config: add runtime flags

config/runtime_flags.go

@@ -0,0 +1,26 @@
+package config
+
+// GRPCDatabrokerKeepalive enables gRPC keepalive to the databroker service
+var GRPCDatabrokerKeepalive = runtimeFlag("grpc_databroker_keepalive", false)
+
+// RuntimeFlag is a runtime flag that can flip on/off certain features
+type RuntimeFlag string
+
+// RuntimeFlags is a map of runtime flags
+type RuntimeFlags map[RuntimeFlag]bool
+
+func runtimeFlag(txt string, def bool) RuntimeFlag {
+	key := RuntimeFlag(txt)
+	defaultRuntimeFlags[key] = def
+	return key
+}
+
+var defaultRuntimeFlags = map[RuntimeFlag]bool{}
+
+func DefaultRuntimeFlags() RuntimeFlags {
+	out := make(RuntimeFlags, len(defaultRuntimeFlags))
+	for k, v := range defaultRuntimeFlags {
+		out[k] = v
+	}
+	return out
+}