scheduler: adds implicit constraint for secrets plugin node attributes (#26303)

client/fingerprint/fingerprint.go

@@ -43,6 +43,7 @@ var (
 		"nomad":               NewNomadFingerprint,
 		"plugins_cni":         NewPluginsCNIFingerprint,
 		"host_volume_plugins": NewPluginsHostVolumeFingerprint,
+		"secrets":             NewPluginsSecretsFingerprint,
 		"signal":              NewSignalFingerprint,
 		"storage":             NewStorageFingerprint,
 		"vault":               NewVaultFingerprint,

client/fingerprint/secrets.go

@@ -0,0 +1,33 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package fingerprint
+
+import (
+	"time"
+
+	"github.com/hashicorp/go-hclog"
+)
+
+type SecretsPluginFingerprint struct {
+	logger hclog.Logger
+}
+
+func NewPluginsSecretsFingerprint(logger hclog.Logger) Fingerprint {
+	return &SecretsPluginFingerprint{
+		logger: logger.Named("secrets_plugins"),
+	}
+}
+
+func (s *SecretsPluginFingerprint) Fingerprint(request *FingerprintRequest, response *FingerprintResponse) error {
+	// Add builtin secrets providers
+	response.AddAttribute("plugins.secrets.nomad.version", "1.0.0")
+	response.AddAttribute("plugins.secrets.vault.version", "1.0.0")
+	response.Detected = true
+
+	return nil
+}
+
+func (s *SecretsPluginFingerprint) Periodic() (bool, time.Duration) {
+	return false, 0
+}

client/fingerprint/secrets_test.go

@@ -0,0 +1,24 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package fingerprint
+
+import (
+	"testing"
+
+	"github.com/hashicorp/nomad/helper/testlog"
+	"github.com/shoenig/test/must"
+)
+
+func TestPluginsSecretsFingerprint(t *testing.T) {
+	fp := NewPluginsSecretsFingerprint(testlog.HCLogger(t))
+
+	resp := FingerprintResponse{}
+	err := fp.Fingerprint(&FingerprintRequest{}, &resp)
+	must.NoError(t, err)
+	must.True(t, resp.Detected)
+	must.MapContainsKeys(t, resp.Attributes, []string{
+		"plugins.secrets.nomad.version",
+		"plugins.secrets.vault.version",
+	})
+}