I have a docker image already. I want to be able to add a directory from the host file system to the docker filesystem. I know that if I am using a base image, I could use the ADD command in the dockerfile but I am not actually using a base image, I want to build a new docker image based on my image with some directories added to it from my host file system. Is there a way to do that?
Just create another docker image based your image.
FROM base-image-name
ADD host_dir /destination_dir
You do not need a new image, just run it like this:
docker run your_image -v host_dir:local_dir
Related
I am trying to run the postgres container and get error as bellow.
"Unable to find image 'name:latest' locally
docker: Error response from daemon: pull access denied for name, repository does not exist or may require 'docker login': denied: requested access to the resource is denied."
I have been working on the problem for a couple of days I do not know what the problem is.
This is of my command:
The issue is with your command:
docker run -- name
While --name should be with no any spaces, but you have space between -- and name.
Run your command again with the correct syntax.
To clarify more:
When you run docker run -- name, docker assumes that you are trying to pull and download an image called name, and since your name does not include any tags, so it says I cannot find any image called name:latest.
Just in case anyone gets this error for the same reason I did. I had built an image locally and Docker was complaining the image could not be found. It seems the error was happening because I built the image locally, but specified a different platform for docker run (I had copied the command from somewhere else). Example:
docker build -t my-image .
docker run ... --platform=linux/amd64 my-image
linux/amd64 is not my current platform. So I removed this argument and it worked.
Answer : You can't use that image because you didn't login to your Docker Hub Account
After creating an account find the image you want to use and then pull the image .
You can simply use docker pull [OPTIONS] NAME[:TAG|#DIGEST] for pulling an image from docker.hub and the using it as a container
According to the docker reference
Most of your images will be created on top of a base image from the Docker Hub registry.
Docker Hub contains many pre-built images that you can pull and try without needing to define and configure your own.
To download a particular image, or set of images (i.e., a repository), use docker pull.
P.S : Thank you for contributing in stackoverflow community, but for your next question please ensure that you are asking your question properly by reading
Code of Conduct
Before you pull the image from DockerHub, use docker login and then enter your username and password.
If you have not yet registered in DockerHub, register from the link below
here
then you can use this command for pull your images.
docker pull imageName
be notice that the image you want to receive must already be in DockerHub.
I need to create a docker image with a Dockerfile which is available on a remote computer.
will the below work in Powershell ?
docker build -t MyFirstDockerImage -f //RemoteServerpath/FolderStructure/ .
The docker build can only read local files. But not the remote files. i.e Files should be copied on to the machine where docker build is being executed.
I have a container called "postgres", build with plain docker command, that has a configured PostgreSQL inside it. Also, I have a docker-compose setup with two services - "api" and "nginx".
How to add the "postgres" container to my existing docker-compose setup as a service, without rebuilding? The PostgreSQL database is configured manually, and filled with data, so rebuilding is a really, really bad option.
I went through the docker-compose documentation, but found no way to do this without a re-build, sadly.
Unfortunately this is not possible.
You don't refer containers on docker-compose, you use images.
You need to create a volume and/or bind mount it to keep your database data.
This is because containers do not save data, if you have filled it with data and did not make a bind mount or a volume to it, you will lose everything on using docker container stop.
Recommendation:
docker cp
Docker cp will copy the contents from container to host. https://docs.docker.com/engine/reference/commandline/container_cp/
Create a folder to save all your PostgreSQL data (ex: /home/user/postgre_data/)
Save the contents of your PostgreSQL container data to this folder (docker hub postgres page for further reference: ;
Run a new PostgreSQL (same version) container with a bind mount poiting to the new folder;
This will maintain all your data and you will be able to volume or bind mount it to use on docker-compose.
Reference of docker-compose volumes: https://docs.docker.com/compose/compose-file/#volumes
Reference of postgres docker image: https://hub.docker.com/_/postgres/
Reference of volumes and bind mounts: https://docs.docker.com/storage/bind-mounts/#choosing-the--v-or---mount-flag
You can save this container in a new image using docker container commit and use that newly created image in your docker-compose
docker container commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]]
I however prefer creating images with the use of Dockerfiles and scripts to fill my data etc.
I want to copy some files from my docker container to my host system using
docker cp container_id:/path/to/file/that/is/annoyingly/long/poit.foo ~/local/
I really would like there to be tabcompletion for the path. Is there a way to achieve it?
I'd like to make the deployment to production the easiest it can be, but struggling with the way how to do it.
If I will have docker for production, it will be nice to have docker image with my application deployables, but I'm not sure if it is good approach.
I have several concerns:
wouldn't the layer system bloat, when I will replace the file every time in new version of image?
Is it good idea to make DB scripts and migration tool part of this image?
The last concern is how to run it conveniently. I don't want to go there stop the tomcat container and start it again using volume from new application image(as the new app container name cannot be the same).
I have seen ways to do that, but I don't like them very much i.e. deploy to Tomcat docker image ,create Tomcat image with application already bundled or use host system volume. I like to have something like install "CD". I'd like to evaluate my idea with other approaches, speaking about the proper tool to run it is maybe for other question.
wouldn't the layer system bloat, when I will replace the file every time in new version of image?
No because you can clean up dangling images
docker rmi $(docker images --filter "dangling=true" -q --no-trunc)
Is it good idea to make DB scripts and migration tool part of this image?
Yes, if your startup script knows to detect if it needs to apply them.
I don't like them very much i.e. deploy to Tomcat docker image ,create Tomcat image with application already bundled or use host system volume.
If your data volume container is separate from the app, that shouldn't be an issue.
From the discussion, the OP adds:
using this docker create --name <container_name> <image_name> with different image name can retain the container name and I can run Tomcat container with the same volumes-from?
docker run -it --rm -p 8888:8080 --volumes-from <container_name> <image_name>
That is the idea, but it won't work if there is already a create data container with that name.
If there is no persistent data in it, one can docker rm that data container, and recreate it with the same name.
If there are persistent data, then it is best to copy the new updated data through an intermediate (docker run) container which would mount temporarily the data container.