Bastion Hosts on AWS

A bastion host is a server whose purpose is to provide access to a private network from an external network, such as the Internet. Because of its exposure to potential attack, a bastion host must minimize the chances of penetration. For example, you can use a bastion host to mitigate the risk of allowing SSH connections from an external network to the Linux instances launched in a private subnet of your Amazon Virtual Private Cloud (VPC).

https://aws.amazon.com/blogs/security/how-to-record-ssh-sessions-established-through-a-bastion-host/

https://aws.amazon.com/quickstart/architecture/linux-bastion/

Oracle Cloud Infrastructure Foundations Associate

Current certification as an introduction to OCI (Oracle Cloud Infrastructure).

• Dynamic Routing Gateway (DRG, a virtual router): (for on-premises) Fast connect, and IPSec VPN (Site-2-site)
• Internet Gateway (internet)   
• Service Gateway (oci services)
• NAT Gateway: only outbound
• Peering:  Local & Remote VCN peering (diff VCN regions)

https://www.oracle.com/corporate/blog/free-certifications-oracle-oci-autonomous-033020.html

https://www.oracle.com/cloud/

https://www.oracle.com/cloud/compute/

https://www.oracle.com/cloud/iaas/sla.html

https://www.oracle.com/cloud/iaas/faq.html (resilience)

https://amarkalvikatte.wordpress.com/2020/04/04/oracle-cloud-infrastructure-foundations-2020-associate/

Instant Insanity solution

Solution of my youngest son for Insanity:

fasc5c

JMH samples

https://github.com/devwebcl/jmh-samples

JMH
JMH is a Java harness for building, running, and analysing nano/micro/milli/macro benchmarks written in Java and other languages targetting the JVM. [1]

1. http://openjdk.java.net/projects/code-tools/jmh/
2. http://s-j.github.io/getting-started-with-jmh/
3. http://tutorials.jenkov.com/java-performance/jmh.html#the-benchmarks-jar-file
4. https://www.sitepoint.com/which-java-logging-framework-has-the-best-performance/

When something is unfinished

XSS Visual

An interesting list of XSS explained by diagrams:

1. https://blog.scottlogic.com/2016/02/29/Cross-site-scripting.html
2. http://nerv0.blogspot.com/2012/06/xss-persistent-and-reflected.html
3. https://www.thesecuritybuddy.com/vulnerabilities/what-is-xss-or-cross-site-scripting-attack/
4. https://www.wordstream.com/blog/ws/2019/03/07/prevent-xss-attacks
5. https://dejanstojanovic.net/aspnet/2018/march/handling-cross-site-scripting-xss-in-aspnet-mvc/
6. https://medium.com/@marvin.soto/qu%C3%A9-es-xss-b9330eedbc07
7. https://www.wordstream.com/blog/ws/2019/03/07/prevent-xss-attacks
8. https://dev.to/maleta/cors-xss-and-csrf-with-examples-in-10-minutes-35k3
   

AWS Architectures

AWS Architectures examples taken from two crucial blog post, with serverless scope:

https://www.jeremydaly.com/serverless-microservice-patterns-for-aws/

https://medium.com/totalcloudio/aws-dynamodb-for-serverless-microservices-2acbbbff1bca

https://medium.com/@eduardoromero/serverless-architectural-patterns-261d8743020

http://aws-de-media.s3.amazonaws.com/images/DevDays%202018/SER3-Serverless%20Architectural%20Patterns.pdf


Most common architectures I've used:

 

 The Aggregator

 

 The Robust API

 

The Circuit breaker

Continuous stream processor

tcpdump cheat sheet

sudo tcpdump -i en0 -s 0 -B 524288 -A -w z2.txt

tcpdump host 192.168.122.10

tcpdump port 8080
tcpdump host poftut.com port 80

tcpdump -A -i eth0

 

tcpdump -s0 -nn -i any port 80 
tcpdump -s0 -nn -i any port 80 and host 10.10.250.124

 

(https), it will be seen as a binary


https://danielmiessler.com/study/tcpdump/#port
https://www.thegeekstuff.com/2010/08/tcpdump-command-examples/
https://theagileadmin.com/2017/05/26/tcpdump-and-wireshark-on-osx/
https://www.poftut.com/how-to-specify-host-port-and-protocol-for-tcpdump/
https://www.thegeekstuff.com/2010/08/tcpdump-command-examples/
https://stackoverflow.com/questions/25013221/sniff-traffic-on-a-particular-port-using-scapy

Singleton Spring

Singleton Spring Beans are not like the GoF Singleton design pattern.

 Spring can have more than one if they have different id's; meanwhile, GoF only allows one instance of the class (object) in the complete classloader.

 None option can solve some thread-safe issues that may appear by the composition of other objects that are nor thread-safe, JDBC connections, HTTP session, SimpleDateFormat, etc.

Update:

https://www.javadevjournal.com/spring/spring-singleton-vs-singleton-pattern/

From that URL:

Summary

Spring Singleton is very different from Singleton pattern. Spring guarantees to create only one bean instance for given bean id definition per container.Singleton pattern ensures that one and only one instance is created per ClassLoader.

Rules Workflow Constrains

Always there is the necessity to handle workflow, decisions, rules, validations.

The big question is to identify if we build it from scratch or we use different frameworks/tools/enterprise solutions for it.

This is a simple list (among others) of feasible options:

• camunda
• drools
• easy flow
• spring state machine
• openValidation
• jbpm

UPDATE:

Bueno yendose a la nube existen varios otras servicios que ofrecen la misma versatibilidad:

• AWS Step Function.