chore: add demo gif

Author: tomverelst

README.md

@@ -2,6 +2,8 @@
 
 [![CI](https://github.com/cymo-eu/kannika-bridge/actions/workflows/ci.yml/badge.svg)](https://github.com/cymo-eu/kannika-bridge/actions/workflows/ci.yml)
 
+![Demo](examples/demo.gif)
+
 > ✉️ 🚀 Restore consumer offsets on kafka cluster.
 
 A powerful tool for migrating Kafka consumer group offsets between clusters, enabling seamless cluster migrations and disaster recovery scenarios.

examples/demo.gif

@@ -0,0 +1,35 @@
+# VHS tape file for kbridge demo
+# Run with: ./scripts/generate-demo.sh
+# Requires local-dev setup (docker compose)
+
+Output examples/demo.gif
+
+Set FontSize 14
+Set Width 1000
+Set Height 600
+Set LineHeight 1.4
+Set Theme "Catppuccin Mocha"
+Set WindowBar Colorful
+
+Type "kbridge fetch -b localhost:9092 -p group.id=kbridge > source_offsets.csv"
+Enter
+Wait@60s
+
+Type "cat source_offsets.csv"
+Enter
+Sleep 3s
+
+Type "kbridge calculate -b localhost:9093 -H Offset -i source_offsets.csv -p group.id=kbridge > target_offsets.csv"
+Enter
+Hide
+Wait@60s
+Show
+
+Type "kbridge apply -b localhost:9093 -i target_offsets.csv -p group.id=kbridge"
+Enter
+Sleep 2s
+
+Type "Y"
+Enter
+Wait@30s
+Sleep 5s

examples/demo.tape

@@ -35,3 +35,6 @@ run-example:
 run-docs:
 	cargo doc --no-deps && \
 	docker compose -f docker-compose-docs.yml up --build
+
+generate-demo:
+	./scripts/generate-demo.sh

justfile

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+
+if ! command -v vhs &> /dev/null; then
+    echo "Error: vhs not found. Please install: https://github.com/charmbracelet/vhs"
+    exit 1
+fi
+
+# Build and add to PATH so vhs can find kbridge
+cargo build --release
+export PATH="$PWD/target/release:$PATH"
+
+# Make sure everything is gone
+just teardown
+
+just setup-local-dev
+
+vhs examples/demo.tape
+echo "Generated examples/demo.gif"

scripts/generate-demo.sh

@@ -33,7 +33,7 @@ kafka-console-consumer \
     --topic $TOPIC \
     --max-messages $NUM_MESSAGES \
     --from-beginning \
-| sed 's/^\([0-9]*\)\s/Offset:\1|/' | sed 's/\s/|/g' \
+| awk -F'[:\t]' -v OFS='|' '{print "Offset:"$2*2, $3, $4}' \
     > "$PIPE_FILE"
 
 wait $PRODUCER_ID