Day 8/40 - Kubernetes Deployment, Replication Controller and ReplicaSet Explained

[@pritamsawant7366]

completed 8th video today. The more I am learning these concepts, I get so excited for next video. Thank you for your time and efforts for making this series! really appreciate.👏

[@TechTutorialswithPiyush]

Let's go

[@kowshiks229]

After going through your vidoes. I realized that , i was fooled by hearing K8's is difficult to learn. Thanks for your dedicated work....👋

[@TechTutorialswithPiyush]

By the end of this series, you will start loving Kubernetes

[@ferdakavak861]

Fantastic instructions. Learned so much with a lot of retention. Gaining competency quickly thanks to Piyush's excellent teaching methods.

[@TechTutorialswithPiyush]

I am glad to know that :)

[@akifsalah9686]

I have seen Many videos on Kubernetes but still i was having some doubts But after watch this kubernetes Playlist till Day 8 I have Understood the the Kubernetes Archtecture Pods Node Control panel Thanks for this

[@TechTutorialswithPiyush]

That is a huge compliment for me, THank you so much

[@tech_titans1994]

Hi Piyush, Your explanation is awesome. I have challenged myself to complete the series with 100% dedication. Thank you.

[@TechTutorialswithPiyush]

Awesome! Glad it's resonating with you. let's go 🚀 💪

[@Ganeshbabu-px3lb]

I am joining as a DevOps engineer as a fresher. Your videos have been very helpful for me; thank you very much! Please continue sharing your knowledge on KZbin.

[@TechTutorialswithPiyush]

All the best Ganesh, It feels great to know, keep doing the great work :)

[@vijaykumar6370]

One of the best teacher for k8s cka. Thanks lots

[@TechTutorialswithPiyush]

Glad you think so!

[@nope-ms4rx]

You simplify and make learning so easy. You are the man for the time and care that you put into your work. Thank you again for all that you do!

[@TechTutorialswithPiyush]

You are very welcome and thank you once again for the kind words.

[@KrupakarReddy-q9z]

fantastic content, as always!!! what stood out to me most were the quick tips you share so effortlessly, like Vim shortcuts and shortcuts in VS code.

[@TechTutorialswithPiyush]

I try my best :) Thank you

[@SinghBalraj102]

That video was mind-blowing! The explanation was like a walk in the park.

[@TechTutorialswithPiyush]

Wow, thanks! Super happy to hear that

[@mY_heAveN4356]

I am planning to take CKA certification, and your video is very helpful and interesting.

[@TechTutorialswithPiyush]

Thank you so much! All the best for your exam

[@shubhamku044]

this is a very nice series, everything you explained in a crystal clear manner. Thank you for the playlist

[@TechTutorialswithPiyush]

You're welcome!

[@AhmedElsaid]

You are great . keep up the good spirit

[@TechTutorialswithPiyush]

Thanks a lot for the motivation!

[@ruddyivanclarosfernandez8526]

Wonderful video, Piyush! Thank you for all!

[@TechTutorialswithPiyush]

Thank you so much! 🙏

[@floehden]

Thank you for showing us the horizontal scaling and the new rollout without downtime!

[@TechTutorialswithPiyush]

You're welcome

[@somnathpande-k3e]

Very details explained each and every concept

[@TechTutorialswithPiyush]

Thank you so much!

[@Anuradhakumari-mn9wb]

good job, I like the way you keep things simple. expecting many more such video in future.

[@TechTutorialswithPiyush]

Thanks a lot 😊

[@LaxmiAdavalli-o5k]

Even though the session is not two way interaction, though the each minute content is depth and amazing.. Thanks for making this...😇

[@TechTutorialswithPiyush]

I am glad you found it helpful

[@abc-edm]

Thanks, really enjoy working on those tasks, really helpful!

[@TechTutorialswithPiyush]

Glad to hear that, keep learning!

[@vinodchandra2206]

How can it be that simple.............wonderfully explained👏👏

[@TechTutorialswithPiyush]

Kubernetes is easy 😄

[@kundankumar5395]

wonderfully explained replicaset and deployment.💯

[@TechTutorialswithPiyush]

Thanks

[@syamkumar7751]

wonderfully explained, simple it's awesome

[@TechTutorialswithPiyush]

Thanks a lot 😊

[@kaarthickpk]

Great Salute for a neat and clean explanation... Looking forward for the complete course

[@TechTutorialswithPiyush]

Thanks a lot!

[@ruddyivanclarosfernandez8526]

Piyush, great job!

[@TechTutorialswithPiyush]

Thank You!

[@baivabmukhopadhyay8970]

Thanks for such informative content

[@nithinprabhakar6583]

awesome

[@OleksandraPalmer]

great lesson!

[@TechTutorialswithPiyush]

Thank you 😊

[@shriramsahu7287]

Thank you for such valuable content

[@TechTutorialswithPiyush]

You're welcome!

[@baraththangapandian210]

Thanks a lot Piysh🤩🤩🤩

[@TechTutorialswithPiyush]

You're welcome

[@ebenezerbarning5093]

Thanks sir. always clear

[@TechTutorialswithPiyush]

Welcome buddy!

[@saiteja-f1r]

nice explaining in clear way topic wise . i hope this wil help me in cracking interviews ,, please do terraform series as well after this series and some real time projects...

[@TechTutorialswithPiyush]

Thank you! Video 42 has realtime project. Will plan Terraform shortly

[@sagarbirla2879]

amazing content

[@TechTutorialswithPiyush]

Thank you!

[@mohanmurali7975]

You have good teaching skills bro😊

[@TechTutorialswithPiyush]

Thank you

[@abiorh]

thank you

[@TechTutorialswithPiyush]

Glad it was helpful! 🚀

[@moon-x8m]

Thanks 🙂🙂🙂🙂

[@TechTutorialswithPiyush]

Welcome :)

[@aashisaxena3182]

Amazing

[@TechTutorialswithPiyush]

Thank you

[@nousheensafoora206]

day-8 completed

[@AndeSahith]

Amazing like always, and yeah got a clear understanding on replication controller, replica set and deployment, thanks @piyush bruh.

[@TechTutorialswithPiyush]

Awesome, thats all I want. Make sure to practise the hands-on task given in the day08 folder of the repo.

[@AndeSahith]

@@TechTutorialswithPiyush yeah bruh, had done it already, waiting for the upcoming videos.

[@nikhildubba9387]

Awesome content! Thank you.

[@TechTutorialswithPiyush]

Welcome!

[@AbdulMateen-bm3kv]

excellent sir

[@TechTutorialswithPiyush]

Many many thanks

[@harishnetula6446]

so much helpful Piyush

[@TechTutorialswithPiyush]

Thank you

[@saheedabdulrahman2536]

great videos

[@TechTutorialswithPiyush]

Glad you like them!

[@Sklb]

Nice series, mate

[@TechTutorialswithPiyush]

Glad you enjoy it!

[@Sklb]

@@TechTutorialswithPiyush I am. Its really great. Will finish whole series and then move to other ones. :) Also, thank you!

[@Imran_kpk]

Vvvvvv fantastic ❤❤❤

[@RaviKumar-fw1di]

Thanks much !

[@TechTutorialswithPiyush]

You're welcome!

[@AnujDixit-h1o]

nice content

[@TechTutorialswithPiyush]

Thankyou!

[@khznm2174]

good vidoe and very good informative

[@TechTutorialswithPiyush]

Thank you 😊

[@balamurugant6479]

Thanks for sharing this❤

[@TechTutorialswithPiyush]

My pleasure 😊

[@yamiyami3100]

🎉🎉

[@bapirajumadarapu4050]

Amazing content broo

[@TechTutorialswithPiyush]

Thank you

[@AmitMondal-gc6zk]

These are excellent videos, please do the terraform series in the same way .

[@TechTutorialswithPiyush]

I will try my best

[@radhikagudidesi5486]

I always thought that Kubernetes is tough but after watching your videos my assumption is wrong., Thanks

[@TechTutorialswithPiyush]

I will change everyone's perception , thank you for the supprt

[@GizMOLoopTech]

thanks!!

[@TechTutorialswithPiyush]

You're welcome!

[@SinaTavakkol]

Many thanks

[@TechTutorialswithPiyush]

You are welcome

[@strangemate]

thats some commands galore 🙂

[@TechTutorialswithPiyush]

I know! bdw I replied to your message over discord let me know if you still have doubts

[@kundanchannekar8048]

I have completed the given tasks and correct me if I am wrong , in the first yaml we need to change the apiversion to apps/v1 since it is a deployment and in the second yaml the matchlabels is wrong it should be demo not dev. PS thanks for making such valuable content....

[@TechTutorialswithPiyush]

Yes, those are correct. Thank you for the feedback :)

[@uttamsharma9042]

thanks

[@bhanubisht8]

Done with video no. 8. Also revised all the previous video also. I am also preparing for the AWS cloud practitioner certification also....can you give some tips on that also....

[@TechTutorialswithPiyush]

Follow the exam guide

[@strangemate]

Created the RS.yaml file exactly as you did, however getting this error while trying to apply it. PS D:\Resources\Day08> kubectl apply -f rs.yaml The ReplicaSet "nginx-rs" is invalid: spec.template.metadata.labels: Invalid value: map[string]string{"env":"nginx"}: `selector` does not match template `labels`

[@TechTutorialswithPiyush]

As discussed over discord, you labels and selectors should match for it to work!

[@adityapradhan2025]

Can someone pls tell me what exactly is rs/nginx-rs? (at 20:16 ) Cuz im getting an error that says "NotFound"

[@TechTutorialswithPiyush]

replicaset with the name nginx-rs kubectl get rs nginx-rs or kubectl get ns/nginx-rs let me know if you need more details

[@Abedunnisa-b8t]

Hi Piyush, your way of teaching is really amazing, clear to understand.. I have little confusion in this Day 8, when you created ReplicationController and mentioned about template. After template you added again metadata and specs... can you please help me to understand it.. or can i read any article to understand it once more..

[@TechTutorialswithPiyush]

Thank you for the feedback! The metadata and spec inside template is from the pod. When we are creating a replicaset we are creating a template that it will be using incase a pod fails, the rs has to create a new pod using a template which has the image details, port details, etc

[@Jalal921]

Its a great explanation Piyush, one doubt about deployments, when rolling out update happens, lets say its banking application and user is making transaction to the application, when rolling update happens, then user transaction gets effected? how this works on a real scenairo?

[@TechTutorialswithPiyush]

Critical applications such as Banking, usually make changes in non business hours so that they have minimum impact on users. Relational dbs also have ACID properties which ensures that either the entire transaction is completed or rollbacked completely. Deployment strategies such as blue green, canary, rolling updates also play a significant role here

[@akifsalah9686]

In the yml file we have give the pod name as nginx but when u run Kubectl get pod why its is taking ReplicationController name menioned in metadata

[@TechTutorialswithPiyush]

Can you mention the timestamp? are you referring to pod name or container name?

[@abhigujjar7439]

I am not getting the syntax, when you are doing Rs/ deploy/ instead of writing deploy and then the name of deployment

[@prabhusriram8867]

please share the git hub repository for practice k8s..

[@TechTutorialswithPiyush]

It's there in the description of the video.

[@yashgajendragadkar]

If I change the image in pod.yml (e.g., from nginx to another version), how will it affect the associated Deployment and its Pods?

[@TechTutorialswithPiyush]

Hello Yash, Image is asscociated with a container, not a pod. Updating the container image will restart the pod but if you just update the image in the pod , it will not be reflected in the deployment that means, when the pod gets recreated by the deployment, it will not have the recent changes done on the pod level. A pod is controlled by the deployment, the template section in the deployment is the source of truth, any changes in the deployment will be reflected on the pod but not the other way around. I hope I was able to answer your doubt but let me know if you still need some clarification? Happy to help

[@yashgajendragadkar]

Thanks !@@TechTutorialswithPiyush

[@NidhishAbraham]

Pod: Use for debugging, single-container tasks, or simple setups. Deployment: Use for production applications, where scalability, reliability, and updates are needed. Always update the Deployment manifest, not the individual Pods, to ensure changes are persistent and propagate to all managed Pods. Consider the Deployment as the "source of truth" for defining the desired state of your application in Kubernetes.

[@techrohhit]

having one doubt, in the live real world applications we used deployment only no rc and rs correct ?

[@TechTutorialswithPiyush]

You got it right, RC and RS are mostly used in older versions, Deployments are the way to go for newer Kubernetes applications.

[@BharatVeerYadavHindi]

You have created a Netflix-style series on Kubernetes that I can easily understand.

[@TechTutorialswithPiyush]

Thanks for the awesome comparison!

[@salmanbintariq007]

so, instead of using replicaset individualy we have to use it inside deployment yaml file. What is the good practice to do it?

[@TechTutorialswithPiyush]

When you create a deployment, it automatically creates the replicaset. You dont have to create it seperately.

[@PiyushGhosh-l4k]

For ex , rs named a pod as `aaa-123` so here aaa is rs and 123 is pod ?? when pod is destroyed, then the new pod gets a new name(bbb-456) or or just pod name gets changed(aaa-678) and what happens in case node scale down ? does name of rs all to gether changes ??

[@TechTutorialswithPiyush]

yes , new pod will have a name aaa-456. only the last pod identifier will change. In case of node scale down , the workload will be recreated on a new node and it will have the name aaa-something. You can try it out as well

[@javeriasohail1321]

Hi Piyush, when i try to run this command (kubectl set image deploy/nginx-deploy nginx=nginx:1.9.1) it give me this error error: unable to find container named "nginx" but it solve with this command(kubectl set image deployment/nginx-deploy nginx-container=nginx:1.9.1)

[@TechTutorialswithPiyush]

Hello, It is because you set the image for a container and not the deployment, you have to provide the container name

[@NidhishAbraham]

𝐤𝐮𝐛𝐞𝐜𝐭𝐥 𝐬𝐞𝐭 𝐢𝐦𝐚𝐠𝐞 𝐝𝐞𝐩𝐥𝐨𝐲𝐦𝐞𝐧𝐭/𝐧𝐠𝐢𝐧𝐱-𝐝𝐞𝐩𝐥𝐨𝐲 𝐜𝐨𝐧𝐭𝐚𝐢𝐧𝐞𝐫-𝐧𝐚𝐦𝐞=𝐢𝐦𝐚𝐠𝐞:𝐭𝐚𝐠

[@strangemate]

hi piyush, whats the reason behind this command not working. I am trying to create the replicaset.yaml or replicacontroller.yaml from the command line kubectl run rc rc/nginxnew-rc --image=nginx --replicas=3 --dry-run=client -o yaml > rcnewCommand12.yaml error: unknown flag: --replicas See 'kubectl run --help' for usage. AND kubectl create rc rc/nginxnew-rc --image=nginx --replicas=3 --dry-run=client -o yaml > rcnewCommand.yaml error: unknown flag: --image See 'kubectl create --help' for usage. It works fine if we remove the --replica word from the first command but we dont get the replica keyword. For the second command, it first gives the issue with image and then replicas tag. Pls tell the reason. Thanks.

[@TechTutorialswithPiyush]

You either use rc rcname or rc/rcname but you are using rc rc/rcname

[@strangemate]

@@TechTutorialswithPiyush Thanks for the quick reply. I have just replaced the word "deploy" with rc. Didn't change anything else. I am unable to comprehend your reply. Could you revert with a working command for rc and rs and I will try at my end. Also, whats the difference between using kubectl run and kubectl create in the command line to create the .yaml files?

[@TechTutorialswithPiyush]

@@strangemate kubectl run works just to create a pod. Kubectl create for another objects

[@strangemate]

@@TechTutorialswithPiyush thanks again for the response to the second question. Could you pls provide me with the complete command to create the rs.yaml and rc.yaml files using the command line export just like we did wth the deploy yaml?

[@TechTutorialswithPiyush]

@@strangemate it will be better if we continue conversation over discord

[@Ganesh-tc4pi]

Hi piyush please decrease your image size to view screen Thank you!

[@TechTutorialswithPiyush]

Yes, I have fixed that in the latest videos. Thanks for the feedback

[@uttamsharma9042]

CKA practice question, Please share

[@TechTutorialswithPiyush]

Check out the Github repository, day 08 folder for the practise tasks related to this video

[@Ali-o2v3r]

👍

[@karnajeetsawant5635]

Thank you for such an elaborate video, Piyush. Indeed a Great explanation. This time I have a few doubts 😅😅 1. How can we see the containers in the pod. Like I saw in the video that we can see the pods, deployments, replicationsets. but canwe do the same for containers? Also, does pod have limit for number of containers it can have? 2. in one of the previous videos and this video you showed us a way of generating a yaml file through the CLI commands (the dry run method). Can we do something like that for DockerFile as well?

[@TechTutorialswithPiyush]

Having doubts are good :) Let me try to answer: 1) There is a dedicated video for multi-containers pod, day11 will cover these things. There is no limit as such , it depends on the resources that you have available plus it is advisable to only have multiple containers if absolutely need such as side car containers for monitoring pod, init containers that does a specific task before the main container and so on. 2) YAML can be generated for only kubernetes resource/objects not for dockerfile. However, if you want to generate dockerfile, try out docker init command, it was a recent feature released by docker which generates the dockerfile as per your project structure.

[@karnajeetsawant5635]

@@TechTutorialswithPiyush gotcha. Thanks a ton Piyush for taking some time out and answering my doubts. I really appreciate it.

[@Imran_kpk]

Sir for CKA who is best trainer in udemy😊

[@TechTutorialswithPiyush]

I am not saying my series is best but it has udemy quality content and available free of cost, why would you still want to buy a udemy course? any particular reason?

[@venkyvemula-k6n]

If any group is there in kubernates I have some questions I will send that question in that group can you please send me group piyusha

[@wamique99]

I wish you made these videos in Hindi

[@TechTutorialswithPiyush]

I started this channel in english so that I can create the maximum impact for non-hindi audience as well. When you give an interview, they dont ask your questions in hindi and you dont reply back in hindi, then shouldnt we learn in the same laguage that we will be using during the interview and to interact with any clients?

[@wamique99]

@@TechTutorialswithPiyush Yes I can understand this but if you made video in hindi/urdu that is more helpful for me in understanding the concept.

[@TechTutorialswithPiyush]

@@wamique99 I have been running this channel for 3 years and I cannot change the format now. Sorry about that

[@wamique99]

@@TechTutorialswithPiyush ok no problem

[@revanthchinthala645]

Thanks

[@vm_naveen]

Thank you !😀

[@TechTutorialswithPiyush]

You're welcome 😊

[@kanikv4480]

Thank you a lot sir ❤.

[@TechTutorialswithPiyush]

welcome

[@varunjoshi4410]

Thank you!