eclass/sys-user.eclass

   1 # Copyright 1999-2017 Gentoo Foundation
   2 # Distributed under the terms of the GNU General Public License v2
   3
   4 # @ECLASS: sys-user.eclass
   5 # @MAINTAINER:
   6 # Michael Orlitzky <mjo@gentoo.org>
   7 # @BLURB: handle installation and removal of system users.
   8 # @DESCRIPTION:
   9 # This eclass does most of the work for the sys-user/ packages that
  10 # supply system user accounts.
  11
  12 inherit user
  13
  14 EXPORT_FUNCTIONS pkg_pretend src_unpack src_configure src_compile src_install src_test pkg_preinst pkg_postinst pkg_prerm
  15
  16 : ${HOMEPAGE:="https://www.gentoo.org/"}
  17 : ${DESCRIPTION:="The ${PN} system user"}
  18 : ${LICENSE:="GPL-2"}
  19
  20 # If you want a different username, use a different package name. This
  21 # prevents different people from claiming the same username.
  22 SYS_USER_NAME="${PN}"
  23
  24 # @ECLASS-VARIABLE: SYS_USER_GROUPS
  25 # @DESCRIPTION:
  26 # etc.
  27 : ${SYS_USER_GROUPS:=${PN}}
  28
  29 # @ECLASS-VARIABLE: SYS_USER_UID
  30 # @REQUIRED
  31 # @DESCRIPTION:
  32 # etc. (use -1 to get next available using user.eclass)
  33 [[ -z "${SYS_USER_UID}" ]] && die "SYS_USER_UID must be set"
  34
  35 # @ECLASS-VARIABLE: SYS_USER_UID_IMPORTANT
  36 # @REQUIRED
  37 # @DESCRIPTION:
  38 # Set to "true" if you want to die() if you don't get your desired UID.
  39 : ${SYS_USER_UID_IMPORTANT:=false}
  40
  41 # In many cases, if the UID of a user changes, packages depending on it
  42 # will want to rebuild. We always use SLOT=0, because you can't install
  43 # the same user twice. Then we use the UID as our subslot so that
  44 # subslot deps can be used to rebuild packages when our UID changes.
  45 SLOT="0/${SYS_USER_UID}"
  46
  47 # @ECLASS-VARIABLE: SYS_USER_HOME
  48 # @DESCRIPTION:
  49 # etc. (use -1 to get user.eclass default)
  50 : ${SYS_USER_HOME:=-1}
  51
  52 # @ECLASS-VARIABLE: SYS_USER_SHELL
  53 # @DESCRIPTION:
  54 # etc. (use -1 to get user.eclass default)
  55 : ${SYS_USER_SHELL:=-1}
  56
  57 case ${EAPI} in
  58         6) ;;
  59         *)
  60                 die "${ECLASS} is not compatible with EAPI=${EAPI}"
  61 esac
  62
  63 # Depend on any groups we might need.
  64 for _group in ${SYS_USER_GROUPS}; do
  65         DEPEND+=" sys-group/${_group} "
  66         RDEPEND+=" sys-group/${_group}:= "
  67 done
  68 unset _group
  69
  70 S="${WORKDIR}"
  71
  72 sys-user_src_unpack() { :; }
  73 sys-user_src_compile() { :; }
  74 sys-user_src_test() { :; }
  75
  76 sys-user_next_uid() {
  77         local euid;
  78         for (( euid = 101; euid <= 999; euid++ )); do
  79                 [[ -z $(egetent passwd "${euid}") ]] && break
  80         done
  81         if (( "${euid}" == 999 )); then
  82                 die "out of available UIDs!"
  83         else
  84                 echo "${euid}"
  85         fi
  86 }
  87
  88 sys-user_pkg_pretend() {
  89         # Sanity checks that would otherwise run code in global scope.
  90         #
  91         # First ensure that the user didn't say his UID is important and
  92         # then fail to specify one.
  93         if (( "${SYS_USER_UID}" == -1 )) &&
  94                    [[ "${SYS_USER_UID_IMPORTANT}" == "true" ]]; then
  95                 # Don't make no damn sense.
  96                 die "arbitrary UID requested with SYS_USER_UID_IMPORTANT=true"
  97         fi
  98
  99         # Next ensure that no other username owns an important UID.
 100         if [[ "${SYS_USER_UID_IMPORTANT}" == "true" ]]; then
 101                 # Ok, the UID is important. Make sure nobody else has it. Or
 102                 # rather, nobody else *with a different username* has it.
 103                 local oldname=$(egetent passwd "${SYS_USER_UID}" | cut -f1 -d':')
 104                 if [[ "${SYS_USER_NAME}" != "${oldname}" ]]; then
 105                         die "important UID ${SYS_USER_UID} already belongs to ${oldname}"
 106                 fi
 107         fi
 108
 109         # Finally, ensure that this username doesn't already exist with
 110         # another UID if its UID is supposedly important.
 111         if [[ -n $(egetent passwd "${SYS_USER_NAME}") ]]; then
 112                 local olduid=$(id --real --user "${SYS_USER_NAME}")
 113                 if [[ "${SYS_USER_UID_IMPORTANT}" == "true" ]] && \
 114                            [[ "${SYS_USER_UID}" != "${olduid}" ]]; then
 115                         # The UID is important and specified, but there is already a
 116                         # system user with this name and a different UID. Halp.
 117                         die "user ${SYS_USER_NAME} already exists with UID ${olduid}"
 118                 fi
 119         fi
 120 }
 121
 122 sys-user_src_configure() {
 123         if [[ -n $(egetent passwd "${SYS_USER_NAME}") ]]; then
 124                 # UPGRADE PATH: This user already exists, so if the eclass
 125                 # consumer doesn't care about some settings, we can reuse the
 126                 # pre-existing ones.
 127                 #
 128                 # This is also useful for sys-user package upgrades, because it
 129                 # prevents us from incrementing the UID on a reinstall, and doing
 130                 # so would break most packages that need a system user to exist.
 131                 if [[ "${SYS_USER_UID_IMPORTANT}" != "true" ]]; then
 132                         SYS_USER_UID=$(id --real --user "${SYS_USER_NAME}")
 133                 fi
 134
 135                 if (( "${SYS_USER_HOME}" == -1 )); then
 136                         SYS_USER_HOME=$(egethome "${SYS_USER_NAME}")
 137                 fi
 138
 139                 if (( "${SYS_USER_SHELL}" == -1 )); then
 140                         SYS_USER_SHELL=$(egetshell "${SYS_USER_NAME}")
 141
 142                         if [[ ${SYS_USER_SHELL} == */false ]] || \
 143                                    [[ ${SYS_USER_SHELL} == */nologin ]]; then
 144                                 # WHYYYYY? enewuser complains if we try to set a default
 145                                 # shell explicitly.
 146                                 SYS_USER_SHELL="-1"
 147                         fi
 148                 fi
 149         elif (( "${SYS_USER_UID}" == -1 )); then
 150                 # There is no pre-existing user (i.e. this isn't along the
 151                 # upgrade path), and the consumer says he doesn't care about the
 152                 # UID, so pick the next one.
 153                 SYS_USER_UID=$(sys-user_next_uid)
 154         fi
 155 }
 156
 157 sys-user_src_install() {
 158         # Install a placeholder file to /var/lib/sys-user/$uid. This will
 159         # cause collisions if two packages try to install users with the
 160         # same UID. The same problem potentially exists with the username,
 161         # but as long as SYS_USER_NAME is hard-coded to $PN, that shouldn't
 162         # be possible.
 163         #
 164         # Beware, this only works if SYS_USER_UID is guaranteed to have a
 165         # real UID and not, for example, -1. That is taken care of in
 166         # src_configure() for now.
 167         touch "${T}/${SYS_USER_UID}" || die
 168         insinto "/var/lib/sys-user"
 169         doins "${T}/${SYS_USER_UID}"
 170 }
 171
 172 sys-user_pkg_preinst() {
 173         if [[ -z $(egetent passwd "${SYS_USER_NAME}") ]]; then
 174                 # The user does not already exist. This is the nice and easy
 175                 # case because no matter how we got here, we want to go ahead
 176                 # and create the (new) user.
 177                 enewuser "${SYS_USER_NAME}" \
 178                                  "${SYS_USER_UID}" \
 179                                  "${SYS_USER_SHELL}" \
 180                                  "${SYS_USER_HOME}" \
 181                                  "${SYS_USER_GROUPS}" \
 182                         || die "failed to add user ${SYS_USER_NAME}"
 183         elif [[ -n "${REPLACING_VERSIONS}" ]]; then
 184                 #
 185                 # This case is done in pkg_postint() to avoid clobbering a
 186                 # new user when we remove the old one.
 187                 #
 188                 :
 189         else
 190                 # UPGRADE PATH: Ok, the user exists but this isn't an upgrade of
 191                 # a sys-user package. This is the upgrade path from the old
 192                 # style of user/group management to the new style. Lets see if
 193                 # the new user is compatible with the old one; it usually will be.
 194                 # We only bail out if there's a homedir or shell conflict.
 195                 #
 196                 # We should make it policy that new sys-user packages have the
 197                 # same homedir and shell as the existing ones created by
 198                 # ebuilds, but it can't hurt to check again here. These checks
 199                 # are done here (and not in pkg_pretend, where they would be
 200                 # more consistent) because the PMS states that REPLACING_VERSIONS
 201                 # may not be defined there.
 202                 #
 203                 # If a homedir/shell changes during a sys-user upgrade, we don't
 204                 # consider that a problem, because the change was knowingly made
 205                 # by a developer who just edited an ebuild to make that change.
 206                 local oldhome=$(egethome "${SYS_USER_NAME}")
 207                 local oldshell=$(egetshell "${SYS_USER_NAME}")
 208
 209                 if [[ "${oldhome}" != "${SYS_USER_HOME}" ]]; then
 210                         die "home directory conflict for new user: ${SYS_USER_HOME}"
 211                 fi
 212
 213                 if [[ "${oldhshell}" != "${SYS_USER_SHELL}" ]]; then
 214                         die "shell conflict for new user: ${SYS_USER_SHELL}"
 215                 fi
 216
 217                 # The user already exists, so all we have left to do is to try
 218                 # to append SYS_USER_GROUPS to the existing groups. The "usermod"
 219                 # tool expects a comma-separated list, so change our spaces to
 220                 # commas. This does succeed if you append duplicates.
 221                 usermod --append --groups "${SYS_USER_GROUPS// /,}" \
 222                         || die "failed to append groups to existing user ${SYS_USER_NAME}"
 223         fi
 224 }
 225
 226 sys-user_pkg_postinst() {
 227         if [[ -n "${REPLACING_VERSIONS}" ]]; then
 228            # This is an upgrade from a previous version of a sys-user
 229            # package. This case has to be handled carefully to make sure
 230            # that the pkg_prerm() of the old version doesn't remove the user
 231            # that this new version is going to add. At this point, in our
 232            # pkg_postinst(), the old version's pkg_prerm() phase should have
 233            # already happened.
 234            if [[ -n $(egetent passwd "${SYS_USER_NAME}") ]]; then
 235                    die "User ${SYS_USER_NAME} already exists during an upgrade."
 236            else
 237                    enewuser "${SYS_USER_NAME}" \
 238                                         "${SYS_USER_UID}" \
 239                                         "${SYS_USER_SHELL}" \
 240                                         "${SYS_USER_HOME}" \
 241                                         "${SYS_USER_GROUPS}" \
 242                            || die "failed to add user ${SYS_USER_NAME}"
 243            fi
 244         fi
 245 }
 246
 247 sys-user_pkg_prerm() {
 248         if [[ -z $(egetent passwd "${SYS_USER_NAME}") ]]; then
 249                 # We have successfully done nothing.
 250                 ewarn "Tried to remove nonexistent user ${SYS_USER_NAME}."
 251         else
 252                 userdel "${SYS_USER_NAME}" || \
 253                         die "failed to remove user ${SYS_USER_NAME}"
 254                 einfo "Removed user ${SYS_USER_NAME} from the system."
 255         fi
 256 }