[yocto] Problems with postinstall

[Neuer User]

Hi

I am desperately trying to get some postinstall scripts working. They
should replace some defualt files with custom files I have. They are all
in one package. The package looks like this:

do_install() {
    install -d ${D}${sbindir}
    install -m 0700 ${S}/sbin/* ${D}${sbindir}

    install -d ${D}${bindir}
    install -m 0755 ${S}/bin/LEDstatus ${D}${bindir}

    install -d ${D}/etc/udev/rules.d
    install -m 0644 ${S}/udev/* ${D}/etc/udev/rules.d/

    install -d ${D}/etc/ssh
    install -m 0600 ${S}/ssh/ssh_* ${D}/etc/ssh/
    install -m 0644 ${S}/ssh/authorized_keys ${D}/etc/ssh/

    install -d ${D}/etc/gnupg
    install -m 0600 ${S}/gnupg/trustedkeys.gpg ${D}/etc/gnupg/
}

# Overwrite some configuration data with specific files
pkg_postinst_${PN} () {
    install -o root -g root -m 0600 ${S}/ssh/sshd_config ${D}/etc/ssh/
    install -m 0755 ${S}/etc/rc.local ${D}/etc/
    install -m 0644 ${S}/etc/watchdog.conf ${D}/etc/
    install -m 0400 ${S}/etc/shadow ${D}/etc/
    install -m 0440 ${S}/etc/sudoers ${D}/etc/
    install -d ${D}/etc/default
    install -o root -g root -m 0644 ${S}/etc/default-ntpdate
${D}/etc/default/ntpdate
}

RDEPENDS_${PN} += "ntpdate udev ssh sudo"

FILES_${PN} += "/*"


I even tried changing the ownership of the files, but that did not
change aything.

Am I doing this completely wrong?

Thanks for any hints

Michael