feat: topology config file support

topology.go

@@ -0,0 +1,74 @@
+// Copyright 2024 Blink Labs Software
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package node
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+)
+
+// TopologyConfig represents a Cardano node topology config
+type TopologyConfig struct {
+	Producers          []TopologyConfigLegacyProducer `json:"Producers"`
+	LocalRoots         []TopologyConfigP2PLocalRoot   `json:"localRoots"`
+	PublicRoots        []TopologyConfigP2PPublicRoot  `json:"publicRoots"`
+	UseLedgerAfterSlot uint64                         `json:"useLedgerAfterSlot"`
+}
+
+type TopologyConfigLegacyProducer struct {
+	Address   string `json:"addr"`
+	Port      uint   `json:"port"`
+	Valency   uint   `json:"valency"`
+	Continent string `json:"continent"`
+	State     string `json:"state"`
+}
+
+type TopologyConfigP2PAccessPoint struct {
+	Address string `json:"address"`
+	Port    uint   `json:"port"`
+}
+
+type TopologyConfigP2PLocalRoot struct {
+	AccessPoints []TopologyConfigP2PAccessPoint `json:"accessPoints"`
+	Advertise    bool                           `json:"advertise"`
+	Valency      uint                           `json:"valency"`
+}
+
+type TopologyConfigP2PPublicRoot struct {
+	AccessPoints []TopologyConfigP2PAccessPoint `json:"accessPoints"`
+	Advertise    bool                           `json:"advertise"`
+	Valency      uint                           `json:"valency"`
+}
+
+func NewTopologyConfigFromFile(path string) (*TopologyConfig, error) {
+	dataFile, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	return NewTopologyConfigFromReader(dataFile)
+}
+
+func NewTopologyConfigFromReader(r io.Reader) (*TopologyConfig, error) {
+	t := &TopologyConfig{}
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(data, t); err != nil {
+		return nil, err
+	}
+	return t, nil
+}

topology_test.go

@@ -0,0 +1,135 @@
+// Copyright 2024 Blink Labs Software
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package node_test
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/blinklabs-io/node"
+)
+
+type topologyTestDefinition struct {
+	jsonData       string
+	expectedObject *node.TopologyConfig
+}
+
+var topologyTests = []topologyTestDefinition{
+	{
+		jsonData: `
+{
+  "Producers": [
+    {
+      "addr": "backbone.cardano.iog.io",
+      "port": 3001,
+      "valency": 2
+    }
+  ]
+}
+`,
+		expectedObject: &node.TopologyConfig{
+			Producers: []node.TopologyConfigLegacyProducer{
+				{
+					Address: "backbone.cardano.iog.io",
+					Port:    3001,
+					Valency: 2,
+				},
+			},
+		},
+	},
+	{
+		jsonData: `
+{
+  "localRoots": [
+    {
+      "accessPoints": [],
+      "advertise": false,
+      "valency": 1
+    }
+  ],
+  "publicRoots": [
+    {
+      "accessPoints": [
+        {
+          "address": "backbone.cardano.iog.io",
+          "port": 3001
+        }
+      ],
+      "advertise": false
+    },
+    {
+      "accessPoints": [
+        {
+          "address": "backbone.mainnet.emurgornd.com",
+          "port": 3001
+        }
+      ],
+      "advertise": false
+    }
+  ],
+  "useLedgerAfterSlot": 99532743
+}
+`,
+		expectedObject: &node.TopologyConfig{
+			LocalRoots: []node.TopologyConfigP2PLocalRoot{
+				{
+					AccessPoints: []node.TopologyConfigP2PAccessPoint{},
+					Advertise:    false,
+					Valency:      1,
+				},
+			},
+			PublicRoots: []node.TopologyConfigP2PPublicRoot{
+				{
+					AccessPoints: []node.TopologyConfigP2PAccessPoint{
+						{
+							Address: "backbone.cardano.iog.io",
+							Port:    3001,
+						},
+					},
+					Advertise: false,
+				},
+				{
+					AccessPoints: []node.TopologyConfigP2PAccessPoint{
+						{
+							Address: "backbone.mainnet.emurgornd.com",
+							Port:    3001,
+						},
+					},
+					Advertise: false,
+				},
+			},
+			UseLedgerAfterSlot: 99532743,
+		},
+	},
+}
+
+func TestParseTopologyConfig(t *testing.T) {
+	for _, test := range topologyTests {
+		topology, err := node.NewTopologyConfigFromReader(
+			strings.NewReader(test.jsonData),
+		)
+		if err != nil {
+			t.Fatalf("failed to load TopologyConfig from JSON data: %s", err)
+		}
+		if !reflect.DeepEqual(topology, test.expectedObject) {
+			t.Fatalf(
+				"did not get expected object\n  got:\n    %#v\n  wanted:\n    %#v",
+				topology,
+				test.expectedObject,
+			)
+		}
+	}
+}