From 12fc305312ef9b2e7526deeb63d962bac2542c8a Mon Sep 17 00:00:00 2001
From: Jannis R <mail@jannisr.de>
Date: Mon, 13 Jan 2025 12:08:51 +0100
Subject: [PATCH] =?UTF-8?q?matching:=20expect=20GTFS=5FRT=5F2=20stream=20&?=
 =?UTF-8?q?=20consumer=20to=20be=20created=20by=20the=20user=20?=
 =?UTF-8?q?=F0=9F=92=A5=F0=9F=93=9D?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/match.js | 13 -------------
 readme.md    | 21 +++++++++++++++++++--
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/lib/match.js b/lib/match.js
index de8be1d..fb49ec3 100644
--- a/lib/match.js
+++ b/lib/match.js
@@ -339,19 +339,6 @@ const runGtfsMatching = async (cfg, opt = {}) => {
 				streamInfo,
 			}, 'using NATS JetStream stream for AUS IstFahrts')
 		}
-		{
-			// create/update NATS JetStream stream for GTFS-RT data
-			const streamInfo = await natsJetstreamManager.streams.add({
-				name: NATS_JETSTREAM_GTFSRT_STREAM_NAME,
-				subjects: [
-					GTFS_RT_TOPIC_PREFIX + '>',
-				],
-				// todo: limits?
-			})
-			serviceLogger.debug({
-				streamInfo,
-			}, 'created/re-used NATS JetStream stream for GTFS-RT data')
-		}
 
 		const istFahrtsConsumer = await natsJetstreamClient.consumers.get(
 			NATS_JETSTREAM_AUS_ISTFAHRT_STREAM_NAME,
diff --git a/readme.md b/readme.md
index bd7c842..32ba601 100644
--- a/readme.md
+++ b/readme.md
@@ -175,7 +175,7 @@ By default, `gtfs-rt-feed` will connect as `gtfs-rt-$MAJOR_VERSION` to `localhos
 
 #### create NATS stream & consumer
 
-We also need to create a [NATS JetStream](https://docs.nats.io/nats-concepts/jetstream) [stream](https://docs.nats.io/nats-concepts/jetstream/streams) called `AUS_ISTFAHRT_2` that `gtfs-rt-feed` will read (unmatched) GTFS-RT messages from. This can be done using the [NATS CLI](https://github.com/nats-io/natscli):
+We also need to create a [NATS JetStream](https://docs.nats.io/nats-concepts/jetstream) [stream](https://docs.nats.io/nats-concepts/jetstream/streams) called `AUS_ISTFAHRT_2` that `gtfs-rt-feed` will read (unmatched) VDV-454 `AUS` `IstFahrt` messages from. This can be done using the [NATS CLI](https://github.com/nats-io/natscli):
 
 ```shell
 nats stream add \
@@ -192,7 +192,7 @@ nats stream add \
 	AUS_ISTFAHRT_2
 ```
 
-On the `AUS_ISTFAHRT_2` stream, we create a durable [consumer]():
+On the `AUS_ISTFAHRT_2` stream, we create a durable [consumer](https://docs.nats.io/nats-concepts/jetstream/consumers) called `gtfs-rt-feed`:
 
 ```shell
 nats consumer add \
@@ -219,6 +219,23 @@ nats consumer add \
 	gtfs-rt-feed
 ```
 
+Next, again using the NATS CLI, we'll create a stream called `GTFS_RT_2` that the `gtfs-rt-feed` service will write (matched) GTFS-RT messages into:
+
+```shell
+nats stream add \
+	# omit this if you want to configure more details
+	--defaults \
+	# collect all messages published to these subjects
+	--subjects='gtfsrt.>' \
+	# acknowledge publishes
+	--ack \
+	# with limited storage, discard the oldest limits first
+	--retention=limits --discard=old \
+	--description='GTFS-RT messages' \
+	# name of the stream
+	GTFS_RT_2
+```
+
 #### configure access to Redis
 
 `gtfs-rt-feed` uses [`ioredis`](https://npmjs.com/package/ioredis) to connect to PostgreSQL; For details about supported environment variables and their defaults, refer to [its docs](https://github.com/redis/ioredis#readme).