role: ...}", func(t *testing.T) {
+		cmd := cmdWithJSON(t, `{"role":{"spec":{"identity_type":"SERVICE_PRINCIPAL"}}}`)
+		err := rejectWrappedRoleJSON(cmd)
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "should NOT be wrapped")
+		assert.Contains(t, err.Error(), `databricks postgres create-role`)
+	})
+
+	t.Run("passes when body has spec at top level", func(t *testing.T) {
+		cmd := cmdWithJSON(t, `{"spec":{"identity_type":"SERVICE_PRINCIPAL"}}`)
+		assert.NoError(t, rejectWrappedRoleJSON(cmd))
+	})
+
+	t.Run("passes when --json was not provided", func(t *testing.T) {
+		cmd := cmdWithJSON(t, "")
+		assert.NoError(t, rejectWrappedRoleJSON(cmd))
+	})
+
+	t.Run("passes through non-object JSON to the generated diagnostics path", func(t *testing.T) {
+		cmd := cmdWithJSON(t, `"not-an-object"`)
+		assert.NoError(t, rejectWrappedRoleJSON(cmd))
+	})
+
+	t.Run("passes when --json flag is absent on the command", func(t *testing.T) {
+		assert.NoError(t, rejectWrappedRoleJSON(&cobra.Command{}))
+	})
+}

libs/flags/json_flag.go

@@ -113,3 +113,10 @@ func (j *JsonFlag) Unmarshal(v any) diag.Diagnostics {
 func (j *JsonFlag) Type() string {
 	return "JSON"
 }
+
+// Raw returns the raw JSON bytes the flag was set to (or nil when the flag
+// was not provided). Exposed so command overrides can do shape-level
+// validation before the generated Unmarshal call.
+func (j *JsonFlag) Raw() []byte {
+	return j.raw
+}