From bb665683a8198195fb4cb07e64de6b4659d4aef5 Mon Sep 17 00:00:00 2001
From: Michael Nairn <mnairn@redhat.com>
Date: Mon, 29 Apr 2024 16:14:13 +0100
Subject: [PATCH] Increase metallb useable ips (#584)

The number of IPs available to metallb is currently really small (4)
which means you can only create a small number of gateways (3, istio
takes one) before it stops dishing out new IPs.

These changes increase the number of ips to 16 and assumes the network
will always give us a range allowing the use of all 256 ips,
0.0.0.[0-255] (This appears to be the case for kind networks created
with podman(10.89.0.0/24) and docker(172.18.0.0/16)).

Also adds an option to specify an offest (default is 0) when creating a
kuadrant cluster with local-setup allowing multiple instances to be
created using a different range of IPs.

```
make local-setup KIND_CLUSTER_NAME=kuadrant-local-1 SUBNET_OFFSET=0
make local-setup KIND_CLUSTER_NAME=kuadrant-local-2 SUBNET_OFFSET=1
```
---
 Makefile                              |  3 ++-
 utils/docker-network-ipaddresspool.sh | 15 ++++++++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 97ee65c55..257ac4628 100644
--- a/Makefile
+++ b/Makefile
@@ -424,11 +424,12 @@ deploy-dependencies: kustomize dependencies-manifests ## Deploy dependencies to
 	kubectl -n "$(KUADRANT_NAMESPACE)" wait --timeout=300s --for=condition=Available deployments --all
 
 .PHONY: install-metallb
+install-metallb: SUBNET_OFFSET=0
 install-metallb: kustomize yq ## Installs the metallb load balancer allowing use of an LoadBalancer type with a gateway
 	$(KUSTOMIZE) build config/metallb | kubectl apply -f -
 	kubectl -n metallb-system wait --for=condition=Available deployments controller --timeout=300s
 	kubectl -n metallb-system wait --for=condition=ready pod --selector=app=metallb --timeout=60s
-	./utils/docker-network-ipaddresspool.sh kind $(YQ) | kubectl apply -n metallb-system -f -
+	./utils/docker-network-ipaddresspool.sh kind $(YQ) ${SUBNET_OFFSET} | kubectl apply -n metallb-system -f -
 
 .PHONY: uninstall-metallb
 uninstall-metallb: $(KUSTOMIZE)
diff --git a/utils/docker-network-ipaddresspool.sh b/utils/docker-network-ipaddresspool.sh
index 364072c80..2e0b1b18f 100755
--- a/utils/docker-network-ipaddresspool.sh
+++ b/utils/docker-network-ipaddresspool.sh
@@ -10,6 +10,9 @@ set -euo pipefail
 
 networkName=$1
 YQ="${2:-yq}"
+offset=${3:-0}
+cidr=28
+numIPs=16
 
 ## Parse kind network subnet
 ## Take only IPv4 subnets, exclude IPv6
@@ -37,11 +40,17 @@ if [[ -z "$SUBNET" ]]; then
   exit 1
 fi
 
+network=$(echo $SUBNET | cut -d/ -f1)
 # shellcheck disable=SC2206
-subnetParts=(${SUBNET//./ })
-cidr="${subnetParts[0]}.${subnetParts[1]}.0.252/30"
+octets=(${network//./ })
 
-cat <<EOF | ADDRESS=$cidr ${YQ} '(select(.kind == "IPAddressPool") | .spec.addresses[0]) = env(ADDRESS)'
+# Default values of numIPs:16 and cidr:28 allows up to 16 clusters (offset 0-15) each with 16 possible IPs
+# Note: Assumes the network will always give us a range allowing the use of all 256 ips, 0.0.0.[0-255]
+address="${octets[0]}.${octets[1]}.${octets[2]}.$((numIPs * offset))/${cidr}"
+
+echo "IPAddressPool address calculated to be '$address' for docker network subnet: '$SUBNET', numIps: '$numIPs' and offset: '$offset'" >&2
+
+cat <<EOF | ADDRESS=$address ${YQ} '(select(.kind == "IPAddressPool") | .spec.addresses[0]) = env(ADDRESS)'
 ---
 apiVersion: metallb.io/v1beta1
 kind: IPAddressPool