test(simulation): skip replication simulation without docker harness

Author: zawadzkidiana

simulation/replication/replication_simulation_test.go

@@ -36,7 +36,9 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"net"
 	"net/http"
+	"os"
 	"reflect"
 	"sort"
 	"strings"
@@ -54,15 +56,34 @@ import (
 func TestReplicationSimulation(t *testing.T) {
 	flag.Parse()
 
-	simTypes.Logf(t, "Starting Replication Simulation")
+	// This is a docker-compose based integration test. It expects the Cadence clusters to be reachable via the
+	// docker network aliases defined in `docker/github_actions/docker-compose-local-replication-simulation.yml`.
+	// For local runs, use `./simulation/replication/run.sh --scenario <scenario>`.
+	if os.Getenv("REPLICATION_SIMULATION_CONFIG") == "" {
+		t.Skip("replication simulation requires docker-compose; run ./simulation/replication/run.sh --scenario <scenario>")
+	}
 
-	simTypes.Logf(t, "Sleeping for 30 seconds to allow services to start/warmup")
-	time.Sleep(30 * time.Second)
+	simTypes.Logf(t, "Starting Replication Simulation")
 
 	// load config
 	simCfg, err := simTypes.LoadConfig()
 	require.NoError(t, err, "failed to load config")
 
+	// Fast-fail with a helpful message if the cluster endpoints are not resolvable (common when running outside
+	// of the docker compose network).
+	for clusterName, clusterCfg := range simCfg.Clusters {
+		host, _, err := net.SplitHostPort(clusterCfg.GRPCEndpoint)
+		if err != nil {
+			t.Fatalf("invalid grpcEndpoint for cluster %s: %q: %v", clusterName, clusterCfg.GRPCEndpoint, err)
+		}
+		if _, err := net.LookupHost(host); err != nil {
+			t.Skipf("cluster endpoint %q is not resolvable (%v); run ./simulation/replication/run.sh --scenario <scenario>", clusterCfg.GRPCEndpoint, err)
+		}
+	}
+
+	simTypes.Logf(t, "Sleeping for 30 seconds to allow services to start/warmup")
+	time.Sleep(30 * time.Second)
+
 	// initialize replication simulation
 	sim := simTypes.NewReplicationSimulation()