I am running containers in Firecracker micro-VM using firecracker contained. I was able to create a firecracker VM and run a container inside it. However, I haven't found any APIs in firecracker-containerd to snapshot and restore a VM running container that I can directly use in my GO code. Are there any APIs there for that? I have seen APIs for snapshotting and restoring VMs in FIrecracker-microvm/firecracker repo where it sends requests to the API server for pausing/snapshotting/resuming/ restoring VMs.
https://github.com/firecracker-microvm/firecracker/blob/main/docs/snapshotting/snapshot-support.md
Is it the way to follow for snapshotting a firecracker VM running containers?
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I have a single Java application. We developed the application in Eclipse. It is a Maven project. We already have a system for launching our application to AWS EC2. It works but is rudimentary and we would like to learn about the more common and modern approaches other teams use to launch their Java Maven apps to EC2. We have heard of Docker and I researched the tool yesterday. I understand the basics of building an image, tagging it and pushing to either Docker Hub or Amazon's ECS service. I have also read through a few tutorials describing how to pull a Docker image into an EC2 instance. However, I don't know if this is what we are trying to do, given that I am a bit confused about the role Docker can play in our situation to help make our dev ops more robust and efficient.
Currently, we are building our Maven app in Eclipse. When the build completes, we run a second Java file that uses the AWS JDK for Java to
launch an EC2 instance
copy the.jar artifact from the build into this instance
add the instance to a load balancer and
test the app
My understanding of how we can use Docker is as follows. We would Dockerize our application and push it to an online repository according to the steps in this video.
Then we would create an EC2 instance and pull the Docker image into this new instance according to the steps in this tutorial.
If this is the typical flow, then what is the purpose of using Docker here? What is the added benefit, when we are currently ...
creating the instance,
deploying the app directly to the instance and also
testing the running app
all using a simple single Java file and functions from the AWS SDK for Java?
#GNG what are your objectives for containerization?
Amazon ECS is the best method if you want to operate in only AWS environment.
Docker is effective in hybrid environments i.e., on physical servers and VMs.
the Docker image is portable and complete executable of your application: it delivers your jar, but it can also include property files, static resources, etc... You package everything you need and deploy to AWS, but you could decide also to deploy the same image on other platforms (or locally).
Another benefit is the image contains the whole runtime (OS, jdk) so you dont rely on what AWS provides ensuring also isolation from the underlying infrastructure.
I am actually new to the Kubernetes and i am in the process of learning Kubernetes by installing minikube in my local desktop. May be i am unaware of this, but i wanted to ask this question to the experts
Here is what i am trying to achieve. I have 3 docker containers created in my local environment. 2 java web based application(app1, app2) docker containers and 1 oracle database container (oracleDB).
app1 application depends on the oracleDB. I installed minikube in my local environment for trying out Kubernetes.
I was able to deploy my applications app1, app2 and oracleDB in the minikube and bring up the applications and also able to access those application using the url like http://local_minikube_ip:31213/app1
After few hours my app was not responding, so i had to restart the minikube. When i restart the minikube, i found out that i lost the database imported into the oracle docker container. I had to re-import the database and also ssh into the app1 and start the app1 and app2 containers.
So i want to know how everyone handles this scenario ? is there anyway i can maintain the data in the oracle database container during the restarts of Kubernetes ?
Can someone help me with this please ?
For data persistence you need to define Volumes in your PODs, it is often done in conjunction with Persistent Volume Clams and Persistent Volumes.
Take a look at https://kubernetes.io/docs/concepts/storage/volumes/ and https://kubernetes.io/docs/concepts/storage/persistent-volumes/ to get a better picture of how to achieve that
I have the 2 containers mentioned running with Vagrant how do I connect my Django app from one container to Postgresql on the other?
The idea:
TL;DR: Read this to know how to link containers
I should be able to easily connect containers when they are running with a project already setup/coded, either in the host machine or a VM.
I have read a bit here and there. Found out how to install everything I need in a container, but that would not be isolating db setup from app. These are the conclusions I've drawn so far:
Docker's use cases are to run/test projects in an isolated manner, the process of programming and setting up the project (in my case, a Django app) is done in a Vagrant VM or on the host machine. Then after a certain point in development, I'd run the project in a container to test the behavior. So the premise that I'd be developing in a Docker, while possible, is not part of their philosophy.
Docker's purpose is, after testing/development, to deploy in containers using the same or better setup used to test the project.
I have some professional servers, and I want to create a cluster of 7-15 machines with CoreOS. I'm a little familiar with Proxmox, but I'm not clear about how create a virtual machine(VM) with CoreOS on proxmox. Also, I'm not sure if the idea of cluster of CoreOS's VM on proxmox it's right to do.
Then, I need:
How create a VM with CoreOS on proxmox.
If will be viable proxmox to create CoreOS's cluster.
I have no experience with Proxmox, but if you can make an image that runs then you can use it to stamp out the cluster. What you'd need to do is boot the ISO, run the installer and then make an image of that. Be sure to delete /etc/machine-id before you create the image.
CoreOS uses cloud-config to connect the machines together and configure a few parameters related to networking -- basically anything to get the machines talking to the cluster. A cloud-config file should be provided as a config-drive image, which is basically like mounting a CD-ROM to the VM. You'll have to check the docs on Proxmox to see if it supports that. More info here: http://coreos.com/docs/cluster-management/setup/cloudinit-config-drive/
The other option you have is to skip the VMs altogether and instead of using Proxmox, just boot CoreOS directly on your hardware. You can do this by booting the ISO and installing or doing something like iPXE: http://coreos.com/docs/running-coreos/bare-metal/booting-with-ipxe/
I have TeamCity (7.0.2) successfully spinning up an EC2 VM from a custom AMI, running our build, and sending back the build artifacts.
However, even when I used to do this with older TeamCity versions, I was always unhappy with the notion that it simply terminates the instances after they are done, and then creates new instances using the configured AMI next time a build agent is needed.
Can I get TeamCity to issue "stop" commands instead, followed by "start" commands? This has a tonne of advantages - quicker spin-up time, allowing for named instances in the agent stats, and saving the Mercurial clone to EBS for the next build are just three.
p.s. I guess I could use chained builds to call the EC2 API directly rather than use the in-built cloud support, but that sounds like a lot of work and feels flaky
We plan to provide support of EBS instances start stop in TeamCity 7.1
Please vote for TW-16419
TeamCity 7.0 may leak EBS volumes TW-12517