I am using docker and trying to enable kubernetes and set CPU and Memory via command line.
I have looked at this answer but unfortunately cannot find this file.
Is there any way to enable Kubernetes on Docker for Mac via terminal?
Docker does not have an app-ified version for Linux that I know of, so there is no relation to the Docker for Mac/Windows app. There are many tools to locally install Kubernetes on Linux so they probably didn't see much reason to make something new. Minikube is the traditional one, but you can also check out microk8s, k3s, KinD, and many others.
Related
Maybe a trivial question but that's my problem:
I attached to a running docker container, after some use I needed to run a Unit Test and gdb at "the same time".
So I openned another shell tab (konsole tab) and attached again to the same docker container $ docker attach container_name but everything I did echoed in both attachments. If I execute cd /home/user/folder_foo the other tab will "do the same", ended up both konsole tabs in the same folder. Like the same command was echoed to both tabs. Maybe it's a unique user structure and what I isn't even possible.
I really need to do two thing in parallel in the same docker container, how it could be done?
$ docker --version
Docker version 20.10.9, build c2ea9bc
I am using Ubuntu 21.04
Run multiple services in a container
It is generally recommended that you separate areas of concern by using one service per container.
But for development purposes, you can follow mentioned guide.
Additionally, there is a similar answer already provided
You can run docker exec -it <container> bash from multiple terminals to launch several sessions connected to the same container.
I am writing software on macOS. As a subroutine I would like to call certain Linux-only CLI tools, e.g., > mytool inputfile. Can I use Docker for Mac to compile the Linux tool inside a container and call it from outside the container (after copying input files into the container?). And if I can, is it a good idea or will there be issues installing and compiling Linux packages?
From my understanding of docker as basically a lightweight VM that uses a stripped down version of a Linux distribution, this approach seems to make sense, but the stripped down aspect might be an impediment.
Can Docker be used to run Linux CLI tools from macOS?
Docker supports macOS according to documentation.
Can I use Docker for Mac to compile the Linux tool inside a container and call it from outside the container (after copying input files into the container?
Yes.
And if I can, is it a good idea
Depends on the term "good" - it's subjective and highly depends on specific case.
or will there be issues installing and compiling Linux packages?
No.
From my understanding of docker as basically a lightweight VM
Yes.
that uses a stripped down version of a Linux distribution, this approach seems to make sense, but the stripped down aspect might be an impediment.
What is in docker container depends on the container. Overall, usually man pages and system package manager repository information are removed from images. I would disagree - mostly docker containers come with full Linux distributions and can be used as such.
You should do as follow:
docker run --rm -v /:/host -ti ubuntu ... your command referring to /host...
And this is the command parameters explanation:
--rm : remove sthe container after running (but keep cached the image for next calls).
-t : allocates a visibile shell terminal.
-i : runs in interactive mode.
-v /:/host : maps your root folder to container /host folder.
ubuntu : pulls the ubuntu image, which you can change with any other you prefer.
As last parameter put the commands to run into the container but relatives to /host.
What's the point of having Node.js and Vue.js installed on my host and then also getting a Node/Vue image for Docker? Every Vue.js tutorial says to install Node and Vue to the host first and then get the Docker image, is this not redundant?
Examples:
https://morioh.com/p/3021edac7ef1
https://jonathanmh.com/deploying-a-vue-js-single-page-app-including-router-with-docker/
https://mherman.org/blog/dockerizing-a-vue-app/
I'm using a Windows 10 host and was trying to avoid installing Node and Vue to Windows if possible, unless there are particular advantages to doing so, which hopefully someone can enumerate. Otherwise, maybe someone can confirm that it's redundant to also install Node/Vue on the host and state why it's silly and redundant.
Like you say, it is redundant but easier. A container is a running instance of an image, an image that was created (probably) using a Dockerfile with the instructions, so how would you go about doing everything from the container?
Would you add the creation of the app to the Dockerfile or would you connect to the container using bash and run the commands from there? If you connect with bash you'll lost everything once you remove the container. Once your app is created inside your container how would you get it out? I mean you need to write your app's code. You could store you data using docker volumes but that gets complicated depending were you are running Docker. For example on Mac a virtual machine is created for Docker, so to find that data you'll need to connect to the virtual machine...
It is just easier to do all of that from your local machine and use docker to host your app.
I am working on a project of online python compiler. When user sends a python, Server will execute it. What I want do is,create a sandbox with virtual filesystem, execute that script instide it, and that sandbox should far from real-server's filesystem, but nodejs should be able to control stdin and stdout of that sandbox.
How to make it possible?
Docker is a great way to sandbox things.
You can run
docker run --network none python:3
from your node.js server. Look at other switches of docker run to plug in as many security holes as possible.
The shtick is, you run the docker command from your node.js server and pass the user's python code via stdin.
Now, if your node.js server is on one machine and the sendbox should run on another machine, you tell docker to connect to the other machine using the DOCKER_HOST environment variable.
Docker containers wrap up the software in a complete filesystem that contains everything it needs to run: code, runtime, system tools, system libraries — basically anything you can install on a server. This guarantees that it will always run the same, regardless of the environment it is running in.
This might be worth to read https://instabug.com/blog/the-difference-between-virtual-machines-and-containers/
I have a web app project, and it uses Mongo, so one of my NPM scripts is "start-mongo-dev": "mongod", for spinning up the Mongo daemon during development.
I used to use OSX, but just got a new computer and run Linux Ubuntu. Now the command to begin the daemon is sudo service mongod start, so it would seem I should change the NPM script to that.
But that is a red flag. What if I go back to the old computer at all? What if I collaborate on this project with someone who uses OSX?
In short, how is one expected to handle developing with multiple OS's?
Ian's solution may be better but one alternative would be to create a bash script inside your project that detects the OS and runs the appropriate command. You can find more info on how to do that here How to detect the OS from a Bash script?
In some packages, I see divisions like this indicated with a :. For example:
"scripts": {
"start-mongo-dev:osx": "mongod",
"start-mongo-dev:ubuntu": "sudo service mongod start"
}
I am not aware of a canonical solution, but that doesn't mean there isn't one. I happen to like this one, though. #opinion