Added an endpoint that allows querying for status of node.

node/src/main/kotlin/com/r3corda/node/api/APIServer.kt

@@ -11,6 +11,7 @@ import javax.ws.rs.GET
 import javax.ws.rs.Path
 import javax.ws.rs.Produces
 import javax.ws.rs.core.MediaType
+import javax.ws.rs.core.Response
 
 /**
  * Top level interface to external interaction with the distributed ledger.
@@ -30,6 +31,14 @@ interface APIServer {
     @Produces(MediaType.APPLICATION_JSON)
     fun serverTime(): LocalDateTime
 
+    /**
+     * Report whether this node is started up or not
+     */
+    @GET
+    @Path("status")
+    @Produces(MediaType.TEXT_PLAIN)
+    fun status(): Response
+
     /**
      * Query your "local" states (containing only outputs involving you) and return the hashes & indexes associated with them
      * to probably be later inflated by fetchLedgerTransactions() or fetchStates() although because immutable you can cache them

node/src/main/kotlin/com/r3corda/node/internal/APIServerImpl.kt

@@ -10,6 +10,7 @@ import com.r3corda.core.serialization.SerializedBytes
 import com.r3corda.node.api.*
 import java.time.LocalDateTime
 import java.util.*
+import javax.ws.rs.core.Response
 import kotlin.reflect.KParameter
 import kotlin.reflect.jvm.javaType
 
@@ -17,6 +18,14 @@ class APIServerImpl(val node: AbstractNode) : APIServer {
 
     override fun serverTime(): LocalDateTime = LocalDateTime.now(node.services.clock)
 
+    override fun status(): Response {
+        return if(node.started) {
+            Response.ok("started").build()
+        } else {
+            Response.status(Response.Status.SERVICE_UNAVAILABLE).entity("not started").build()
+        }
+    }
+
     override fun queryStates(query: StatesQuery): List<StateRef> {
         // We're going to hard code two options here for now and assume that all LinearStates are deals
         // Would like to maybe move to a model where we take something like a JEXL string, although don't want to develop