Add Terraform and Linux questions and exercises

Also updated the script that counts questions to actually update
the number in README.md

README.md

@@ -2,7 +2,7 @@
 
 :information_source:  This repo contains questions and exercises on various technical topics, sometimes related to DevOps and SRE
 
-:bar_chart:  There are currently **2538** exercises and questions
+:bar_chart:  There are currently **2557** exercises and questions
 
 :warning:  You can use these for preparing for an interview but most of the questions and exercises don't represent an actual interview. Please read [FAQ page](faq.md) for more details
 
@@ -23,7 +23,7 @@
     <td align="center"><a href="topics/git/README.md"><img src="images/git.png" width="75px;" height="75px;" alt="Git"/><br /><b>Git</b></a></td>
     <td align="center"><a href="topics/ansible/README.md"><img src="images/ansible.png" width="75px;" height="75px;" alt="ansible"/><br /><b>Ansible</b></a></td>
     <td align="center"><a href="#network"><img src="images/network.png" width="75px;" height="75px;" alt="Network"/><br /><b>Network</b></a></td>
-    <td align="center"><a href="topics/linux/README.md"><img src="images/logos/linux.png" width="75px;" height="75px;" alt="Linux"/><br /><b>Linux</b></a></td>
+
 
   </tr>
   <tr>
@@ -32,54 +32,62 @@
     <td align="center"><a href="https://github.com/bregman-arie/go-exercises"><img src="images/Go.png" width="75px;" height="75px;" alt="go"/><br /><b>Go</b></a></td>
     <td align="center"><a href="topics/shell/README.md"><img src="images/bash.png" width="75px;" height="75px;" alt="Bash"/><br /><b>Shell Scripting</b></a></td>
     <td align="center"><a href="topics/kubernetes/README.md"><img src="images/kubernetes.png" width="75px;" height="75px;" alt="kubernetes"/><br /><b>Kubernetes</b></a></td>
-    <td align="center"><a href="#prometheus"><img src="images/prometheus.png" width="75px;" height="75px;" alt="Prometheus"/><br /><b>Prometheus</b></a></td>
+
   </tr>
   <tr>
     <td align="center"><a href="topics/cloud/README.md"><img src="images/cloud.png" width="75px;" height="75px;" alt="Cloud"/><br /><b>Cloud</b></a></td>
     <td align="center"><a href="topics/aws/README.md"><img src="images/aws.png" width="100px;" height="75px;" alt="aws"/><br /><b>AWS</b></a></td>
     <td align="center"><a href="topics/azure/README.md"><img src="images/azure.png" width="75px;" height="75px;" alt="azure"/><br /><b>Azure</b></a></td>
     <td align="center"><a href="topics/gcp/README.md"><img src="images/googlecloud.png" width="70px;" height="70px;" alt="Google Cloud Platform"/><br /><b>Google Cloud Platform</b></a></td>
     <td align="center"><a href="#openstack"><img src="images/openstack.png" width="75px;" height="75px;" alt="openstack"/><br /><b>OpenStack</b></a></td>
-    <td align="center"><a href="topics/security/README.md"><img src="images/security.png" width="75px;" height="75px;" alt="security"/><br /><b>Security</b></a></td>
   </tr>
   <tr>
     <td align="center"><a href="#operating-system"><img src="images/os.png" width="75px;" height="75px;" alt="Operating System"/><br /><b>Operating System</b></a></td>
     <td align="center"><a href="#monitoring"><img src="images/monitoring.png" width="75px;" height="75px;" alt="Monitoring"/><br /><b>Monitoring</b></a></td>
     <td align="center"><a href="#elastic"><img src="images/elastic.png" width="75px;" height="75px;" alt="Elastic"/><br /><b>Elastic</b></a></td>
     <td align="center"><a href="#virtualization"><img src="images/virtualization.png" width="75px;" height="75px;" alt="Virtualization"/><br /><b>Virtualization</b></a></td>
     <td align="center"><a href="topics/dns/README.md"><img src="images/dns.png" width="75px;" height="75px;" alt="DNS"/><br /><b>DNS</b></a></td>
-    <td align="center"><a href="#Misc"><img src="images/general.png" width="75px;" height="75px;" alt="Misc"/><br /><b>Misc</b></a></td>
   </tr>
   <tr>
     <td align="center"><a href="#testing"><img src="images/testing.png" width="75px;" height="75px;" alt="Testing"/><br /><b>Testing</b></a></td>
     <td align="center"><a href="#databases"><img src="images/databases.png" width="75px;" height="75px;" alt="Databases"/><br /><b>Databases</b></a></td>
     <td align="center"><a href="#regex"><img src="images/regex.png" width="75px;" height="75px;" alt="RegEx"/><br /><b>Regex</b></a></td>
     <td align="center"><a href="#system-design"><img src="images/design.png" width="75px;" height="75px;" alt="Design"/><br /><b>System Design</b></a></td>
     <td align="center"><a href="#hardware"><img src="images/hardware.png" width="75px;" height="75px;" alt="Hardware"/><br /><b>Hardware</b></a></td>
-    <td align="center"><a href="#big-data"><img src="images/big-data.png" width="75px;" height="75px;" alt="Big Data"/><br /><b>Big Data</b></a></td>
   </tr>
   <tr>
     <td align="center"><a href="#certificates"><img src="images/certificates.png" width="75px;" height="75px;" alt="Certificates"/><br /><b>Certificates</b></a></td>
     <td align="center"><a href="topics/containers/README.md"><img src="images/containers.png" width="75px;" height="75px;" alt="Containers"/><br /><b>Containers</b></a></td>
     <td align="center"><a href="#sql"><img src="images/sql.png" width="75px;" height="75px;" alt="sql"/><br /><b>SQL</b></a></td>
     <td align="center"><a href="topics/openshift/README.md"><img src="images/openshift.png" width="75px;" height="75px;" alt="OpenShift"/><br /><b>OpenShift</b></a></td>
     <td align="center"><a href="#storage"><img src="images/storage.png" width="75px;" height="75px;" alt="Storage"/><br /><b>Storage</b></a></td>
-    <td align="center"><a href="topics/soft_skills/README.md"><img src="images/HR.png" width="75px;" height="75px;" alt="HR"/><br /><b>Soft Skills</b></a></td>
   </tr>
   <tr>
       <td align="center"><a href="topics/terraform/README.md"><img src="images/terraform.png" width="75px;" height="75px;" alt="Terraform"/><br /><b>Terraform</b></a></td>
       <td align="center"><a href="#mongo"><img src="images/mongo.png" width="75px;" height="75px;" alt="Mongo"/><br /><b>Mongo</b></a></td>
       <td align="center"><a href="#puppet"><img src="images/puppet.png" width="75px;" height="75px;" alt="puppet"/><br /><b>Puppet</b></a></td>
       <td align="center"><a href="#distributed"><img src="images/distributed.png" width="75px;" height="75px;" alt="Distributed"/><br /><b>Distributed</b></a></td>
       <td align="center"><a href="#questions-you-ask"><img src="images/you.png" width="75px;" height="75px;" alt="you"/><br /><b>Questions you can ask</b></a></td>
-      <td align="center"><a href="topics/perl/README.md"><img src="images/perl.png" width="75px;" height="75px;" alt="perl"/><br /><b>Perl</b></a></td>
   </tr>
   <tr>
       <td align="center"><a href="topics/circleci/README.md"><img src="images/logos/circleci.png" width="70px;" height="70px;" alt="Circle CI"/><br /><b>Circle CI</b></a></td>
       <td align="center"><a href="topics/argo/README.md"><img src="images/logos/argo.png" width="80px;" height="80px;" alt="Argo"/><br /><b>Argo</b></a></td>
-      <td align="center"><a href="topics/kafka/README.md"><img src="images/logos/kafka.png" width="70px;" height="80px;" alt="Kafka"/><br /><b>Kafka</b></a></td>
+      <td align="center"><a href="topics/kafka/README.md"><img src="images/logos/kafka.png" width="85px;" height="80px;" alt="Kafka"/><br /><b>Kafka</b></a></td>
       <td align="center"><a href="topics/datadog/README.md"><img src="images/logos/datadog.png" width="80px;" height="80px;" alt="DataDog"/><br /><b></b></a></td>
+      <td align="center"><a href="topics/perl/README.md"><img src="images/perl.png" width="75px;" height="75px;" alt="perl"/><br /><b>Perl</b></a></td>
   </tr>
+   <tr>
+    <td align="center"><a href="topics/linux/README.md"><img src="images/logos/linux.png" width="75px;" height="75px;" alt="Linux"/><br /><b>Linux</b></a></td>
+    <td align="center"><a href="#prometheus"><img src="images/prometheus.png" width="75px;" height="75px;" alt="Prometheus"/><br /><b>Prometheus</b></a></td>
+    <td align="center"><a href="#big-data"><img src="images/big-data.png" width="75px;" height="75px;" alt="Big Data"/><br /><b>Big Data</b></a></td>
+    <td align="center"><a href="topics/soft_skills/README.md"><img src="images/HR.png" width="75px;" height="75px;" alt="HR"/><br /><b>Soft Skills</b></a></td>
+    <td align="center"><a href="topics/security/README.md"><img src="images/security.png" width="75px;" height="75px;" alt="security"/><br /><b>Security</b></a></td>
+   </tr>
+   <tr>
+    <td align="center"><a href="topics/chaos_engineering/README.md"><img src="images/logos/chaos_engineering.png" width="75px;" height="75px;" alt="Chaos Engineering"/><br /><b>Chaos Engineering</b></a></td>
+    <td align="center"><a href="#Misc"><img src="images/general.png" width="75px;" height="75px;" alt="Misc"/><br /><b>Misc</b></a></td>
+   </tr>
+
 </table>
 </center>
 <!-- markdownlint-enable -->
@@ -89,35 +97,28 @@
 ## Network
 
 <details>
-<summary>What do you need in order to communicate?</summary><br><b>
+<summary>In general, what do you need in order to communicate?</summary><br><b>
 
   - A common language (for the two ends to understand)
   - A way to address who do you want to communicate with
   - A Connection (so the content of the communication can reach the recipients)
+
 </b></details>
 
 <details>
 <summary>What is TCP/IP?</summary><br><b>
 
 A set of protocols that define how two or more devices can communicate with each other.
-To learn more about TCP/IP, read [here](http://www.penguintutor.com/linux/basic-network-reference)
-</b></details>
 
-<details>
-<summary>What is APIPA?</summary><br><b>
-APIPA is a set of it addresses that devices are allocated
-when the main DHCP server is not reachable
-</b></details>
+To learn more about TCP/IP, read [here](http://www.penguintutor.com/linux/basic-network-reference)
 
-<details>
-<summary>What ip range does APIPA use?</summary><br><b>
-APIPA uses the ip range: 169.254.0.1 - 169.254.255.254.
 </b></details>
 
 <details>
 <summary>What is Ethernet?</summary><br><b>
 
 Ethernet simply refers to the most common type of Local Area Network (LAN) used today. A LAN—in contrast to a WAN (Wide Area Network), which spans a larger geographical area—is a connected network of computers in a small area, like your office, college campus, or even home.
+
 </b></details>
 
 <details>
@@ -416,7 +417,22 @@ For example, your computer's private IP could be 192.168.1.100, but your router
 <summary>Which factors affect network performances</summary><br><b>
 </b></details>
 
-#### Network - Data and Control planes
+<details>
+<summary>What is APIPA?</summary><br><b>
+
+APIPA is a set of it addresses that devices are allocated
+when the main DHCP server is not reachable
+
+</b></details>
+
+<details>
+<summary>What ip range does APIPA use?</summary><br><b>
+
+APIPA uses the ip range: 169.254.0.1 - 169.254.255.254.
+
+</b></details>
+
+#### Control Plane and Data Plane
 
 <details>
 <summary>What "control plane" refers to?</summary><br><b>
@@ -2887,9 +2903,8 @@ Google Drive
 <summary>Explain MBR</summary><br><b>
 </b></details>
 
-## Questions you CAN ask
-
 <a name="questions-you-ask"></a>
+## Questions you CAN ask
 
 A list of questions you as a candidate can ask the interviewer during or after the interview.
 These are only a suggestion, use them carefully. Not every interviewer will be able to answer these (or happy to) which should be perhaps a red flag warning for your regarding working in such place but that's really up to you.
@@ -3679,7 +3694,9 @@ If you are looking for a way to prepare for a certain exam this is the section f
 
 * [Certified Kubernetes Administrator (CKA)](topics/kubernetes/CKA.md) (Latest update: 2022)
 
-## Other DevOps Projects
+## Additional DevOps and SRE Projects
+
+<p align="center"><a href="https://github.com/bregman-arie/sre-checklist"><img width="500px" src="images/sre_checklist.png"/></a></p>
 
 <p align="center"><a href="https://github.com/bregman-arie/howtheydevops"><img src="images/how_they_devops.png"/></a></p>
 <p align="center"><a href="https://github.com/bregman-arie/devops-resources"><img src="images/devops_resources.png"/></a></p>

scripts/count_questions.sh

@@ -1,3 +1,9 @@
 #!/usr/bin/env bash
 
-echo $(( $(grep -E "\[Exercise\]|</summary>" -c README.md topics/*/README.md | awk -F: '{ s+=$2 } END { print s }' )))
+set -eu
+
+count=$(echo $(( $(grep -E "\[Exercise\]|</summary>" -c README.md topics/*/README.md | awk -F: '{ s+=$2 } END { print s }' ))))
+
+echo "There are $count questions and exercises"
+
+sed -i "s/currently \*\*[0-9]*\*\*/currently \*\*$count\\**/" README.md

topics/chaos_engineering/README.md

@@ -0,0 +1,31 @@
+# Chaos Engineering
+
+- [Chaos Engineering](#chaos-engineering)
+  - [Chaos Engineering Questions](#chaos-engineering-questions)
+    - [Basics](#basics)
+
+## Chaos Engineering Questions
+
+### Basics
+
+<details>
+<summary>What is Chaos Engineering?</summary><br><b>
+
+[Wikipedia](https://en.wikipedia.org/wiki/Chaos_engineering): "Chaos Engineering is the discipline of experimenting on a system in order to build confidence in the system's capability to withstand turbulent conditions in production."
+
+[TechTarget](https://www.techtarget.com/searchitoperations/definition/chaos-engineering): "Chaos engineering is the process of testing a distributed computing system to ensure that it can withstand unexpected disruptions."
+
+</b></details>
+
+<details>
+<summary>What's a typical Chaos Engineering workflow?</summary><br><b>
+
+According to [Gremlin](gremlin.com) there are three steps:
+
+1. Planning an experiment where you design and choose a scenario in which your system should fail to operate properly
+2. You execute the smallest possible experiment to test your theory
+3. If nothing goes wrong, you scale your experiment and make the blast radius bigger. If your system breaks, you better understand why and start dealing with it
+
+The process then repeats itself either with same scenario or a new one.
+
+</b></details>

topics/linux/README.md

@@ -2,46 +2,69 @@
 
 ## Linux Master Application
 
-A completely free application for testing your knowledge on Linux
-
-<a href="https://play.google.com/store/apps/details?id=com.codingshell.linuxmaster"><img src="images/linux_master.jpeg"/></a>
-
-## Linux Self Assessment
-
-* [Linux 101](#questions-linux-101)
-* [Linux I/O Redirection](#questions-linux-redirection)
-* [Linux Filesystem Hierarchy Standard](#questions-linux-fhs)
-* [Linux Permissions](#questions-linux-permissions)
-* [Linux Scenarios](#questions-linux-scenarios)
-* [Linux Systemd](#questions-linux-systemd)
-* [Linux Troubleshooting and Debugging](#questions-linux-troubleshooting)
-* [Linux kernel](#questions-linux-kernel)
-* [Linux SSH](#questions-linux-ssh)
-* [Linux Globbing and Wildcards](#questions-linux-wildcards)
-* [Linux Boot Process](#questions-linux-boot)
-* [Linux Disk and Filesystem](#questions-linux-disk-fs)
-* [Linux Performance Analysis](#questions-linux-performance-analysis)
-* [Linux Processes](#questions-linux-processes)
-* [Linux Security](#questions-linux-security)
-* [Linux Networking](#questions-linux-networking)
-* [Linux DNS](#questions-linux-dns)
-* [Linux Packaging](#questions-linux-packaging)
-* [Linux DNF](#questions-linux-dnf)
-* [Linux Applications and Services](#questions-linux-apps-and-services)
-* [Linux Users and Groups](#questions-linux-users-and-groups)
-* [Linux Hardware](#questions-linux-hardware)
-* [Linux Namepsaces](#questions-linux-namespaces)
-* [Linux Virtualization](#questions-linux-virtualization)
-* [Linux AWK](#questions-linux-awk)
-* [Linux System Calls](#questions-linux-system-calls)
-* [Linux Filesystem and Files](#questions-linux-fs-files)
-* [Linux Advanced Networking](#questions-linux-advanced-networking)
-* [Linux Memory](#questions-linux-memory)
-* [Linux Distributions](#questions-linux-distributions)
-* [Linux Sed](#questions-linux-sed)
-* [Linux Misc](#questions-linux-misc)
-
-<a name="questions-linux-101"></a>
+A completely free application for testing your knowledge on Linux.
+Desclaimer: developed by repository owner
+
+<a href="https://play.google.com/store/apps/details?id=com.codingshell.linuxmaster"><img src="../../images/linux_master.jpeg"/></a>
+
+- [Linux](#linux)
+  - [Linux Master Application](#linux-master-application)
+  - [Linux Exercises](#linux-exercises)
+    - [Basics](#basics)
+    - [Misc](#misc)
+  - [Linux Questions](#linux-questions)
+    - [Linux 101](#linux-101)
+    - [I/O Redirection](#io-redirection)
+    - [Filesystem Hierarchy Standard](#filesystem-hierarchy-standard)
+    - [Permissions](#permissions)
+    - [Scenarios](#scenarios)
+    - [Systemd](#systemd)
+    - [Troubleshooting and Debugging](#troubleshooting-and-debugging)
+      - [Scenarios](#scenarios-1)
+    - [Kernel](#kernel)
+    - [SSH](#ssh)
+    - [Globbing & Wildcards](#globbing--wildcards)
+    - [Boot Process](#boot-process)
+    - [Disk and Filesystem](#disk-and-filesystem)
+    - [Performance Analysis](#performance-analysis)
+    - [Processes](#processes)
+    - [Security](#security)
+    - [Networking](#networking)
+    - [DNS](#dns)
+    - [Packaging](#packaging)
+    - [DNF](#dnf)
+    - [Applications and Services](#applications-and-services)
+    - [Users and Groups](#users-and-groups)
+    - [Hardware](#hardware)
+    - [Namespaces](#namespaces)
+    - [Virtualization](#virtualization)
+    - [AWK](#awk)
+    - [System Calls](#system-calls)
+    - [Filesystem & Files](#filesystem--files)
+    - [Advanced Networking](#advanced-networking)
+    - [Memory](#memory)
+    - [Distributions](#distributions)
+    - [Sed](#sed)
+    - [Misc](#misc-1)
+
+## Linux Exercises
+
+### Basics
+
+|Name|Topic|Objective & Instructions|Solution|Comments|
+|--------|--------|------|----|----|
+| Navigation | cd, pwd | [Exercise](exercises/navigation/README.md) | [Solution](exercises/navigation/solution.md)
+| Create and Destroy | touch, rm, mkdir | [Exercise](exercises/create_remove/README.md) | [Solution](exercises/create_remove/solution.md)
+| Copy Time | touch, cp, ls | [Exercise](exercises/copy/README.md) | [Solution](exercises/copy/solution.md)
+
+### Misc
+
+|Name|Topic|Objective & Instructions|Solution|Comments|
+|--------|--------|------|----|----|
+| Unique Count |  | [Exercise](exercises/uniqe_count/README.md) | [Solution](exercises/uniqe_count/solution.md)
+
+## Linux Questions
+
 ### Linux 101
 
 <details>
@@ -50,6 +73,7 @@ A completely free application for testing your knowledge on Linux
 [Wikipedia](https://en.wikipedia.org/wiki/Linux): "Linux is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged in a Linux distribution."
 
 [Red Hat](https://www.redhat.com/en/topics/linux/what-is-linux): "Linux® is an open source operating system (OS). An operating system is the software that directly manages a system’s hardware and resources, like CPU, memory, and storage. The OS sits between applications and hardware and makes the connections between all of your software and the physical resources that do the work."
+
 </b></details>
 
 <details>
@@ -479,8 +503,7 @@ To stop a service: `systemctl stop <service name>`
 <summary>Describe how to make a certain process/app a service</summary><br><b>
 </b></details>
 
-<a name="questions-linux-troubleshooting"></a>
-### Troubleshooting & Debugging
+### Troubleshooting and Debugging
 
 <details>
 <summary>Where system logs are located?</summary><br><b>
@@ -551,7 +574,16 @@ tail -f <file_name>
 <summary>How you measure time execution of a program?</summary><br><b>
 </b></details>
 
-<a name="questions-linux-kernel"></a>
+#### Scenarios
+
+<details>
+<summary>You have a process writing to a file. You don't know which process exactly, you just know the path of the file. You would like to kill the process as it's no longer needed. How would you achieve it?</summary><br><b>
+
+1. Run `lsof <FILE_PATH>`
+2. Use the pid (process ID) from the lsof command and run `kill <PID>`
+
+</b></details>
+
 ### Kernel
 
 <details>