tmpnet: Separate network into orchestration and configuration

- Move methods to read/write network into network_config.go

tests/fixture/e2e/env.go

@@ -132,5 +132,5 @@ func (te *TestEnvironment) NewPrivateNetwork() *tmpnet.Network {
 	privateNetworksDir := filepath.Join(sharedNetwork.Dir, PrivateNetworksDirName)
 	te.require.NoError(os.MkdirAll(privateNetworksDir, perms.ReadWriteExecute))
 
-	return StartNetwork(sharedNetwork.AvalancheGoPath, privateNetworksDir)
+	return StartNetwork(sharedNetwork.DefaultRuntimeConfig.AvalancheGoPath, privateNetworksDir)
 }

tests/fixture/e2e/helpers.go

@@ -207,22 +207,14 @@ func CheckBootstrapIsPossible(network *tmpnet.Network) {
 }
 
 // Start a temporary network with the provided avalanchego binary.
-func StartNetwork(avalancheGoExecPath string, networkDir string) *tmpnet.Network {
+func StartNetwork(avalancheGoExecPath string, rootNetworkDir string) *tmpnet.Network {
 	require := require.New(ginkgo.GinkgoT())
 
-	network, err := tmpnet.StartNetwork(
-		DefaultContext(),
-		ginkgo.GinkgoWriter,
-		networkDir,
-		&tmpnet.Network{
-			NodeRuntimeConfig: tmpnet.NodeRuntimeConfig{
-				AvalancheGoPath: avalancheGoExecPath,
-			},
-		},
-		tmpnet.DefaultNodeCount,
-		tmpnet.DefaultPreFundedKeyCount,
-	)
+	network, err := tmpnet.NewDefaultNetwork(ginkgo.GinkgoWriter, avalancheGoExecPath, tmpnet.DefaultNodeCount)
 	require.NoError(err)
+	require.NoError(network.Create(rootNetworkDir))
+	require.NoError(network.Start(DefaultContext(), ginkgo.GinkgoWriter))
+
 	ginkgo.DeferCleanup(func() {
 		tests.Outf("Shutting down network\n")
 		ctx, cancel := context.WithTimeout(context.Background(), DefaultTimeout)

tests/fixture/tmpnet/README.md

@@ -30,6 +30,7 @@ the following non-test files:
 | flags.go          | FlagsMap    | Simplifies configuration of avalanchego flags  |
 | genesis.go        |             | Creates test genesis                           |
 | network.go        | Network     | Orchestrates and configures temporary networks |
+| network_config.go | Network     | Reads and writes network configuration         |
 | node.go           | Node        | Orchestrates and configures nodes              |
 | node_config.go    | Node        | Reads and writes node configuration            |
 | node_process.go   | NodeProcess | Orchestrates node processes                    |
@@ -73,17 +74,15 @@ network.
 A temporary network can be managed in code:
 
 ```golang
-network, _ := tmpnet.StartNetwork(
-    ctx,                                           // Context used to limit duration of waiting for network health
-    ginkgo.GinkgoWriter,                           // Writer to report progress of network start
-    "",                                            // Use default root dir (~/.tmpnet)
-    &tmpnet.Network{
-        DefaultRuntime: tmpnet.NodeRuntimeConfig{
-            ExecPath: "/path/to/avalanchego",      // Defining the avalanchego exec path is required
-        },
-    },
-    5,                                             // Number of initial validating nodes
-    50,                                            // Number of pre-funded keys to create
+network, _ := tmpnet.NewDefaultNetwork(   // Create base configuration
+    ginkgo.GinkgoWriter,                  // Writer to report progress of initialization
+    "/path/to/avalanchego",               // The path to the binary that nodes will execute
+    5,                                    // Number of initial validating nodes
+)
+_ = network.Create("")                    // Finalize network configuration and write to disk
+_ = network.Start(                        // Start the nodes of the network and wait until they report healthy
+    ctx,                                  // Context used to limit duration of waiting for network health
+    ginkgo.GinkgoWriter,                  // Writer to report progress of network start
 )
 
 uris := network.GetURIs()
@@ -94,35 +93,7 @@ uris := network.GetURIs()
 network.Stop()
 ```
 
-If non-default node behavior is required, the `Network` instance
-supplied to `StartNetwork()` can be initialized with explicit node
-configuration and by supplying a nodeCount argument of `0`:
-
-```golang
-network, _ := tmpnet.StartNetwork(
-    ctx,
-    ginkgo.GinkgoWriter,
-    "",
-    &tmpnet.Network{
-        DefaultRuntime: tmpnet.NodeRuntimeConfig{
-            ExecPath: "/path/to/avalanchego",
-        },
-        Nodes: []*Node{
-            {                                                       // node1 configuration is customized
-                Flags: FlagsMap{                                    // Any and all node flags can be configured here
-                    config.DataDirKey: "/custom/path/to/node/data",
-                }
-            },
-        },
-        {},                                                         // node2 uses default configuration
-        {},                                                         // node3 uses default configuration
-        {},                                                         // node4 uses default configuration
-        {},                                                         // node5 uses default configuration
-    },
-    0,                                                              // Node count must be zero when setting node config
-    50,
-)
-```
+#### TODO(marun) Document how to customize network configuration (defaults, nodes, etc)
 
 Further examples of code-based usage are located in the [e2e
 tests](../../e2e/e2e_test.go).
@@ -161,18 +132,18 @@ HOME
             ├── chains
             │   └── C
             │       └── config.json                      // C-Chain config for all nodes
-            ├── defaults.json                            // Default flags and configuration for network
+            ├── config.json                              // Common configuration (including defaults and pre-funded keys)
             ├── genesis.json                             // Genesis for all nodes
             └── network.env                              // Sets network dir env var to simplify network usage
 ```
 
-### Default flags and configuration
+### Common networking configuration
 
-The default avalanchego node flags (e.g. `--staking-port=`) and
-default configuration like the avalanchego path are stored at
-`[network-dir]/defaults.json`. The value for a given defaulted flag
-will be set on initial and subsequently added nodes that do not supply
-values for a given defaulted flag.
+Network configuration such as default flags (e.g. `--log-level=`),
+runtime defaults (e.g. avalanchego path) and pre-funded private keys
+are stored at `[network-dir]/config.json`. A given default will only
+be applied to a new node on its addition to the network if the node
+does not explicitly set a given value.
 
 ### Genesis
 

tests/fixture/tmpnet/cmd/main.go

@@ -10,6 +10,7 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
+	"time"
 
 	"github.com/spf13/cobra"
 
@@ -45,10 +46,9 @@ func main() {
 	rootCmd.AddCommand(versionCmd)
 
 	var (
-		rootDir           string
-		execPath          string
-		nodeCount         uint8
-		preFundedKeyCount uint8
+		rootDir   string
+		execPath  string
+		nodeCount uint8
 	)
 	startNetworkCmd := &cobra.Command{
 		Use:   "start-network",
@@ -60,15 +60,21 @@ func main() {
 
 			// Root dir will be defaulted on start if not provided
 
-			network := &tmpnet.Network{
-				NodeRuntimeConfig: tmpnet.NodeRuntimeConfig{
-					AvalancheGoPath: execPath,
-				},
+			network, err := tmpnet.NewDefaultNetwork(os.Stdout, execPath, int(nodeCount))
+			if err != nil {
+				return err
 			}
-			ctx, cancel := context.WithTimeout(context.Background(), tmpnet.DefaultNetworkTimeout)
+
+			if err := network.Create(rootDir); err != nil {
+				return err
+			}
+
+			// Extreme upper bound, should never take this long
+			networkStartTimeout := 2 * time.Minute
+
+			ctx, cancel := context.WithTimeout(context.Background(), networkStartTimeout)
 			defer cancel()
-			network, err := tmpnet.StartNetwork(ctx, os.Stdout, rootDir, network, int(nodeCount), int(preFundedKeyCount))
-			if err != nil {
+			if err := network.Start(ctx, os.Stdout); err != nil {
 				return err
 			}
 
@@ -94,7 +100,6 @@ func main() {
 	startNetworkCmd.PersistentFlags().StringVar(&rootDir, "root-dir", os.Getenv(tmpnet.RootDirEnvName), "The path to the root directory for temporary networks")
 	startNetworkCmd.PersistentFlags().StringVar(&execPath, "avalanchego-path", os.Getenv(tmpnet.AvalancheGoPathEnvName), "The path to an avalanchego binary")
 	startNetworkCmd.PersistentFlags().Uint8Var(&nodeCount, "node-count", tmpnet.DefaultNodeCount, "Number of nodes the network should initially consist of")
-	startNetworkCmd.PersistentFlags().Uint8Var(&preFundedKeyCount, "pre-funded-key-count", tmpnet.DefaultPreFundedKeyCount, "Number of pre-funded keys the network should start with")
 	rootCmd.AddCommand(startNetworkCmd)
 
 	var networkDir string

tests/fixture/tmpnet/defaults.go

@@ -10,11 +10,6 @@ import (
 )
 
 const (
-	// Constants defining the names of shell variables whose value can
-	// configure temporary network orchestration.
-	NetworkDirEnvName = "TMPNET_NETWORK_DIR"
-	RootDirEnvName    = "TMPNET_ROOT_DIR"
-
 	DefaultNetworkTimeout = 2 * time.Minute
 
 	// Minimum required to ensure connectivity-based health checks will pass
@@ -48,12 +43,14 @@ func DefaultFlags() FlagsMap {
 	}
 }
 
-// C-Chain config for testing.
-func DefaultCChainConfig() FlagsMap {
-	// Supply only non-default configuration to ensure that default
-	// values will be used. Available C-Chain configuration options are
-	// defined in the `github.com/ava-labs/coreth/evm` package.
-	return FlagsMap{
-		"log-level": "trace",
+// A set of chain configurations appropriate for testing.
+func DefaultChainConfigs() map[string]FlagsMap {
+	return map[string]FlagsMap{
+		// Supply only non-default configuration to ensure that default
+		// values will be used. Available C-Chain configuration options are
+		// defined in the `github.com/ava-labs/coreth/evm` package.
+		"C": {
+			"log-level": "trace",
+		},
 	}
 }