Subnet docker conflict check; enterprice domain alias.

infrastructure_files/getting-started.sh

@@ -108,6 +108,14 @@ check_nb_domain() {
     echo "The NETBIRD_DOMAIN cannot be netbird.example.com" > /dev/stderr
     return 1
   fi
+
+  # Letters, digits, dots, and hyphens only; the domain is embedded in
+  # generated YAML and env files
+  local re='^[A-Za-z0-9]([A-Za-z0-9.-]*[A-Za-z0-9])?$'
+  if [[ "$DOMAIN" != "use-ip" ]] && [[ ! "$DOMAIN" =~ $re ]]; then
+    echo "The NETBIRD_DOMAIN may only contain letters, digits, dots, and hyphens." > /dev/stderr
+    return 1
+  fi
   return 0
 }
 
@@ -337,6 +345,103 @@ wait_management_direct() {
   return 0
 }
 
+############################################
+# Docker Network Subnet Override and Conflict Check
+############################################
+
+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+
+  case "$1" in
+    0.*|127.*|169.254.*|22[4-9].*|2[34][0-9].*|25[0-5].*) return 1 ;;
+  esac
+  return 0
+}
+
+# Apply NETBIRD_DOCKER_SUBNET and derive the gateway (.1) and Traefik IP (.10)
+apply_docker_subnet_override() {
+  if [[ -n "${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, 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"
+  command -v docker &> /dev/null || return 0
+
+  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.sh" > /dev/stderr
+        exit 1
+      fi
+    done
+  done < <(docker network inspect --format '{{.Name}}|{{range .IPAM.Config}}{{.Subnet}} {{end}}' $(docker network ls -q 2>/dev/null) 2>/dev/null || true)
+  return 0
+}
+
+configure_docker_subnet() {
+  # Only the built-in Traefik mode pins a subnet; other modes let Docker pick
+  if [[ "$REVERSE_PROXY_TYPE" != "0" ]]; then
+    return 0
+  fi
+
+  # Skip our own network (<project>_netbird) in the conflict check;
+  # normalization matches compose-go's NormalizeProjectName
+  local project
+  project="${COMPOSE_PROJECT_NAME:-$(basename "$PWD")}"
+  project=$(echo "$project" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9_-]//g; s/^[_-]*//')
+  check_docker_subnet_conflicts "${project}_netbird"
+  return 0
+}
+
 ############################################
 # Initialization and Configuration
 ############################################
@@ -368,7 +473,11 @@ initialize_default_values() {
   BIND_LOCALHOST_ONLY="true"
   EXTERNAL_PROXY_NETWORK=""
 
-  # Traefik static IP within the internal bridge network
+  # Internal bridge network. Management and proxy trust forwarded headers
+  # from TRAEFIK_IP 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"
 
   # NetBird Proxy configuration
@@ -663,8 +772,10 @@ init_environment() {
   check_docker_sock_perms
 
   initialize_default_values
+  apply_docker_subnet_override
   configure_domain
   configure_reverse_proxy
+  configure_docker_subnet
 
   check_jq
 
@@ -686,6 +797,7 @@ render_docker_compose_traefik_builtin() {
   local crowdsec_volumes=""
   local traefik_file_provider=""
   local traefik_dynamic_volume=""
+
   if [[ "$ENABLE_PROXY" == "true" ]]; then
     traefik_file_provider='      - "--providers.file.filename=/etc/traefik/dynamic.yaml"'
     traefik_dynamic_volume="      - ./traefik-dynamic.yaml:/etc/traefik/dynamic.yaml:ro"
@@ -884,8 +996,8 @@ networks:
     driver: bridge
     ipam:
       config:
-        - subnet: 172.30.0.0/24
-          gateway: 172.30.0.1
+        - subnet: $DOCKER_SUBNET
+          gateway: $DOCKER_GATEWAY
 EOF
   return 0
 }