PoC: Network simulation framework (#1555)

* simv2: wip

* simulation: exec adapter start/stop

* simulation: add node status to exec adapter

* simulation: initial simulation code

* simulation: exec adapter, configure path to executable

* simulation: initial docker adapter

* simulation: wip kubernetes adapter

* simulation: kubernetes adapter proxy

* simulation: implement GetAll/StartAll/StopAll

* simulation: kuberentes adapter - set env vars and resource limits

* simulation: discovery test

* simulation: remove port definitions within docker adapter

* simulation: simplify wait for healthy loop

* simulation: get nat ip addr from interface

* simulation: pull docker images automatically

* simulation: NodeStatus -> NodeInfo

* simulation: move discovery test to example dir

* simulation: example snapshot usage

* simulation: add goclient specific simulation

* simulation: add peer connections to snapshot

* simulation: close rpc client

* simulation: don't export kubernetes proxy server

* simulation: merge simulation code

* simulation: don't export nodemap

* simulation: rename SimulationSnapshot -> Snapshot

* simulation: linting fixes

* simulation: add k8s available helper func

* simulation: vendor

* simulation: fix 'no non-test Go files' when building

* simulation: remove errors from interface methods where non were returned

* simulation: run getHealthInfo check in parallel

simulation/exec_test.go

@@ -0,0 +1,94 @@
+package simulation
+
+import (
+	"encoding/hex"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+func TestExecAdapter(t *testing.T) {
+
+	execPath := "../build/bin/swarm"
+
+	// Skip test if binary doesn't exist
+	if _, err := os.Stat(execPath); err != nil {
+		if os.IsNotExist(err) {
+			t.Skip("swarm binary not found. build it before running the test")
+		}
+	}
+
+	tmpdir, err := ioutil.TempDir("", "test-adapter-exec")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpdir)
+
+	adapter, err := NewExecAdapter(ExecAdapterConfig{
+		ExecutablePath:    execPath,
+		BaseDataDirectory: tmpdir,
+	})
+	if err != nil {
+		t.Fatalf("could not create exec adapter: %v", err)
+	}
+
+	bzzkey, err := crypto.GenerateKey()
+	if err != nil {
+		t.Fatalf("could not generate key: %v", err)
+	}
+	bzzkeyhex := hex.EncodeToString(crypto.FromECDSA(bzzkey))
+
+	nodekey, err := crypto.GenerateKey()
+	if err != nil {
+		t.Fatalf("could not generate key: %v", err)
+	}
+	nodekeyhex := hex.EncodeToString(crypto.FromECDSA(nodekey))
+
+	args := []string{
+		"--bootnodes", "",
+		"--bzzkeyhex", bzzkeyhex,
+		"--nodekeyhex", nodekeyhex,
+		"--bzznetworkid", "499",
+	}
+	nodeconfig := NodeConfig{
+		ID:     "node1",
+		Args:   args,
+		Stdout: os.Stdout,
+		Stderr: os.Stderr,
+	}
+	node := adapter.NewNode(nodeconfig)
+	info := node.Info()
+	if info.ID != "node1" {
+		t.Fatal("node id is different")
+	}
+
+	err = node.Start()
+	if err != nil {
+		t.Fatalf("node did not start: %v", err)
+	}
+
+	infoA := node.Info()
+
+	err = node.Stop()
+	if err != nil {
+		t.Fatalf("node didn't stop: %v", err)
+	}
+
+	err = node.Start()
+	if err != nil {
+		t.Fatalf("node didn't start again: %v", err)
+	}
+
+	infoB := node.Info()
+
+	if infoA.BzzAddr != infoB.BzzAddr {
+		t.Errorf("bzzaddr should be the same: %s - %s", infoA.Enode, infoB.Enode)
+	}
+
+	err = node.Stop()
+	if err != nil {
+		t.Fatalf("node didn't stop: %v", err)
+	}
+}