feat: add live feedback during pushes (sideband streaming)

config.schema.json

@@ -297,6 +297,11 @@
       "description": "Flag to enable CSRF protections for UI",
       "type": "boolean"
     },
+    "sidebandProgress": {
+      "description": "Stream per-step validation progress messages to the git client's terminal during a push, using git sideband channel 2 (displayed as \"remote: ...\" lines). Requires the client to negotiate the side-band-64k capability, which all modern git clients do. When disabled, or when the client did not negotiate sideband, pushes receive a single buffered response as before. Operators behind intermediaries that buffer HTTP responses may wish to disable this.",
+      "type": "boolean",
+      "default": true
+    },
     "plugins": {
       "type": "array",
       "description": "List of plugins to integrate on GitProxy's push or pull actions. Each value is either a file path or a module name.",

proxy.config.json

@@ -147,6 +147,7 @@
   "urlShortener": "",
   "contactEmail": "",
   "csrfProtection": true,
+  "sidebandProgress": true,
   "plugins": [],
   "apiAuthentication": [
     {

src/config/generated/config.ts

@@ -95,6 +95,15 @@ export interface GitProxyConfig {
    */
   serverPort?: number;
   sessionMaxAgeHours?: number;
+  /**
+   * Stream per-step validation progress messages to the git client's terminal during a push,
+   * using git sideband channel 2 (displayed as "remote: ..." lines). Requires the client to
+   * negotiate the side-band-64k capability, which all modern git clients do. When disabled,
+   * or when the client did not negotiate sideband, pushes receive a single buffered response
+   * as before. Operators behind intermediaries that buffer HTTP responses may wish to disable
+   * this.
+   */
+  sidebandProgress?: boolean;
   /**
    * List of database sources. The first source in the configuration with enabled=true will be
    * used.
@@ -901,6 +910,7 @@ const typeMap: any = {
       { json: 'rateLimit', js: 'rateLimit', typ: u(undefined, r('RateLimit')) },
       { json: 'serverPort', js: 'serverPort', typ: u(undefined, 3.14) },
       { json: 'sessionMaxAgeHours', js: 'sessionMaxAgeHours', typ: u(undefined, 3.14) },
+      { json: 'sidebandProgress', js: 'sidebandProgress', typ: u(undefined, true) },
       { json: 'sink', js: 'sink', typ: u(undefined, a(r('Database'))) },
       { json: 'ssh', js: 'ssh', typ: u(undefined, r('SSH')) },
       { json: 'sslCertPemPath', js: 'sslCertPemPath', typ: u(undefined, '') },

src/config/index.ts

@@ -55,6 +55,7 @@ const REQUIRED_TOP_LEVEL_CONFIG_KEYS = [
   'rateLimit',
   'serverPort',
   'sessionMaxAgeHours',
+  'sidebandProgress',
   'sink',
   'tempPassword',
   'tls',
@@ -484,6 +485,16 @@ export const getMaxPackSizeBytes = (): number => {
   return fallback;
 };
 
+/**
+ * Whether per-step validation progress should be streamed to the git client's
+ * terminal during a push using git sideband channel 2.
+ * @return {boolean} true when sideband progress streaming is enabled
+ */
+export const getSidebandProgressEnabled = (): boolean => {
+  const config = loadFullConfiguration();
+  return config.sidebandProgress ?? true;
+};
+
 export const getSSHConfig = () => {
   const defaultHostKey = {
     privateKeyPath: '.ssh/proxy_host_key',

src/proxy/actions/Action.ts

@@ -75,6 +75,7 @@ class Action {
   tagData?: TagData[];
   newIdxFiles?: string[];
   protocol?: 'https' | 'ssh';
+  capabilities?: string[];
   pullAuthStrategy?:
     | 'basic'
     | 'ssh-user-key'

src/proxy/chain.ts

@@ -22,6 +22,7 @@ import * as proc from './processors';
 import { Processor } from './processors/types';
 import { attemptAutoApproval, attemptAutoRejection } from './actions/autoActions';
 import { handleErrorAndLog } from '../utils/errors';
+import { createProgressWriter } from './sideband';
 
 const branchPushChain: Processor['exec'][] = [
   proc.push.checkEmptyBranch,
@@ -57,7 +58,40 @@ const defaultActionChain: Processor['exec'][] = [proc.push.checkRepoInAuthorised
 
 let pluginsInserted = false;
 
-export const executeChain = async (req: Request, _res: Response): Promise<Action> => {
+const stepProgressLabels: Record<string, string> = {
+  'checkEmptyBranch.exec': 'Checking for empty branch',
+  'checkRepoInAuthorisedList.exec': 'Checking repository is authorised',
+  'checkMessages.exec': 'Checking commit messages',
+  'checkAuthorEmails.exec': 'Checking author emails',
+  'checkUserPushPermission.exec': 'Checking push permissions',
+  'pullRemote.exec': 'Fetching remote repository',
+  'writePack.exec': 'writing pack data',
+  'checkHiddenCommits.exec': 'Checking for hidden commits',
+  'checkIfWaitingAuth.exec': 'Checking approval status',
+  'executeExternalPreReceiveHook.exec': 'Running pre-receive hook',
+  'getDiff.exec': 'Computing diff',
+  'gitleaks.exec': 'Scanning for secrets',
+  'scanDiff.exec': 'Scanning diff contents',
+  'blockForAuth.exec': 'Requesting approval',
+};
+
+/**
+ * Obtain the message to display before a chain step.
+ * @param {Processor['exec']} fn The chain step about to be executed.
+ * @return {string} The message to display.
+ */
+const getProgressMessage = (fn: Processor['exec']): string => {
+  const displayName = (fn as { displayName?: string }).displayName;
+  if (displayName && stepProgressLabels[displayName]) {
+    return stepProgressLabels[displayName];
+  }
+  if (displayName) {
+    return `running ${displayName.replace(/\.exec$/, '')}`;
+  }
+  return 'running plugin';
+};
+
+export const executeChain = async (req: Request, res: Response): Promise<Action> => {
   let action: Action = {} as Action;
   let checkoutCleanUpRequired = false;
 
@@ -71,8 +105,13 @@ export const executeChain = async (req: Request, _res: Response): Promise<Action
     // 3) Select the correct chain now that action.actionType is set
     const actionFns = await getChain(action);
 
+    const progress = createProgressWriter(res, action);
+
     // 4) Execute each step in the selected chain
     for (const fn of actionFns) {
+      if (progress.active && action.continue()) {
+        progress.message(`${getProgressMessage(fn)}...`);
+      }
       action = await fn(req, action);
       if (!action.continue() || action.allowPush) {
         break;

src/proxy/processors/constants.ts → src/proxy/constants.ts

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { CommitData } from './types';
+import { CommitData } from './processors/types';
 
 export const REFS_PREFIX = 'refs/';
 export const BRANCH_PREFIX = 'refs/heads/';
@@ -46,3 +46,12 @@ export const SAMPLE_REPO = {
     canAuthorise: ['bob'],
   },
 };
+
+/**
+ * Maximum payload bytes for a single side-band-64k packet
+ * 65520 bytes total minus 4 bytes of pkt-line length and 1 band byte.
+ */
+export const MAX_SIDEBAND_PAYLOAD_BYTES = 65515;
+
+/** Capability that must be negotiated by the client for streamed progress */
+export const SIDE_BAND_64K_CAPABILITY = 'side-band-64k';

src/proxy/processors/pktLineParser.ts

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { PACKET_SIZE } from './constants';
+import { PACKET_SIZE } from '../constants';
 
 /**
  * Parses the packet lines from a buffer into an array of strings.

src/proxy/processors/pre-processor/parsePush.ts

@@ -30,7 +30,7 @@ import {
   PACKET_SIZE,
   GIT_OBJECT_TYPE_COMMIT,
   GIT_OBJECT_TYPE_TAG,
-} from '../constants';
+} from '../../constants';
 import { parsePacketLines } from '../pktLineParser';
 import { getErrorMessage } from '../../../utils/errors';
 
@@ -72,6 +72,13 @@ async function exec(req: Request, action: Action): Promise<Action> {
       throw new Error('Your push has been blocked. No ref updates found.');
     }
 
+    // The client's capability list (side-band-64k, report-status, agent=..., etc.)
+    // is appended after a NUL byte on the first ref update line.
+    const capabilityString = refUpdates[0].split('\0')[1];
+    action.capabilities = capabilityString
+      ? capabilityString.trim().split(/\s+/).filter(Boolean)
+      : [];
+
     const parsedRefs = refUpdates.map((line) => {
       const [commitParts] = line.split('\0');
       const parts = commitParts.split(' ');

src/proxy/processors/push-action/checkEmptyBranch.ts

@@ -18,7 +18,7 @@ import { Request } from 'express';
 import simpleGit from 'simple-git';
 
 import { Action, Step } from '../../actions';
-import { EMPTY_COMMIT_HASH } from '../constants';
+import { EMPTY_COMMIT_HASH } from '../../constants';
 import { handleErrorAndLog } from '../../../utils/errors';
 
 const isEmptyBranch = async (action: Action): Promise<boolean> => {

src/proxy/processors/push-action/checkHiddenCommits.ts

@@ -17,7 +17,7 @@
 import path from 'path';
 import { Action, Step } from '../../actions';
 import { spawnSync } from 'child_process';
-import { EMPTY_COMMIT_HASH } from '../constants';
+import { EMPTY_COMMIT_HASH } from '../../constants';
 import { Request } from 'express';
 import { getErrorMessage } from '../../../utils/errors';
 

src/proxy/processors/push-action/getDiff.ts

@@ -18,7 +18,7 @@ import { Request } from 'express';
 import simpleGit from 'simple-git';
 
 import { Action, Step } from '../../actions';
-import { EMPTY_COMMIT_HASH } from '../constants';
+import { EMPTY_COMMIT_HASH } from '../../constants';
 import { getErrorMessage } from '../../../utils/errors';
 
 const exec = async (_req: Request, action: Action): Promise<Action> => {