Category Archives: Amazon Cloud

News from the blog 2021-12-07

Charity

I’ve donated to Equitas Health.

Equitas Health helps thousands of HIV-positive in Ohio, Dayton and Columbus.

Thousands more are reached with our prevention, testing, and other services. We are excited about embracing our expanded mission as a strategic step to further that legacy and its reach by providing care for all – with a focus on a safe and open space and highest quality healthcare for the LGBTQ community and others who are medically underserved.
https://equitashealth.com/get-involved/give/donate-now/

I did my donation following a post by Terra Field, a former colleague at Blizzard and later leading Netflix’s Trans *ERG, but I didn’t see that she organized a gofund campaign, so I donated again :)

If you want to help them:

https://www.gofundme.com/f/transphobia-is-not-a-joke?utm_source=customer&utm_medium=copy_link_all&utm_campaign=m_pd+share-sheet

https://equitashealth.com/get-involved/give/donate-now/

Articles

I created an article about provisioning to Amazon AWS EC2 and running playbooks (recipes) using Ansible, and Dynamic Directory to store the public ip’s or dns public names in an inventory.

As I saw that there is a lack of clarity in the articles about this theme.

I also provided two alternatives ways, one pure Python3 and the other Bash based (grep awk tr)

Books

The books I publish in LeanPub have two prices, the suggested price, which is the price I consider the right price for the book, and the minimum price, which is the minimum price I authorized a reader can pay to have it.

You can buy it for the minimum price. You know better than anyone your economy.

So when a reader buys one of my books for the suggested price, instead of the minimum price, it’s really showing how they appreciate may work.

So thanks for all the support and appreciation you show!. :)

One of the motives I chose Leanpub platform is because I think is fair. No DRM, no BS. And the reader can ask for a refund within 45 days if they don’t like the book. It also makes very happy seeing that I don’t have any refunds. I appreciate it as a token of the usefulness of my work. Thanks. :)

Updates to Docker Combat File book (v.16 2021-11-24)

I added a nice trick to reverse engineering the original Dockerfile from a running Image.

I also added another typical copy and paste error into the Troubleshoot section.

https://leanpub.com/docker-combat-guide

Automating and Provisioning Amazon AWS (EC2, EBS, S3, CloudWatch) with boto3 (Amazon’s SDK for Python 3) and Python 3 book

I’m writing a book about how to automate your Amazon AWS tasks using Amazon’s AWS Python 3 SDK boto3, provisioning new instances, stopping, starting, creating volumes, creating/deleting buckets in S3, uploading/downloading files from S3…

It is currently 20% completed. With 43 pages it shows EC2 section already.

https://leanpub.com/amazon-aws-boto3

Open Source

I’ve working in carleslibs v.1.0.3. I added MenuUtils class, which allows to assemble menus super quickly, that execute the code referenced in the menu array. Ideal for building CLI applications very fast.

I also added KeyboardUtils class, which allows to ask the user for String within certain lengths allowing or not spaces and/or underscores, and ask user for Integer values within a certain min and max, having 0 for go back.

The plan is to release the new version of carleslibs as soon as I’ve tested it properly.

Social part

For those who follow my recommendations, as always, I have updated the list of new movies I watched and the list of new videogames I played.

News from the Blog 2021-11-11

New Articles

How to communicate with your Python program running inside a Docker Container, using Linux Signals

Hope you’ll have fun reading this article:

Communicating with Docker Containers via Linux Signals and Python

I migrated my last services from Amazon and the blog to Google Compute Engine (GCE / GCP)

I wrote a Postmortem analysis about the process of migrating my last services from my 11 year old Amazon account.

Updates

Updates to articles

I updated the article about Python weird things that you may not know adding the Ellipsis …

I’ve been working in some Cassandra examples. I may publish an article soon about using it from Python and Docker.

Updates to My Books

I updated my Python and Docker books.

I’m currently writing a book about using Amazon AWS Python SDK (boto3).

Updates to Open Source projects

I have updated ctop, fixed two bugs and increased Code Coverage.

I made a new tag and released the last Stable Version:

https://gitlab.com/carles.mateo/ctop/-/tags/0.8.7

On top of my local Unit Testing, I have Jenkins checking that I don’t commit anything that breaks the Tests.

Some time ago I wrote some articles about how you can setup jenkins in a Docker Container.

Miscellaneous

Charity

I’ve donated to Wikipedia.

Only 2% of the viewers donate, so I answered the call every time it was made.

This is my 5th donation to Wikimedia.

I consider that Freedom is very important.

I bought these new books

One of my secrets to be on top is that I’m always studying.

I study all the time, at work and in my free time.

I use Linux Academy and I buy books in paper. I don’t connect with reading in tablets. I think information is stored better when read in paper. I use also a marker and pointers to keep a direct access to the most interesting points on the books.

And I study all kind of themes. Obviously I know a lot of Web Scraping, but there is always room for learning more. And whatever new I learn helps me to be better with my students and more clear writing my books.

I’ve never been a Front End, but I’ve been able to fix bugs in the Front End engines from the companies I worked for, like Privalia. I was passed a bug that prevented the Internet Explorer users to buy just one hour before we launching a massive campaign. I debugged and I found a variable named “value” so the html looked like <input name="value" value="">. In less than 30 minutes I proved to the incredulous Head of Development and the CTO that a bug in Internet Explored was causing a conflict when fetching the value from the input named value. We deployed to Production the update and the campaign was a total success. So I consider knowing Javascript and Front also a need, even if I don’t work directly with it. I want to be able to understand all the requirements and possibilities, and weaknesses, so I can fix bugs and save the day. That allowed me to fix scalability problems in Nodejs and Phantomjs projects too. (They are Javascript Server Side, event driven, projects)

It seems that Amazon.co.uk works well again for Ireland. My two last orders arrived on time and I had no problems of border taxes apparently.

Nice Python article

I enjoyed a lot this article, cause explains part of what I did with my student and friend Albert, in a project that analyzes the access logs from Apache for patterns of attempts of exploits, then feeds a database, and then blocks those offender Ip Addresses in the Firewall.

The article only covers the part of Pandas, of reading the access.log file and working with it, but is a very well redacted article:

https://mmas.github.io/read-apache-access-log-pandas

Nice Virtual Volumes article from VMware

I prefer Open Source, but there are very good commercial products too.

I liked this article about Virtual Volumes from VMWare:

Understanding Virtual Volumes (vVols) in VMware vSphere 6.7/7.0 (2113013)

https://kb.vmware.com/s/article/2113013

Thanks Blizzard (again)

There is a very nice initiative where we can nominate 4 colleagues a year, that we think that deserve a recognition.

My colleagues voted for me, so I received a gift voucher that I can spend in Ireland stores like Ikea, Pc World, Argos, Adidas, App Store & iTunes…

So thanks a million buds. :)

Migrating my 11 years Amazon AWS account services (Postmortem Analysis)

I started to explain that I was migrating some services from Amazon and that some of my sites were under Maintenance and that I would provide more information.

Here is the complete history of why I migrated all the services from my 11 years old Amazon account to other CSP.

Some lessons can be learned from my adventure.

I migrated my last services from Amazon to GCP

Amazon sent me an email on October 6th, this year 2021, telling me that they will disable EC2-Classic by August 2022. I thought I would not be able to keep my Static Ip’s as in the past VPC Ip’s and EC2-Classic Ip’s were not transferable, so considering that I would loss my Static Ip’s anyway I started to migrate to some to other providers like Digital Ocean.

Is not cool losing Static Ip (Elastic Ip in AWS) Addresses as this is bad for SEO, so given that I though I would lose my Static Ips that have been with me for years, I started to migrate certain services to providers much more economic.

Amazon is terrible communicating, and I talked with some product managers in the past about that, when they lost one of my Volumes, and the email was so cold and terrible that actually that hurt more than Amazon losing my Data. I believed that it was a poorly made Scam and when I realized it was true I reached one of my friends, that is manager there, as I know they care for doing things right, and he organized a meeting with two PM so I can pass my feedback.

The Cloud providers are changing things very fast, and nobody is able to be up to date with the changes, unless their work position allows plenty of time to get updated. Even if pages of documentation are provided, you have to react to an event that they externally generated forcing you to action. Action to read all the documentation about EC2-Classic migrations, action to prepare to have migrated by August 2022.

So August 2022… I was counting that I had plenty of time but I’m writing a new book about using the Amazon SDK for Python, boto3, and I was doing some API calls and they started to fail in a very unusual way, Exceptions with timeout, but only for the only region where I had EC2-Classic.

urllib3.exceptions.NewConnectionError: <botocore.awsrequest.AWSHTTPSConnection object at 0x7f0347d545e0>: Failed to establish a new connection: [Errno -2] Name or service not known

My config was:

        o_config = Config(
            region_name="us-east-1a",
            signature_version="v4",
            retries={
                'max_attempts': 10,
                'mode': 'standard'
            }
        )

But if I switched to another region name, it would work:

            region_name='us-west-2',

I made a mistake in here, the region name is “us-east-1” and not “us-east-1a“. “us-east-1a” is the availability zone. So the SDK was giving a timeout because in order to connect to the endpoint it uses the region name as part of the hostname. So it doesn’t find that endpoint because it doesn’t exist.

I never understood why a company like Amazon is unable to provide the SDK with a sample project or projects 100% working, with the source code so people has a base that works to build up.

Every API that I have created, I have provided it with documentation but also with example for several languages for how to use it.

In 2013 I was CTO of an online travel agency, and we had meta-searchers consuming our API and we were having several hundreds of thousands requests per second. Everything was perfectly documented, examples were provided for several languages, the document and the SDK had version numbers…

Everybody forgets about Developers and companies throw terrible and cold products to the poor Developers, so difficult to use. How many Developers would like to say: Listen Mr. President of the big Cloud Company XXXX, I only want to spawn a VM that works, and fast, with easy wizards. I don’t want to learn 50 hours before being able to use your overpriced platform, by doing 20 things before your Ip’s are reflexes of your infrastructure and based in Microservices. Modern JavaScript frameworks can create nice gently wizards even if you have supercold APIs.

Honestly, I didn’t realize my typo in the region and I connected to the Amazon Console to investigate and I saw this.

Honestly, when I read it I understood that they were going to end my EC2 Networking the 30th of October. It was 29th. I misunderstood.

It was my fault not reading it well to the end, I got shocked by the first part telling about shutdown and I didn’t fully understood as they were going to shutdown EC2-Classic for the zones I didn’t had anything running only.

From the long errors (3 exceptions chained) I didn’t realize that the endpoint is built with the region name. (And I was passing the availability zone)

botocore.exceptions.EndpointConnectionError: Could not connect to the endpoint URL: "https://ec2.us-east-1a.amazonaws.com/"

Here is when I say that a good SDM would had thought and cared for the Developers more, and would had made the SDK to check if that region exists. How difficult is to create a SDK a bit more clever that detects a invalid region id?. It is not difficult.

It is true that it was late in the evening and I was tired of all the day, and two days of the week between work and zoom university classes I work 15 hours and 13 hours respectively, not counting the assignments, so by the end of the week I am very tired. But that’s why it is very important to follow methodology and to read well. I think Amazon has 50% of the fault by the way they do things: how the created the SDK, how they communicate, and by the errors that the console returned me when I tried to create a VPC instance of an EC2-Classic AMI (they seem related to the fact I had old VPC Network objects with shorter hash than the current they use) and the other 50% was my fault for not identifying the source of the error, and not reading the message in their website well.

But the fact that there were having those errors in the API’s and timeouts made me believe they were going to cut the EC2-Classic Networking the next day.

All the mistakes fall together in a perfect storm.

I checked for documentation and I saw it was possible to migrate my Static Ip’s to VPC Static Ip’s.

It was Friday evening, and I cancelled my plans, in order to migrate the Blog to VPC in an attempt to keep running it with Amazon.

As Cloud Architect, I like to have running instances in several CSP as it allows me to stay up to date with the changes they do.

I checked the documentation for the migration. Disassociating the Static Ip (Elastic Ip in AWS jargon) was easy. Turning into VPC as well.

As I progressed, what had to be easy turned into a nightmare, as I was getting many errors from the Amazon API, without any information, and my Instances were not created.

I figured out that their API could have problems with old VPC objects I created time ago, so I had to create new objects for several things.

I managed to spawn my instances but they were being launch and terminated instantly without information. Frustrating.

When launching a new instance from the AMI (a Snapshot of the blog), I was giving shown options to add more volumes without any sense. My Instance was using 16GB from a 20GB total Space, and I was shown different volume configs, depending on the instance, in some case an additional 20GB volume, in other small SSD, ephemeral and 10 GB for the AMI (which requires at least 16GB).

After some fight I manage to make it work after deleting the volumes that made no sense, and keeping only one of 20GB, the same size of my AMI.

But then my nightmare started to make the VPC Instance to have Internet access and to be seen from outside. I had to create a new Internet Gateway, NAT, Network, etc…

As mentioned the old objects I was trying to reusing were making the process to fail.

I was running out of time, and I thought in few time they were going to shutdown EC2-Classic network (as I did not read correctly), so I decided to download everything and to migrate to another provider. For doing that first I blocked all the traffic, except for my Ip.

I worked in parallel, creating the new config in Google Cloud, just in case I had forgot something. I had created a document for the migration and it was accurate.

I managed to do everything fast enough. The slower part was to download all the Data, as I hold entire VM’s for projects like Cassandra Universal Driver.

Then I powered off my Amazon Instance for the Blog forever.

In GCP I blocked all the traffic in the firewall, except for my Ip, so I could work calmly.

When everything was ready, I had to redirect the DNS to the new static Ip from Google.

The DNS provider I used had implemented some changes in their API so I was getting errors replacing my old entry ‘.’ (their JSON calls returned Internal Server Error). Finally I figured it out how to workaround it and I was able to confirm that the first service was up and running.

I did some tests to make sure there were not unexpected permission problems, entries in the logs, etc…

Only then I opened the Google Firewall. I have a second firewall in each instance where I block or open at Ip tables level what I want. Basically abusive bot’s IPs trying to find exploits or brute force by dictionary passwords.

I checked with my phone, without Wifi that the Firewall was all good. (It is always a good idea to use another external Ip, different from the management one, to check)

I added a post explaining that I was migrating some of my Services and were under maintenance.

I mentioned in the blog that some of my services were being migrated from Amazon to Digital Ocean.

For some reasons, in the Backup of the Database one user was lost, so I created it in the MySQL with the typical commands:

CREATE USER 'username'@'localhost' IDENTIFIED BY 'password';
FLUSH PRIVILEGES;
GRANT ALL PRIVILEGES ON mydatabase.* TO 'username'@'localhost';

News from the blog 2021-09-20

I’ve published a very simple game, Tic Tac Toe, that I created for my Python 3 Exercises for Beginners book.
I’ve raised back the price for my books to normal levels.
I’ve been keeping the price to the minimum to help people that wanted to learn during covid-19. I consider that who wanted to learn has already done it.

I still have bundles with a somewhat reduced price, and I authorized LeanPub platform to do discounts up to 50% at their discretion.

https://leanpub.com/b/python3-exercises-zfs-assemble-computer

I’ve been deleting AMIs, Snapshots, Volumes and backups from Amazon instances I’ll no longer use.

I’ve migrated to Docker some sites and WordPress sites and now I’m CSP (Cloud Service Provider) agnostic. I can deploy wherever I want.

We pay per GB used of storage, so my money will get a better usage.

As I said in my old article from 2013, The Cloud is for Scaling. For Startups and for Enterprises. It is too expensive for small and medium companies.

For those studying Python there is a Virtual Meetup about Data Analysis, in Spanish ,the 23th of September

https://www.meetup.com/tech-barcelona/events/280791310/

More meetups:

Migrating some Services from Amazon to Digital Ocean

Analyzing the needs

I start with a VM, to learn about the providers and the migration project as I go.

My VM has been running in Amazon AWS for years.

It has 3.5GB of RAM and 1 Core. However is uses only 580MB of RAM. I’m paying around $85/month for this with Amazon.

I need to migrate:

DNS Server
Email
Web
Database

For the DNS Server I don’t need it anymore, each Domain provider has included DNS Service for free, so I do not longer to have my two DNS.

For the email I find myself in the same scenario, most providers offer 3 email accounts for your domain, and some alias, for free.

I’ll start the Service as Docker in the new CSP, so I will make it work in my computer first, locally, and so I can move easily in the future.

Note: exporting big images is not the idea I have to make backups.

I locate a Digital Ocean droplet with 1GB of RAM and 1 core and SSD disks for $5, for $6 I can have a NVMe version. That I choose.

Disk Space for the Statics

The first thing I do is to analyze the disk space needs of the service.

In this old AWS CentOS based image I have:

[root@ip-10-xxx-yyy-zzz ec2-user]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/xvda1       79G   11G   69G  14% /
devtmpfs        1.8G   12K  1.8G   1% /dev
tmpfs           1.8G     0  1.8G   0% /dev/shm

Ok, so if I keep the same I have I need 11GB.

I have plenty of space on this server so I do a zip of all the contents of the blog:

cd /var/www/wordpress
zip -r /home/ec2-user/wp_sizeZ.zip wp_siteZ

Database dump

I need a dump of the databases I want to migrate.

I check what databases are in this Server.

mysql -u root -p

mysql> show databases;

I do a dump of the databases that I want:

sudo mysqldump --password='XXXXXXXX' --databases wp_mysiteZ > wp_mysiteZ.sql

I get an error, meaning MySQL needs repair:

mysqldump: Got error: 145: Table './wp_mysiteZ/wp_visitor_maps_wo' is marked as crashed and should be repaired when using LOCK TABLES

So I launch a repair:

sudo mysqlcheck --password='XXXXXXXX' --repair --all-databases

And after the dump works.

My dump takes 88MB, not much, but I compress it with gzip.

gzip wp_mysiteZ.sql

It takes only 15MB compressed.

Do not forget the parameter –databases even if only one database is exported, otherwise the CREATE DATABASE and USE `wp_mysiteZ`; will not be added to your dump.

I will need to take some data form the mysql database, referring to the user used for accessing the blog’s database.

I always keep the CREATE USER and the GRANT permissions, if you don’t check the wp-config.php file. Note that the SQL format to create users and grant permissions may be different from a SQL version to another.

I create a file named mysql.sql with this part and I compress with gzip.

Checking PHP version

php -v
PHP 7.3.23 (cli) (built: Oct 21 2020 20:24:49) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.23, Copyright (c) 1998-2018 Zend Technologies

WordPress is updated, and PHP is not that old.

The new Ubuntu 20.04 LTS comes with PHP 7.4. It will work:

php -v
PHP 7.4.3 (cli) (built: Jul  5 2021 15:13:35) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with Zend OPcache v7.4.3, Copyright (c), by Zend Technologies

The Dockerfile

FROM ubuntu:20.04

MAINTAINER Carles Mateo

ARG DEBIAN_FRONTEND=noninteractive

# RUN echo "nameserver 8.8.8.8" > /etc/resolv.conf

RUN echo "Europe/Ireland" | tee /etc/timezone

# Note: You should install everything in a single line concatenated with
#       && and finalizing with 
# apt autoremove && apt clean

#       In order to use the less space possible, as every command 
#       is a layer

RUN apt update && apt install -y apache2 ntpdate libapache2-mod-php7.4 mysql-server php7.4-mysql php-dev libmcrypt-dev php-pear git mysql-server less zip vim mc && apt autoremove && apt clean

RUN a2enmod rewrite

RUN mkdir -p /www

# If you want to activate Debug
# RUN sed -i "s/display_errors = Off/display_errors = On/" /etc/php/7.2/apache2/php.ini 
# RUN sed -i "s/error_reporting = E_ALL & ~E_DEPRECATED & ~E_STRICT/error_reporting = E_ALL/" /etc/php/7.2/apache2/php.ini 
# RUN sed -i "s/display_startup_errors = Off/display_startup_errors = On/" /etc/php/7.2/apache2/php.ini 
# To Debug remember to change:
# config/{production.php|preproduction.php|devel.php|docker.php} 
# in order to avoid Error Reporting being set to 0.

ENV PATH_WP_MYSITEZ /var/www/wordpress/wp_mysitez/
ENV PATH_WORDPRESS_SITES /var/www/wordpress/

ENV APACHE_RUN_USER  www-data
ENV APACHE_RUN_GROUP www-data
ENV APACHE_LOG_DIR   /var/log/apache2
ENV APACHE_PID_FILE  /var/run/apache2/apache2.pid
ENV APACHE_RUN_DIR   /var/run/apache2
ENV APACHE_LOCK_DIR  /var/lock/apache2
ENV APACHE_LOG_DIR   /var/log/apache2

RUN mkdir -p $APACHE_RUN_DIR
RUN mkdir -p $APACHE_LOCK_DIR
RUN mkdir -p $APACHE_LOG_DIR
RUN mkdir -p $PATH_WP_MYSITEZ

# Remove the default Server
RUN sed -i '/<Directory \/var\/www\/>/,/<\/Directory>/{/<\/Directory>/ s/.*/# var-www commented/; t; d}' /etc/apache2/apache2.conf 

RUN rm /etc/apache2/sites-enabled/000-default.conf

COPY wp_mysitez.conf /etc/apache2/sites-available/

RUN chown --recursive $APACHE_RUN_USER.$APACHE_RUN_GROUP $PATH_WP_MYSITEZ

RUN ln -s /etc/apache2/sites-available/wp_mysitez.conf /etc/apache2/sites-enabled/

# Please note: It would be better to git clone from another location and
# gunzip and delete temporary files in the same line, 
# to save space in the layer.
COPY *.sql.gz /tmp/

RUN gunzip /tmp/*.sql.gz; echo "Starting MySQL"; service mysql start && mysql -u root < /tmp/wp_mysitez.sql && mysql -u root < /tmp/mysql.sql; rm -f /tmp/*.sql; rm -f /tmp/*.gz
# After this root will have password assigned

COPY *.zip /tmp/

COPY services_up.sh $PATH_WORDPRESS_SITES

RUN echo "Unzipping..."; cd /var/www/wordpress/; unzip /tmp/*.zip; rm /tmp/*.zip

RUN chown --recursive $APACHE_RUN_USER.$APACHE_RUN_GROUP $PATH_WP_MYSITEZ

EXPOSE 80

CMD ["/var/www/wordpress/services_up.sh"]

Services up

For starting MySQL and Apache I relay in services_up.sh script.

#!/bin/bash
echo "Starting MySql"
service mysql start

echo "Starting Apache"
service apache2 start
# /usr/sbin/apache2 -D FOREGROUND

while [ true ];
do
    ps ax | grep mysql | grep -v "grep "
    if [ $? -gt 0 ];
    then
        service mysql start
    fi
    sleep 10
done

You see that instead of launching apache2 as FOREGROUND, what keeps the loop, not exiting from my Container is a while [ true ]; that will keep looping and checking if MySQL is up, and restarting otherwise.

MySQL shutting down

Some of my sites receive DoS attacks. More than trying to shutdown my sites, are spammers trying to publish comment announcing fake glasses, or medicines for impotence, etc… also some try to hack into the Server to gain control of it with dictionary attacks or trying to explode vulnerabilities.

The downside of those attacks is that some times the Database is under pressure, and uses more and more memory until it crashes.

More memory alleviate the problem and buys time, but I decided not to invest more than $6 USD per month on this old site. I’m just keeping the contents alive and even this site still receives many visits. A restart of the MySQL if it dies is enough for me.

As you have seen in my Dockerfile I only have one Docker Container that runs both Apache and MySQL. One of the advantages of doing like that is that if MySQL dies, the container does not exit. However I could have had two containers with both scripts with the while [ true ];

When planning I decided to have just one single Container, all-in-one, as when I export the image for a Backup, I’ll be dealing only with a single image, not two.

Building and Running the Container

I created a Bash script named build_docker.sh that does the build for me, stopping and cleaning previous Containers:

#!/bin/bash

# Execute with sudo

s_DOCKER_IMAGE_NAME="wp_sitez"

printf "Stopping old image %s\n" "${s_DOCKER_IMAGE_NAME}"
sudo docker stop "${s_DOCKER_IMAGE_NAME}"

printf "Removing old image %s\n" "${s_DOCKER_IMAGE_NAME}"
sudo docker rm "${s_DOCKER_IMAGE_NAME}"

printf "Creating Docker Image %s\n" "${s_DOCKER_IMAGE_NAME}"
# sudo docker build -t ${s_DOCKER_IMAGE_NAME} . --no-cache
sudo docker build -t ${s_DOCKER_IMAGE_NAME} .

i_EXIT_CODE=$?
if [ $i_EXIT_CODE -ne 0 ]; then
    printf "Error. Exit code %s\n" ${i_EXIT_CODE}
    exit
fi

echo "Ready to run ${s_DOCKER_IMAGE_NAME} Docker Container"
echo "To run type: sudo docker run -d -p 80:80 --name ${s_DOCKER_IMAGE_NAME} ${s_DOCKER_IMAGE_NAME}"
echo "or just use run_in_docker.sh"
echo
echo "Debug running Docker:"
echo "docker exec -it ${s_DOCKER_IMAGE_NAME} /bin/bash"
echo

I assign to the image and the Running Container the same name.

Running in Production

Once it works in local, I set the Firewall rules and I deploy the Droplet (VM) with Digital Ocean, I upload the files via SFTP, and then I just run my script build_docker.sh

And assuming everything went well, I run it:

sudo docker run -d -p 80:80 --name wp_mysitez wp_mysitez

I check that the page works, and here we go.

Some improvements

This could also have been put in a private Git repository. You only have to care about not storing the passwords in it. (Like the MySQL grants)

It may be interesting for you to disable directory browsing.

The build from the Git repository can be validated with a Jenkins. Here you have an article about setup a Jenkins for yourself.

News from the blog 2020-09-21

I’ve published two new articles:
- How to recover the Data/functionality of an Amazon AWS instance if you loss access to it
- Programs that I usually use on Windows workstations

I have benchmarked three different CPUs and two Compute optimized Amazon AWS instances with CMIPS 1.0.5 64bit. The two Intel Xeon baremetals equip 2 x Intel Xeon Processor and the third baremetal equips a single Intel Core i7-7800X:

If you’re surprised by the number of cores reported by the Amazon instance m5d.24xlarge, and even more for the baremetal c5n.metal, you’re guessing well that this comes from having Servers with 4 CPUs for Compute Optimized series.

CMIPS Score	Execution time (seconds)	Type of instance	Total cores	CPU model seen by Linux
58536	34.16	Amazon AWS m5d.24xlarge	96	4 x Intel(R) Xeon(R) Platinum 8175M CPU @ 2.50GHz
54169	36.92	Amazon AWS c5n.metal	72	4 x Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz
26329	75.96	Baremetal	48	2 x Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz
21732	92.02	Baremetal	40	2 x Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz
9810	203.87	Desktop computer	12	Intel(R) Core(TM) i7-7800X CPU @ 3.50 GHz

I can recommend these courses in Linux Academy:

https://linuxacademy.com/cp/library/catalog/view/DevOpsCourses

I’m finishing the 24 hours long Implementing a Full CI/CD Pipeline:

https://linuxacademy.com/cp/modules/view/id/218

When I can choose I use Linux, but in many companies I work with Windows workstations. I’ve published a list of useful Software I use in all my Windows workstations.

WFH I currently use two external monitors attached to the laptop. I planned to add a new one using a Display Port connected to the Dell USB-C dongle that provides me Ethernet and one additional HDMI as well. I got the cable from Amazon but unfortunately something is not working. In order to make myself comfortable and see some the graphs of the systems worldwide as I have on the office’s displays, I created a small HTML page, that joins several monitor pages in one single web page using frames.
This way I only have one page loaded on the browser, maximized, and this monitor is dedicated to those graphs of the stats of the Systems.
Something very simple, but very useful. You can extend the number of columns and rows it to have more graphics in the same screen.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN"
   "http://www.w3.org/TR/html4/frameset.dtd">
<HTML>
<HEAD>
<TITLE>Casa Monitor</TITLE>
</HEAD>
<FRAMESET cols="50%,50%">
  <FRAMESET rows="50%,*">
      <FRAME src="http://players-all-games/">
      <FRAME src="http://monthly-graphs/">
  </FRAMESET>
  <FRAMESET rows="50%,*">
	  <FRAME src="http://grafana/databases/">
	  <FRAME src="http://kibana/clusters/">
  </FRAMESET>
</FRAMESET>
</HTML>

If you don’t have the space or the resources for more monitors you can use the ingenious.

I have a cheap HDMI switch that allows me to do PinP (Picture in Picture) with one main source on the monitor, and two using a fraction of their original space. It may allow you to see variants in graphics.

And in you have only a single monitor, you can use a chrome extension that rotates tabs, which is also very useful.

Be careful if you use the reload features with software like Jira or Confluence. If they are slow normally, imagine if you mess it by reloading every 30 seconds… I discourage you to use auto refresh on these kind of Softwares.

This past week I have connected the XBOX One X Controller to the Windows laptop for the first time. Normally I use the Pc only for strategy games, but I wanted to play other games like Lost Planet 3, or Fall Guys in a console mode way. I figured that would be very easy and it was. You turn on the controller, press the connect button like you did to pair with the console, and in Windows indicate pair to a Xbox One controller. That’s it.

I’ve also updated my Python 3 Combat Guide, to add the explanation, step by step, about how to refactor and make resilient, and add Unit Testing to a spaghetti code, and turn it into a modern OOP. Is currently 255 DIN-A4 pages.

This is something I wanted to share with you for a while.
One of the most funny things in my career is what I call:
Squirrel Strikes Back

I named this as the first incident where a provider told that the reason of a fiber failure was a squirrel chewing the cable.

I popularized this with my friends in Systems Administration and SRE and when they suffer a Squirrel Attack incident, they forward it to me, for great joy.

I’m used to construction or gas, water, electricity, highways repair operations on the cities accidentally cutting fiber cables, thunders or truck accidents on the highway breaking the floor and cutting tubes and issues like that. I’ve been seeing that for around 25 years.

So the first time I saw a provider referring to a squirrel cutting the cables it was pretty hilarious. :)

In my funny mental picture: I could visually imagine a cable thrown in the middle of the forest, over trees, and a squirrel chewing it as it tastes like peanuts. :) or a shark cutting a Google’s or Facebook’s intercontinental cable thrown without any protection. ;)

The sense of humor and the good vibes, are two of the most important things in life.

How to recover access to your Amazon AWS EC2 instance if you loss your Private Key for SSH

This article covers the desperate situation where you had generated one or more instances, instructed Amazon to use a SSH Key Pair certs where only you have the Private Key, your instances are running, for example, an eCommerce site, running for months, and then you loss your Private Key (.pem file), and with it the SSH access to your instances’ Data.

Actually I’ve seen this situation happening several times, in actual companies. Mainly Start ups. And I solved it for them.

Assuming that you didn’t have a secondary method to access, which is another combination of username/password or other user/KeyPairs, and so you completely lost the access to the Database, the Webservers, etc… I’m going to show you how to recover the data.

For this article I will consider an scenario where there is only one Instance, which contains everything for your eCommerce: Webserver, code, and Database… and is a simple config, with a single persistent drive.

Warning: be very careful as if you use ephemeral drives, contents will be lost is you power off the instance.

Method 1: Quicker, launching a new instance from the previous

Step1: The first step you will take is to close the access from outside, using the Firewall, to avoid any new changes going to the disk. You can allow access to the instance only from your static Ip in the office/home.

Step 2: You’ll wait for 5 minutes to allow any transaction going on to conclude, and pending writes to be flushed to disk.

Step 3: From Amazon AWS Console, EC2, you’ll request an Snapshot. That step is to try to get extra security. Taking an Snapshot from a live, mounted, filesystem, is not the best of ideas, specially of a Database, but we are facing a desperate situation so we’re increasing the numbers of leaving this situation without Data loss. This is just for extra security and if everything goes well at the end you will not need this snapshot.

Make sure you select No reboot.

Step 4: Be very careful if you have extra drives and ephemeral drives.

Step 5: Wait till the Snapshot completes.

Step 6: Then request a graceful poweroff. Amazon will try to poweroff the Server in a gentle way. This may take two minutes.

Step 7: When the instance is powered off, request a new Snapshot. This is the one we really want. The other was just to be more safe. If you feel confident you can just unclick No Reboot on the previous Step and do only one Snapshot.

Step 8: Wait till the Snapshot completes.

Step 9: Generate and upload the new key you will use to AWS Console, or ask Amazon to generate a key pair for you. You can do it while creating the new instance through the wizard.

Step 10: Launch a new instance, based on your snapshot AMI. This will generate a copy of your previous instance (using the Snapshot) for the new one. Select the new Key pair. Finish assigning the Security groups, the elastic ip…

Step 11: Start the new instance. You can select a different flavor, like a more powerful instance, if you prefer. (scale vertically)

Step 12: Test your access by login via SSH with the new pair keys and from your static Ip which has access in the Firewall.

ssh -i /home/carles/Desktop/Data/keys/carles-ecommerce.pem ubuntu@54.208.225.14

Step 13: Check that the web Starts correctly, check the Database logs to see if there is any corruption. Should not have any if graceful shutdown went well.

Step 14: Reopen the access from the Firewall, so the world can connect to your instance.

Method 2: Slower, access the Data and rebuild whatever you need

The second method is exactly the same until Step 6 included.

Step 7: After this, you will create a new instance based on your favorite OS, with a new pair of Keys.

Step 8: You’ll detach the Volume from the eCommerce previous instance (the one you lost access).

Step 9: You’ll attach the Volume to the new instance.

Step 10: You’ll have access to the Data from the previous instance in the new volume. type cat /proc/partitions or df -h to see the mountpoints available. You can then download or backup, or install the Software again and import the Database…

Step 11: Check that everything works, and enable the access worldwide to the Web in the Firewall (Security Group Inbound Rules).

If you are confident enough, you can use this method to upgrade the OS or base Software of your instance, making it part of your maintenance window. For example, to get the last version of Ubuntu or CentOS, MySQL, Python or PHP, etc…

The Cloud is for Scaling

Last Update: 2022-08-03 I added the Enterprises, as more and more services have been provided by Amazon and the other major Cloud Providers and they offer a suitable solution for Enterprises requiring high availability in services managed by Amazon, without the need to configure and maintain their own setups manually.

The Cloud is for Startups, and for Scaling. Nothing more.

In the future will be used by phone operators, to re-dimension their infrastructure and bandwidth in real time according to demand, but nowadays the Cloud is for Startups.

Examine the prices in my post in cmips, take a look, examine the performance also of the different CPU. You see that according to CMIPS v.1.03 a Desktop Processor Intel i7-4770S, worth USD $300, performs better than an Amazon M2 High Memory Quadruple Extra Large and than a Rackspace First gen. 30 GB RAM 8 Cores?.

Today the public cost of an Amazon M2 High Memory Quadruple Extra Large running for a month is USD $1,180.80 so USD $1.64 per hour and the Rackspace First Generation 30 GB RAM 8 Cores 1200 GB of disk costs is USD $1,425.60 so USD $1.98 per hour running.

And that’s the key, the cost per hour.

Because the greatness, the majesty of the Cloud is that you pay per hour, you pay as you need, or as you go. No attaching contracts. All on demand.

I had my company at a time where the hosting companies and the Data Centers were forcing customers to sign yearly contracts. What if a company only needs to host their Servers for three months? What if they have to close?. No options. You take it or you leave it.

Even renting a dedicated hosting was for at least a month or more, and what if the latency was not good? What if the bandwidth of the provider was not enough?.

Amazon irrupted in the market with strength. I really like that company because they grew the best eCommerce company for buying books, they did a system that really worked, and was able to recommend very useful computer books, and the delivery, logistics was so good, also post-sales service. They simply started to rent the same infrastructure they were using to attend their millions of customers and was a total success.

And for a while few people knew about Amazon deep technologies and functionalities, but later became a fashion.

Now people is using Amazon or whatever provider/Service that contains the word “Cloud” because the Cloud is in the mouth of everyone. Magazines and newspapers speak about the Cloud, so many many companies use it simply because everyone is talking about the Cloud. And those ISP that didn’t had a Cloud have invested heavily to create a Cloud, just because they didn’t want to be the ones without a Cloud, since everyone was asking for it and all the ISP companies were offering their “Clouds”.

Every company claims to have “Cloud” where the only many of them have is Vmware servers, Xen servers, Open Stack… running the tenants or instances of the customers always on the same host servers. No real Cloud, professional Cloud, abstract layered in a Professional way like Amazon, only the traditional “shared hosting” with another name, sharing CPU and RAM and Disk storage using virtual machines called instances.

So, Cloud fashion has become a confusing craziness where no one knows why they are in the Cloud but they believe they have to be in.

But do companies need the Cloud?. Cloud instances?

It depends. The best would be to ask that companies Why you choose the Cloud?.

If you compare the cost of having an instance in the Cloud, is much much more expensive than having a dedicated server. And for that high cost you don’t get more performance.

Virtualization is always slower and disk speed is always an issue in Cloud providers, where all the data travels via network from the disk cabins NAS to the Host servers running the guest instances. Data cannot be at local disks, since every time you start an instance, the resources like CPU and RAM are provisioned, and your instance run in totally different hardware. Only your data remain in the NAS (Network Attached Storage).

So unless you run your in-the-Cloud instance in a special provider that offers local disks, like DigitalOcean that offers SSD but monthly paying, (and so you pay the price by losing the hardware abstraction capability because you’re attached to the CPU that has the disk connected, and also you loss the flexibility of paying per hour of use, as you go), then you’ll face a bottleneck that is the hard disk performance (that for real takes all the data from NAS, where is stored, through the local network).

So what are the motivations to use the Cloud?. I try to put some examples, out of these it has no much sense, I think. You can send me your happy-in-Cloud scenarios if you found other good uses.

Example A) Saving initial costs, avoid contract attachment and grow easily own-made

Imagine a Developer that start its own project. May be it works, may be not, but instead of having a monthly contract for a dedicated server, he starts with an Amazon Free Tier (better not, use Small instance at least) and runs a web. If it does not work, simply stop the instance and pay no more. If the project works and has more and more users he can re-dimension the server with a click. Just stop the instance, change the type of instance, start it again with more RAM and more CPU power. Fast.

Hiring a dedicated server implies at least monthly contracts, average of USD $100 per month, and is not easy to move to a bigger server, not fast and is expensive as it requires the ISP tech guys to move the data, to migrate from a Server to another.

Also the available bandwidth is to be taken in consideration. Bandwidth is expensive and Amazon can offer 150 Mbit to smaller machines. Not all the Internet Service Providers can offer that bandwidth even with most advanced packets.

If the project still grows, with a click, in seconds, 20 instances with a lot of bandwidth can be deployed and serving traffic to your customers very quick.

You save the init costs of buying Servers, and the time to deal with hardware, bandwidth limitations and avoid contracts, but you pay an hourly rate a lot more expensive. So in the long run is much much expensive using Amazon and less powerful than having dedicated servers. That happened to Zynga, that was paying $63M annually to Amazon and decided to step back from Amazon to their own Data Centers again. (another fortune tech link)

The limited CPU power was also a deal breaker for many companies that needed really powerful CPU and gigs of RAM for their Database Servers. Now this situation is much better with the introduction of the new Servers.

This developer can benefit from doing bacups with a click, cloning, starting instances from an image, having more static ip’s with a click, deploying built-in (from the Cloud provider) load balancers, using monitoring services like CloudWatch, creating Volumes and attaching to the servers for additional space…

Example B) An Startup with fluctuating number of users and hopes of growing

Imagine an Startup with a wonderful Facebook Application.

During 80% of the day has few visits, may be only need 3 Servers, but during 20% of the hours of the day from 10:00 to 15:00 users connect like hell, so they need 20 servers to attend this traffic and workload, and may be tomorrow needs 30 servers.

With the Cloud they pay for 3 servers 24 hours per day and for the other 17 servers only pay the hours they are on, that’s 5 hours per day. Doing that they save money and they have an unlimited * amount of power. (* There are limits for real, you have to specially request authorisation to run more than default max. servers for the zone, that is normally 20 instances for Amazon. Also it can happen theoretically that when you request new instances the Zone has no instances available).

So well, for an Startup growing, avoiding hiring 20 dedicated servers and instead running into the Cloud as many as they need, for just the time they need, Auto-Scaling up and down, and can use the servers NOW and pay the next month with Visa card, all of that can make a difference for a growing Startup.

If the servers chosen are not powerful enough that is solved with a click, changing instance type. So fast. A minute.

It’s only a matter of money.

Example C) e-Learning companies and online universities

e-Learning platforms also get benefits from the Auto-Scaling for the full occupation hours.

The built-in functionalities of the Cloud to clone instances is very useful to deploy new web servers, or new environments for students doing practices, in the case of teaching Information Technology subjects, where the users need to practice against a real server (Linux or windows).

Those servers can be created and destroyed, cloned from the main -ready to go- template. And also servers can be scheduled to stop at a certain hour and to start also, so saving the money from the hours not needed.

Example D) Digital agencies, sports and other events

When there is an Special event, like motorcycle running, when a Football Team scores, when there is an spot in tv announcing a product…

At those moments the traffic to the site can multiply, so more servers and more bandwidth have to be deployed instantly. That cannot be done with physical servers, hardware, but is very easy to provision instances from the Cloud.

Mass mailing email campaigns can also benefit from creating new Servers when needed.

Example E) Proximity and SEO

Cloud providers have Data Centres everywhere. If you want to have servers in Asia, or static content to be deployed faster, or in South-America, or in Europe… the Cloud providers have plenty of Data Centers all over the world.

Example F) Game aficionado and friends sharing contents

People that loves cooperative games can find the needed hungry bandwidth and at a moderate price. If they run their private server few hours, at night, from 22:00 to 01:00 as example, they will benefit from a great bandwidth from the big Cloud provider and pay only 3 hours per day (the exceed of traffic uses to be paid in most providers, but price of additional GB uses to be really really competitive).

Friends sharing contents in an Ftp also, can benefit from this Cloud servers, but probably they will find more easy to use services like Dropbox.

Example G) Startup serving contents

An Startup serving videos, images, or books, can benefit not only from the great bandwidth of big Cloud providers (this has been covered before), but for a very cheap price for exceeding Gigabyte transferred.

Local ISP can’t offer 150 Mbit for an instance of USD $20 and USD $0.12 per additional GB transferred.

Many Cloud providers also allow unlimited incoming traffic from the Internet, and from Server to Server through private ip’s.

Example H) Enterprises that want to outsource the solutions and having better availability

Since I wrote this article in 2013, many CSP have been incorporation more and more powerful services to their catalalog.

For instance Amazon has service like DynamoDB, RDS, Load Balancers able to balance servers in different availability zones, with Auto-Scaling, SQS for Message Queues, ElastiCache, Lambda, S3…

Many Enterprise find convenient to have all their services offloaded to Amazon, Google Cloud, Microsoft Azure… so they require less Operations and System Administration Engineers.

Other cases

For other cases Dedicated Servers are much more Powerful, faster and cheaper, at the price of being “static” in the sense of attached, not layer abstracted, but all the aspects of your Project have to be taken in count before deciding stepping into or out of the Cloud.

In general terms I would say that the Cloud is for Scaling, but in 2022 it’s also to outsource Operation Services, to fully managed services by the CSPs.