Coronavirus disease 2019

COVID-19 is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic.

The symptoms of COVID‑19 can vary but often include fever,[7] fatigue, cough, breathing difficulties, loss of smell, and loss of taste.[8][9][10] Symptoms may begin one to fourteen days after exposure to the virus. At least a third of people who are infected do not develop noticeable symptoms.[11][12] Of those who develop symptoms noticeable enough to be classified as patients, most (81%) develop mild to moderate symptoms (up to mild pneumonia), while 14% develop severe symptoms (dyspnea, hypoxia, or more than 50% lung involvement on imaging), and 5% develop critical symptoms (respiratory failure, shock, or multiorgan dysfunction).[13] Older people have a higher risk of developing severe symptoms. Some complications result in death. Some people continue to experience a range of effects (long COVID) for months or years after infection, and damage to organs has been observed.[14] Multi-year studies on the long-term effects are ongoing.[15]

COVID‑19 transmission occurs when infectious particles are breathed in or come into contact with the eyes, nose, or mouth. The risk is highest when people are in close proximity, but small airborne particles containing the virus can remain suspended in the air and travel over longer distances, particularly indoors. Transmission can also occur when people touch their eyes, nose, or mouth after touching surfaces or objects that have been contaminated by the virus. People remain contagious for up to 20 days and can spread the virus even if they do not develop symptoms.[16]

Testing methods for COVID-19 to detect the virus’s nucleic acid include real-time reverse transcription polymerase chain reaction (RT‑PCR),[17][18] transcription-mediated amplification,[17][18][19] and reverse transcription loop-mediated isothermal amplification (RT‑LAMP)[17][18] from a nasopharyngeal swab.[20]

Several COVID-19 vaccines have been approved and distributed in various countries, many of which have initiated mass vaccination campaigns. Other preventive measures include physical or social distancing, quarantining, ventilation of indoor spaces, use of face masks or coverings in public, covering coughs and sneezes, hand washing, and keeping unwashed hands away from the face. While drugs have been developed to inhibit the virus, the primary treatment is still symptomatic, managing the disease through supportive care, isolation, and experimental measures.

Updating Centos 7.9 firmware for Raspbery Pi 4 Model B

I purchased a Raspberry Pi 4 Model B 2019 Quad Core 64 Bit WiFi Bluetooth (4GB). Every other Pi I use in production uses Centos 7 so of course I go to load it on a microSD and boot. I’m then halted with progress by this error:

start4.elf is not compatible this board requires newer software

The fix is very simple. Download this archive:
*http://bay.uchicago.edu/centos-altarch/7/isos/aarch64/images/CentOS-Userland-7-aarch64-RaspberryPI-Minimal-4-2009-sda.raw.xz
and then extract the raw image file.

Then run upd-image-fw from:
*https://forums.raspberrypi.com/viewtopic.php?p=1714655#p1714655
*(direct link to program) https://forums.raspberrypi.com/download/file.php?id=41880&sid=0a370ba73c65275426888fdfcf0b01f0

and then simply run:

sudo ./upd-image-fw CentOS-Userland-7-aarch64-RaspberryPI-Minimal-4-2009-sda.raw

I like to use balenaEtcher to write the image to SD.

Unbound stats graphed with Xymon

Refer to this overall guide for a master overview and below is an example hopefully others can find useful.  This is for the Unbound stats we wanted to monitor initially and it may change.

Script to collect data

On the Xymon client:

touch ~xymon/ext/unboundstats.sh && chown xymon:xymon unboundstats.sh && chmod 744 unboundstats.sh

unboundstatsh.sh:

#!/bin/sh

/usr/sbin/unbound-control stats | \
grep -E “^total.num.queries|^total.num.queries_ip_ratelimited|^total.num.cachehits|^total.num.cachemiss|^total.recursion.time.avg|num.query.tcp|^unwanted.queries|^unwanted.replies” | \
awk -F= -v OFS=: ‘{gsub(/\./, “”, $1); print}’ > /tmp/unbound.stats

#sed would remove decimal in the recursion time value
#sed s,=,:, | sed s,\\.,,g > /tmp/unbound.stats

$XYMON $XYMSRV “status $MACHINE.unboundstats green `date`

`cat /tmp/unbound.stats`
”

exit 0

You need to restart the Xymon server!  Generally this is systemctl restart xymon or /etc/init.d/xymonlaunch.cfg restart

I’m not sure if this is the right way of going about the permissions issue, but the Xymon user needs to be able to read the SSL key/pem…

chgrp xymon /etc/unbound/unbound_control.pem /etc/unbound/unbound_control.key /etc/unbound/unbound_server.pem /etc/unbound/unbound_server.key

Now make the Xymon client run the above script in ~xymon/etc/clientlaunch.cfg:

#this collects unbound stats
[unboundstats]
ENVFILE $XYMONCLIENTHOME/etc/xymonclient.cfg
CMD $XYMONCLIENTHOME/ext/unboundstats.sh
INTERVAL 5m

On the Xymon server you will want to turn this test submission data into RRD.  In ~xymon/server/etc/xymonserver.cfg:

TEST2RRD=”cpu=la,defaultdefaultdefault,unboundstats=ncv”

SPLITNCV_unboundstats=”totalnumqueries:GAUGE,totalnumqueries_ip_ratelimited:GAUGE,totalnumcachehits:GAUGE,totalnumcachemiss:GAUGE,totalrecursiontimeavg:GAUGE,numquerytcp:GAUGE,numquerytcpout:GAUGE,unwantedqueries:GAUGE,unwantedreplies:GAUGE”

GRAPHS=”defaultdefaultdefault”

GRAPHS_unboundstats=”unboundstats,unboundstats1″ #note this requires xymon 4.3.20 https://lists.xymon.com/archive/2017-April/044560.html

After a few minutes you should see RRD files

# ls /var/lib/xymon/rrd/HOST.FOOBAR.COM/unboundstats,*
/var/lib/xymon/rrd/HOST.FOOBAR.COM/unboundstats,numquerytcpout.rrd
…

Add the graph definition (this translates from the RRD files to pretty graphs and once the file is edited/saved you can refresh the test page on Xymon/unboundstats for live viewing) in ~xymon/server/etc/graphs.cfg:

[unboundstats]
TITLE Unbound Stats
YAXIS Num
DEF:numqueries=unboundstats,totalnumqueries.rrd:lambda:AVERAGE
DEF:numqueriesiprate=unboundstats,totalnumqueries_ip_ratelimited.rrd:lambda:AVERAGE
DEF:numcachehits=unboundstats,totalnumcachehits.rrd:lambda:AVERAGE
DEF:totalnumcachemiss=unboundstats,totalnumcachemiss.rrd:lambda:AVERAGE

LINE2:numqueries#00CCCC:Total Queries
LINE2:numqueriesiprate#00FF00:Queries IP Rate
LINE2:numcachehits#FF0000:Total Cache Hits
LINE2:totalnumcachemiss#0000FF:Total Cache Miss

COMMENT:\n
GPRINT:numqueries:LAST:Total Queries \: %5.1lf%s (cur)
GPRINT:numqueries:MAX: \: %5.1lf%s (max)
GPRINT:numqueries:MIN: \: %5.1lf%s (min)
GPRINT:numqueries:AVERAGE: \: %5.1lf%s (avg)\n

GPRINT:numqueriesiprate:LAST:IP Rate Queries \: %5.1lf%s (cur)
GPRINT:numqueriesiprate:MAX: \: %5.1lf%s (max)
GPRINT:numqueriesiprate:MIN: \: %5.1lf%s (min)
GPRINT:numqueriesiprate:AVERAGE: \: %5.1lf%s (avg)\n

GPRINT:numcachehits:LAST:Cache Hits\: %5.1lf%s (cur)
GPRINT:numcachehits:MAX: \: %5.1lf%s (max)
GPRINT:numcachehits:MIN: \: %5.1lf%s (min)
GPRINT:numcachehits:AVERAGE: \: %5.1lf%s (avg)\n

GPRINT:totalnumcachemiss:LAST:Cache Miss\: %5.1lf%s (cur)
GPRINT:totalnumcachemiss:MAX: \: %5.1lf%s (max)
GPRINT:totalnumcachemiss:MIN: \: %5.1lf%s (min)
GPRINT:totalnumcachemiss:AVERAGE: \: %5.1lf%s (avg)\n

[unboundstats1]
TITLE Unbound Stats
YAXIS Num
DEF:totalrecursiontimeavg=unboundstats,totalrecursiontimeavg.rrd:lambda:AVERAGE
DEF:numquerytcp=unboundstats,numquerytcp.rrd:lambda:AVERAGE
DEF:numquerytcpout=unboundstats,numquerytcpout.rrd:lambda:AVERAGE
DEF:unwantedqueries=unboundstats,unwantedqueries.rrd:lambda:AVERAGE
DEF:unwantedreplies=unboundstats,unwantedreplies.rrd:lambda:AVERAGE

LINE2:totalrecursiontimeavg#AAA1AA:Average Recusion Time
LINE2:numquerytcp#C6913B:Queries w TCP
LINE2:numquerytcpout#8BBFFF:Queries out w TCP
LINE2:unwantedqueries#FF69B4:Unwanted Queries
LINE2:unwantedreplies#FFFF00:Unwanted Replies

COMMENT:\n
GPRINT:totalrecursiontimeavg:LAST:Recursion Time Avg\: %5.1lf%s (cur)
GPRINT:totalrecursiontimeavg:MAX: \: %5.1lf%s (max)
GPRINT:totalrecursiontimeavg:MIN: \: %5.1lf%s (min)
GPRINT:totalrecursiontimeavg:AVERAGE: \: %5.1lf%s (avg)\n

GPRINT:numquerytcp:LAST:TCP Queries\: %5.1lf%s (cur)
GPRINT:numquerytcp:MAX: \: %5.1lf%s (max)
GPRINT:numquerytcp:MIN: \: %5.1lf%s (min)
GPRINT:numquerytcp:AVERAGE: \: %5.1lf%s (avg)\n

GPRINT:numquerytcpout:LAST:TCP Queries Out\: %5.1lf%s (cur)
GPRINT:numquerytcpout:MAX: \: %5.1lf%s (max)
GPRINT:numquerytcpout:MIN: \: %5.1lf%s (min)
GPRINT:numquerytcpout:AVERAGE: \: %5.1lf%s (avg)\n

GPRINT:unwantedqueries:LAST:Unwanted Queries\: %5.1lf%s (cur)
GPRINT:unwantedqueries:MAX: \: %5.1lf%s (max)
GPRINT:unwantedqueries:MIN: \: %5.1lf%s (min)
GPRINT:unwantedqueries:AVERAGE: \: %5.1lf%s (avg)\n

GPRINT:unwantedreplies:LAST:Unwanted Replies\: %5.1lf%s (cur)
GPRINT:unwantedreplies:MAX: \: %5.1lf%s (max)
GPRINT:unwantedreplies:MIN: \: %5.1lf%s (min)
GPRINT:unwantedreplies:AVERAGE: \: %5.1lf%s (avg)\n

 

Extract one column from a CSV

Assuming your CSV looks like this

“ID”,”DeviceName”,”IPAddress”,”LastStatusChange”
“211”,”customer name here”,”172.16.10.19″,”2018-08-1309:51:28″
“339”,”fue bah”,”10.13.0.1″,”2018-09-0619:28:30″

We can use Notepadd++ (or other tool) and some regex to extract the IP address.

Find what: ^(.*?),(.*?),(.*?),(.*?)$
Replace with: $3

Be sure to use regex if you’re on Windows/Notepad++!  This works with four “column” documents, to adjust it for more or less be sure to mirror the number of commas and use one – (.*?) – for each column.

CentOS 6 with Python 2.7

https://danieleriksson.net/2017/02/08/how-to-install-latest-python-on-centos/

 

wget http://python.org/ftp/python/2.7.14/Python-2.7.14.tar.xz
tar xf Python-2.7.14.tar.xz
cdPython-2.7.14
./configure–prefix=/usr/local–enable-unicode=ucs4–enable-shared LDFLAGS=”-Wl,-rpath /usr/local/lib”
make&&makealtinstall


wget https://bootstrap.pypa.io/get-pip.py

# Then execute it using Python 2.7 and/or Python 3.6:
python2.7 get-pip.py

# With pip installed you can now do things like this:
pip2.7 install [packagename]
pip2.7 install –upgrade [packagename]
pip2.7 uninstall [packagename]

Clean Config Output

One of the best alias ideas I've ever seen!  This strips all the comments and such out of a config file so you can see, generally, what it looks like to the program reading it.

# alias
alias cleanconfig='sed -e '\''s/#.*//'\'' -e '\''s/[ ^I]*$//'\'' -e '\''/^$/ d'\'''

# cleanconfig /etc/ntp.conf
driftfile /var/lib/ntp/drift
restrict default kod nomodify notrap nopeer noquery