e2e: allow running of single node using the e2e app (backport) (#7024)

test/e2e/node/config.go

@@ -0,0 +1,68 @@
+//nolint: goconst
+package main
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/BurntSushi/toml"
+
+	"github.com/tendermint/tendermint/test/e2e/app"
+)
+
+// Config is the application configuration.
+type Config struct {
+	ChainID          string `toml:"chain_id"`
+	Listen           string
+	Protocol         string
+	Dir              string
+	Mode             string                      `toml:"mode"`
+	PersistInterval  uint64                      `toml:"persist_interval"`
+	SnapshotInterval uint64                      `toml:"snapshot_interval"`
+	RetainBlocks     uint64                      `toml:"retain_blocks"`
+	ValidatorUpdates map[string]map[string]uint8 `toml:"validator_update"`
+	PrivValServer    string                      `toml:"privval_server"`
+	PrivValKey       string                      `toml:"privval_key"`
+	PrivValState     string                      `toml:"privval_state"`
+	Misbehaviors     map[string]string           `toml:"misbehaviors"`
+	KeyType          string                      `toml:"key_type"`
+}
+
+// App extracts out the application specific configuration parameters
+func (cfg *Config) App() *app.Config {
+	return &app.Config{
+		Dir:              cfg.Dir,
+		SnapshotInterval: cfg.SnapshotInterval,
+		RetainBlocks:     cfg.RetainBlocks,
+		KeyType:          cfg.KeyType,
+		ValidatorUpdates: cfg.ValidatorUpdates,
+		PersistInterval:  cfg.PersistInterval,
+	}
+}
+
+// LoadConfig loads the configuration from disk.
+func LoadConfig(file string) (*Config, error) {
+	cfg := &Config{
+		Listen:          "unix:///var/run/app.sock",
+		Protocol:        "socket",
+		PersistInterval: 1,
+	}
+	_, err := toml.DecodeFile(file, &cfg)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load config from %q: %w", file, err)
+	}
+	return cfg, cfg.Validate()
+}
+
+// Validate validates the configuration. We don't do exhaustive config
+// validation here, instead relying on Testnet.Validate() to handle it.
+func (cfg Config) Validate() error {
+	switch {
+	case cfg.ChainID == "":
+		return errors.New("chain_id parameter is required")
+	case cfg.Listen == "" && cfg.Protocol != "builtin":
+		return errors.New("listen parameter is required")
+	default:
+		return nil
+	}
+}