[POSTFIX] first progress

.env.example

@@ -1,9 +1,12 @@
 REALM=EXAMPLE.COM
 WORKGROUP=EXAMPLE
 DOMAIN=example.com
-JOIN_USER=administrator
+JOIN_USER=FileShare_ServiceAccount
-JOIN_PASSWORD=ChangeMe
+JOIN_PASSWORD=ReplaceWithLongRandomPassword
-PUBLIC_GROUP=Domain Users
+DOMAIN_USERS_SID=S-1-5-21-1111111111-2222222222-3333333333-513
-# SAMBA_HOSTNAME=ad-samba-file-server
+DOMAIN_ADMINS_SID=S-1-5-21-1111111111-2222222222-3333333333-512
+PUBLIC_GROUP_SID=S-1-5-21-1111111111-2222222222-3333333333-513
+# SAMBA_HOSTNAME=adsambafsrv
+# NETBIOS_NAME=ADSAMBAFSRV
 # LDAP_URI=ldaps://example.com
 # LDAP_BASE_DN=DC=example,DC=com

README.md

@@ -14,6 +14,8 @@ This repository provides a production-oriented Samba file server container that
   - `/data/groups/<objectGUID>`
 - Samba machine trust/key material is persisted in `/var/lib/samba` to survive container recreation.
 - Container hostname is fixed (`SAMBA_HOSTNAME`) to keep AD computer identity stable.
+- NetBIOS name defaults to `ADSAMBAFSRV` and is clamped to 15 characters (`NETBIOS_NAME` override supported).
+- Setup prompts for well-known authorization groups by SID (`DOMAIN_USERS_SID`, `DOMAIN_ADMINS_SID`) to avoid localized group names.
 - Reconciliation is executed:
   - once on startup
   - every 5 minutes via cron
@@ -48,7 +50,8 @@ CREATE TABLE shares (
 ## AD Requirements
 
 - Existing AD DS domain reachable from the Docker host.
-- A service account with rights to join computers to the domain (`net ads join`).
+- Initial admin credentials with rights to create/reset `FileShare_ServiceAccount` during `./setup`.
+- `FileShare_ServiceAccount` must be allowed to join computers to the domain (`net ads join`) in your AD policy.
 - Dynamic group discovery primarily uses machine-account LDAP (`net ads search -P`); join credentials are only used as a fallback LDAP bind path.
 - Group naming convention for dynamic shares:
   - `FileShare_<ShareName>`
@@ -91,16 +94,27 @@ Kerberos requires close time alignment.
    - `REALM`
    - `WORKGROUP`
    - `DOMAIN`
-   - `JOIN_USER`
+   - initial admin credentials (used once for provisioning)
-   - `JOIN_PASSWORD`
+   - `DOMAIN_USERS_SID`
+   - `DOMAIN_ADMINS_SID`
+   - optional `PUBLIC_GROUP_SID` (defaults to `DOMAIN_USERS_SID`)
 
-3. The setup script writes `.env` and starts the service with:
+   Optional:
+   - `SAMBA_HOSTNAME` (defaults to `adsambafsrv`)
+   - `NETBIOS_NAME` (defaults to `ADSAMBAFSRV`, max 15 chars)
+
+3. Setup behavior:
+   - creates or updates AD account `FileShare_ServiceAccount`
+   - always sets a long random password
+   - writes only service-account credentials to `.env` (initial admin credentials are not stored)
+
+4. The setup script then starts the service with:
 
    ```bash
    docker compose up -d
    ```
 
-4. After startup:
+5. After startup:
     - container joins AD (idempotent)
     - startup reconciliation runs
     - cron runs reconciliation every 5 minutes
@@ -123,7 +137,7 @@ Kerberos requires close time alignment.
 
 - Share: `\\server\Public`
 - Path: `/data/public`
-- Read/write for authenticated users in configurable `PUBLIC_GROUP` (default `Domain Users`).
+- Read/write for authenticated users in configurable `PUBLIC_GROUP_SID` (default: `DOMAIN_USERS_SID`, resolved through winbind).
 - No guest access.
 
 ### Dynamic Group Shares
@@ -147,7 +161,7 @@ docker compose exec samba testparm -s
 
 ### Domain join fails
 
-- Verify credentials in `.env`.
+- Verify service account credentials in `.env`.
 - Verify DNS resolution from container:
 
   ```bash
@@ -155,6 +169,11 @@ docker compose exec samba testparm -s
   ```
 
 - Verify time sync on host and AD DCs.
+- Verify NetBIOS name length is <= 15:
+
+  ```bash
+  docker compose exec samba testparm -s | grep -i 'netbios name'
+  ```
 
 ### Winbind user/group resolution fails
 

app/init.sh

@@ -18,6 +18,55 @@ append_winbind_to_nss() {
   sed -ri '/^group:/ { /winbind/! s/$/ winbind/ }' /etc/nsswitch.conf
 }
 
+derive_netbios_name() {
+  local raw_name="${NETBIOS_NAME:-ADSAMBAFSRV}"
+  local upper_name="${raw_name^^}"
+  local cleaned_name
+  cleaned_name="$(printf '%s' "$upper_name" | tr -cd 'A-Z0-9')"
+
+  if [[ -z "$cleaned_name" ]]; then
+    cleaned_name="SAMBAFS"
+  fi
+
+  if [[ ${#cleaned_name} -gt 15 ]]; then
+    log "NETBIOS_NAME derived from '${raw_name}' exceeds 15 chars, truncating."
+  fi
+
+  export NETBIOS_NAME="${cleaned_name:0:15}"
+}
+
+resolve_sid_to_group() {
+  local sid="$1"
+  local group_name=""
+  local sid_output=""
+
+  if sid_output="$(wbinfo --sid-to-fullname "$sid" 2>/dev/null)"; then
+    group_name="${sid_output%%$'\t'*}"
+  fi
+
+  if [[ -z "$group_name" ]] && sid_output="$(wbinfo -s "$sid" 2>/dev/null)"; then
+    group_name="$(printf '%s' "$sid_output" | sed -E 's/[[:space:]]+[0-9]+$//')"
+  fi
+
+  if [[ -z "$group_name" ]]; then
+    printf '[init] ERROR: unable to resolve SID %s via winbind\n' "$sid" >&2
+    return 1
+  fi
+
+  printf '%s\n' "$group_name"
+}
+
+resolve_share_groups_from_sids() {
+  export DOMAIN_USERS_GROUP
+  DOMAIN_USERS_GROUP="$(resolve_sid_to_group "$DOMAIN_USERS_SID")"
+
+  export DOMAIN_ADMINS_GROUP
+  DOMAIN_ADMINS_GROUP="$(resolve_sid_to_group "$DOMAIN_ADMINS_SID")"
+
+  export PUBLIC_GROUP
+  PUBLIC_GROUP="$(resolve_sid_to_group "$PUBLIC_GROUP_SID")"
+}
+
 render_krb5_conf() {
   cat > /etc/krb5.conf <<EOF
 [libdefaults]
@@ -50,13 +99,19 @@ write_runtime_env_file() {
     printf 'export REALM=%q\n' "$REALM"
     printf 'export WORKGROUP=%q\n' "$WORKGROUP"
     printf 'export DOMAIN=%q\n' "$DOMAIN"
+    printf 'export NETBIOS_NAME=%q\n' "$NETBIOS_NAME"
+    printf 'export DOMAIN_USERS_SID=%q\n' "$DOMAIN_USERS_SID"
+    printf 'export DOMAIN_ADMINS_SID=%q\n' "$DOMAIN_ADMINS_SID"
+    printf 'export PUBLIC_GROUP_SID=%q\n' "$PUBLIC_GROUP_SID"
+    printf 'export DOMAIN_USERS_GROUP=%q\n' "$DOMAIN_USERS_GROUP"
+    printf 'export DOMAIN_ADMINS_GROUP=%q\n' "$DOMAIN_ADMINS_GROUP"
+    printf 'export PUBLIC_GROUP=%q\n' "$PUBLIC_GROUP"
     if [[ -n "${JOIN_USER:-}" ]]; then
       printf 'export JOIN_USER=%q\n' "$JOIN_USER"
     fi
     if [[ -n "${JOIN_PASSWORD:-}" ]]; then
       printf 'export JOIN_PASSWORD=%q\n' "$JOIN_PASSWORD"
     fi
-    printf 'export PUBLIC_GROUP=%q\n' "$PUBLIC_GROUP"
     if [[ -n "${LDAP_URI:-}" ]]; then
       printf 'export LDAP_URI=%q\n' "$LDAP_URI"
     fi
@@ -109,9 +164,14 @@ EOF
 require_env REALM
 require_env WORKGROUP
 require_env DOMAIN
+require_env DOMAIN_USERS_SID
+require_env DOMAIN_ADMINS_SID
 
 export REALM WORKGROUP DOMAIN
-export PUBLIC_GROUP="${PUBLIC_GROUP:-Domain Users}"
+export PUBLIC_GROUP_SID="${PUBLIC_GROUP_SID:-${DOMAIN_USERS_SID}}"
+export DOMAIN_USERS_GROUP="${DOMAIN_USERS_SID}"
+export DOMAIN_ADMINS_GROUP="${DOMAIN_ADMINS_SID}"
+export PUBLIC_GROUP="${PUBLIC_GROUP_SID}"
 if [[ -n "${JOIN_USER:-}" ]]; then
   export JOIN_USER
 fi
@@ -123,7 +183,7 @@ mkdir -p /data/private /data/public /data/groups /state /etc/samba/generated /va
 touch /etc/samba/generated/shares.conf /var/log/reconcile.log
 
 append_winbind_to_nss
-write_runtime_env_file
+derive_netbios_name
 render_krb5_conf
 render_smb_conf
 join_domain_if_needed
@@ -133,6 +193,10 @@ winbindd -F --no-process-group &
 
 wait_for_winbind
 
+resolve_share_groups_from_sids
+render_smb_conf
+write_runtime_env_file
+
 log 'Running startup reconciliation'
 python3 /app/reconcile_shares.py
 

app/reconcile_shares.py

@@ -336,7 +336,7 @@ def render_dynamic_shares(conn: sqlite3.Connection) -> None:
                 "create mask = 0660",
                 "directory mask = 2770",
                 "inherit permissions = yes",
-                "access based share enumeration = yes",
+                "access based share enum = yes",
                 "",
             ]
         )
@@ -433,7 +433,9 @@ def list_domain_users() -> List[str]:
 def sync_public_directory() -> None:
     workgroup = os.environ["WORKGROUP"]
     public_group = os.getenv("PUBLIC_GROUP", "Domain Users")
-    qualified_group = f"{workgroup}\\{public_group}"
+    qualified_group = (
+        public_group if "\\" in public_group else f"{workgroup}\\{public_group}"
+    )
 
     os.makedirs(PUBLIC_ROOT, exist_ok=True)
     gid = resolve_group_gid(qualified_group)

docker-compose.yml

@@ -3,10 +3,12 @@ services:
     build:
       context: .
     container_name: ad-samba-file-server
-    hostname: ${SAMBA_HOSTNAME:-ad-samba-file-server}
+    hostname: ${SAMBA_HOSTNAME:-adsambafsrv}
     restart: unless-stopped
     env_file:
       - .env
+    environment:
+      NETBIOS_NAME: ${NETBIOS_NAME:-ADSAMBAFSRV}
     ports:
       - "445:445"
       - "139:139"

etc/samba/smb.conf

@@ -3,6 +3,7 @@
    kerberos method = secrets and keytab
    realm = ${REALM}
    workgroup = ${WORKGROUP}
+   netbios name = ${NETBIOS_NAME}
 
    idmap config * : backend = tdb
    idmap config * : range = 3000-7999
@@ -21,7 +22,7 @@
    server min protocol = SMB2
    client min protocol = SMB2
 
-   access based share enumeration = yes
+   access based share enum = yes
 
    dedicated keytab file = /var/lib/samba/private/krb5.keytab
    kerberos encryption types = all
@@ -41,10 +42,10 @@
    read only = no
    browseable = yes
    guest ok = no
-   valid users = @"${WORKGROUP}\\Domain Users"
+   valid users = @"${DOMAIN_USERS_GROUP}"
-   admin users = @"${WORKGROUP}\\Domain Admins"
+   admin users = @"${DOMAIN_ADMINS_GROUP}"
    hide unreadable = yes
-   access based share enumeration = yes
+   access based share enum = yes
    ea support = yes
 
 [Public]
@@ -52,9 +53,9 @@
    read only = no
    browseable = yes
    guest ok = no
-   valid users = @"${WORKGROUP}\\${PUBLIC_GROUP}"
+   valid users = @"${PUBLIC_GROUP}"
-   force group = "${WORKGROUP}\\${PUBLIC_GROUP}"
+   force group = "${PUBLIC_GROUP}"
    create mask = 0660
    directory mask = 2770
    inherit permissions = yes
-   access based share enumeration = yes
+   access based share enum = yes

setup

@@ -2,6 +2,26 @@
 set -euo pipefail
 
 ENV_FILE=".env"
+SERVICE_ACCOUNT_NAME="FileShare_ServiceAccount"
+
+BOOTSTRAP_ENV_FILE=""
+cleanup() {
+  if [[ -n "$BOOTSTRAP_ENV_FILE" && -f "$BOOTSTRAP_ENV_FILE" ]]; then
+    rm -f "$BOOTSTRAP_ENV_FILE"
+  fi
+}
+trap cleanup EXIT
+
+sanitize_netbios_name() {
+  local raw_name="$1"
+  local upper_name="${raw_name^^}"
+  local cleaned_name
+  cleaned_name="$(printf '%s' "$upper_name" | tr -cd 'A-Z0-9')"
+  if [[ -z "$cleaned_name" ]]; then
+    cleaned_name="ADSAMBAFSRV"
+  fi
+  printf '%s' "${cleaned_name:0:15}"
+}
 
 prompt_value() {
   local var_name="$1"
@@ -25,23 +45,106 @@ write_env_file() {
   local realm=""
   local workgroup=""
   local domain=""
-  local join_user=""
+  local admin_user=""
-  local join_password=""
+  local admin_password=""
+  local domain_users_sid=""
+  local domain_admins_sid=""
+  local public_group_sid=""
+  local samba_hostname="adsambafsrv"
+  local netbios_name="ADSAMBAFSRV"
+  local service_password=""
+  local public_group_prompt=""
+  local samba_hostname_input=""
+  local netbios_name_input=""
+  local sanitized_netbios_name=""
 
   prompt_value realm "REALM (e.g. EXAMPLE.COM)"
   prompt_value workgroup "WORKGROUP (NetBIOS, e.g. EXAMPLE)"
   prompt_value domain "DOMAIN (AD DNS name or reachable DC FQDN)"
-  prompt_value join_user "JOIN_USER (AD account with join rights)"
+  prompt_value admin_user "Initial admin user (for provisioning service account)"
-  prompt_value join_password "JOIN_PASSWORD" true
+  prompt_value admin_password "Initial admin password" true
+  prompt_value domain_users_sid "DOMAIN_USERS_SID (e.g. ...-513)"
+  prompt_value domain_admins_sid "DOMAIN_ADMINS_SID (e.g. ...-512)"
+
+  public_group_prompt="PUBLIC_GROUP_SID (press Enter to reuse DOMAIN_USERS_SID)"
+  read -r -p "${public_group_prompt}: " public_group_sid
+  if [[ -z "$public_group_sid" ]]; then
+    public_group_sid="$domain_users_sid"
+  fi
+
+  read -r -p "SAMBA_HOSTNAME [adsambafsrv]: " samba_hostname_input
+  if [[ -n "${samba_hostname_input:-}" ]]; then
+    samba_hostname="$samba_hostname_input"
+  fi
+
+  read -r -p "NETBIOS_NAME [ADSAMBAFSRV]: " netbios_name_input
+  if [[ -n "${netbios_name_input:-}" ]]; then
+    netbios_name="$netbios_name_input"
+  fi
+  sanitized_netbios_name="$(sanitize_netbios_name "$netbios_name")"
+  if [[ "$sanitized_netbios_name" != "$netbios_name" ]]; then
+    printf "Using sanitized NETBIOS_NAME: %s\n" "$sanitized_netbios_name"
+  fi
+  netbios_name="$sanitized_netbios_name"
+
+  service_password="$(tr -dc 'A-Za-z0-9@#%+=:_-' </dev/urandom | head -c 48)"
+
+  BOOTSTRAP_ENV_FILE="$(mktemp)"
+  chmod 600 "$BOOTSTRAP_ENV_FILE"
+
+  cat > "$BOOTSTRAP_ENV_FILE" <<EOF
+REALM=${realm}
+WORKGROUP=${workgroup}
+DOMAIN=${domain}
+JOIN_USER=${admin_user}
+JOIN_PASSWORD=${admin_password}
+SERVICE_ACCOUNT_NAME=${SERVICE_ACCOUNT_NAME}
+SERVICE_ACCOUNT_PASSWORD=${service_password}
+DOMAIN_USERS_SID=${domain_users_sid}
+DOMAIN_ADMINS_SID=${domain_admins_sid}
+PUBLIC_GROUP_SID=${public_group_sid}
+SAMBA_HOSTNAME=${samba_hostname}
+NETBIOS_NAME=${netbios_name}
+EOF
+
+  printf "Building image...\n"
+  docker compose build samba
+
+  printf "Provisioning service account %s...\n" "$SERVICE_ACCOUNT_NAME"
+  docker compose --env-file "$BOOTSTRAP_ENV_FILE" run --rm --entrypoint /bin/bash samba -lc '
+set -euo pipefail
+
+cat > /tmp/bootstrap-smb.conf <<EOF
+[global]
+   security = ADS
+   kerberos method = secrets and keytab
+   realm = ${REALM}
+   workgroup = ${WORKGROUP}
+   netbios name = ${NETBIOS_NAME}
+EOF
+
+run_net() {
+  printf "%s\n" "$JOIN_PASSWORD" | net -s /tmp/bootstrap-smb.conf -U "$JOIN_USER" -S "$DOMAIN" "$@"
+}
+
+if run_net ads search "(&(objectClass=user)(sAMAccountName=${SERVICE_ACCOUNT_NAME}))" sAMAccountName | grep -q "^sAMAccountName: ${SERVICE_ACCOUNT_NAME}$"; then
+  run_net ads password "${SERVICE_ACCOUNT_NAME}" "${SERVICE_ACCOUNT_PASSWORD}"
+else
+  run_net ads user add "${SERVICE_ACCOUNT_NAME}" "${SERVICE_ACCOUNT_PASSWORD}"
+fi
+'
 
   cat > "$ENV_FILE" <<EOF
 REALM=${realm}
 WORKGROUP=${workgroup}
 DOMAIN=${domain}
-JOIN_USER=${join_user}
+JOIN_USER=${SERVICE_ACCOUNT_NAME}
-JOIN_PASSWORD=${join_password}
+JOIN_PASSWORD=${service_password}
-PUBLIC_GROUP=Domain Users
+DOMAIN_USERS_SID=${domain_users_sid}
-# SAMBA_HOSTNAME=ad-samba-file-server
+DOMAIN_ADMINS_SID=${domain_admins_sid}
+PUBLIC_GROUP_SID=${public_group_sid}
+SAMBA_HOSTNAME=${samba_hostname}
+NETBIOS_NAME=${netbios_name}
 # Optional overrides:
 # LDAP_URI=ldaps://${domain}
 # LDAP_BASE_DN=DC=example,DC=com