Search for a command to run...
I'm a developer who grew up in Houston, TX. I've done a lot of things in my life and have finally found that software and development is truly what makes me happy.
I've been a musician, a teacher, a flight attendant, and airline pilot, and now a full stack software engineer.
I get to learn about new tech every day. And I'm here to share it all with you.
No comments yet. Be the first to comment.
Quickly Set Up Your Own Strapi Instance on Fly.io
Boost your JavaScript expertise and streamline your coding process
Develop a Full-Stack Application Quickly Using Next.js and Supabase
Top Practices for Responsive Design in Next.js with TailwindCSS: Full Setup Guide
Next.js for Newcomers: A Clear Guide to Essentials
Building upon my last post, we’re going to take our node application and turn it into a Docker image. We’ll ultimately be using Docker images in our kubernetes cluster later in the series.
With Docker, we can package the entire app into a portable image and then run that image on some other server. The image has its own little ecosystem so there’s no need to install all of the dependencies on the server for the app. As long as the server you’re wanting to use has Docker, you’re all set!
You can turn almost any application into a Docker image. You can even run an entire Postgres database in a container!
The Docker file is the ‘blueprint’ for how an image is build. Let’s create a Dockerfile in the root of our project. As well as a .dockerignore file.
touch Dockerfile
touch .dockerignore
The .dockerignore file includes files and directories that we do not want included inour image. Add the following to your .dockerignore file:
# .dockerignore
node_modules
And in your Dockerfile:
FROM node:18-alpine
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY . .
RUN npm install
EXPOSE 3000
CMD ['npm', 'run', 'start']
FROM node:18-alpine
Since this is a node application, we need node to run it. This line defines what image we will use to build our image. Alpine is a very lightweight Linux distribution - coming in at only 5MB.
RUN mkdir -p /usr/src/app
RUN commands allow you to run linux commands during the build of your image. This command makes our working directory.
WORKDIR /usr/src/app
WORKDIR defines the working directory of our application inside the container.
COPY . .
We want to copy everything from the directory where our Dockerfile is to the working directory of the container. The first period specifies the relative path locally. The second period specifies where in the container we want those files copied.
RUN npm install
Install the dependencies.
EXPOSE 3000
The application binds to port 3000. This will let the docker daemon know where to bind the app.
CMD ['npm', 'run', 'start']
CMD is the command that will be run when the container is ‘brought up’. There can only be one CMD in a Dockerfile
We need to build the image so that we can push it to our Docker registry. In your terminal, run:
docker build -t <your-registry-name>/node-weather:latest .
-t is the image name and tag. The trailing . is saying that you want to build the Dockerfile in your present directory.
If you’re logged into Docker hub, run the following:
docker push <your-registry-name>/node-weather:latest>
You may need to create an account and then login with docker login
Now let’s try it out! To run the image locally and start a container, run the following command:
docker run -p 3000:3000 <your-registry-name>/node-weather:latest
Visit http://localhost:3000 and you’ll see your express server up and running.
That’s all 😃
In the next tutorial, we’ll jump into kubernetes. We’ll create a deployment for the image we just created in order to run a pod in a kubernetes cluster.