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Old 03-29-2011, 03:19 AM
"Aaron W. Swenson"
 
Default RFC: postgresql.eselect

Dear List,

This module is to replace the existing one that is shipped with
<app-admin/eselect-postgresql-1.0.3. It is an entire rewrite.

Changes can be tracked at:
http://git.overlays.gentoo.org/gitweb/?p=proj/pgsql-patches.git;a=shortlog;h=refs/heads/eselect

Before you start reading the attached module, please bear in mind that I
am a novice at writing BASH scripts, and am not intimately familiar with
all the nuances of the language.

There is some duplication of work within the module when compared with
the current postgresql-{base,server}-*.ebuilds in the tree. The plan is
to move that work being handled in the ebuilds to the module.

Setting a service slot has been dropped from the module as it is no
longer necessary.

Features:
* Supports --brief output
* Prefix compatible
* Slot specific application links (e.g., psql90, createdb84)
* Automatically sets the highest slot available as the default unless a
valid slot is already set
* Properly orders LDPATH giving preference to the set slot and then
lists the other slots in descending order

Thank you.

Sincerely,
Mr. Aaron W. Swenson (TitanOfOld)
# Copyright 1999-2011 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: $

inherit config multilib output package-manager path-manipulation

DESCRIPTION="Manage active PostgreSQL client applications and libraries"
MAINTAINER="pgsql-bugs@gentoo.org"
SVN_DATE='$Date: $'
VERSION="1.0.4"

# Global Data
B_PATH="${EROOT%/}/usr"
E_PATH="${EROOT%/}/etc/eselect/postgresql"
ENV_FILE="${EROOT%/}/etc/env.d/50postgresql"
if [ -r ${E_PATH}/active -a -n ${E_PATH}/active ] ; then
ACTIVE_SLOT=$(<${E_PATH}/active)
else
ACTIVE_SLOT="(none)"
fi
LIB_LIST=$(list_libdirs)
if [[ ${LIB_LIST} =~ .*lib64.* && "$(ls -d ${B_PATH}/lib64/postgresql-*/lib)" != "" ]] ; then
LIBDIR="lib64"
elif [[ ${LIB_LIST} =~ .*lib32.* && "$(ls -d ${B_PATH}/lib32/postgresql-*/lib)" != "" ]] ; then
LIBDIR="lib32"
else
LIBDIR="lib"
fi

### Linker Function ###
# Takes three arguments:
# - Full source path (e.g. /usr/lib/postgresql-9.0/lib/lib*.{a,so})
# - Full target directory path (e.g. /usr/bin)
# - Suffix (Optional) (e.g 84 to make /usr/bin/psql84)
linker() {
local source_dir=$1
local target_dir=$2
local suffix=$3
local link_source

for link_source in $(eval ls ${source_dir} 2> /dev/null) ; do
local link_target="${target_dir%/}/$(basename ${link_source})${suffix}"

# For good measure, remove target before creating the symlink
[ -h ${link_target} ] && rm -f ${link_target}
[ -e ${link_target} ] && die -q "The target '${link_target}' still exists and could not be removed!"

ln -s ${link_source} ${link_target} || die -q "Unable to create link!"
echo ${link_target} >> ${E_PATH}/active.links${suffix}
done
}

### Unlinker Function ###
# Takes one argument:
# - Full path to active links file (e.g. /etc/eselect/postgresql/active.links)
unlinker() {
local active_link_file=$1
if [ -r ${active_link_file} ] ; then
local active_links=($(<${active_link_file}))
for (( i=0; $i < ${#active_links[@]}; i++ )) ; do
[ -h ${active_links[$i]} ] && rm -f ${active_links[$i]}
[ -e ${active_links[$i]} ] && die -q "The target '${active_links[$i]}' still exists and could not be removed!"
done

rm -f ${active_link_file}
fi
}

### Get Slots Function ###
# Find all available slots in the preferred LIBDIR and return them.
get_slots() {
echo $(ls -dv ${B_PATH}/${LIBDIR}/postgresql-* 2> /dev/null | sed -re 's#^.+-##')
}

### List Action ###
describe_list() {
echo "List available PostgreSQL slots."
}

do_list() {
write_list_start "Available PostgreSQL Slots"

if $(is_output_mode brief) ; then
echo $(get_slots)
else
local slot
for slot in $(get_slots) ; do
local postgres_ebuilds=""
local src
for src in ${E_PATH}/slots/${slot}/{server,service,base,docs} ; do
[ -r ${src} ] && source ${src}
done

case "${slot}" in
"${ACTIVE_SLOT}" ) write_kv_list_entry "$(highlight_marker ${slot})" "${postgres_ebuilds//postgresql-/}";;
* ) write_kv_list_entry "${slot}" "${postgres_ebuilds//postgresql-/}";;
esac
done

[ -z "${postgres_ebuilds}" ] && write_warning_msg "No slots available."
fi
}

### Show Action ###
describe_show() {
echo "Show which slot is currently active."
}

do_show() {
echo ${ACTIVE_SLOT}
}

### Show Service Action ###
# Here for backwards compatibility with ebuilds
describe_show-service() {
echo "Deprecated. For ebuild use; returns no useful information."
}

do_show-service() {
echo 1
}

### Set Action ###
describe_set() {
echo "Create symbolic links for PostgreSQL libraries and applications."
}

do_set() {
local SLOT=$1
if [ ! -d ${B_PATH}/${LIBDIR}/postgresql-${SLOT} ] ; then
die -q "Not a valid slot."
fi

echo "Setting ${SLOT} as the default installation..."

# Remove the active links to start a fresh list
echo -ne " Removing old links..."
unlinker ${E_PATH}/active.links
echo "done."

echo -ne " Generating new links..."
# Sources and targets for header files
local sources=(
${B_PATH}/include/postgresql-${SLOT}
${B_PATH}/include/postgresql-${SLOT}/libpq-fe.h
${B_PATH}/include/postgresql-${SLOT}/pg_config_manual.h
${B_PATH}/include/postgresql-${SLOT}/libpq
${B_PATH}/include/postgresql-${SLOT}/postgres_ext.h
)
local targets=(
${B_PATH}/include/postgresql
${B_PATH}/include/libpq-fe.h
${B_PATH}/include/pg_config_manual.h
${B_PATH}/include/libpq
${B_PATH}/include/postgres_ext.h
)
# The linker function cannot accomadate this special purpose.
local i
for (( i=0; $i < ${#sources[@]}; i++ )) ; do
# Remove target before creating the symlink
rm -f ${targets[$i]}

# Check if link_target still exists
[ -e ${targets[$i]} ] && die -q "The target '${targets[$i]}' exists and could not be removed!"

ln -s ${sources[$i]} ${targets[$i]} || die -q "Unable to create link!"
echo ${targets[$i]} >> ${E_PATH}/active.links
done

# Link modules to /usr/lib{,lib32,lib64}/
local x
for x in ${LIB_LIST} ; do
if [ -d ${B_PATH}/${x}/postgresql-${SLOT}/${x} ] ; then
# 'linker' function doesn't work for linking directories.
# Default lib path
ln -s ${B_PATH}/${x}/postgresql-${SLOT}/${x} ${B_PATH}/${x}/postgresql
echo ${B_PATH}/${x}/postgresql >> ${E_PATH}/active.links
# Linker works for files
linker "${B_PATH}/${x}/postgresql-${SLOT}/${x}/lib*.{a,dylib,so}" "${B_PATH}/${x}"
fi
done

# Link binaries to /usr/bin/
linker "${B_PATH}/${LIBDIR}/postgresql-${SLOT}/bin/*" "${B_PATH}/bin"

# Default share path
ln -s ${B_PATH}/share/postgresql-${SLOT} ${B_PATH}/share/postgresql
echo ${B_PATH}/share/postgresql >> ${E_PATH}/active.links

echo ${SLOT} > ${E_PATH}/active
echo "done."
echo -e "33[1mSetting ${SLOT} as default was successful!33[0m"
}

### Unset Action ###
describe_unset() {
echo "Remove symbolic links."
}

do_unset() {
local SLOT=$1
if [ "${SLOT}" = "${ACTIVE_SLOT}" ] ; then
echo -n "Unsetting ${SLOT} as the default installation..."
unlinker ${E_PATH}/active.links
rm -f ${E_PATH}/active
echo "done."
else
echo "Inactive slot selected. No work to do."
fi
}

### Reset Action ###
describe_reset() {
echo "Recreate symbolic links for currently active slot."
}

do_reset() {
[ "${ACTIVE_SLOT}" = "(none)" ] && die -q "No active slot to reset."
do_unset ${ACTIVE_SLOT}
do_set ${ACTIVE_SLOT}
}

### Update Action ###
describe_update() {
echo "Refreshes all symbolic links managed by this module"
}

do_update() {
# Check for files managed by postgresql.eselect before 1.0
[ -h /etc/eselect/postgresql/active ] && ACTIVE_SLOT="$(basename $(canonicalise /etc/eselect/postgesql/active))"
# Remove service file outright.
[ -h /etc/eselect/postgresql/service ] && rm -f /etc/eselect/postgresql/service

local slots=($(get_slots))
local index=${#slots[@]}

# In case all slots have been unmerged
if [ ${index} -eq 0 ] ; then
write_warning_msg "No slots found!"
write_warning_msg "Removing files (Control-C to abort) in..."
local i=6
while [ $[i--] -gt 0 ] ; do
echo -n " $i"
sleep 1
done
for sym_links in ${E_PATH}/active.links* ; do
unlinker ${sym_links}
done
rm -f ${E_PATH}/active
rm -f ${ENV_FILE}
do_action env update &> /dev/null
echo "Done!"
return 0
fi

# Reset, otherwise set the highest slot available.
if [[ ${slots[@]} =~ ${ACTIVE_SLOT} ]] ; then
do_reset
else
# best_version doesn't work here as pkg_postrm runs before the world
# file is updated, thereby returning a false positive.
do_set ${slots[$index-1]}
fi

echo -en "
Cleaning out old links before refreshing..."
local sym_links
for sym_links in ${E_PATH}/active.links?* ; do
unlinker ${sym_links}
done
echo "done."

# Update paths to libs and docs
local ldpath
local x
for x in ${LIB_LIST} ; do
[ -h ${B_PATH}/${x}/postgresql ] && ldpath+="${B_PATH}/${x}/postgresql:"
done
ldpath="${ldpath%:}"
local manpath="${B_PATH}/share/postgresql/"
while [ $[--index] -gt -1 ] ; do
local curslot="${slots[$index]}"
echo -n "Refreshing symbolic links for ${curslot} applications (like /usr/bin/psql${curslot//.})..."
for x in ${LIB_LIST} ; do
local lib_path="${B_PATH}/${x}/postgresql-${curslot}/${x}/"
[ -d ${lib_path} ] && ldpath+=":${lib_path}"
done
local share_path="${B_PATH}/share/postgresql-${curslot}/"
[ -d ${share_path} ] && manpath+=":${share_path}"
linker "${B_PATH}/${LIBDIR}/postgresql-${curslot}/bin/*" "${B_PATH}/bin" "${curslot//.}"
echo "done."
done

# Remove environment files that have been generated by the ebuilds
rm -f ${ENV_FILE}-*

store_config ${ENV_FILE} LDPATH "${ldpath}"
store_config ${ENV_FILE} MANPATH "${manpath}"
do_action env update &> /dev/null
}
 
Old 03-29-2011, 09:06 AM
Ulrich Mueller
 
Default RFC: postgresql.eselect

>>>>> On Mon, 28 Mar 2011, Aaron W Swenson wrote:

> This module is to replace the existing one that is shipped with
> <app-admin/eselect-postgresql-1.0.3. It is an entire rewrite.

Some remarks:

- Global scope code is a no-no in eselect modules, especially if it
calls external programs or accesses external files. Your module
will be sourced for commands like "eselect modules list" and there
shouldn't be any global scope code being run on such occasions.

- Don't use eval. It's almost always an indication that you're doing
something wrong.

- For tests, please use [[ ]] rather than [ ] throughout.

- "output" and "path-manipulation" libraries are always loaded, so you
need not (and in fact, you shouldn't) inherit them.

- Don't hardcode terminal specific escape sequences (like "33[1m").
Use the highlighting functions of the output library instead (which
in turn use tput).

- Suppressing stdout of commands like "do_action env update" is fine,
but why suppress stderr?

- Please avoid lines wider than 79 positions.

See also eselect's README and the developer guide:
<http://sources.gentoo.org/cgi-bin/viewvc.cgi/eselect/trunk/README>
<http://www.gentoo.org/proj/en/eselect/dev-guide.xml>

Ulrich
 
Old 03-29-2011, 09:05 PM
"Aaron W. Swenson"
 
Default RFC: postgresql.eselect

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Hash: SHA256

On 03/29/2011 05:06 AM, Ulrich Mueller wrote:
>>>>>> On Mon, 28 Mar 2011, Aaron W Swenson wrote:
>
>> This module is to replace the existing one that is shipped with
>> <app-admin/eselect-postgresql-1.0.3. It is an entire rewrite.
>
> Some remarks:
>
> - Global scope code is a no-no in eselect modules, especially if it
> calls external programs or accesses external files. Your module
> will be sourced for commands like "eselect modules list" and there
> shouldn't be any global scope code being run on such occasions.
>
Fixed.

> - Don't use eval. It's almost always an indication that you're doing
> something wrong.
>
Yeah, I should have used 'find' as fewer "tricks" are needed. Wonder why
I didn't do that in the first place....

> - For tests, please use [[ ]] rather than [ ] throughout.
>
Done.

> - "output" and "path-manipulation" libraries are always loaded, so you
> need not (and in fact, you shouldn't) inherit them.
>
The dev guide could be clearer on that. Removed them from the inherit line.

> - Don't hardcode terminal specific escape sequences (like "33[1m").
> Use the highlighting functions of the output library instead (which
> in turn use tput).
>
Except $(highlight ...) doesn't work in plain echo. So, I just stripped
it out.

> - Suppressing stdout of commands like "do_action env update" is fine,
> but why suppress stderr?
>
Because 'ls' would complain that files didn't exist, such as lib*.dylib
when on a Linux system. It doesn't matter. But, using 'find' avoids this
mess.

> - Please avoid lines wider than 79 positions.
>
Did where I could.

> See also eselect's README and the developer guide:
> <http://sources.gentoo.org/cgi-bin/viewvc.cgi/eselect/trunk/README>
Never knew that existed. Thanks for pointing that out.

> <http://www.gentoo.org/proj/en/eselect/dev-guide.xml>
>
That's where I got all of my information.

> Ulrich
>

Thank you for the feedback. It was quite helpful.

Now, I'm a bit sketchy on the handling of choosing which bitness for the
executables. (psql and friends.)

Sincerely,
Mr. Aaron W. Swenson
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Old 03-30-2011, 04:35 AM
Ryan Hill
 
Default RFC: postgresql.eselect

On Tue, 29 Mar 2011 17:05:01 -0400
"Aaron W. Swenson" <titanofold@gentoo.org> wrote:

> > - Suppressing stdout of commands like "do_action env update" is fine,
> > but why suppress stderr?
> >
> Because 'ls' would complain that files didn't exist, such as lib*.dylib
> when on a Linux system. It doesn't matter. But, using 'find' avoids this
> mess.

Never use ls to get filenames in a script. Instead of

for link_source in $(eval ls ${source_dir} 2> /dev/null) ; do

just use

for link_source in "${source_dir}"/* ; do

I see you already fixed this one, but you do some funky stuff with ls -d
earlier on.

http://mywiki.wooledge.org/BashPitfalls#for_i_in_.24.28ls_.2A.mp3.29


--
fonts, gcc-porting, it makes no sense how it makes no sense
toolchain, wxwidgets but i'll take it free anytime
@ gentoo.org EFFD 380E 047A 4B51 D2BD C64F 8AA8 8346 F9A4 0662
 
Old 03-30-2011, 07:58 AM
Fabian Groffen
 
Default RFC: postgresql.eselect

On 29-03-2011 22:35:48 -0600, Ryan Hill wrote:
> > Because 'ls' would complain that files didn't exist, such as lib*.dylib
> > when on a Linux system. It doesn't matter. But, using 'find' avoids this
> > mess.
>
> Never use ls to get filenames in a script. Instead of
>
> for link_source in $(eval ls ${source_dir} 2> /dev/null) ; do
>
> just use
>
> for link_source in "${source_dir}"/* ; do
>
> I see you already fixed this one, but you do some funky stuff with ls -d
> earlier on.

Make sure though, when you use a glob, that you check for the asterisk.

When there are no matches, bash assumes you meant the literal '*' and
hence will return "/foo/bar/*" in link_source.
So make sure you check the existence of whatever is in link_source
before using it.


--
Fabian Groffen
Gentoo on a different level
 
Old 03-30-2011, 11:00 AM
"Aaron W. Swenson"
 
Default RFC: postgresql.eselect

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

On 03/30/2011 03:58 AM, Fabian Groffen wrote:
> On 29-03-2011 22:35:48 -0600, Ryan Hill wrote:
>>> Because 'ls' would complain that files didn't exist, such as lib*.dylib
>>> when on a Linux system. It doesn't matter. But, using 'find' avoids this
>>> mess.
>>
>> Never use ls to get filenames in a script. Instead of
>>
>> for link_source in $(eval ls ${source_dir} 2> /dev/null) ; do
>>
>> just use
>>
>> for link_source in "${source_dir}"/* ; do
>>
>> I see you already fixed this one, but you do some funky stuff with ls -d
>> earlier on.
>
> Make sure though, when you use a glob, that you check for the asterisk.
>
> When there are no matches, bash assumes you meant the literal '*' and
> hence will return "/foo/bar/*" in link_source.
> So make sure you check the existence of whatever is in link_source
> before using it.
>
>
Yup, that's part of the reason why I changed to 'find' rather than 'ls'
there. 'find' will return a list matching the criteria, or it'll be
empty. Again, why I didn't use it earlier is beyond me. I think 'ls'
just worked for me and I moved on to getting other bits to work and
forgot about it.

As for the lib_dir(), I'm unsure if that's a good way to handle things.
Or, if it's really the best way, even though it's ugly. There's nothing
preventing me from making it a user configurable...it's just that at
some point I do need to determine the default bitness for the applications.

- - Aaron
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Old 03-30-2011, 10:53 PM
Ryan Hill
 
Default RFC: postgresql.eselect

On Wed, 30 Mar 2011 07:00:21 -0400
"Aaron W. Swenson" <titanofold@gentoo.org> wrote:

> As for the lib_dir(), I'm unsure if that's a good way to handle things.
> Or, if it's really the best way, even though it's ugly. There's nothing
> preventing me from making it a user configurable...it's just that at
> some point I do need to determine the default bitness for the applications.

Actually I was thinking about it and the libdir stuff isn't that bad since
you're just comparing to "", ie. not bad in that it should always work as
intended.


--
fonts, gcc-porting, it makes no sense how it makes no sense
toolchain, wxwidgets but i'll take it free anytime
@ gentoo.org EFFD 380E 047A 4B51 D2BD C64F 8AA8 8346 F9A4 0662
 

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