# https://catalog.workshops.aws/msk-labs/en-US/addingbrokers/reassignpartitions

$ cat <<EOF > topics-to-move.json
{ "topics": [ { "topic" : "my-topic"}, { "topic" : "__consumer_offsets"} ], "version":1}
EOF

$ cat <<EOF > client.properties
security.protocol=SSL
# ...
EOF

$ export KAFKA_BROKERS="..."

# Example of repalancing partitions amoung 6 brokers:
$ bin/kafka-reassign-partitions.sh --bootstrap-server "${KAFKA_BROKERS}" --command-config client.properties --topics-to-move-json-file topics-to-move.json --broker-list "1,2,3,4,5,6"  --generate | awk -F: '/Proposed partition reassignment configuration/ { getline; print $0 }' | jq . > expand-cluster-reassignment.json

$ cat expand-cluster-reassignment.json

$ bin/kafka-reassign-partitions.sh --bootstrap-server "${KAFKA_BROKERS}" --command-config client.properties --reassignment-json-file expand-cluster-reassignment.json --execute

$ bin/kafka-reassign-partitions.sh --bootstrap-server "${KAFKA_BROKERS}" --command-config client.properties --reassignment-json-file expand-cluster-reassignment.json --verify