[infrastructure] Add Docker subnet override, conflict check, and enterprise domain alias to the self-hosted install scripts

infrastructure_files/getting-started-enterprise.sh

@@ -12,7 +12,10 @@ SED_STRIP_PADDING='s/=//g'
 NETBIRD_EULA_URL="https://netbird.io/self-hosted-EULA"
 
 # Static IP for Traefik inside the compose bridge network. The management
-# server trusts X-Forwarded-* headers from this address only.
+# server trusts X-Forwarded-* headers from this address only, so all three
+# values derive from the same /24. Override with NETBIRD_DOCKER_SUBNET.
+DOCKER_SUBNET="172.30.0.0/24"
+DOCKER_GATEWAY="172.30.0.1"
 TRAEFIK_IP="172.30.0.10"
 
 check_docker_compose() {
@@ -43,6 +46,132 @@ rand_b64_key() {
   openssl rand -base64 32
 }
 
+# ------------------------------------------------------------------
+# Docker network subnet override and conflict check
+# (kept in sync with getting-started.sh; only the compose network
+# name differs)
+# ------------------------------------------------------------------
+
+ip_to_int() {
+  local a b c d
+  IFS=. read -r a b c d <<< "$1"
+  echo $(( (10#$a << 24) + (10#$b << 16) + (10#$c << 8) + 10#$d ))
+}
+
+# cidrs_overlap <cidr> <cidr> — succeeds if the networks overlap
+cidrs_overlap() {
+  local net1="${1%/*}" len1="${1#*/}" net2="${2%/*}" len2="${2#*/}"
+  local min_len=$(( len1 < len2 ? len1 : len2 ))
+  local mask=0
+  if [[ "$min_len" -gt 0 ]]; then
+    mask=$(( (0xFFFFFFFF << (32 - min_len)) & 0xFFFFFFFF ))
+  fi
+  [[ $(( $(ip_to_int "$net1") & mask )) -eq $(( $(ip_to_int "$net2") & mask )) ]]
+}
+
+# valid_ipv4_slash24 <cidr> — accepts a unicast IPv4 /24 like 10.123.45.0/24
+valid_ipv4_slash24() {
+  local octet='(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])'
+  local re="^${octet}\.${octet}\.${octet}\.0/24$"
+  [[ "$1" =~ $re ]] || return 1
+  # Reject non-unicast/reserved ranges: 0/8, loopback, link-local, 224+.
+  # 100.64/10 is rejected too: NetBird allocates overlay peer addresses from
+  # it by default, and a bridge there shadows the overlay without any Docker
+  # network overlapping, so the conflict check below would not catch it.
+  case "$1" in
+    0.*|127.*|169.254.*|22[4-9].*|2[34][0-9].*|25[0-5].*) return 1 ;;
+    100.6[4-9].*|100.[7-9][0-9].*|100.1[01][0-9].*|100.12[0-7].*) return 1 ;;
+  esac
+  return 0
+}
+
+# Apply NETBIRD_DOCKER_SUBNET and derive the gateway (.1) and Traefik IP (.10)
+apply_docker_subnet_override() {
+  if [[ -n "${NETBIRD_DOCKER_SUBNET:-}" ]]; then
+    if ! valid_ipv4_slash24 "$NETBIRD_DOCKER_SUBNET"; then
+      echo "NETBIRD_DOCKER_SUBNET must be a unicast IPv4 /24 network like 10.123.45.0/24 (0/8, 127/8, 169.254/16, 100.64/10, and 224+ are not allowed), got: $NETBIRD_DOCKER_SUBNET" > /dev/stderr
+      exit 1
+    fi
+    DOCKER_SUBNET="$NETBIRD_DOCKER_SUBNET"
+  fi
+  local base="${DOCKER_SUBNET%.0/24}"
+  DOCKER_GATEWAY="${base}.1"
+  TRAEFIK_IP="${base}.10"
+  return 0
+}
+
+# check_docker_subnet_conflicts <compose network name>
+# Fail early if an existing Docker network overlaps DOCKER_SUBNET, instead
+# of letting "docker compose up" fail later. Host routes are not checked;
+# NETBIRD_DOCKER_SUBNET covers those cases.
+check_docker_subnet_conflicts() {
+  local expected_network="$1"
+  if ! command -v docker &> /dev/null; then
+    echo "ERROR: the Docker CLI was not found in PATH." > /dev/stderr
+    echo "It is required to verify that $DOCKER_SUBNET is free before this install pins it." > /dev/stderr
+    echo "Install Docker (https://docs.docker.com/engine/install/) and run this script again." > /dev/stderr
+    exit 1
+  fi
+
+  # docker's own stderr is left visible on purpose: "is the daemon running"
+  # and socket permission errors are the actionable part. Only the exit status
+  # is handled here, because skipping the check silently would resurface later
+  # as a confusing "docker compose up" failure.
+  local ids_raw ls_status=0
+  ids_raw="$(docker network ls -q)" || ls_status=$?
+  if [[ "$ls_status" -ne 0 ]]; then
+    echo "ERROR: could not list the existing Docker networks (docker network ls exited $ls_status)." > /dev/stderr
+    echo "Without it this script cannot verify that $DOCKER_SUBNET is free." > /dev/stderr
+    echo "Make sure the Docker daemon is running and reachable by this user, then run this script again." > /dev/stderr
+    exit 1
+  fi
+
+  # Collect the IDs in an array so they reach docker as separate arguments
+  local network_ids=() id
+  while IFS= read -r id; do
+    if [[ -n "$id" ]]; then
+      network_ids+=("$id")
+    fi
+  done <<< "$ids_raw"
+
+  # No Docker networks at all: nothing can overlap, so there is nothing to check
+  [[ "${#network_ids[@]}" -gt 0 ]] || return 0
+
+  local inspect_output inspect_status=0
+  inspect_output="$(docker network inspect --format '{{.Name}}|{{range .IPAM.Config}}{{.Subnet}} {{end}}' "${network_ids[@]}")" || inspect_status=$?
+  if [[ "$inspect_status" -ne 0 ]]; then
+    echo "ERROR: could not inspect the existing Docker networks (docker network inspect exited $inspect_status)." > /dev/stderr
+    echo "Without it this script cannot verify that $DOCKER_SUBNET is free." > /dev/stderr
+    echo "If a Docker network was removed while this script was running, run the script again." > /dev/stderr
+    exit 1
+  fi
+
+  local name subnets subnet
+  while IFS='|' read -r name subnets; do
+    for subnet in $subnets; do
+      [[ "$subnet" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/[0-9]+$ ]] || continue
+      if [[ "$name" == "$expected_network" ]]; then
+        # Our own leftover network: compose reuses it as-is, so its subnet
+        # must match the one we render
+        if [[ "$subnet" != "$DOCKER_SUBNET" ]]; then
+          echo "ERROR: the Docker network '$name', left over from a previous NetBird install, uses $subnet instead of $DOCKER_SUBNET." > /dev/stderr
+          echo "docker compose would reuse it as-is, and the generated configuration would not match it." > /dev/stderr
+          echo "Remove it and run this script again:" > /dev/stderr
+          echo "  docker network rm $name" > /dev/stderr
+          exit 1
+        fi
+      elif cidrs_overlap "$DOCKER_SUBNET" "$subnet"; then
+        echo "ERROR: the existing Docker network '$name' ($subnet) overlaps $DOCKER_SUBNET, the subnet NetBird would use." > /dev/stderr
+        echo "That network is not managed by this script and is left untouched." > /dev/stderr
+        echo "Pick a free /24 for NetBird instead and run this script again:" > /dev/stderr
+        echo "  NETBIRD_DOCKER_SUBNET=10.123.45.0/24 ./getting-started-enterprise.sh" > /dev/stderr
+        exit 1
+      fi
+    done
+  done <<< "$inspect_output"
+  return 0
+}
+
 check_nb_domain() {
   local domain="$1"
   if [[ -z "$domain" ]]; then
@@ -224,6 +353,9 @@ wait_postgres() {
 init_environment() {
   check_openssl
   DOCKER_COMPOSE_COMMAND=$(check_docker_compose)
+  # Settle the subnet (and fail on conflicts) before the EULA and prompts
+  apply_docker_subnet_override
+  check_docker_subnet_conflicts "netbird"
 
   if [[ -f .env ]] || [[ -f docker-compose.yml ]] || [[ -f config.yaml ]]; then
     echo "Generated files already exist in $(pwd)."
@@ -273,6 +405,7 @@ init_environment() {
   echo "  Traffic flow: ${NETBIRD_TRAFFIC_FLOW}"
   echo "  Domain:       ${NETBIRD_DOMAIN}"
   echo "  ACME email:   ${NETBIRD_LETSENCRYPT_EMAIL}"
+  echo "  Subnet:       ${DOCKER_SUBNET} (Traefik at ${TRAEFIK_IP})"
   echo ""
   echo "Rendering files into $(pwd) ..."
   install -m 600 /dev/null .env
@@ -334,7 +467,12 @@ NETBIRD_DOMAIN=${NETBIRD_DOMAIN}
 # Reverse proxy (Traefik)
 NETBIRD_LETSENCRYPT_EMAIL=${NETBIRD_LETSENCRYPT_EMAIL}
 NETBIRD_TRAEFIK_TAG=${NETBIRD_TRAEFIK_TAG:-v3.6}
+# These three must stay in step with the /32 trust pins in config.yaml
+# (reverseProxy.trustedPeers/trustedHTTPProxies). Shell env vars override
+# this file at compose time.
 NETBIRD_TRAEFIK_IP=${TRAEFIK_IP}
+NETBIRD_NETWORK_SUBNET=${DOCKER_SUBNET}
+NETBIRD_NETWORK_GATEWAY=${DOCKER_GATEWAY}
 
 # Image tags. Default to "latest"
 NETBIRD_DASHBOARD_TAG=${NETBIRD_DASHBOARD_TAG:-latest}
@@ -417,6 +555,9 @@ render_compose_common() {
     networks:
       netbird:
         ipv4_address: ${NETBIRD_TRAEFIK_IP}
+        # Resolve the public domain inside this network (avoids hairpin NAT)
+        aliases:
+          - "${NETBIRD_DOMAIN}"
     command:
       # Logging
       - "--log.level=INFO"
@@ -660,8 +801,8 @@ networks:
     driver: bridge
     ipam:
       config:
-        - subnet: 172.30.0.0/24
-          gateway: 172.30.0.1
+        - subnet: ${NETBIRD_NETWORK_SUBNET}
+          gateway: ${NETBIRD_NETWORK_GATEWAY}
 EOF
 }