enh: Add samba image for files_external tests in server

samba/Dockerfile

@@ -0,0 +1,25 @@
+# Inspired by https://hub.docker.com/r/silvershell/samba/
+FROM debian:bookworm
+
+ENV SMB_USER smbuser
+ENV SMB_PASSWORD smbpassword
+
+RUN apt-get update && apt-get install -y \
+	samba \
+	smbclient \
+	&& rm -rf /var/lib/apt/lists/*
+
+RUN mkdir -p /opt/samba/share
+RUN chmod 777 /opt/samba/share
+
+RUN mkdir -p /opt/samba/user
+RUN chmod 777 /opt/samba/user
+
+RUN useradd -s /bin/false "$SMB_USER"
+RUN (echo "$SMB_PASSWORD"; echo "$SMB_PASSWORD" ) | pdbedit -a -u "$SMB_USER"
+
+EXPOSE 137/udp 138/udp 139 445
+
+COPY smb.conf /etc/samba/smb.conf
+
+CMD /usr/sbin/smbd --daemon --foreground --debug-stdout

samba/smb.conf

@@ -0,0 +1,46 @@
+[global]
+    security = user
+
+    load printers = no
+    printcap name = /dev/null
+    printing = bsd
+
+    unix charset = UTF-8
+    dos charset = CP932
+
+    workgroup = WORKGROUP
+
+    server string = %h server (Samba, Ubuntu)
+    dns proxy = no
+    interfaces = eth* lo
+    bind interfaces only = no
+    log file = /var/log/samba/log.%m
+    max log size = 1000
+    syslog = 0
+    panic action = /usr/share/samba/panic-action %d
+    server role = standalone server
+    passdb backend = tdbsam
+    obey pam restrictions = yes
+    unix password sync = yes
+    passwd program = /usr/bin/passwd %u
+    passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
+    pam password change = yes
+    map to guest = Bad User
+    usershare allow guests = yes
+
+[public]
+    path = /opt/samba/share
+    writable = yes
+    printable = no
+    public = yes
+    guest only = yes
+    create mode = 0777
+    directory mode = 0777
+
+[user]
+    path = /opt/samba/user
+    writable = yes
+    printable = no
+    public = no
+    create mode = 0777
+    directory mode = 0777