I'm trying to use docker with a node.js web app i'm working on.
I have familiarized myself with the docker concepts and gotten up and running with the example here: https://docs.docker.com/examples/nodejs_web_app/
I get the general process...write a Dockerfile -> Build a docker image -> run it in a VM.
However, it seems impractical to rebuild the image and restart the container every time I change a file.
I currently have a gulp / live-reload setup that works great for development so I was wondering if there was any recommended way of accomplishing something like this with docker.
Thanks!
You can mount the source directory in the container as a volume and use the same gulp/livereload setup that you currently use now. Here's an example project with this setup. If you run into port issues with livereload see here.
Related
Is there one equivalent of Google's JIB or BuildPacks for Node.JS ?
It is my understanding that JIB allows to build OCI container images from within the project's build tool like Gradle or Maven, as a developer we only have to include a plugin into the build and are able to package up the application into a container and having JIB implement all the best practices of packing up a Java application into container with no questions asked.
I have search around but have not found something equivalent for the Node.JS ecosystem.
It should be possible just into a node developer time dependency and it take care on packaging up my javascript/typescript Express.js for example app into a docker container or OCI image.
Thank you, Oscar
For posterity, I'll list some NodeJS-native Docker image creation packages (these usually can be added to your project's package.json). In no particular order:
nodejs-container-image-builder - container registry client and image builder with no dependency on docker (by Google)
Dockta - A Docker image builder for researchers
EZDocker - build docker images in Javascript
I did try Dockta and it has SUPER simple one-liner docker file/image build (either a simple package.json script or direct command line), it works nicely.
Yes, Heroku has a Node.js Buildpack. You can run it using the Pack CLI like this:
$ pack build myimage --builder heroku/buildpacks:18 --buildpack heroku/nodejs
If you are using GitLab, you can simply use Kaniko as well.
I'm experimenting with docker micro-services and I'm refactoring an existing NodeJS app to run as several separate entities. What I'm used to doing is running it locally (using npm start) and whenever I save my changes, it redeploys everything locally instantly.
How do I set up VSCode with it's docker extension to work in this way? I've let VSCode create the Dockerfile \ docker-compose.yml files for each micro-service.
The guides I'm finding around the place imply pushing each change to an image repo, which when you're making small changes, seems long winded
EDIT - Okay. I got it building and deploying manually. I've had to run the build command in CMD instead of GIT Bash (minor frustration... but nothing I can't live with). Is there a way to automate this instead? So whenever a change happens inside of the directory, it just starts the build process again.
I'm trying to deploy a Next.js project using a Docker image and I was wondering if it's possible to simply use an already generated dist folder (.next) and start the next.js server (npm run start) without having to trigger the build step again in the container.
The container will be hosted in AWS Elastic Beanstalk and I also want to avoid uploading the source code and installing the npm packages there, as I already have a CI pipeline that is generating the production artifacts.
Answering because I was going through issues with this myself and found this question. My research shows the only way to accomplish this is to run a docker environment on beanstalk and not node.js. The primary reason is that there are absolute paths in the .next build artifacts so you have to build on each instance and you have to make sure that BUILD_ID is synced across those instances.
If you CI pipeline can handle creating and pushing the Docker image, then its pretty easy to deploy on Beanstalk without any rebuilding etc. Hope that helps!
I am building a NodeJS application using MongoDB as the database. I am thinking that it will make more sense in terms of portability across different platforms and also versioning and comparison to have the application deployed in Docker. Going through various recommendations on internet, here are my specific questions :
(a) Do I copy my application code (nodejs) within Docker? Or do I keep Source code on the host machine and have the code base available to Docker using Volumes? (Just for experimenting, I had docker file instruction pulling the code from repository within the image directly. It works, but is it a good practice, or should I pull the code outside the docker container and make it available to docker container using Volumes / copy the code)?
(b) When I install all my application dependencies, my node_module size explodes to almost 250 MB. So would you recommend that run npm install (for dependencies) as Docker step, which will increase the size of my image ? Or is there any other alternative that you can recommend?
(c) For connecting to the database, what will be the recommendation? Would you recommend, using another docker container with MongoDB image and define the dependency between the web and the db using docker? Along with that have configurable runtime property such that app in different environments (PROD, STAGE, DEV) can have the ability to connect to different database (mongodb).
Thoughts / suggestions greatly appreciated. I am sure, I may be asking questions which all of you may have run into at some point in time and have adopted different approaches, with pros and cons.
Do I copy my application code (nodejs) within Docker? Or do I keep
Source code on the host machine and have the code base available to
Docker using Volumes?
You should have the nodejs code inside the container. Keeping the source code on your machine will make your image not portable since if you switch to another machine, you need to copy the code there.
You can also pull the code directly into the container if you have git installed inside the container. But remember to remove the .git folder to have a smaller image.
When I install all my application dependencies, my node_module size
explodes to almost 250 MB. So would you recommend that run npm install
(for dependencies) as Docker step, which will increase the size of my
image ? Or is there any other alternative that you can recommend?
This is node pulling over all the internet. You have to install you dependencies. However, you should run npm cache clean --force after the install to do some clean up to have a smaller image
For connecting to the database, what will be the recommendation? Would
you recommend, using another docker container with MongoDB image and
define the dependency between the web and the db using docker? Along
with that have configurable runtime property such that app in
different environments (PROD, STAGE, DEV) can have the ability to
connect to different database (mongodb)
It is a good idea to create a new container for the database and connect your app to the database using docker networks. You can have multiple DB at the same time, but preferably keep one db container inside the network, and if you want to use another one, just remove the old one and add the new one to the network.
A
During development
Using a directory in the host is fast. You modify your code, relaunch the docker image and it will start your app quickly.
Docker image for production/deployement
It is good to pull the code from git. it's heavier to run, but easier to deploy.
B
During development
Don't run npm install inside docker, you can handle the dependencies manually.
Docker image for production/deployement
Make a single npm i in image building, because it's supposed to be static anyway.
More explanation
When you are developing, you change your code, use a new package, adapt your package.json, update packages ...
You basically need to control what happen with npm. It is easier to interact with it if you can directly execute commands lines and access the files (outside docker in local directory). You make your change, you relaunch your docker and it get started!
When you are deploying your app, you don't have the need to interact with npm modules. You want a packaged application with an appropriate version number and release date that do not move and that you can rely on.
Because npm is not 100% trustworthy, it happen that with exact same package.json some stuff you get as you npm i makes the application to crash. So I would not recommend to use npm i at every application relaunch or deployement, because imagine some package get fucked up, you gotta rush to find out a soluce. Moreover there is no need at all to reload packages that should be the exact same (they should!). It's not in deployement that you want to update the package! But in your developement environment where you can npm update safely and test everything up.
(Sorry about english!)
C
Use two docker image and connect them using a docker network. So you can deploy easily your app anywhere.
Some commands to help maybe about Docker networking! (i'm actually using it in my company)
// To create your own network with docker
sudo docker network create --subnet=172.42.0.0/24 docker-network
// Run the mondogb docker
sudo docker run -i -t --net docker-network --ip 172.42.0.2 -v ~/DIRECTORY:/database mongodb-docker
// Run the app docker
sudo docker run -i -t --net docker-network --ip 172.42.0.3 -v ~/DIRECTORY:/local-git backend-docker
A while back I found a application or Docker image that automatically detected the application language. Once it detected the language it would automatically setup the Docker container for that application, for example install Node.js and run the main file.
Does anybody know the name of this application or Docker image?
Automatic detection of application language
Buildstep
The first such image I found was buildstep.
https://github.com/progrium/buildstep
Buildstep leverages a clever idea pioneered by Heroku called buildpacks to create a language agnostic application deployment process.
Buildstep is one of the core technologies that powers the very clever Dokku PAAS.
https://github.com/progrium/dokku
http://progrium.com/blog/2013/06/19/dokku-the-smallest-paas-implementation-youve-ever-seen/
Buildstep derivatives
Centurylink created their own buildstep look-alike called building:
https://github.com/CenturyLinkLabs/building
http://www.centurylinklabs.com/heroku-on-docker/
And so did tutum cloud
https://github.com/tutumcloud/buildstep
Buildstep inspired
The author of buildstep participated in the Flynn project which built sometime similar called the slug builder and runner (Again using Heroku buildpacks)
https://github.com/flynn/flynn/tree/master/slugbuilder
https://github.com/flynn/flynn/tree/master/slugrunner
Alternative approach using base images
Docker official images
Docker have released a number of language specific Docker containers, designed to make building applications much easier. These images are designed to be built against a local source code repository using the special ONBUILD instruction.
The following is the Nodejs image:
https://registry.hub.docker.com/_/node/
The idea is to create a very simpler Docker file in the root directory of the source code:
FROM node:0.10-onbuild
EXPOSE 8888
and simply build and run the container. The source code is magically packaged:
docker build -t my-nodejs-app .
docker run -it --rm --name my-running-app my-nodejs-app
Redhat STI
Redhat have an alternative approach to image building called STI (Source to image).
Similar to Docker's language stacks, STI also does not use buildpacks. It provides a convention and set of commands that can be used to control all aspect an application's packaging as a docker container. This technology is a major part of their next version of Openshift V3:
https://github.com/openshift/source-to-image
https://blog.openshift.com/builds-deployments-services-v3/
I haven't found a completely automated one but phusion's passenger-docker is pretty popular and easy to set up for Ruby, Python, and Node apps.