Basics of running a custom Docker container locally
A tiny cheat sheet for those of us that don't use Docker enough to have muscle memory and want to get things done.
February 26, 2022
Creating a custom image
Create a file named
Dockerfile with your configuration. Although this post will not cover the ins and outs of this, here's an example of what I was using to modify the
ghost image to support Amazon S3 storage.
FROM ghost:4.9.4 WORKDIR /var/lib/ghost ENV AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID ENV AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY ENV AWS_DEFAULT_REGION=$AWS_DEFAULT_REGION ENV storage__active=s3 ENV storage__s3__bucket=$GHOST_STORAGE_ADAPTER_S3_PATH_BUCKET ENV storage__s3__assetHost=$GHOST_STORAGE_ADAPTER_S3_ASSET_HOST ENV storage__s3__serverSideEncryption=AES256 ENV storage__s3__acl=private ENV url=$INSTANCE_DNS_NAME RUN npm install -g ghost-storage-adapter-s3 && \ ln -s /usr/local/lib/node_modules/ghost-storage-adapter-s3 ./current/core/server/adapters/storage/s3
FROMis the original image. You can use something like
ubuntuif you want to start from scratch, though I encourage you to find an official image with more bells and whistles of what you're trying to accomplish if possible
WORKDIRis the directory that you'll be working out of in thee Docker instance.
ENVare environment variables that you can reference in the instance
RUNwill run the commands in the terminal when you build your image
ghost image I'm using here already has commands to start running so those are not set by me, but if you're creating your own own
Dockerfile from scratch you'll need to start your server, database, etc. that you're building with the
Building your custom image
Assuming that you have a valid
Dockerfile in your local directory, the following command will create a Docker container with a name that you can easily reference.
docker build -t <image-name> .
docker build -t website .
Running the container (isolated)
To run the container without any connection to your local file system, run:
docker run -d \ -p <local-port>:<container-port> \ --name <container-name> \ <image-name>
docker run -d \ -p 2368:2368 \ --name website \ website
-dmakes the container run in the background
-pmaps the Docker port to your local port
--namesets a name for the instance that you can refer to later for restarting, stopping, removing, etc.
websiteis the name we assigned to the custom image we built earlier
Running the container (mounted to your local directory)
docker run -d \ -v <local-directory>:<container-directory> -p <local-port>:<container-port> \ --name <container-name> \ <image-name>
docker run -d \ -v $(pwd):/var/lib/ghost -p 2368:2368 \ --name website \ website
Viewing the logs
To view most recent logs, run:
docker logs <container-name>
To continue "tailing" the logs in your terminal, run:
docker logs <container-name> --follow
And when you're done following the container logs, hit
<Cmd> + C to exit and go back to your terminal.
Stopping the container
docker stop <container-name>
Restarting the container
docker restart <container-name>
Deleting the container
If you've already stopped the container, you can run the
docker rm <container-name>
If the container has not been stopped, you can skip that step with the
docker rm <container-name> --force
Happy Dockering! SL