We have lost the bubble…again

New guidance from President Donald Trump’s administration that declares teachers to be “critical infrastructure workers” could give the green light to exempting teachers from quarantine requirements after being exposed to COVID-19 and instead send them back into the classroom. Teachers could stay in classroom if exposed to COVID-19

I understand the idea of essential workers. More I understand the desire, or need for some parents to get the kids out of the house, but am I the only one who wonders about the priorities of this nation when they say, essentially, we don’t care if you are sick, the kids are going to recover and if you spread COVID around, well, that’s OK too.

And we wonder why no other county on the planet will let US citizens come and visit without a mandatory quarantine period. And Canada still has the northern border closed.

This Could Stop Now

It has been unusually warm in Northern Virginia. As you may know, most of the south (NoVA is considered to be in the south) is under a heat dome, and temperatures are warmer than usual. But we have passed the point of hot enough for you and progressed to enough already!

Let me explain.

The DC region has a standing record of 21 days in a row of above 90-degree temperatures. Forget the feels like (that is with the humidex 1 included. This is the raw bulb temperature. Because of two days below 90° (it only got up to 89° even though the humidex put us into the middle 90s) in the middle of the streak, we have not broken the consecutive day record – yet. But since June 25th, again except those two blustery cold days, every day has seen temperatures in the mid to upper 90s and little to no rain. Sure, we get a gully washer for ten minutes that causes more damage than penetration, but that is about all. And it is expected to continue until the end of this week. Almost six weeks of 90+ temperatures. And it is not August yet, which is when our hottest temperatures are experienced (and higher humidity). I am not sure my body can take much more of this. Much less my air conditioner.

Stay cool!

  1. The humidex is an index number used by Canadian meteorologists to describe how hot the weather feels to the average person, by combining the effect of heat and humidity. The term humidex was first coined in 1965. The humidex is a nominally dimensionless quantity based on the dew point. Wikipedia

AWS Template Creation by Script

During an AWS architecture class, we had to create and launch an AWS Stack. Within the stack, it was Infrastructure as Code, but the actual launch of the stack was done at the console. Once upon a time, I knew I had worked with stack creation as IaC. I dug back through some of my old examples and found the code (below) that I used to create the stack, along with some of the variables.

The Code

Line numbers are for reference. Note that this is a single bash shell block (hence the “\” at the end of each line starting in line 2.

1.  cfn_stack_name="${JOB_NAME}-${pipeline_instance_id}"
2.  cfn_stack_id=$(aws cloudformation create-stack \
3.     --disable-rollback \
4.     --region $region \
5.     --stack-name "$cfn_stack_name" \
6.     --template-body "file://${cfn_template_path}" \
7.     --parameters ParameterKey=amiID,ParameterValue=$baseami \
8.         ParameterKey=vpcID,ParameterValue=$vpc \
9.         ParameterKey=subnetID,ParameterValue=$subnet \
10.        ParameterKey=keypairName,ParameterValue=$jenkins_key_name \
11.    --tags Key=BuiltBy,Value="Jenkins_$(hostname)" \
12.    --tags Key=AWS_OP_ENV,Value="$aws_op_env" \
13.    --tags Key=Server,Value="$server_function" \
14.    --tags Key=System,Value="$system" \
15.    --query 'StackId' --output text)
16. max_waitime=600
17. wait_interval=5
18. # wait until the stack is created
19. echo "Waiting for CFN stack to be created..."
20. time monitor_stack --region "$region" --stack "$cfn_stack_name"
21. cfn_instance_id=$(aws cloudformation describe-stacks --region $region --stack-name="$cfn_stack_name" --query 'Stacks[0].Outputs[0].OutputValue' --output text)
22. echo "CGN stack created!"

The other thing to note is you need to have the AWS CLI installed in your build environment for this to work. In most cases, you will be building this inside AWS, so the CLI will be available to you.

The Explanation

In the code starting on line 1:


The JOB_NAME and pipeline_instance_id are generated by the Jenkins job. You can name it however you want, that was just what we used. We originally started with just date/time stamps.

Line 2 begins the actually stack creation:

cfn_stack_id=$(aws cloudformation create-stack

The cfn_stack_id is generated at the end of the code block: --query 'StackID' --output text. The syntax may be old, check the documentation for the correct call for the StackID. The rest of the data is necessary to define the stack.

Most of the variables are defined higher up in the script, most based on calls to a DymanoDB instance where we would store various bits of data that may or may not have changed throughout the build process, or as defined by the customer. We also saved the stack name in that same DB system so we could tear it down later.

Finally we wrapped it with a timer value. This may need to be adjusted based on the speed of the environment or number of variables you are pushing into the stack. You want the system to error out if things are too busy, otherwise the script will hang and the build server will appear to be stuck. We also had some additional verbiage at the bottom of the script that pushed text to the log file/console output so you could see it succeed as shown in lines 18 – 22.

One other thing to note is that the stack also launches an AMI (again pulled from reference). Once this stack and associated AMI are up, the next part of the pipeline starts. This could populate the AMI, test it, turn it into a Jenkins build server, whatever was necessary. The key here is it is all code.

Installing MediaWiki on Ubuntu 18

A buddy send a request. He was installing MediaWiki on Ubuntu and he was having issues so he asked me to take a look. I reviewed a link on Linux Support and HowtoForge on installing MediaWiki, and found them to be a tad dated. So, I went through the installation myself, and here is how I installed it.

All steps are done as an sudoer or as the root user. I did this on AWS with a Ubuntu 18.04 minimal base image. I assume you know how to log into a console. I used Apache. You can use Nginx, but the server directions are different and I did not have a chance to try them out.

Update the OS

sudo apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xF1656F24C74CD1D8
sudo add-apt-repository "deb [arch=amd64,arm64,ppc64el] http://mariadb.mirror.liquidtelecom.com/repo/10.4/ubuntu $(lsb_release -cs) main"
sudo apt-get update
sudo apt-get upgrade

Install basic packages

sudo apt-get install -y apache2 software-properties-common
sudo apt -y install mariadb-server mariadb-client
sudo apt install php libapache2-mod-php
sudo apt-get install imagemagick php7.2-fpm php7.2-intl php7.2-xml php7.2-curl php7.2-gd php7.2-mbstring php7.2-mysql php7.2-mysql php-apcu php7.2-zip

Once PHP is installed you will get a notice similar to:

NOTICE: Not enabling PHP 7.2 FPM by default.
NOTICE: To enable PHP 7.2 FPM in Apache2 do:
NOTICE: a2enmod proxy_fcgi setenvif
NOTICE: a2enconf php7.2-fpm

I enabled it after the fact and it worked. You can do it now or later as you desire.

Modify PHP settings (Optional)

If you are putting your server into production, use the following settings initially. If you are just looking around, the default php.ini settings are fine except for the timezone settings. You should set the timezone appropriately.

For production, edit /etc/php/7.2/apache2/php.ini and make the following changes:

memory_limit = 256M
upload_max_filesize = 100M
max_execution_time = 360
date.timezone = America/New York

Run the secure installation for MariaDB (Optional)

If you are running a production server, you should do a secure installation.

sudo mysql_secure_installation

Create the MediaWiki table space

Login to MariaDB

mariadb -u root -p

And create the MediaWIki user and db as follows

CREATE USER 'media'@'localhost' IDENTIFIED BY 'password';
GRANT ALL ON mediadb.* TO 'media'@'localhost' IDENTIFIED BY 'password' WITH GRANT OPTION;

Where password is a secure password. This will be put into the MediaWiki configuration later, so do not forget it. The database mediadb and user media can be anything you want them to be.

Edit Apache’s site configuration

You will need to add MediaWiki to the site configuration. Create a new file called mediawiki.conf

sudo vi /etc/apache2/sites-available/mediawiki.conf

And add the following:

<VirtualHost *:80>
ServerAdmin admin@example.com
DocumentRoot /var/www/html/mediawiki/
ServerName example.com
<Directory /var/www/html/mediawiki/>
Options +FollowSymLinks
AllowOverride All
ErrorLog /var/log/apache2/media-error_log
CustomLog /var/log/apache2/media-access_log common

Where the ServerAdmin variable should be real email address and the ServerName should be the domain name of the server. Also, ensure that the DocumentRoot is correct. If you only want to use MediaWiki, you can set the DocumentRoot to /var/www/html, but you have to modify a step below as well.

Restart everything

Do not restart the server yet! Instead, restart the key services.

sudo a2ensite mediawiki.conf
sudo a2enmod rewrite
sudo systemctl start apache2
sudo systemctl enable apache2
sudo systemctl start mariadb
sudo systemctl enable mariadb

Download the current MediaWiki source

From the MediaWiki site, make sure you have the correct version. As of this writing, it is: mediawiki-1.33.1

Change to a temporary directory, download, untar, and move the file to the web server:

wget https://releases.wikimedia.org/mediawiki/1.33/mediawiki-1.33.1.tar.gz
tar zxvf mediawiki-1.33.1.tar.gz 
sudo mkdir -p /var/www/html/mediawiki
sudo mv mediawiki*/* /var/www/html/mediawiki

If you modified the DocumentRoot in the Apache configuration to /var/www/html, you will need to modify the command above. You will only need to move the contents of the base mediawiki folder:

sudo mv mediawiki*/* /var/www/html

Point your browser at the web site

Depending on your confirmation you can either use localhost or the hostname of your server. If you use the mediawiki folder option, you have to put the folder on the end.


Good luck!

Web Links

MAX and Human Errors

What Really Brought Down the Boeing 737 Max? – The New York Times

In the drama of the 737 Max, it was the decisions made by four of those pilots, more than the failure of a single obscure component, that led to 346 deaths and the worldwide grounding of the entire fleet.

I am not a pilot, and I have never been at the controls of an airplane. This very long article does go into a number of issues surrounding a complicated piece of technology. Take a read. It does not take any responsibility off of Boeing, but it certainly does not make them out to be the only villain in the story.

Checks and Balances

Trump impeachment: Lindsey Graham will ‘not pretend to be a fair juror’

Asked if it was appropriate for him as a prospective juror to be discussing the case in such terms, he said: “Well, I must think so because I’m doing it.”

Once upon a time, the Founding Fathers instituted a provision to remove a sitting President for High Crimes and Misdemeanors. Since that time four US Presidents have come under those provisions. Prior to this case, the Senators who should be trying the case (as jurors) kept their opinions to themselves. Not this time. This time, they are coming out and telling us exactly how they are going to vote. Before even hearing one witness. Before even seeing one document. They feel that this is a hit job and this is how they are going to vote.

If they were a real jury of their peers, they would be dismissed, at the very lest. I am sure there would be others ramifications. But these are United States Senators. The Founding Fathers are wondering what has happened to the Republic they strove so hard to create.

That is a big hole

Scientists have discovered deepest point on land | WTOP

The trough is about 3.5 km (about 2 miles) below sea level but there is no ocean water there. Instead, it is filled with ice flowing from the interior of the ice sheet towards the coast. The trough measures about 100 km in length and is 20 km wide, according to the study.

Think about how long 100 km is. The District of Columbia is 16 km on a side. According to Wikipedia, 100 km is 9/10 as long as the English Channel and not quite as wide as the narrowest point. And it is on land! Think about that with your morning coffee.