I have to take a Docker image from a vendor site and then push the image into the private repository (Artifactory). This way the CI/CD pipeline can retrieve the image from the private repository and deploy the image.
What is the best way to achieve it, do I need to recreate the image?
steps:
take a pull of the base docker image from vendor.
create new folder for your new docker image.
create a Dockerfile.
write your base docker image.
do the changes inside this folder.
build new docker image using cmd.
push the image into docker hub.
refer this (not exactly according to your need, but this helps): https://www.howtoforge.com/tutorial/how-to-create-docker-images-with-dockerfile/
for cmd and Dockerfile changes, refer docker office doc site
I believe its a tar or zip file that they have given you by docker save and docker export.
You can perform below operations.
1. Perform docker load < file.tar - You will get the image name that's loaded. Note down the name.
1. Download the tar or zip file to your local.
2. Perform cat file.tar | docker import image_name_that_you_noted_above
3. You are good to use the image now. tag it to your repo and push, or directly run using docker run
Related
I've created a docker image of a project (very large project that takes time to compile) and I forgot to add a file in it.
I does not have to do with the build, it's just a test file.
Is it possible to add this file into my image without rebuilding everything ?
Thanks
Here's a full example to pull an image, add a local file to it, retag the image and push it back:
export IMAGE_URL=example.com/your_image:your_tag
docker pull $IMAGE_URL
docker create --name temp_container $IMAGE_URL
docker cp /host/path/to/file temp_container:/container/path/to/file
docker commit temp_container $IMAGE_URL
docker push $IMAGE_URL
Yes its possible, do the steps:
Mount the image and make a container
Do the command:
docker cp textFile.txt docker_container_name:/textFile.txt
Commit the container to build a new image with new tag version or another name;
Add the image using docker commit of a container as described above, or using Dockerfile.
Create a directory say temp and navigate into it
Move file file-to-be-added.extension to be added to the docker image into the newly created temp directory
Create a Dockerfile with below contents
Dockerfile
FROM your-registry/your-image:tag
COPY file-to-be-added.extension /destination/path/of/file-to-be-added.extension
Run below command to build the new image:
docker build -t your-registry/your-image:new-tag .
If required, push the image
docker push your-registry/your-image:new-tag
You should try to use docker commit.
Example: docker commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]]
There's docker cp too, but it only works in running containers.
I hope this helps!
Brhaka
The ADD command is used to copy files/directories into a Docker image. It can copy data in three ways:
1. List item Copy files from the local storage to a destination in the Docker image.
2. Copy a tarball from the local storage and extract it automatically inside a destination in the Docker image.
3. Copy files from a URL to a destination inside the Docker image.
source: https://www.educative.io/edpresso/what-is-the-docker-add-command
I have 2 hosts running the same docker customized image. I have modified the image on host 1 and saved the image to a custom.tar. If I take that image and load it onto host 2 will it just update or should I remove the old docker image first?
There are 2 ways to do that with repository and without repository using load and save.
With repository below are the steps.
Log in on Docker Hub
Click on Create Repository.
Choose a name and a description for your repository and click
Create.
Log into the Docker Hub from the command line
docker login --username=yourhubusername --email=youremail#company.com
tag your image
docker tag <existing-image> <hub-user>/<repo-name>[:<tag>]
Push your image to the repository you created
docker push <hub-user>/<repo-name>:<tag>
Pull the image to host 2
docker pull <hub-user>/<repo-name>:<tag>
This will add the image to docker hub and available on internet and now you can pull this image to any system.
With this approach you can keep the same images with different tags on system. But if you don't need old images better to delete that to avoid junk.
Without docker hub.
This command will create tar bundle.
docker save [OPTIONS] IMAGE [IMAGE...]
example: docker save busybox > busybox.tar
Load an image from a tar archive or STDIN
docker load [OPTIONS]
example:docker load < busybox.tar.gz
Recommended: Docker hub or DTR approach easy to manage unless you have bandwidth issue in case your file is large.
Refer:
Docker Hub Repositories
I am trying to create a docker image using the below command .
docker build -t mytestapp .
My DockerFile looks like this
# Set the base image
FROM rhel7:latest
USER root
# Dockerfile author / maintainer
MAINTAINER Name <email.id#example.com>
# Update application repository list and install the Redis server.
RUN mkdir /usr/local/myapp/
ADD myapp-0.0.1-jar /usr/local/myapp/
RUN java -Dspring.profiles.active=qa -jar /usr/local/myapp/myapp-0.0.1.jar
# Expose default port
EXPOSE 8080
Questions:
1) Is it fine the way I am adding the JAR file. Will it be available inside /usr/local on the container after I prepared am image from the above build.
2) When I build the image using docker build command , is the build image is pushed to docker repository hub by default.
Since the WAR file contains credentials, I don't want to push the image to Docker Hub but we would like to push to our local Docker registry using Docker distribution and pushing with docker push.
Please clarify.
Answering your questions:
Docker recommends using the COPY instructions for adding single files into an image. It will be available inside the container at /usr/local/myapp/myapp-0.0.1-jar
When you build the image it will be available on your local docker-host. It won't leave the server unless you explicitly tell it so.
Another tip I want to give you is the recommended docker image naming convention, which is [Repository/Author]/[Imagename]:[Version].
So for your image it might be called zama/mytestapp:1.0
If you want to push it into your local registry, you'll have to name your image after the syntax [LocalRegistry:Port]/[Repository/Author]/[Imagename]:[Version].
So your image might now be called registry.example.com:5000/zama/mystestapp:1.0
If you have authentication on your registry, you need to docker login first and then simply push the image with docker push registry.example.com:5000/zama/mystestapp:1.0.
I would like to be able to pull a docker image from dockerhub and edit the dockerfile.. I am wondering if dockerhub actually downloads the dockerfile to the localhost and to where it is stored (I am running it from a MAC).
You dont download the docker image and edit their Dockerfile. The Dockerfile is an instruction set on how to build an image. Once the image is made, theres no going backwards. However if its on Dockerhub there should be a link to the Dockerfile. Look around at the page for links to the Dockerfile. Probably just a link to Github.
Once you have the dockerfile you then build it. For instance if you have a terminal open in the same folder as a Dockerimage file you could run
docker build -t myimage .
where myimage is the tag of your image. You will then have an instance of myimage on your local machine.
Also you can make a docker file that extends theres using FROM. For instance your docker file might start with
FROM java:6b38-jdk
# append to their image.
An image does not include a complete Dockerfile. When pulling an image you get an image manifest along with the required file system layers.
You can see some of the build steps with docker history --no-trunc IMAGE but it's not the complete Dockerfile.
There are utilities that try and generate a Dockerfile from the image history
Inheritance of an image is normally done using docker's from command, for example.
from centos7:centos7
In my case, I have a Dockerfile which I want to use as a base image builder, and I have two sub dockerfiles which customize that file.
I do not want to commit the original dockerfile as a container to dockerhub, so for example, I would like to do:
Dockerfile
slave/Dockerfile
master/Dockerfile
Where slave/Dockerfile looks something like this:
from ../Dockerfile
Is this (or anything similar) possible ? Or do I have to actually convert the top level Dockerfile to a container, and commit it as a dockerhub image, before I can leverage it using the docker FROM directive.
You don't have to push your images to dockerhub to be able to use them as base images. But you need to build them locally so that they are stored in your local docker repository. You can not use an image as a base image based on a relative path such as ../Dockerfile- you must base your own images on other image files that exists in your local repository.
Let's say that your base image uses the following (in the Dockerfile):
FROM centos7:centos7
// More stuff...
And when you build it you use the following:
docker build -t my/base .
What happens here is that the image centos7:centos7 is downloaded from dockerhub. Then your image my/base is built and stored (without versioning) in your local repository. You can also provide versioning to your docker container by simply providing version information like this:
docker build -t my/base:2.0 .
When an image has been built as in the example above it can then be used as a FROM-image to build other sub-images, at least on the same machine (the same local repository). So, in your sub-image you can use the following:
FROM my/base
Basically you don't have to push anything anywhere. All images lives locally on your machine. However, if you attempt to build your sub-image without a previously built base image you get an error.
For more information about building and tagging, check out the docs:
docker build
docker tag
create your own image