Add axios support for esplora unix sockets

backend/src/__fixtures__/mempool-config.template.json

@@ -42,7 +42,8 @@
     "TLS_ENABLED": true
   },
   "ESPLORA": {
-    "REST_API_URL": "__ESPLORA_REST_API_URL__"
+    "REST_API_URL": "__ESPLORA_REST_API_URL__",
+    "UNIX_SOCKET_PATH": "__ESPLORA_UNIX_SOCKET_PATH__"
   },
   "SECOND_CORE_RPC": {
     "HOST": "__SECOND_CORE_RPC_HOST__",

backend/src/__tests__/config.test.ts

@@ -46,7 +46,7 @@ describe('Mempool Backend Config', () => {
 
       expect(config.ELECTRUM).toStrictEqual({ HOST: '127.0.0.1', PORT: 3306, TLS_ENABLED: true });
 
-      expect(config.ESPLORA).toStrictEqual({ REST_API_URL: 'http://127.0.0.1:3000' });
+      expect(config.ESPLORA).toStrictEqual({ REST_API_URL: 'http://127.0.0.1:3000', UNIX_SOCKET_PATH: null });
 
       expect(config.CORE_RPC).toStrictEqual({
         HOST: '127.0.0.1',

backend/src/api/bitcoin/esplora-api.ts

@@ -5,11 +5,14 @@ import { AbstractBitcoinApi } from './bitcoin-api-abstract-factory';
 import { IEsploraApi } from './esplora-api.interface';
 
 const axiosConnection = axios.create({
-  httpAgent: new http.Agent({ keepAlive: true })
+  httpAgent: new http.Agent({ keepAlive: true, })
 });
 
 class ElectrsApi implements AbstractBitcoinApi {
-  axiosConfig: AxiosRequestConfig = {
+  axiosConfig: AxiosRequestConfig = config.ESPLORA.UNIX_SOCKET_PATH ? {
+    socketPath: config.ESPLORA.UNIX_SOCKET_PATH,
+    timeout: 10000,
+  } : {
     timeout: 10000,
   };
 

backend/src/config.ts

@@ -36,6 +36,7 @@ interface IConfig {
   };
   ESPLORA: {
     REST_API_URL: string;
+    UNIX_SOCKET_PATH: string | void | null;
   };
   LIGHTNING: {
     ENABLED: boolean;
@@ -158,6 +159,7 @@ const defaults: IConfig = {
   },
   'ESPLORA': {
     'REST_API_URL': 'http://127.0.0.1:3000',
+    'UNIX_SOCKET_PATH': null,
   },
   'ELECTRUM': {
     'HOST': '127.0.0.1',