What an intelligent, thoughtful individual.
I find it difficult to forgive 44 for failing to pardon this patriot and instead pursuing him until the end of his term.
If not you, then who?
Great discussion of journalism, it's place in society, and that anyone who witnesses wrongdoing has a moral obligation to humanity to communicate it loudly and in a full voice.
Monday, May 11, 2020
Tuesday, January 20, 2015
Mouse feet and teflon glides
Searching for mouse glides feet
[ptfe mouse tape]
CS Hyde Mouse Discs with One Side Clean Removal Adhesive, 0.002" Thick, 1/4" Diameter (150 pcs/roll)
http://www.hyperglide.net/?hg=mx_skates_1
caveat: 20 days shipping to US
US retailer for hyperglide:
http://www.frozencpu.com/products/3048/pad-100/Hyperglide_Mouse_Skates_MX-2_-_8_Skates_-_Logitech_MX_300_G1.html
http://www.slicksurf.com/slicksurf/home/
forum post with tape experiences:
http://forums.anandtech.com/showthread.php?t=234427
I do recommend:
Try Audible and Get Two Free Audiobooks
[ptfe mouse tape]
CS Hyde Mouse Discs with One Side Clean Removal Adhesive, 0.002" Thick, 1/4" Diameter (150 pcs/roll)
http://www.hyperglide.net/?hg=mx_skates_1
caveat: 20 days shipping to US
US retailer for hyperglide:
http://www.frozencpu.com/products/3048/pad-100/Hyperglide_Mouse_Skates_MX-2_-_8_Skates_-_Logitech_MX_300_G1.html
http://www.slicksurf.com/slicksurf/home/
forum post with tape experiences:
http://forums.anandtech.com/showthread.php?t=234427
I do recommend:
Try Audible and Get Two Free Audiobooks
Saturday, April 26, 2014
CLANG error
https://langui.sh/2014/03/10/wunused-command-line-argument-hard-error-in-future-is-a-harsh-mistress/
I do recommend:
Try Audible and Get Two Free Audiobooks
For now you can work around the issue using
export ARCHFLAGS="-Wno-error=unused-command-line-argument-hard-error-in-future"I do recommend:
Try Audible and Get Two Free Audiobooks
Monday, February 24, 2014
there's nothing like a static location for SSH_AUTH_SOCK
Place in your .bash_profile, and your gnuscreen sessions will resume working when a new agent comes along (such as after log out).
#!/bin/bash
# If you're on a multi-user system you might consider choosing
# a more secure (permissions-wise) directory than just $HOME/.
# Though it is just a symlink, and the destination of the symlink should already be secure.
# If it's not already our canonical file, and it exists... make it canonical:
[[ "${SSH_AUTH_SOCK}" != $HOME/.ssh-agent-$USER-screen ]] || \
[[ -f ${SSH_AUTH_SOCK} ]] && \
ln -sf ${SSH_AUTH_SOCK} $HOME/.ssh-agent-$USER-screen
# Other end of the link:
export SSH_AUTH_SOCK_ORIG=${SSH_AUTH_SOCK}
export SSH_AUTH_SOCK="$HOME/.ssh-agent-$USER-screen"
#!/bin/bash
# If you're on a multi-user system you might consider choosing
# a more secure (permissions-wise) directory than just $HOME/.
# Though it is just a symlink, and the destination of the symlink should already be secure.
# If it's not already our canonical file, and it exists... make it canonical:
[[ "${SSH_AUTH_SOCK}" != $HOME/.ssh-agent-$USER-screen ]] || \
[[ -f ${SSH_AUTH_SOCK} ]] && \
ln -sf ${SSH_AUTH_SOCK} $HOME/.ssh-agent-$USER-screen
# Other end of the link:
export SSH_AUTH_SOCK_ORIG=${SSH_AUTH_SOCK}
export SSH_AUTH_SOCK="$HOME/.ssh-agent-$USER-screen"
Sunday, December 15, 2013
gphoto2 device (jl2005c) supported by brew, but not macports.
Even though both have the latest 2.5.2 version.
Jeilin JL2005C gphoto2 support via macports was broken.
brew wound up working.
conversion of the resulting .ppm files then required:
brew install netpbm
download and convert all command:
gphoto2 -P ; for i in *.ppm ; do pnmtojpeg ${i} > ${i/%ppm/jpg} ; done
Jeilin JL2005C gphoto2 support via macports was broken.
brew wound up working.
conversion of the resulting .ppm files then required:
brew install netpbm
download and convert all command:
gphoto2 -P ; for i in *.ppm ; do pnmtojpeg ${i} > ${i/%ppm/jpg} ; done
Tuesday, September 17, 2013
Cassandra cleanup script -- with percentage goal awareness.
#!/bin/bash
# Purpose:
# This script is run daily from cron before the compaction script.
# On the same days the compaction script triggers, this script should also.
# On triggered days, this script should trim old files to
# bring disk usage below 60%.
# Options accepted:
#
# $1 = directory to cleanup, defaults to "/mnt/cassandra/data/myschema"
DATADIR=${1:-/mnt/cassandra/data/myschema}
## ____ Config Variables ____
# Attempt to delete filesets one by one until disk Use% is less than:
goal_percentage_less_than=60
## ____ No user serviceable parts below this line ____
if [[ ! -d ${DATADIR} ]] ; then
echo "Argument: ${DATADIR} directory does not exist. Aborting"
exit 1
fi
# Day of week (0=Sunday)
declare -r -i todays_dow=$(date +%w)
readonly -a days_of_week=( Sunday Monday Tuesday Wednesday Thursday Friday Saturday )
usage () {
echo "$0 <no options allowed yet>";
}
# we are not the compaction script, but if we were:
#
# if [[ ! -e /var/log/cassandra ]] ; then
# mkdir /var/log/cassandra
# elif [[ ! -d /var/log/cassandra ]] ; then
# echo "/var/log/cassandra is not a directory."
# exit 1
# fi
# learn and parse ring
declare -a ring=( $(/usr/bin/cassandra-nodetool -h 127.0.0.1 -p 12352 ring \
| grep ^[0-9] | cut -f1 -d\ ) )
declare -i ringsize=${#ring[@]}
# sanity check
if [[ ringsize -lt 1 ]] ; then
echo "count of ring nodes was less than 1. aborting."
exit 2
fi
declare -r this_hosts_ip=$(host $(hostname) | grep 'has address' | awk '{print $NF}')
echo "My hostname,IP is: $(hostname),${this_hosts_ip}"
if [[ -z ${this_hosts_ip} ]] ; then
echo "unable to convert local hostname into an IP address. aborting."
exit 3
fi
declare -r this_hosts_ip_regex=$(echo ${this_hosts_ip} | sed 's/\./\\./g')
# Sanity check, am I a member of this ring?
if [[ ! ${ring[@]} =~ ${this_hosts_ip_regex} ]] ; then
echo "Couldn't find myself (${this_hosts_ip} in ring: ${ring[@]}. aborting"
exit 4
fi
# In a list of zero-indexed nodes, which one am I?
let my_index=unset
for i in ${!ring[@]} ; do
[[ ${ring[i]} =~ ${this_hosts_ip_regex} ]] && {
my_index=$i
break
}
done
# Sanity check, enforce that we found our index:
[[ ${my_index} == "unset" ]] && exit 5
my_day_of_week=$(( ${my_index} % 7 ))
# Check for the case where I am the last node, but my
# day of week is Sunday (same as first node's).
# Choose (3=Wednesday) to avoid adjacent (0=Sunday).
# old way: let "! (( ringsize - 1 ) % 7)" && my_day_of_week=3
if [[ ${my_index} -eq $(( ${ringsize} - 1 )) && ${my_day_of_week} -eq 0 ]] ; then
my_day_of_week=3
fi
echo "I will compact on ${days_of_week[$my_day_of_week]}s."
echo "Today is ${days_of_week[$todays_dow]}."
# DO NOT SUBMIT
# uncommment for production:
if [[ ${my_day_of_week} -ne ${todays_dow} ]] ; then
echo Not our lucky day.
exit 0
fi
echo "It's our lucky day. BEGIN ***cleaning up older files***"
# Clean up oldest filesets until disk is less than 60% full.
cd ${DATADIR}
declare -a -r DFSTATS=( $(df -kP ${DATADIR} | tail -1) )
echo df reported capacity=${DFSTATS[4]/[%]/}%
echo Calculated Capacity=$(( ( 100 * ${DFSTATS[2]} ) / ${DFSTATS[1]} ))%
declare -a filesizes=() filenames=()
function load_filedata {
local size name
while read size name ; do
filesizes+=(${size})
filenames+=(${name})
done < <(ls -1krst ${1})
}
function current_fileset_size_sum {
local -i total
for i in ${filesizes[@]} ; do
total+=$i
done
echo "$total"
return $total
}
# Get all fileset numbers and put them in an array.
filesets_numbers_by_time=( $(ls -1kst | egrep -v ^total | awk -F- '{print $2}' | sort -n | uniq) )
declare -r filesets_count=${#filesets_numbers_by_time[@]}
# Add each fileset's filesizes into one value.
# Note: this creates a sparse array.
for i in ${filesets_numbers_by_time[@]} ; do
filesizes=()
filenames=()
load_filedata "*-${i}-*"
filesets_sizes[$i]=$(current_fileset_size_sum)
# echo "set filesets_sizes[$i] to $(current_fileset_size_sum)"
done
function load_oldest_fileset_data {
load_filedata "*-${filesets_numbers_by_time[0]}-*"
return ${filesets_numbers_by_time[0]}
}
declare -i count_of_filesets_to_delete=0
declare -i expected_capacity=100 # Sane default
declare -i accumulated_deletes_in_kbytes=0
declare -a filesets_to_delete=()
# External variables modified by this function
# $expected_capacity
function current_expected_capacity {
local -i total_of_filesets=0
for i in ${filesets_to_delete[@]} ; do
total_of_filesets+=${filesets_sizes[$i]}
echo fileset # $i size is == ${filesets_sizes[$i]}
done
echo -n Calculated %-Capacity after removing filesets \"${filesets_to_delete[@]}\"= >/dev/stderr
expected_capacity=$(( ( 100 * ( ${DFSTATS[2]} - ${total_of_filesets} ) ) / ${DFSTATS[1]} ))
echo ${expected_capacity}% >/dev/stderr
return ${expected_capacity}
}
# External variables modified by this function
# $filesets_to_delete
# $filesets_numbers_by_time
# $count_of_filesets_to_delete
function add_oldest_fileset {
filesets_to_delete+=( ${filesets_numbers_by_time[0]} )
echo filesets_to_delete=${filesets_to_delete[@]}
# drop the oldest fileset from this list:
filesets_numbers_by_time=( ${filesets_numbers_by_time[@]:1} )
count_of_filesets_to_delete+=1
}
# sets initial value of $expected_capacity
current_expected_capacity
while [[ expected_capacity -gt ${goal_percentage_less_than} ]] ; do
add_oldest_fileset
current_expected_capacity
[[ count_of_filesets_to_delete -gt 3 ]] && {
echo "Planner thinks we need to delete more than 4 sets,"
echo "We might have a problem here... Aborting."
exit 6
}
done
# Check that we are not deleting more than half the filesets:
if [[ ${#filesets_to_delete[@]} -gt $(( filesets_count / 2 )) ]] ; then
echo -n "Plan is to delete too many filesets: "
echo "${#filesets_to_delete[@]} of ${filesets_count}"
echo Aborting
exit 7
fi
# do the deletes
echo If I was a real cleanup script, I would now delete:
for i in ${filesets_to_delete[@]} ; do
ls -l *-"${i}"-*
done
# Purpose:
# This script is run daily from cron before the compaction script.
# On the same days the compaction script triggers, this script should also.
# On triggered days, this script should trim old files to
# bring disk usage below 60%.
# Options accepted:
#
# $1 = directory to cleanup, defaults to "/mnt/cassandra/data/myschema"
DATADIR=${1:-/mnt/cassandra/data/myschema}
## ____ Config Variables ____
# Attempt to delete filesets one by one until disk Use% is less than:
goal_percentage_less_than=60
## ____ No user serviceable parts below this line ____
if [[ ! -d ${DATADIR} ]] ; then
echo "Argument: ${DATADIR} directory does not exist. Aborting"
exit 1
fi
# Day of week (0=Sunday)
declare -r -i todays_dow=$(date +%w)
readonly -a days_of_week=( Sunday Monday Tuesday Wednesday Thursday Friday Saturday )
usage () {
echo "$0 <no options allowed yet>";
}
# we are not the compaction script, but if we were:
#
# if [[ ! -e /var/log/cassandra ]] ; then
# mkdir /var/log/cassandra
# elif [[ ! -d /var/log/cassandra ]] ; then
# echo "/var/log/cassandra is not a directory."
# exit 1
# fi
# learn and parse ring
declare -a ring=( $(/usr/bin/cassandra-nodetool -h 127.0.0.1 -p 12352 ring \
| grep ^[0-9] | cut -f1 -d\ ) )
declare -i ringsize=${#ring[@]}
# sanity check
if [[ ringsize -lt 1 ]] ; then
echo "count of ring nodes was less than 1. aborting."
exit 2
fi
declare -r this_hosts_ip=$(host $(hostname) | grep 'has address' | awk '{print $NF}')
echo "My hostname,IP is: $(hostname),${this_hosts_ip}"
if [[ -z ${this_hosts_ip} ]] ; then
echo "unable to convert local hostname into an IP address. aborting."
exit 3
fi
declare -r this_hosts_ip_regex=$(echo ${this_hosts_ip} | sed 's/\./\\./g')
# Sanity check, am I a member of this ring?
if [[ ! ${ring[@]} =~ ${this_hosts_ip_regex} ]] ; then
echo "Couldn't find myself (${this_hosts_ip} in ring: ${ring[@]}. aborting"
exit 4
fi
# In a list of zero-indexed nodes, which one am I?
let my_index=unset
for i in ${!ring[@]} ; do
[[ ${ring[i]} =~ ${this_hosts_ip_regex} ]] && {
my_index=$i
break
}
done
# Sanity check, enforce that we found our index:
[[ ${my_index} == "unset" ]] && exit 5
my_day_of_week=$(( ${my_index} % 7 ))
# Check for the case where I am the last node, but my
# day of week is Sunday (same as first node's).
# Choose (3=Wednesday) to avoid adjacent (0=Sunday).
# old way: let "! (( ringsize - 1 ) % 7)" && my_day_of_week=3
if [[ ${my_index} -eq $(( ${ringsize} - 1 )) && ${my_day_of_week} -eq 0 ]] ; then
my_day_of_week=3
fi
echo "I will compact on ${days_of_week[$my_day_of_week]}s."
echo "Today is ${days_of_week[$todays_dow]}."
# DO NOT SUBMIT
# uncommment for production:
if [[ ${my_day_of_week} -ne ${todays_dow} ]] ; then
echo Not our lucky day.
exit 0
fi
echo "It's our lucky day. BEGIN ***cleaning up older files***"
# Clean up oldest filesets until disk is less than 60% full.
cd ${DATADIR}
declare -a -r DFSTATS=( $(df -kP ${DATADIR} | tail -1) )
echo df reported capacity=${DFSTATS[4]/[%]/}%
echo Calculated Capacity=$(( ( 100 * ${DFSTATS[2]} ) / ${DFSTATS[1]} ))%
declare -a filesizes=() filenames=()
function load_filedata {
local size name
while read size name ; do
filesizes+=(${size})
filenames+=(${name})
done < <(ls -1krst ${1})
}
function current_fileset_size_sum {
local -i total
for i in ${filesizes[@]} ; do
total+=$i
done
echo "$total"
return $total
}
# Get all fileset numbers and put them in an array.
filesets_numbers_by_time=( $(ls -1kst | egrep -v ^total | awk -F- '{print $2}' | sort -n | uniq) )
declare -r filesets_count=${#filesets_numbers_by_time[@]}
# Add each fileset's filesizes into one value.
# Note: this creates a sparse array.
for i in ${filesets_numbers_by_time[@]} ; do
filesizes=()
filenames=()
load_filedata "*-${i}-*"
filesets_sizes[$i]=$(current_fileset_size_sum)
# echo "set filesets_sizes[$i] to $(current_fileset_size_sum)"
done
function load_oldest_fileset_data {
load_filedata "*-${filesets_numbers_by_time[0]}-*"
return ${filesets_numbers_by_time[0]}
}
declare -i count_of_filesets_to_delete=0
declare -i expected_capacity=100 # Sane default
declare -i accumulated_deletes_in_kbytes=0
declare -a filesets_to_delete=()
# External variables modified by this function
# $expected_capacity
function current_expected_capacity {
local -i total_of_filesets=0
for i in ${filesets_to_delete[@]} ; do
total_of_filesets+=${filesets_sizes[$i]}
echo fileset # $i size is == ${filesets_sizes[$i]}
done
echo -n Calculated %-Capacity after removing filesets \"${filesets_to_delete[@]}\"= >/dev/stderr
expected_capacity=$(( ( 100 * ( ${DFSTATS[2]} - ${total_of_filesets} ) ) / ${DFSTATS[1]} ))
echo ${expected_capacity}% >/dev/stderr
return ${expected_capacity}
}
# External variables modified by this function
# $filesets_to_delete
# $filesets_numbers_by_time
# $count_of_filesets_to_delete
function add_oldest_fileset {
filesets_to_delete+=( ${filesets_numbers_by_time[0]} )
echo filesets_to_delete=${filesets_to_delete[@]}
# drop the oldest fileset from this list:
filesets_numbers_by_time=( ${filesets_numbers_by_time[@]:1} )
count_of_filesets_to_delete+=1
}
# sets initial value of $expected_capacity
current_expected_capacity
while [[ expected_capacity -gt ${goal_percentage_less_than} ]] ; do
add_oldest_fileset
current_expected_capacity
[[ count_of_filesets_to_delete -gt 3 ]] && {
echo "Planner thinks we need to delete more than 4 sets,"
echo "We might have a problem here... Aborting."
exit 6
}
done
# Check that we are not deleting more than half the filesets:
if [[ ${#filesets_to_delete[@]} -gt $(( filesets_count / 2 )) ]] ; then
echo -n "Plan is to delete too many filesets: "
echo "${#filesets_to_delete[@]} of ${filesets_count}"
echo Aborting
exit 7
fi
# do the deletes
echo If I was a real cleanup script, I would now delete:
for i in ${filesets_to_delete[@]} ; do
ls -l *-"${i}"-*
done
Friday, August 16, 2013
Creating a static readonly chroot environment using squashfs.
Goal was to create a hermetic readonly chroot environment, with no external dependencies.
The contents of the environment includes:
files associated with a (tested) checkout/revision of the files used by a nameserver(bind)
the named binary + required libraries
any required support files or devices (/dev/null)
External writeable directories may exist to allow logs and pid file:
/var/run/*.pid
/var/named/chroot/logs/
Package format is a squashfs filesystem.
Capture a successful start and end of named using strace and system call arguments:
(ldd /usr/sbin/named would also have worked here)
mkdir /tmp/tmpdir
cd /tmp/tmpdir
>&1 strace -f -e open,stat,chroot /bin/bash -c 'ulimit -S -c 0 >/dev/null 2>&1 ; /usr/sbin/named -u named -4 -c /etc/named.conf -t /var/named/chroot' | grep -v -e ENOENT -e EACCES > startup.syscalls &
sleep 2
killall named
Gather a list of filenames (excluding /proc /dev) before the chroot() syscall.
(This could also be derived from 'ldd /usr/sbin/named' output...)
awk -F\" '/chroot\(/ { nextfile; } {print $2} startup.syscalls | sort | uniq | grep -v -e /proc -e /dev -e /tmp/tmpdir
# Explanation of above command:
# syscalls before chroot() are at the system level, we only need these right now.
Output should be something like:
.
/etc/group
/etc/ld.so.cache
/etc/localtime
/etc/nsswitch.conf
/etc/passwd
/lib64/libattr.so.1
/lib64/libcap.so.2
/lib64/libcom_err.so.2
/lib64/libc.so.6
/lib64/libdl.so.2
/lib64/libgssapi_krb5.so.2
/lib64/libk5crypto.so.3
/lib64/libkeyutils.so.1
/lib64/libkrb5.so.3
/lib64/libkrb5support.so.0
/lib64/libm.so.6
/lib64/libnss_files.so.2
/lib64/libpthread.so.0
/lib64/libresolv.so.2
/lib64/libselinux.so.1
/lib64/libtinfo.so.5
/lib64/libz.so.1
/usr/lib64/gconv/gconv-modules.cache
/usr/lib64/libbind9.so.90
/usr/lib64/libcrypto.so.10
/usr/lib64/libdns.so.99
/usr/lib64/libisccc.so.90
/usr/lib64/libisccfg.so.90
/usr/lib64/libisc.so.95
/usr/lib64/liblwres.so.90
/usr/lib64/libxml2.so.2
/usr/lib64/tls
/usr/lib/locale/locale-archive
# Drop the blank and '.' entries at the start, and copy non-chroot items to an empty directory:
awk -F\" '/chroot\(/ { nextfile; } {print $2}' startup.open,stat,chroot | sort | uniq | grep -v -e /proc -e /dev -e /tmp/tmpdir | sed -e 1d -e 2d | cpio --make-directories --dereference -p /tmp/tmpdir/
194017 blocks
# Explanation of above:
# Because named is smart enough to open required system devices (/dev/null,/dev/log,/dev/random)
# before chroot()ing, /dev and /proc should NOT need to be mounted (or copied) into the chroot.
# Copy the chroot items:
( cd /var/named/chroot ; find . | cpio --make-directories -p /tmp/tmpdir/var/named/chroot )
( cd /etc/pki ; find . | cpio --make-directories -p /tmp/tmpdir/var/named/chroot/etc/pki )
find /tmp/tmpdir/var/named/chroot/ -type d -exec chmod o+rx '{}' \;
rm /tmp/tmpdir/var/named/chroot/var/named/logs/named.run
chmod 777 /tmp/tmpdir/var/named/chroot/var/named/logs
chmod o+r /tmp/tmpdir/var/named/chroot/etc/rndc.{conf,key}
# TODO: consider use of --force-gid named, --force-uid named
mkdir -p /tmp/tmpdir/usr/sbin
cp /usr/sbin/named /tmp/tmpdir/usr/sbin
for i in /dev/null /dev/random /lib64/ld-linux-x86-64.so.2
echo $i
done | cpio --dereference -p --make-directories /tmp/tmpdir/
rm startup.open,stat,chroot
# and build the filesystem
mksquashfs tmpdir named.squashfs -noappend -all-root
mount -o loop named.squashfs /mnt
mount --bind /tmp/named.logs /var/mnt/var/named/chroot/var/named/logs
chroot /mnt "/usr/sbin/named" -u named -4 -c /etc/named.conf -t /var/named/chroot
----
squashfs stacking
cd /tmp/bind-9.9.3-chroot
mksquashfs * /tmp/bind993.squashfs -all-root
cp /tmp/bind993.squashfs /tmp/stage2.squashfs
cd /var/named/
mksquashfs chroot /tmp/stage2.squashfs -keep-as-directory -all-root
----
Mount and run:
# mount -o loop /tmp/stage2.squashfs /mnt
# mount --bind /tmp/named.logs /mnt/named.chroot/var/named/logs
# chroot /mnt "/usr/sbin/named" -u named -4 -c /etc/named.conf -t /chroot
Resulting mashup:
# ls -l /mnt/
total 0
drwxr-xr-x 2 root root 41 Jul 26 03:00 dev
drwxr-xr-x 2 root root 99 Jul 26 03:17 etc
drwxr-xr-x 2 root root 410 Jul 26 02:51 lib64
drwxrwxrwx 5 root root 48 Jul 27 01:19 chroot
drwxr-xr-x 5 root root 51 Jul 26 02:36 usr
# ls -l /mnt/chroot
total 0
drwxr-x--- 2 root named 53 Jul 26 00:46 dev
drwxr-x--- 2 root named 201 Jul 26 03:34 etc
drwxr-x--- 3 root named 28 Jul 26 00:46 var
The contents of the environment includes:
files associated with a (tested) checkout/revision of the files used by a nameserver(bind)
the named binary + required libraries
any required support files or devices (/dev/null)
External writeable directories may exist to allow logs and pid file:
/var/run/*.pid
/var/named/chroot/logs/
Package format is a squashfs filesystem.
Capture a successful start and end of named using strace and system call arguments:
(ldd /usr/sbin/named would also have worked here)
mkdir /tmp/tmpdir
cd /tmp/tmpdir
>&1 strace -f -e open,stat,chroot /bin/bash -c 'ulimit -S -c 0 >/dev/null 2>&1 ; /usr/sbin/named -u named -4 -c /etc/named.conf -t /var/named/chroot' | grep -v -e ENOENT -e EACCES > startup.syscalls &
sleep 2
killall named
Gather a list of filenames (excluding /proc /dev) before the chroot() syscall.
(This could also be derived from 'ldd /usr/sbin/named' output...)
awk -F\" '/chroot\(/ { nextfile; } {print $2} startup.syscalls | sort | uniq | grep -v -e /proc -e /dev -e /tmp/tmpdir
# Explanation of above command:
# syscalls before chroot() are at the system level, we only need these right now.
Output should be something like:
.
/etc/group
/etc/ld.so.cache
/etc/localtime
/etc/nsswitch.conf
/etc/passwd
/lib64/libattr.so.1
/lib64/libcap.so.2
/lib64/libcom_err.so.2
/lib64/libc.so.6
/lib64/libdl.so.2
/lib64/libgssapi_krb5.so.2
/lib64/libk5crypto.so.3
/lib64/libkeyutils.so.1
/lib64/libkrb5.so.3
/lib64/libkrb5support.so.0
/lib64/libm.so.6
/lib64/libnss_files.so.2
/lib64/libpthread.so.0
/lib64/libresolv.so.2
/lib64/libselinux.so.1
/lib64/libtinfo.so.5
/lib64/libz.so.1
/usr/lib64/gconv/gconv-modules.cache
/usr/lib64/libbind9.so.90
/usr/lib64/libcrypto.so.10
/usr/lib64/libdns.so.99
/usr/lib64/libisccc.so.90
/usr/lib64/libisccfg.so.90
/usr/lib64/libisc.so.95
/usr/lib64/liblwres.so.90
/usr/lib64/libxml2.so.2
/usr/lib64/tls
/usr/lib/locale/locale-archive
# Drop the blank and '.' entries at the start, and copy non-chroot items to an empty directory:
awk -F\" '/chroot\(/ { nextfile; } {print $2}' startup.open,stat,chroot | sort | uniq | grep -v -e /proc -e /dev -e /tmp/tmpdir | sed -e 1d -e 2d | cpio --make-directories --dereference -p /tmp/tmpdir/
194017 blocks
# Explanation of above:
# Because named is smart enough to open required system devices (/dev/null,/dev/log,/dev/random)
# before chroot()ing, /dev and /proc should NOT need to be mounted (or copied) into the chroot.
# Copy the chroot items:
( cd /var/named/chroot ; find . | cpio --make-directories -p /tmp/tmpdir/var/named/chroot )
( cd /etc/pki ; find . | cpio --make-directories -p /tmp/tmpdir/var/named/chroot/etc/pki )
find /tmp/tmpdir/var/named/chroot/ -type d -exec chmod o+rx '{}' \;
rm /tmp/tmpdir/var/named/chroot/var/named/logs/named.run
chmod 777 /tmp/tmpdir/var/named/chroot/var/named/logs
chmod o+r /tmp/tmpdir/var/named/chroot/etc/rndc.{conf,key}
# TODO: consider use of --force-gid named, --force-uid named
mkdir -p /tmp/tmpdir/usr/sbin
cp /usr/sbin/named /tmp/tmpdir/usr/sbin
for i in /dev/null /dev/random /lib64/ld-linux-x86-64.so.2
echo $i
done | cpio --dereference -p --make-directories /tmp/tmpdir/
rm startup.open,stat,chroot
# and build the filesystem
mksquashfs tmpdir named.squashfs -noappend -all-root
mount -o loop named.squashfs /mnt
mount --bind /tmp/named.logs /var/mnt/var/named/chroot/var/named/logs
chroot /mnt "/usr/sbin/named" -u named -4 -c /etc/named.conf -t /var/named/chroot
----
squashfs stacking
cd /tmp/bind-9.9.3-chroot
mksquashfs * /tmp/bind993.squashfs -all-root
cp /tmp/bind993.squashfs /tmp/stage2.squashfs
cd /var/named/
mksquashfs chroot /tmp/stage2.squashfs -keep-as-directory -all-root
----
Mount and run:
# mount -o loop /tmp/stage2.squashfs /mnt
# mount --bind /tmp/named.logs /mnt/named.chroot/var/named/logs
# chroot /mnt "/usr/sbin/named" -u named -4 -c /etc/named.conf -t /chroot
Resulting mashup:
# ls -l /mnt/
total 0
drwxr-xr-x 2 root root 41 Jul 26 03:00 dev
drwxr-xr-x 2 root root 99 Jul 26 03:17 etc
drwxr-xr-x 2 root root 410 Jul 26 02:51 lib64
drwxrwxrwx 5 root root 48 Jul 27 01:19 chroot
drwxr-xr-x 5 root root 51 Jul 26 02:36 usr
# ls -l /mnt/chroot
total 0
drwxr-x--- 2 root named 53 Jul 26 00:46 dev
drwxr-x--- 2 root named 201 Jul 26 03:34 etc
drwxr-x--- 3 root named 28 Jul 26 00:46 var
Thursday, August 15, 2013
List of test driven development resources (TDD) for bash in bash
Tools and utilities:
https://code.google.com/p/bsfl/ - Bash Shell Function Library
https://code.google.com/p/shflags/ - Shell Flags – command-line flags module for Unix shell scripts
https://code.google.com/p/pyrering/ - Test case runner to manage command line test scripts.
http://joyful.com/shelltestrunner/ - shelltestrunner
http://bmizerany.github.io/roundup/ - unit testing tool for running test plans
https://github.com/lehmannro/assert.sh - test-driven development in the Bourne again shell
http://bmizerany.github.io/roundup/ - unit testing tool for running test plans
https://github.com/lehmannro/assert.sh - test-driven development in the Bourne again shell
Q&A lists:
If you have any suggestions to add to the above, please leave a comment.
Saturday, January 26, 2013
how to read a binary file over the network using only bash built-in commands
Using only bash builtin commands, copy a file over the network.
(fork() allowed, exec() not allowed):
receiver:
on another host which has the binary you want sent:
nc -l 10.1.1.1 9999 <./lib64/libc-2.5.so
The above works to restore the libc file in-place.
YMMV.
Comments?
Improvements?
Suggestions?
Please leave a comment.
I do recommend:
Try Audible and Get Two Free Audiobooks
(fork() allowed, exec() not allowed):
receiver:
( while read -r -d '' ; do
printf %s'\0' "${REPLY}" ;
done ;
# When read hits EOF, it returns non-zero which exits the while loop.
# That data still needs to be output:
printf %s "${REPLY}"
) </dev/tcp/10.1.1.1/9999 >/lib64/libc-2.5.so
Do note the memory usage though. This reads input in a null-delimited fashion.
If there are no
If there are no
\0 null bytes in the input then bash will first need to read the entire contents of input into memory, and then output it.on another host which has the binary you want sent:
nc -l 10.1.1.1 9999 <./lib64/libc-2.5.so
The above works to restore the libc file in-place.
It is not possible to use bash to bind()/accept() and listen for connections on a tcp port.
Bash is only able to make connect() calls.
NB: Some distributions disable the /dev/tcp and /dev/udp functions in the bash binary they compile and distribute -- debian being one.
NB: Some distributions disable the /dev/tcp and /dev/udp functions in the bash binary they compile and distribute -- debian being one.
YMMV.
Comments?
Improvements?
Suggestions?
Please leave a comment.
I do recommend:
Try Audible and Get Two Free Audiobooks
Monday, January 21, 2013
upgrading from barrier breaker to attitude_adjustment (uh... wait, that's backwards)
http://downloads.openwrt.org/attitude_adjustment/12.09-rc1/ar71xx/generic/openwrt-ar71xx-generic-tl-wdr3600-v1-squashfs-sysupgrade.bin
populate /etc/sysupgrade.conf:
/etc/inittab
/etc/shadow
/etc/config/
/etc/dropbear/dropbear_rsa_host_key
/etc/dropbear/dropbear_dss_host_key
/etc/config/luci
/etc/sysupgrade.conf
Following http://wiki.openwrt.org/doc/howto/generic.sysupgrade md5sum stuff
• grab and save 'opkg list-installed' package list
-------------- turns out this was a downgrade from my old barrier breaker "trunk" image
-- but I didn't realize it.
trying again:
http://downloads.openwrt.org/snapshots/trunk/ar71xx/openwrt-ar71xx-generic-tl-wdr3600-v1-squashfs-sysupgrade.bin
same sysupdate output:
turns out I needed to remove /etc/config/wireless and start over using luci.
I do recommend:
Try Audible and Get Two Free Audiobooks
populate /etc/sysupgrade.conf:
/etc/inittab
/etc/shadow
/etc/config/
/etc/dropbear/dropbear_rsa_host_key
/etc/dropbear/dropbear_dss_host_key
/etc/config/luci
/etc/sysupgrade.conf
Following http://wiki.openwrt.org/doc/howto/generic.sysupgrade md5sum stuff
# sysupgrade -v openwrt-ar71xx-generic-tl-wdr3600-v1-squashfs-sysupgrade.bin
Saving config files... etc/sysupgrade.conf etc/sysctl.conf etc/shells etc/shadow etc/rc.local etc/profile etc/passwd etc/inittab etc/hosts etc/group etc/firewall.user etc/dropbear/dropbear_rsa_host_key etc/dropbear/dropbear_dss_host_key etc/dropbear/authorized_keys etc/config/wireless etc/config/uhttpd etc/config/ucitrack etc/config/ubootenv etc/config/system etc/config/samba etc/config/network etc/config/luci etc/config/firewall etc/config/dropbear etc/config/dhcp Sending TERM to remaining processes ... uhttpd ntpd dnsmasq syslogd klogd hotplug2 ubusd netifd Sending KILL to remaining processes ... uhttpd Switching to ramdisk... Performing system upgrade... Unlocking firmware ... Writing fromnext time:to firmware ... Appending jffs2 data from /tmp/sysupgrade.tgz to firmware...TRX header not found Error fixing up TRX header Upgrade completed Rebooting system... Write failed: Broken pipe
• grab and save 'opkg list-installed' package list
-------------- turns out this was a downgrade from my old barrier breaker "trunk" image
-- but I didn't realize it.
trying again:
http://downloads.openwrt.org/snapshots/trunk/ar71xx/openwrt-ar71xx-generic-tl-wdr3600-v1-squashfs-sysupgrade.bin
same sysupdate output:
Switching to ramdisk... Performing system upgrade... Unlocking firmware ... Writing fromstill no working wirelessto firmware ... Appending jffs2 data from /tmp/sysupgrade.tgz to firmware...TRX header not found Error fixing up TRX header Upgrade completed Rebooting system...
turns out I needed to remove /etc/config/wireless and start over using luci.
I do recommend:
Try Audible and Get Two Free Audiobooks
Monday, December 24, 2012
keep a dark background when toggling between light/dark inverted modes in OSX
keep a dark background when toggling between light/dark modes in OSX
(Use something other than control-shift-option-8 to trigger, I'm using control-command-8)
If background stays light, toggle state of c-s-o-8 once to get background in sync first.
save as an applescript service that receives no input:
tell application "System Events"
tell current desktop
get properties
set desktop_pic to picture as Unicode text
end tell
end tell
if "Light" is not in desktop_pic then
set desktop_pic to POSIX file "/Library/Desktop Pictures/Solid Colors/Solid Gray Light.png"
else
set desktop_pic to POSIX file "/Library/Desktop Pictures/Solid Colors/Solid Gray Dark.png"
end if
tell application "Finder"
set desktop picture to file desktop_pic
end tell
tell application "System Events"
tell application processes
key code 28 using {command down, option down, control down}
end tell
end tell
inspired by: http://kinderman.net/articles/2007/11/11/reversing-screen-colors-on-a-mac-and-keeping-a-black-background-on-terminal
Wednesday, September 5, 2012
preferred list of openwrt packages
packages we like installed on our openwrt:
bash
less (requires: opkg install less --force-overwrite):
curl
tcpdump
ip
luci-app-qos
ntpdate
Tuesday, August 28, 2012
LVM based mirrors (kinda suck)
I recently noticed that my mirrored LVM volume wasn't.
No notice, no visible warnings in 'lvm' output or anything.
Neat.
Recovery instructions:
http://www.centos.org/docs/5/html/Cluster_Logical_Volume_Manager/mirrorrecover.html
Now to add monitoring.
No notice, no visible warnings in 'lvm' output or anything.
Neat.
Recovery instructions:
http://www.centos.org/docs/5/html/Cluster_Logical_Volume_Manager/mirrorrecover.html
Now to add monitoring.
Tuesday, May 8, 2012
A nice track I heard today
http://soundcloud.com/gustavoassis/g-low-cops-at-the-party
track lists from their set heard on ETN2 (etn.fm)
• http://progressivehouse.com/forums/Radio-Shows/moonbeam--aerofeel5--octave-amp-weiss--moonbeam-music-2012-41626.html
• http://www.protonradio.com/show.php?action=past&showdateid=23978&showid=288
• http://www.mixesdb.com/w/2012-04-19_-_Moonbeam,_Aerofeel5,_Octave_%26_Weiss_-_Moonbeam_Music_062
track lists from their set heard on ETN2 (etn.fm)
• http://progressivehouse.com/forums/Radio-Shows/moonbeam--aerofeel5--octave-amp-weiss--moonbeam-music-2012-41626.html
• http://www.protonradio.com/show.php?action=past&showdateid=23978&showid=288
• http://www.mixesdb.com/w/2012-04-19_-_Moonbeam,_Aerofeel5,_Octave_%26_Weiss_-_Moonbeam_Music_062
Monday, April 30, 2012
Chrome warn before quitting wasn't good enough
Sometimes I'd double-tap Command-Q and that would be enough.
So I mapped it to Command-Option-Q as described here:
http://www.quora.com/How-do-I-disable-Command-q-in-OS-X
So many folks dislike this. I do too.
• http://groups.google.com/a/googleproductforums.com/forum/#!topic/chrome/pLR6h12UNc8
• Chrome Issues List
• Safari remapping: http://hints.macworld.com/article.php?story=2003050112482698
• And an example of removing a pref: http://www.oreillynet.com//cs/user/view/cs_msg/46459
So I mapped it to Command-Option-Q as described here:
http://www.quora.com/How-do-I-disable-Command-q-in-OS-X
So many folks dislike this. I do too.
• http://groups.google.com/a/googleproductforums.com/forum/#!topic/chrome/pLR6h12UNc8
• Chrome Issues List
• Safari remapping: http://hints.macworld.com/article.php?story=2003050112482698
• And an example of removing a pref: http://www.oreillynet.com//cs/user/view/cs_msg/46459
Sunday, April 22, 2012
http://wdc.com/en/products/products.aspx?id=330
Considering the good reviews everywhere -- this looks like it will be my MythTV frontend.
http://www.mythtv.org/wiki/WD_Live_HD_Media_Player
says it will apparently work out of the box.
If it does netflix and huluplus, total win.
Film at 11.
Saturday, April 21, 2012
Chrome loses your preferences - gah.
http://saravananthirumuruganathan.wordpress.com/2010/05/10/how-to-solve-your-profile-could-not-be-opened-correctly-issue-in-chrome-or-chromium-without-losing-your-profile/
Restored from backup /Library/Application Support/Google/Chrome/Default/Preferences
http://support.google.com/chrome/bin/answer.py?hl=en&answer=142059
(which I didn't do.)
http://saravananthirumuruganathan.wordpress.com/2010/05/10/how-to-solve-your-profile-could-not-be-opened-correctly-issue-in-chrome-or-chromium-without-losing-your-profile/
Restored from backup /Library/Application Support/Google/Chrome/Default/Preferences
Create a new browser user profile:
http://support.google.com/chrome/bin/answer.py?hl=en&answer=142059
(which I didn't do.)
Wednesday, February 15, 2012
bash history collector, without external scripts
# history_logger() side effects:
# sets global variable '_last_history_number_logged'
# $HISTCMD special variable should actually provide this,
# But it appears unavailable in functions or at PROMPT_COMMAND eval time.
#
function history_logger() {
local last_exit_code=$? # must be the first command we run in this function local last_history_line=$(history 1)
local _match_me="^ ?([0-9]+)"
# Only log if we are not root:
if [ "$(id -u)" -ne 0 ]; then
# only log if history number changes:
if [[ ${last_history_line} =~ ${_match_me} ]] &&
[[ ${BASH_REMATCH[1]} != $_last_history_number_logged ]] ; then
_last_history_number_logged=${BASH_REMATCH[1]} ;
echo "$(date)] ${HOSTNAME%%.*}[$$:S${WINDOW}:${last_exit_code}] ${PWD/~/\~} ${last_history_line}" >> ~/.shell.log;
fi ;
fi
}
# the plumbing that makes it work:
export PROMPT_COMMAND='history_logger'
A few explanatory comments, as inline comments aren't available:• HISTCMD does not appear to be available at function call or PROMPT_COMMAND time,
so we use the [[ history =~ regex && BASH_REMATCH ]] to hack it
• the assignment to ${_match_me} is because regex matching doesn't work correctly otherwise.
• the shell out to $(date) seems unavoidable.
• gnu screen is setting $WINDOW
• ${PWD/~/\~} is an exercise left to the reader.
I've seen other folks try to do this –– the best I found folks doing involved calling other bash scripts from the PROMPT_COMMAND.
I hit the same problem (inside a PROMPT_COMMAND, $HISTNUM is always == 1).
My solution uses a regex to capture the last history number, and doesn't require calling a separate script or set of scripts.
Comments welcome.
Wednesday, January 18, 2012
X11/xterm bliss in OSX
I was frustrated that selection buffer in Mac's OSX X11/XQuartz(2.7.0) xterm
and the aqua clipboard doesn't sync without manual use of the Edit/Copy menu.
I have menu shortcuts turned off in XQuartz so that Command becomes my xterm Meta key.
I found:
http://gigo.com/archives/blog/apples-x11app-and-xterm-copypa.html
which led me to setup my preferences and .Xresources file thusly:
My X11/XQuartz preferences:
Input tab:
• Enable "Emulate 3 button mouse "
• Disable "Follow system keyboard"
• Disable "Enable key equivalents under X11"
• Enable "Option keys send Alt_L and Alt_R"
Pasteboard tab:
• All are enabled.
~/.Xresources file:
xterm*metaSendsEscape: trueXTerm*VT100.Translations: #override \ Shift <KeyPress> Help: insert-selection(CLIPBOARD,PRIMARY,CUT_BUFFER0) \n\ <KeyPress> Help: select-set(CLIPBOARD,PRIMARY,CUT_BUFFER0) \n\ <BtnUp>: select-end(CLIPBOARD,PRIMARY,CUT_BUFFER0)\n
+ my personal preferences:
xterm*loginShell: true xterm*cursorColor: pink xterm.vt100.reverseVideo: false !xterm.vt100.foreground: yellow !xterm.vt100.background: black xterm.vt100.saveLines: 1023 xterm.vt100.scrollBar: false xterm.vt100.deleteIsDEL: true xterm.vt100.visualBell: true xterm.vt100.popOnBell: true
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#RSFtalks with Edward Snowden
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What an intelligent, thoughtful individual. I find it difficult to forgive 44 for failing to pardon this patriot and instead pursuing him ...
