init

.dockerignore

@@ -0,0 +1,2 @@
+.git
+node_modules

.editorconfig

@@ -0,0 +1,16 @@
+# editorconfig.org
+root = true
+
+[*]
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[**.{js, json}]
+indent_style = tab
+indent_size = 4
+
+[**.{yml,yaml}]
+indent_style = spaces
+indent_size = 2

.github/dependabot.yml

@@ -0,0 +1,11 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: '/'
+    schedule:
+      interval: weekly
+    commit-message:
+      include: scope
+    ignore:
+      - dependency-name: "*"
+        update-types: ["version-update:semver-patch", "version-update:semver-minor"]

.github/workflows/build-publish.yml

@@ -0,0 +1,54 @@
+name: build & publish Docker image
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  lint-test:
+    name: lint & test
+    uses: './.github/workflows/test.yml'
+
+  build-publish:
+    name: build & publish Docker image
+    needs:
+      - lint-test
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+
+    - name: log into the GitHub Container Registry
+      uses: docker/login-action@v3
+      with:
+        registry: ghcr.io
+        username: ${{ github.actor }}
+        password: ${{ github.token }}
+
+    - name: compute Docker image OCI metadata from commit & repo
+      id: docker-metadata
+      uses: docker/metadata-action@v5
+      with:
+        labels: |
+          org.opencontainers.image.version=${{ github.ref_name }}
+
+    - name: set up Docker buildx
+      uses: docker/setup-buildx-action@v3
+    - name: set up QEMU for cross-platform builds
+      uses: docker/setup-qemu-action@v3
+
+    - name: build and push Docker image
+      uses: docker/build-push-action@v5
+      with:
+        push: true
+        tags: |
+          ghcr.io/${{ github.repository }}:latest
+          ghcr.io/${{ github.repository }}:${{ github.ref_name }}
+        labels: ${{ steps.docker-metadata.outputs.labels }}
+        platforms: linux/amd64,linux/arm64
+        # https://docs.docker.com/build/ci/github-actions/cache/#cache-backend-api
+        cache-from: type=gha
+        cache-to: type=gha,mode=max

.github/workflows/test.yml

@@ -0,0 +1,32 @@
+name: lint & test
+
+on:
+  push:
+    branches:
+      - '*'
+  pull_request:
+    branches:
+      - '*'
+  # make this workflow callable from other workflows
+  workflow_call:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version:
+          - '20'
+          - '22'
+
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+    - name: setup Node v${{ matrix.node-version }}
+      uses: actions/setup-node@v4
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm install
+
+    - run: npm run lint
+    - run: npm test

.gitignore

@@ -0,0 +1,8 @@
+.DS_Store
+Thumbs.db
+
+.nvm-version
+node_modules
+
+/package-lock.json
+/yarn.lock

Dockerfile

@@ -0,0 +1,27 @@
+# syntax=docker/dockerfile:1.6
+# ^ needed for ADD --checksum=…
+
+FROM node:22-alpine as builder
+WORKDIR /app
+
+RUN npm install --production
+
+# ---
+
+FROM node:22-alpine
+WORKDIR /app
+
+LABEL org.opencontainers.image.title="nats-consuming-gtfs-rt-server"
+LABEL org.opencontainers.image.description="Reads DIFFERENTIAL-mode GTFS Realtime data from NATS message broker, and serves it as FULL_DATASET via HTTP."
+LABEL org.opencontainers.image.authors="Verkehrsverbund Berlin Brandenburg <[email protected]>"
+
+# install dependencies
+COPY --from=builder /app/node_modules ./node_modules
+
+# add source code
+ADD . /app
+
+# CLI smoke test
+RUN ./cli.js --help >/dev/null
+
+ENTRYPOINT [ "./cli.js"]

cli.js

@@ -0,0 +1,40 @@
+#!/usr/bin/env node
+
+import {parseArgs} from 'node:util'
+
+// todo: use import assertions once they're supported by Node.js & ESLint
+// https://github.com/tc39/proposal-import-assertions
+import {createRequire} from 'node:module'
+const require = createRequire(import.meta.url)
+const pkg = require('./package.json')
+
+const {
+	values: flags,
+	positionals: args,
+} = parseArgs({
+	options: {
+		'help': {
+			type: 'boolean',
+			short: 'h',
+		},
+		'version': {
+			type: 'boolean',
+			short: 'v',
+		},
+	},
+	allowPositionals: true,
+})
+
+if (flags.help) {
+	process.stdout.write(`
+todo
+\n`)
+	process.exit(0)
+}
+
+if (flags.version) {
+	process.stdout.write(`${pkg.name} v${pkg.version}\n`)
+	process.exit(0)
+}
+
+// todo

eslint.config.mjs

@@ -0,0 +1,22 @@
+import eslint from '@eslint/js'
+import globals from 'globals'
+
+export default [
+	eslint.configs.recommended,
+	{
+		languageOptions: {
+			ecmaVersion: 2022,
+			globals: globals.node,
+		},
+		rules: {
+			'no-unused-vars': [
+				'error',
+				{
+					vars: 'all',
+					args: 'none',
+					ignoreRestSiblings: false
+				},
+			],
+		},
+	},
+]

index.js

@@ -0,0 +1 @@
+// todo

license.md

@@ -0,0 +1,5 @@
+Copyright (c) 2024, Jannis R
+
+Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

package.json

@@ -0,0 +1,50 @@
+{
+	"name": "nats-consuming-gtfs-rt-server",
+	"description": "Reads DIFFERENTIAL-mode GTFS Realtime data from NATS message broker, and serves it as FULL_DATASET via HTTP.",
+	"version": "1.0.0",
+	"preferGlobal": true,
+	"type": "module",
+	"main": "index.js",
+	"bin": {
+		"send-vdv-453-data-to-nats": "./cli.js"
+	},
+	"files": [
+		"cli.js",
+		"index.js",
+		"lib"
+	],
+	"keywords": [
+		"vdv 453",
+		"vdv 454",
+		"realtime",
+		"public transport",
+		"transit",
+		"nats"
+	],
+	"author": "Verkehrsverbund Berlin Brandenburg <[email protected]>",
+	"contributors": [
+		"Jannis R <[email protected]>"
+	],
+	"homepage": "https://github.com/OpenDataVBB/nats-consuming-gtfs-rt-server",
+	"repository": {
+		"type": "git",
+		"url": "git+https://github.com/OpenDataVBB/nats-consuming-gtfs-rt-server.git"
+	},
+	"bugs": "https://github.com/OpenDataVBB/nats-consuming-gtfs-rt-server/issues",
+	"license": "ISC",
+	"engines": {
+		"node": ">=22"
+	},
+	"dependencies": {
+	},
+	"devDependencies": {
+		"@eslint/js": "^9.0.0",
+		"eslint": "^9.0.0",
+		"globals": "^15.0.0"
+	},
+	"scripts": {
+		"test": "./test/index.sh",
+		"lint": "eslint .",
+		"prepublishOnly": "npm run lint && npm test"
+	}
+}

readme.md

@@ -0,0 +1,38 @@
+# nats-consuming-gtfs-rt-server
+
+**Reads a continuous stream of [GTFS Realtime (GTFS-RT)](https://developers.google.com/transit/gtfs-realtime/) data with [`DIFFERENTIAL` incrementality](https://gtfs.org/documentation/realtime/reference/#enum-incrementality), converts it into a single [`FULL_DATASET`](https://gtfs.org/documentation/realtime/reference/#enum-incrementality) GTFS-RT feed, and serves it via HTTP.**
+
+![ISC-licensed](https://img.shields.io/github/license/OpenDataVBB/nats-consuming-gtfs-rt-server.svg)
+
+
+## Installation
+
+```shell
+npm install -g OpenDataVBB/nats-consuming-gtfs-rt-server
+```
+
+
+## Getting Started
+
+```shell
+# todo
+```
+
+
+## Usage
+
+```
+todo
+```
+
+
+## Related
+
+- [`gtfs-rt-differential-to-full-dataset`](https://github.com/derhuerst/gtfs-rt-differential-to-full-dataset) – Transform a differential GTFS Realtime feed into a full dataset/dump.
+- [`gtfs-rt-bindings`](https://github.com/derhuerst/gtfs-rt-bindings) – Parse and serialize GTFS Realtime data encoded as protocol buffers. (third-party)
+- [`gtfs-realtime-bindings`](https://npmjs.com/package/gtfs-realtime-bindings) – Javascript classes generated from the GTFS-realtime protocol buffer specification. (official)
+
+
+## Contributing
+
+If you have a question or need support using `nats-consuming-gtfs-rt-server`, please double-check your code and setup first. If you think you have found a bug or want to propose a feature, use [the issues page](https://github.com/OpenDataVBB/nats-consuming-gtfs-rt-server/issues).

test/index.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -eu -o pipefail
+cd "$(dirname $0)"
+set -x
+
+# todo