Monday, August 24, 2020

Integration Design Best Practice

Over the past few years of working on multiple critical systems solution design initiatives, there is one important thing I have learnt. 

" There is a reason we call it solution design and not system design". With the influx of cloud offerings and services, the organization no more rely on one system to automate the business process. Rather business process now relies on multiple systems performing a very specific step of the business process. All these systems are integrated to provide business process automation. This makes integration, not one of the factors but a very critical backbone of the business process." 

Nothing that I said is new and no one will disagree but unfortunately, integrations are still given less priority and design thought. 

I keep getting one question all the time " What are integration design best practices and how can I design a good reliable integration".  I have a long list of to-dos for designing good integration but sometimes being too prescriptive is not useful as it hinders a thinking ability of an architect.  

So if you are still reading and curious to know how to design a good integration than there is only one fact you need to be aware of, this will influence your design decision and push you to design better integrations. 

AND THAT IS 


Design with the above fact in mind and try to make your integration overcome failure and you will have a good design in place. Please don't spend time on developing integrations that will not fail. Such a design is purely a myth

Now let's go one more level down, I have put down design pillars which will help to design the integration.   These design pillars apply to any software development initiatives 





 


if this is helpful, do leave our comment. I would love to hear your design learnings. 

Monday, March 23, 2020

No supported authentication methods available (server sent: publickey)

---------------------------
PuTTY Fatal Error
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PuTTY Fatal Error Disconnected: No supported authentication methods available (server sent: publickey)
---------------------------


Scenario : 
Error while connecting to AWS AMI Instance using PuTTy.


Solution:
in my case "admin" user worked.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/TroubleshootingInstancesConnecting.html#TroubleshootingInstancesConnectingPuTTY

Saturday, March 21, 2020

Docker Error :In the default daemon configuration on Windows, the docker client must be run elevated to connect

error during connect: Post http://%2F%2F.%2Fpipe%2Fdocker_engine/v1.40/auth: open //./pipe/docker_engine: The system cannot find the file specified. In the default daemon configuration on Windows, the docker client must be run elevated to connect. This error may also indicate that the docker daemon is not running.



Fix :
Try one of these:


Second:
Dun docker service with elevated privilege. This error shows up when docker service  is not running. Make sure you docker dashboard shows as "running"


Monday, February 17, 2020

Guide for AWS Cloud Security, Governance, and Compliance

A really good collection to learn and understand basic of AWS Cloud Security, Governance, and Compliance


Could not switch roles using the provided information. Please check your settings and try again. If you continue to have problems, contact your administrator.

Could not switch roles using the provided information. Please check your settings and try again. If you continue to have problems, contact your administrator.


If you get this error than there is a big probability the user has no permission to assume a role. Add a new policy to user to allow assuming roles. check the below article:


if it doesn't work leave a comment. 



Sunday, February 16, 2020

ECS Fargate ERROR : CannotPullContainerError: Error response from daemon

Last week i was asked to look into an issue faced by the team working on a service deployed in ECS Fargate

ERROR

CannotPullContainerError: Error response from daemon: Get https://xxxxxxxxxxxx.dkr.ecr.us-east-x.amazonaws.com/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)



Details:
The container service was failing to provision and stopping with the above error.


Possible Reasons:
The error indicated that the container is failing during "Pull" event and in this case, the only pull request which is configured is for the docker image maintained in ECS registry. 

Most of the times such issue occurs due to lack of access and this case was no different.. There are two possible ares to look at for enabling Fargate resource deployed in private subnet to pull image from ECS registry


  • If task is launched without an public IP, its it required to configure route table on the subnet with has "0.0.0.0/0" going to a NAT Gateway or NAT instance . This is to ensure it can connect to internet. If task is launched with an public IP, configure route table on the subnet to have "0.0.0.0/0" going to an internet gateway to ensure traffic can flow in.


  • Ensure the security groups for the Task allows for outbound access. 

if internet  access is a concern than another option is to deploy registry inside VPC.
Here is link for one of the option 






Thursday, January 23, 2020

OAUTH 2.0 in less than 5 min

As you had requested, here is a short video on OAUTH 2.0. More to come stay tuned.






Wednesday, January 08, 2020

GITLAB commands - High Frequency

I always notice the developers struggling to get the command line right for GIT. I was planning to put together list of frequently used command  but came across cheatsheet put by GitLab

https://about.gitlab.com/images/press/git-cheat-sheet.pdf

If you feel there are more which is good to have handy, just write a comment.

Happy Versioning!!!

Tuesday, January 07, 2020

T and Z in DateTime like 2009-08-28T23:55:16.000Z

A very simple question for a person who codes(hopefully) but for business users this can be very confusing.

What do you mean by below DateTime

2009-08-28T23:55:16.000Z

Lets explain this 

ISO 8601 (The International Standard for the representation of dates and times)
states the following definition

The "T" corresponds to Time of the date(Duhh... no brainer)  and "Z"  is special UTC designator

So the DateTime  2009-08-28T23:55:16.000Z states

Date as 2009-08-28
Time as 23:55:16.000
"Z" stands for UTC

The above time can be also be represnted in EST as
2009-08-28T23:55:16-05:00 (EST) where  -05:00 is Timezone offset


Happy coding!!!

- Metahat


Gray Failures: What is it and how to detect one?

If you are reading this article , i guess you are curious to know about gray failures and different methods to detect gray failures.  Hopefu...