Kubernetes Cheat Sheet

A list of commonly used commands when working with Kubernetes cluster.

Below is a list of common and useful commands for working with kubernetes.

Note: appending <-o wide> to some of the commands below will provide more details.

Get all nodes in a cluster

kubectl get nodes
kubectl get nodes -o wide

Get all services in a cluster

kubectl get services

Get all pods in a cluster

kubectl get pods

Create a resource (Deployment, Service)

kubectl create -f <resource.yaml>

Modify a resource

kubectl apply -f <resourcce.yaml>

Get into a pod with ‘bash’ command

kubectl exec -it <podid> -- bash

Secrets

Get secrets

kubectl get secrets

Create secrets

From string literals:

kubectl create secret generic myunsafesecret --from-literal=password=Password123

From file:

# Create files
echo -n 'admin' > ./username.txt
echo -n '1f2d1e2e67df' > ./password.txt

kubectl create secret generic db-user-pass --from-file=./username.txt --from-file=./password.txt

From yaml resource:

# Content of secret.yaml
apiVersion: v1
kind: Secret
metadata:
  name: mysecret
  type: Opaque
stringData:
  username: {{username}}
  password: {{password}}
#####

kubectl create -f ./secret.yaml

Ref: https://kubernetes.io/docs/concepts/configuration/secret/

Storage

Get storage classes

kubectl get sc

Get persistent volumes

kubectl get pv

Get persistent volume claims

kubectl get pvc

Deployment

Get deployments

kubectl get deploy

Get deployment details

kubectl describe deploy <deploymentname>

Get replica sets

kubectl get rs -o wide

Get deployment rollout status

kubectl rollout status deploy <deploymentname>

Get deployment rollout history

kubectl rollout history deploy <deploymentname>

Tip: Adding –record flag to kubctl apply will stick the command to the object, so that it will appear under CHANGE-CAUSE in history

Get details for a particular deployment revision

kubectl rollout history deploy <deploymentname> --revision=<revisionnumber>

Rollback a deployment

kubectl rollout undo deploy <deploymentname>

Tip: It is better to avoid this rollback mechanism, and downgrade the version in the deployment.yaml itself and reposting it with “kubectl apply”. This “imperative” way could cause inconsistent environment, where the version of the running container instance doesn’t match the yaml manifest, and any redeployment could accidentally deploy unwanted version. “Declarative” approach is preferred.

Logging

Get snapshot logs for a particular pod with only one container

kubctl logs <pod name>

Run kubectl logs -h for all options

Ref: https://kubernetes.io/docs/concepts/cluster-administration/logging/

Misc

Run a container directly

kubectl run -i --tty <name> --image=<imagename> <command>
kubectl run -i --tty loader --image=busybox /bin/sh

Note: This command will create a pod and will run the container inside it. if “–replica=<number>” is used, it will also create a replication controller in the cluster and will monitor the pod. This is useful when testing (i.e.: hitting a service and generating load, checking service/pod network, etc)

Summary and References

This post contains a list of commonly used commands when interacting with a Kubernetes cluster. Shout out to @nigelpoulton and his great ACG course: “Kubernetes Deep Dive“. Also, here is a far better Cheat Sheet from original kubernetes team.

AWS vs GCP – Cloud Services Comparison

The following table provides a side-by-side comparison of the various services available on AWS and Google Cloud.

Service Category

Service

AWS

Google Cloud

Compute

IaaS

Amazon Elastic Compute Cloud

Compute Engine

 

PaaS

AWS Elastic Beanstalk

App Engine

 

FaaS

AWS Lambda

Cloud Functions

Containers

CaaS

Amazon Elastic Kubernetes Service, Amazon Elastic Container Service

Google Kubernetes Engine

 

Containers without infrastructure

AWS Fargate

Cloud Run

 

Container registry

Amazon Elastic Container Registry

Container Registry

Networking

Virtual networks

Amazon Virtual Private Cloud

Virtual Private Cloud

 

Load balancer

Elastic Load Balancer

Cloud Load Balancing

 

Dedicated interconnect

AWS Direct Connect

Cloud Interconnect

 

Domains and DNS

Amazon Route 53

Google Domains, Cloud DNS

 

CDN

Amazon CloudFront

Cloud CDN

 

DDoS firewall

AWS Shield, AWS WAF

Google Cloud Armor

Storage

Object storage

Amazon Simple Storage Service

Cloud Storage

 

Block storage

Amazon Elastic Block Store

Persistent Disk

 

Reduced-availability storage

Amazon S3 Standard-Infrequent Access, Amazon S3 One Zone-Infrequent Access

Cloud Storage Nearline and Cloud Storage Coldline

 

Archival storage

Amazon Glacier

Cloud Storage Archive

 

File storage

Amazon Elastic File System

Filestore

 

In-memory data store

Amazon ElastiCache for Redis

Memorystore

Database

RDBMS

Amazon Relational Database Service, Amazon Aurora

Cloud SQLCloud Spanner

 

NoSQL: Key-value

Amazon DynamoDB

FirestoreCloud Bigtable

 

NoSQL: Indexed

Amazon SimpleDB

Firestore

 

In-memory data store

Amazon ElastiCache for Redis

Memorystore

Data analytics

Data warehouse

Amazon Redshift

BigQuery

 

Query service

Amazon Athena

BigQuery

 

Messaging

Amazon Simple Notification Service, Amazon Simple Queueing Service

Pub/Sub

 

Batch data processing

Amazon Elastic MapReduce, AWS Batch

DataprocDataflow

 

Stream data processing

Amazon Kinesis

Dataflow

 

Stream data ingest

Amazon Kinesis

Pub/Sub

 

Workflow orchestration

Amazon Data Pipeline, AWS Glue

Cloud Composer

Management tools

Deployment

AWS CloudFormation

Cloud Deployment Manager

 

Cost management

AWS Budgets

Cost Management

Operations

Monitoring

Amazon CloudWatch

Cloud Monitoring

 

Logging

Amazon CloudWatch Logs

Cloud Logging

 

Audit logging

AWS CloudTrails

Cloud Audit Logs

 

Debugging

AWS X-Ray

Cloud Debugger

 

Performance tracing

AWS X-Ray

Cloud Trace

Security & identity

IAM

Amazon Identity and Access Management

Cloud Identity and Access Management

 

Secret management

AWS Secrets Manager

Secret Manager

 

Encrypted keys

AWS Key Management Service

Cloud Key Management Service

 

Resource monitoring

AWS Config

Cloud Asset Inventory

 

Vulnerability scanning

Amazon Inspector

Web Security Scanner

 

Threat detection

Amazon GuardDuty

Event Threat Detection (beta)

 

Microsoft Active Directory

AWS Directory Service

Managed Service for Microsoft Active Directory

Machine learning

Speech

Amazon Transcribe

Speech-to-Text

 

Vision

Amazon Rekognition

Cloud Vision

 

Natural Language Processing

Amazon Comprehend

Cloud Natural Language API

 

Translation

Amazon Translate

Cloud Translation

 

Conversational interface

Amazon Lex

Dialogflow Enterprise Edition

 

Video intelligence

Amazon Rekognition Video

Video Intelligence API

 

Auto-generated models

Amazon SageMaker Autopilot

AutoML

 

Fully managed ML

Amazon SageMaker

AI Platform

Internet of Things

IoT services

Amazon IoT

Cloud IoT

Reference: https://cloud.google.com/docs/compare/aws

Comparison of Google Cloud Storage Options

Intro

Considering key technical differentiators for storage options is critical when deciding what services to adopt to migrate workloads to cloud providers. Here is a brief and concise comparison of some of the Google Cloud Storage options in terms of technical details and use cases.

Comparison of Storage Options

Technical Details

Cloud Datastore Cloud Bigtable Cloud Storage Cloud SQL Cloud Spanner BigQuery
Type NoSQL document NoSQL wide column Blob storage Relational SQL for OLTP Relational SQL for OLTP Relational SQL for OLAP
Transactions Yes Single-row No Yes Yes No
Complex Queries No No No Yes Yes Yes
Capacity Terabytes+ Petabytes+ Petabytes+ Terabytes Petabytes Petabytes+
Unit Size 1MB/entity ~10MB/cell
~100MB/row
5TB/object Determined by DB engine 10,240 MiB/row 10MB/row

Use Cases

Cloud Datastore Cloud Bigtable Cloud Storage Cloud SQL Cloud Spanner BigQuery
Best For Semi-structured application data, durable key-value data “Flat” data, heavy read/write, events, analytical data Structured and unstructured binary or object data Web frameworks, existing apps Large-scale database apps (> ~2tb) Interactive querying, offline analytics
Use Cases Getting started, App Engine apps AdTech, Financial and IoT data Images, large media files, backups User credentials, customer orders Whenever high I/O, global consistency is needed Data warehousing

Reference:

Docker Cheat Sheet

Below is a list of common and useful commands for working with docker.

List all images in local machine

docker image ls

List all running instances

docker ps -a

Stop/remove all docker images

docker stop $(docker ps -a -q)
docker rm $(docker ps -a -q)

Run a container from Docker Windows using .NET Core image

docker run --rm -it -v "$(pwd):/app" -p 5000:5000 mcr.microsoft.com/dotnet/core/sdk

(Notice the double-quotes around path, otherwise pwd will not work from Windows)

Run a container with Redis

docker run --rm -it -p 6379:6379 redis

Get into a running container

docker exec -it 55ff7be44aba /bin/bash

(Replace 55ff7be44aba with the actual container name or id)

 

Ref:

7 Tips to Effectively Sell Your Ideas

Intro

Have you ever failed at convincing your colleagues about how great your idea is? Have you felt disappointed because your team didn’t recognize how much productivity they were going to gain by implementing your proposal and didn’t commit to it? Have you ever been at a meeting, talking about something and failing to get the team engaged, then all of a sudden somebody else says the exact same thing and everybody is excited and paying attention?

I’m almost certain that most technology professionals have faced these challenges at some point in their career. Some people are just good at “selling” ideas, but the majority of us have to pay attention and work hard to get better at this.

This article provides 7 tips to help technology professionals become aware and focus on certain areas that will open opportunities to engage others and advance strategic initiatives.

How to make people buy your ideas?

Regardless of how good your intentions are, sometimes is very difficult to make others understand and get on-board with a particular initiative. Why don’t they get it?

This is a very complex area involving not just technical and business expertise, but also a great deal of communication skills and personality traits. It is, however, one area that, if addressed properly, can open many doors in your career.

The 7 points below are some of the simple steps a person can take to at least acquire some awareness and increase the chance of success.

1. Ask yourself: Do they really need it?

This is the first mandatory question. You don’t want to push your agenda without a valid business case first. It will be a waste of resources and time. Be respectful of other people time and money.

2. Ask yourself: Do they understand why they need it?

If there is legitimate business value in your idea, then you must ensure the other side totally understands the message.  Don’t assume they will just get it. You may need to take time to prepare several presentations showing different perspectives. Always use language, data and scenarios where the other side can relate to. Show them how this new idea will make their life easier. Show them what benefits they are getting.

3. Identify key influencers and work with them

Is there someone in the team who can help you convince others? This is the charismatic guy, the trusted technical expert nobody dares to challenge, the person who people follow and listen to. If you are able to convince this guy, he will get others on board and will make your job easier.

4. Understand their biggest challenges and genuinely help solve them

It is very important to understand people’s main challenges. They may be saying no to you right now because they are consumed by other pressing issues and don’t have time to consider alternatives and additional work. If you honestly care for them and offer your help without expecting anything in return, at some point those people will recognize you as one of them and will get on your side, validating your ideas and providing new opportunities. Be cautious though, if you are explicitly getting in just to take advantage, or to make them “own” you a favor, soon enough you will be exposed and will not be able to build strong and lasting relationships.

5. Expand your professional network

This is one of the most basic and important things to building a successful career. It applies to this topic, as well as many other areas. Having a solid professional network can offer countless benefits: guidance, opportunities, support, discovery,  growth, status, resources. See referenced article below for a more details on this topic.

6. Build and maintain your credibility

When you propose something, people will assess your credibility and track record before seriously considering your idea. It is really important to show commitment and deliver quality solutions on every occasion. Also, don’t be shy to share your success stories and lessons learned. People will be more comfortable listening to somebody they trust with a proven record.

7. Get buy in from “decision makers”

Sometimes the only way to get various teams to agree and collaborate is to ensure the priorities are aligned and everybody shares and owns the workload. This can be accomplished by convincing the top managers about how important or critical the work is, and leveraging their decision-making power to remove additional tasks from the team members and focus on one common goal. Sometimes people say no because they are overwhelmed with current responsibilities. If you take some of those tasks off, and ensure the new work is properly prioritized and balanced, that’s a win-win for everybody.

Summary

Being able to share ideas and influence others is a key part of career advancement. People will recognize, support and follow those who show determination, confidence and a proven record. Whether you want to become a leader or not, being able to convince others about certain approaches and directions may open a significant number of doors and will allow you to tap into the collective knowledge and effort to accomplish bigger and better things. The 7 tips provided in this article intend to bring awareness about common areas that are often overlooked, and can increase the chances of success.

Reference

 

HelloWorld in .Net Core really takes less than 10 minutes!

Intro

I have been paying attention to the development of the .NET Core framework and the great features coming out of it. Things like cross-platform compatibility are very appealing and open a whole new window of opportunities to the developer community. I never decided to start experimenting with this until now, and since I saw how easy it was to setup, I decided to share my experience here. In this post I will list the required steps to write a HelloWorld console application using .NET Core framework. It literally took me less than 10 minutes to see “Hello World” in the output window!

Steps to create HelloWorld console application in .NET Core

1. Go to dot.net and download the .NET Core SDK

– Download and install .NET Core SDK for Windows
I am using Windows, but the same steps can be applied to Mac and Linux.

2. Open a command line

c:\Users\luis.carrazana\Documents>
I like Windows PowerShell, but you could use the windows command line, or Terminal if using a Mac.

3. Check if .NET Code SDK was successfully installed

Execute the following command:

c:\Users\luis.carrazana\Documents> dotnet
You should see something like this:
dotnetcore

4. Create a folder for the project and navigate to it

c:\Users\luis.carrazana\Documents> cd "MyProjects"
c:\Users\luis.carrazana\Documents\MyProjects> md "DotNetCore101"
c:\Users\luis.carrazana\Documents\MyProjects> cd "DotNetCore101"
c:\Users\luis.carrazana\Documents\MyProjects\DotNetCore101>

5. Create a new project

Execute the following command:

c:\Users\luis.carrazana\Documents\MyProjects\DotNetCore101> dotnet new
Two files should be created:
Program.cs  (contains the program logic).
project.json  (contains project configuration, including dependencies).
DotNetCore-dir.PNG
This is the simplest boilerplate for a console application, and it contains the required logic to print “Hello World” to the console.

6. Restore dependencies and prepare the project for execution

Execute the following command:

c:\Users\luis.carrazana\Documents\MyProjects\DotNetCore101> dotnet restore
DotNetCore_restore.PNG
This step generates a new file: project.lock.json
This file should not be touched or checked into source control. Its purpose is to cache the result of analyzing project dependencies, so it is faster the next time. More details abut this file here.

7. Run the program

Execute the following command:

c:\Users\luis.carrazana\Documents\MyProjects\DotNetCore101> dotnet run
The logic should get executed and the “Hellow World” message should be displayed.
dotnetcore-helloworld

That’s it! You have a full .NET Core program running.

Editing the program

The steps above are useful for setting up the minimal required infrastructure to execute .NET Core logic. From this point, you will certainly want to start choosing developer tools that will allow you to write code in a very efficient way.
You can choose any text editor (including Notepad), or you may wanna choose a more robust IDE to make the development workflow more efficient. Coming from a pure .NET background, my immediate choice is the lightweight Visual Studio Code, which offers some nice integrations and can be executed in Windows, Mac and Linux.
So to edit and extend this program, I would manually open Visual Studio Code and load the project folder. However, I learned a very useful tip from Scott Hanselman in one of his training videos: from the command line, type “code .” and it will open Visual Studio Code with the current folder already loaded, ready to go. Pretty neat.
c:\Users\luis.carrazana\Documents\MyProjects\DotNetCore101> code .

Summary

This post described the required steps to provision and execute a quick console application using .NET Core. This framework is currently in Preview mode, and any developer can start using it to write code and run it on any platform. Being a Consultant working for big enterprises, I don’t see myself leveraging this framework for production in the near future. However, it is a good idea to pay attention to the great amount of innovation coming out of it. This is opening up a whole new world for writing great applications.

Reference