Add docker-network.sh

docker-network.sh

@@ -0,0 +1,63 @@
+#!/bin/bash
+
+set -euo pipefail
+
+# -------------------------------
+# Prompt user for subnet base
+# -------------------------------
+
+read -rp "Enter the second octet for your Docker network (e.g., 100 for 10.100.0.0/16): " octet
+
+# Validate that it's a number between 1 and 254
+if ! [[ "$octet" =~ ^[0-9]{1,3}$ ]] || ((octet < 1 || octet > 254)); then
+    echo "Invalid input. Must be a number between 1 and 254."
+    exit 1
+fi
+
+# -------------------------------
+# Define values
+# -------------------------------
+
+DOCKER_CONFIG_FILE="/etc/docker/daemon.json"
+ADDRESS_POOL_BASE="10.${octet}.0.0/16"
+ADDRESS_POOL_SIZE=24
+NETWORK_NAME="bridge_default"
+NETWORK_SUBNET="10.${octet}.1.0/24"
+
+# -------------------------------
+# Replace daemon.json
+# -------------------------------
+
+echo "Writing Docker daemon.json with base $ADDRESS_POOL_BASE..."
+
+mkdir -p /etc/docker
+cat > "$DOCKER_CONFIG_FILE" <<EOF
+{
+    "default-address-pools": [
+        {
+            "base": "10.${octet}.0.0/16",
+            "size": 24
+        }
+    ]
+}
+EOF
+
+echo "Docker config updated at $DOCKER_CONFIG_FILE"
+
+# -------------------------------
+# Delete and recreate network
+# -------------------------------
+
+if docker network inspect "$NETWORK_NAME" >/dev/null 2>&1; then
+    echo "Network '$NETWORK_NAME' exists. Deleting it..."
+    docker network rm "$NETWORK_NAME"
+fi
+
+echo "Creating network '$NETWORK_NAME' with subnet $NETWORK_SUBNET..."
+docker network create \
+    --driver=bridge \
+    --subnet="$NETWORK_SUBNET" \
+    "$NETWORK_NAME"
+
+echo "✅ Done. You may need to restart Docker to apply default address pool changes:"
+echo "   sudo systemctl restart docker"