Re: [PATCH] Better support for upgrading packages in opkg and update-rc.d.bbclass

[Martin Jansa <martin.jansa@gmail.com>]

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On Fri, Oct 10, 2014 at 04:20:00AM +1100, Peter Urbanec wrote:
> init-ifupdown inherits default implementations of prerm, postrm, preinst
> and postinst from update-rc.d.bbclass. Unfortunately these default
> implementations don't deal with package upgrades as well as they could.
> 
> What ends up happening is that opkg starts downloading and unpacking
> packages sequentially. As it downloads and unpacks each package, opkg
> calls prerm, preinst and postrm hook scripts. Once all packages are
> unpacked, the postinst script is finally called for all packages as part
> of the "configure" stage.
> 
> The default prerm and preinst scripts stop networking. Networking is not
> brought back up again until postinst is called, but that only happens
> after all the packages have been downloaded, unpacked and installed. This
> leaves a window where any package that needs to be downloaded after
> init-ifupdown is encountered will fail.
> 
> This fixes the problem by enhancing opkg to also provide the "upgrade"
> argument to prerm and postrm, to (partially) match what dpkg does. See
> https://wiki.debian.org/MaintainerScripts for dpkg diagrams that clarify
> the intended process. opkg lacks the full functionality of dpkg, but for
> the purpose of this exercise, they are similar enough.
> 
> I have submitted a patch to the opkg-devel list to include the "upgrade"
> argument.
> 
> The second part of the solution is an update to the default implementations
> of the pre- and post- scripts provided by update-rc.d.bbclass. The scripts
> are now careful to remove themselves using the old package context and to
> delay the restart of a service until the configure stage called from the
> postinst script.

Wrong ML -> oe-core

> 
> ---
>  meta/classes/update-rc.d.bbclass                   | 75 +++++++++++++---------
>  .../opkg/upgrade-argument-for-pre_postrm.patch     | 30 +++++++++
>  meta/recipes-devtools/opkg/opkg_0.2.2.bb           |  1 +
>  3 files changed, 77 insertions(+), 29 deletions(-)
>  create mode 100644 meta/recipes-devtools/opkg/opkg/upgrade-argument-for-pre_postrm.patch
> 
> diff --git a/meta/classes/update-rc.d.bbclass b/meta/classes/update-rc.d.bbclass
> index bc1aa7d..c29457f 100644
> --- a/meta/classes/update-rc.d.bbclass
> +++ b/meta/classes/update-rc.d.bbclass
> @@ -14,45 +14,62 @@ INITSCRIPT_PARAMS ?= "defaults"
>   INIT_D_DIR = "${sysconfdir}/init.d"
>  -updatercd_preinst() {
> -if [ -z "$D" -a -f "${INIT_D_DIR}/${INITSCRIPT_NAME}" ]; then
> -	${INIT_D_DIR}/${INITSCRIPT_NAME} stop
> +# During an upgrade, the pre/postrm scripts from old package are called
> +# and the pre/postinst scripts called are from the new package.
> +# See https://wiki.debian.org/MaintainerScripts for dpkg diagrams.
> +# opkg uses a subset, which lacks most of the error handling.
> +
> +# Old package context, step 1
> +updatercd_prerm() {
> +if [ "x$1" != "xupgrade" ] ; then
> +  ${INIT_D_DIR}/${INITSCRIPT_NAME} stop
>  fi
> -if type update-rc.d >/dev/null 2>/dev/null; then
> -	if [ -n "$D" ]; then
> -		OPT="-f -r $D"
> -	else
> -		OPT="-f"
> -	fi
> -	update-rc.d $OPT ${INITSCRIPT_NAME} remove
> +if [ -z "$D" ]; then
> +  OPT=""
> +else
> +  OPT="-r $D"
>  fi
> -}
> -
> -updatercd_postinst() {
>  if type update-rc.d >/dev/null 2>/dev/null; then
> -	if [ -n "$D" ]; then
> -		OPT="-r $D"
> -	else
> -		OPT="-s"
> -	fi
> -	update-rc.d $OPT ${INITSCRIPT_NAME} ${INITSCRIPT_PARAMS}
> +  update-rc.d $OPT ${INITSCRIPT_NAME} remove
>  fi
>  }
>  -updatercd_prerm() {
> -if [ -z "$D" ]; then
> -	${INIT_D_DIR}/${INITSCRIPT_NAME} stop
> -fi
> +# New package context, step 2
> +updatercd_preinst() {
> +case "$1" in
> +  upgrade)
> +    ;;
> +  *)
> +    ;;
> +esac
>  }
>  +# Old package context, step 3
>  updatercd_postrm() {
> +case "$1" in
> +  upgrade)
> +    ;;
> +  *)
> +    ;;
> +esac
> +}
> +
> +# N.B. Step 4 runs after all packages have been through steps 1-3 and therefore we
> +#      need to delay service restarts during upgrade until here. Otherwise we end
> +#      up with situations, like networking going down in the middle of "opkg upgrade",
> +#      thus resulting in failures to fetch further packages.
> +
> +# New package context, step 4
> +updatercd_postinst() {
>  if type update-rc.d >/dev/null 2>/dev/null; then
> -	if [ -n "$D" ]; then
> -		OPT="-r $D"
> -	else
> -		OPT=""
> -	fi
> -	update-rc.d $OPT ${INITSCRIPT_NAME} remove
> +  if [ -n "$D" ]; then
> +    OPT="-r $D"
> +  else
> +    # This will catch the upgrade case and result in a restart.
> +    ${INIT_D_DIR}/${INITSCRIPT_NAME} stop
> +    OPT="-s"
> +  fi
> +  update-rc.d $OPT ${INITSCRIPT_NAME} ${INITSCRIPT_PARAMS}
>  fi
>  }
>  diff --git a/meta/recipes-devtools/opkg/opkg/upgrade-argument-for-pre_postrm.patch b/meta/recipes-devtools/opkg/opkg/upgrade-argument-for-pre_postrm.patch
> new file mode 100644
> index 0000000..5bea82a
> --- /dev/null
> +++ b/meta/recipes-devtools/opkg/opkg/upgrade-argument-for-pre_postrm.patch
> @@ -0,0 +1,30 @@
> +From: Peter Urbanec
> +Subject: [opkg] Use "upgrade" argument in prerm and postrm scripts
> +
> +Current implementation of opkg makes it difficult to distinguish between
> +package removal or upgrade in prerm and postrm scripts. The following patch
> +will make it easier and is close(r) to what dpkg does.
> +
> +diff --git a/libopkg/opkg_remove.c b/libopkg/opkg_remove.c
> +index 07401b2..52454f8 100644
> +--- a/libopkg/opkg_remove.c
> ++++ b/libopkg/opkg_remove.c
> +@@ -292,7 +292,7 @@ opkg_remove_pkg(pkg_t *pkg, int from_upgrade)
> +      pkg->state_want = SW_DEINSTALL;
> +      opkg_state_changed++;
> + +-     if (pkg_run_script(pkg, "prerm", "remove") != 0) {
> ++     if (pkg_run_script(pkg, "prerm", from_upgrade ? "upgrade" : "remove") != 0) {
> +          if (!conf->force_remove) {
> +              opkg_msg(ERROR, "not removing package \"%s\", "
> +                              "prerm script failed\n", pkg->name);
> +@@ -310,7 +310,7 @@ opkg_remove_pkg(pkg_t *pkg, int from_upgrade)
> +        feel free to fix this. */
> +      remove_data_files_and_list(pkg);
> +
> +-     err = pkg_run_script(pkg, "postrm", "remove");
> ++     err = pkg_run_script(pkg, "postrm", from_upgrade ? "upgrade" : "remove");
> +
> +      remove_maintainer_scripts(pkg);
> +      pkg->state_status = SS_NOT_INSTALLED;
> + diff --git a/meta/recipes-devtools/opkg/opkg_0.2.2.bb b/meta/recipes-devtools/opkg/opkg_0.2.2.bb
> index 3dd7489..9c0045e 100644
> --- a/meta/recipes-devtools/opkg/opkg_0.2.2.bb
> +++ b/meta/recipes-devtools/opkg/opkg_0.2.2.bb
> @@ -4,6 +4,7 @@ SRC_URI = "http://downloads.yoctoproject.org/releases/${BPN}/${BPN}-${PV}.tar.gz
>             file://no-install-recommends.patch \
>             file://add-exclude.patch \
>             file://opkg-configure.service \
> +           file://upgrade-argument-for-pre_postrm.patch \
>  "
>   S = "${WORKDIR}/${BPN}-${PV}"
> -- 
> 2.1.2
> 
> -- 
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-- 
Martin 'JaMa' Jansa     jabber: Martin.Jansa@gmail.com

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