So when you docker pull an image, it by default looks to the Docker Hub registry to find the image. Is there any way that I can make it so when I docker pull, it by default looks into my private registry?
Related
I am trying to cache images locally in a Docker registry using a pull through cache as described here: https://docs.docker.com/registry/recipes/mirror/. But when I do, Docker seems to ignore the pass-through cache and is instead pulling images directly from Docker Hub.
I have a Docker Compose file that I am using to run the registry:
version: '3.9'
services:
registry:
restart: always
image: registry:2
ports:
- 5000:5000
volumes:
- ~/.docker/registry:/var/lib/registry
- ./registry-config.yml:/etc/docker/registry/config.yml
And I have configured Docker to use the registry via the --registry-mirror option, which I have confirmed is taking effect by checking the output of docker info:
$ docker info
...
Registry Mirrors:
https://localhost:5000/
...
But when I try to pull an image, I see no activity in the registry's logs, as if Docker is ignoring the mirror option and just going straight to Docker Hub.
I have also confirmed the registry is working by pulling alpine:latest from Docker Hub, tagging it as localhost:5000/alpine:latest and pushing it to the registry, then pulling it back out again. Both of which work fine.
This is all being done on a Linux VM running Ubuntu.
Can someone please help me understand what I am doing wrong. and how I am supposed to get Docker to pull all images through the pull-through cache?
Thanks in advance for your help.
We need to build docker images using self-hosted linux agent which is deployed as docker container (in Azure Container Instances).
As of now, the agent is Ubuntu image, however to enable building images inside this container I thought of using Kaniko image. However, I haven't figured out how to run Kaniko image without executing the kaniko itself right away (as we need to run devops agent primarily and run kaniko on-demand).
Any hints? Or better ideas how to build docker images in running docker container?
Solved with following code, however Kaniko does not work as expected when running inside my container (tested the same parameters with kaniko inside my container and in default container and in my container does not work (cannot authenticate to ACR)).
Might end up with the VMSS DevOps agent...
FROM whatever-base-image
...
COPY --from gcr.io/kaniko-project/executor /kaniko/executor /kaniko/executor
Ref: https://github.com/GoogleContainerTools/kaniko/issues/2058#issuecomment-1104666901
Maybe I do not understand the concept of Azure Container Instances (ACI) and Azure at all correctly. I am using Azure CLI on my Windows-Computer and want to create a Windows-container (core-image) with dockerfile. But there is no AZ command available. I am able to create a container, there is no problem. But not with a dockerfile. Is there a possibility to run docker commands for Azure (Azure CLI, Azure bash, Azure powershell)? Maybe somebody can clarify my misunderstanding.
Many thanks in advance, J.
Of curse, yes, you can use the Azure CLI command to build containers with Dockerfile. But there is a queue for the steps.
The docker image is the first step, you can use the CLI command az acr build to build the image directly in the ACR, with your Dockerfile. For example, the Dockerfile is in your local machine and it's windows image:
az acr build -t sample/hello-world:{{.Run.ID}} -r MyRegistry . --platform windows
The ACI is the second step, CLI command az container create will help you to create the container instance with your images. The example command here:
az container create -g MyResourceGroup --name mywinapp --image winappimage:latest --os-type Windows --cpu 2 --memory 3.5
Once you have your image, you should publish it to Azure Container Registry or Docker Hub.
Take a look on the following links, it provides the information to:
Create a container image for deployment to Azure Container Instances
Deploy the container from Azure Container Registry
Deploy your application
https://learn.microsoft.com/en-us/azure/container-instances/container-instances-tutorial-prepare-app
https://learn.microsoft.com/en-us/azure/container-instances/container-instances-tutorial-prepare-acr
https://learn.microsoft.com/en-us/azure/container-instances/container-instances-tutorial-deploy-app
I have recently done the same thing. I have deployed my windows service to Azure Container Instance through Azure Container Registry. Here is step by step process you need to follow. Before performing these steps you need to have published folder of application. You need to install Docker Desktop in your machine.
Create Dockerfile with below commands and put it inside published folder:
FROM mcr.microsoft.com/dotnet/framework/runtime:4.8-windowsservercore-ltsc2019
COPY . .
ENTRYPOINT Application.exe
Here you need to use base file as per your neeed. You can find Windows base images [here][1]
Now navigate to this directory(published folder path) in Powershell and execute below command:
docker image build -t IMAGE_NAME:TAG . -- name of the image with tag
docker run --rm IMAGE_NAME:TAG -- you can run it locally
Now to push this image to Azure, below are the commands. First login into azure and then azure container registery.
az login -- it will navigate to browser for login
docker login ACR_LOGIN_SERVER_NAME -u ACR_USERNAME --password ACR_PASSWORD
docker tag IMAGE_NAME:TAG ACR_LOGIN_SERVER_NAME/IMAGE_NAME:TAG -- tag local image to azure inside ACR
docker push ACR_LOGIN_SERVER_NAME/IMAGE_NAME:TAG -- push image to ACR
Once you have pushed docker image to ACR, you can see it under Repositories in ACR. Based on this repository, you need to create Azure Container Instance to run your docker image.
To create ACI, click on "Create a resource" and select Containers > Container Instances. Here, you need to key some info like resource group and docker image credentials. Make sure you select Private as Image type and key image registry credentials. This ACI deployment process may take couple of minutes as it will fetch the docker image and then deploy. Once deployment is done, you will see Container running and you can check logs as well.
Hope it helps!!
I am creating Docker container of nodejs application. Below is the sample of my Docker configuration file
FROM node:6.11
WORKDIR /usr/src/app
COPY package.json .
npm install
copy . /usr/src/app
EXPOSE 80
CMD [ "npm", "start" ]
This will download the node image from Docker hub and then it will create Docker image as per the configuration.
For security reasons I don't want to download nodejs image from Docker hub, Instead I want to use my private repository to download nodejs image.
As I have setup private repository I am not sure how to specify registry credentials in DockerFile.
Can anyone help me with this?
By default, docker pulls all images from Dockerhub. If you want to pull an image from another registry, you have to prefix the image name with the registry URL. Check the official docker pull documentation.
In your case, you have 2 options:
The first is to specify explicitly the registry inside the Dockerfile as such:
FROM <registry>:<port>/node:6.11
WORKDIR /usr/src/app
Once you build, the image will be downloaded from the private registry. Make sure that you are logged in to the registry before building using the docker login command.
Alternatively, if you don't want to change the docker file. Pull the image from the private registry using docker pull <registry>:<port>/node:6.11 and then force docker build to use this image by tagging it with only node:6.11
docker tag <registry>:<port>/node:6.11 node:6.11
Before you build the Docker image you'll have to do docker login to your private repo. Then pulls - explicit or implicit through FROM will use that registry (and while I can't find any documentation to back that up, I suspect it also fallback to Docker Hub if it can't find the image there, but that may be dependent on the registry settings????)
I guess you already have nodejs image in your local docker registry.
If you want to pull the nodejs image from local docker registry:
Make sure your docker daemon is pointing to local docker registry use --insecure-registry <registry_address>:<port> as mentioned here https://docs.docker.com/engine/reference/commandline/dockerd/
Change Dockerfile to point to image in registry. FROM <registry_address>:<port>/node:6.11 (actually this will be the complete name of your nodejs image in local docker registry)
The registry credentials can be set using docker login command https://docs.docker.com/engine/reference/commandline/login/ or you can manually set the credentials in ~/.docker/config.json file.
Now you can build the image, it should pull the base image from registry.
I'd like to create a Docker based Gitlab CI runner which pulls the docker images for the build from a private Docker Registry (v2). I cannot make the Gitlab Runner to pull the image from a local Registry, it tries to GET something from a /v1 API. I get the following error message:
ERROR: Build failed: Error while pulling image: Get http://registry:5000/v1/repositories/maven/images: dial tcp: lookup registry on 127.0.1.1:53: no such host
Here's a minimal example, using docker-compose and a web browser.
I have the following docker-compose.yml file:
version: "2"
services:
gitlab:
image: gitlab/gitlab-ce
ports:
- "22:22"
- "8080:80"
links:
- registry:registry
gitlab_runner:
image: gitlab/gitlab-runner
volumes:
- /var/run/docker.sock:/var/run/docker.sock
links:
- registry:registry
- gitlab:gitlab
registry:
image: registry:2
After the first Gitlab login, I register the runner into the Gitlab instance:
root#130d08732613:/# gitlab-runner register
Running in system-mode.
Please enter the gitlab-ci coordinator URL (e.g. https://gitlab.com/ci):
http://192.168.61.237:8080/ci
Please enter the gitlab-ci token for this runner:
tE_1RKnwkfj2HfHCcrZW
Please enter the gitlab-ci description for this runner:
[130d08732613]: docker
Please enter the gitlab-ci tags for this runner (comma separated):
Registering runner... succeeded runner=tE_1RKnw
Please enter the executor: docker-ssh+machine, docker, docker-ssh, parallels, shell, ssh, virtualbox, docker+machine:
docker
Please enter the default Docker image (eg. ruby:2.1):
maven:latest
Runner registered successfully. Feel free to start it, but if it's running already the config should be automatically reloaded!
After this, I see the Gitlab runner in my Gitlab instance:
After this I push a simple maven image to my newly created Docker repository:
vilmosnagy#vnagy-dell:~/$ docker tag maven:3-jdk-7 172.19.0.2:5000/maven:3-jdk7
vilmosnagy#vnagy-dell:~/$ docker push 172.19.0.2:5000/maven:3-jdk7
The push refers to a repository [172.19.0.2:5000/maven]
79ab7e0adb89: Pushed
f831784a6a81: Pushed
b5fc1e09eaa7: Pushed
446c0d4b63e5: Pushed
338cb8e0e9ed: Pushed
d1c800db26c7: Pushed
42755cf4ee95: Pushed
3-jdk7: digest: sha256:135e7324ccfc7a360c7641ae20719b068f257647231d037960ae5c4ead0c3771 size: 1794
(I got the 172.19.0.2 IP-address from a docker inspect command's output)
After this I create a test project in the Gitlab and add a simple .gitlab-ci.yml file:
image: registry:5000/maven:3-jdk-7
stages:
- build
- test
- analyze
maven_build:
stage: build
script:
- "mvn -version"
And after the build the Gitlab gives the error in seen in the beginning of the post.
If I enter into the running gitlab-runner container, I can access the registry under the given URL:
vilmosnagy#vnagy-dell:~/$ docker exec -it comptest_gitlab_runner_1 bash
root#c0c5cebcc06f:/# curl http://registry:5000/v2/maven/tags/list
{"name":"maven","tags":["3-jdk7"]}
root#c0c5cebcc06f:/# exit
exit
vilmosnagy#vnagy-dell:~/$
But the error still the same:
Do you have any idea how to force the gitlab-runner to use the v2 api of the private registry?
Current Gitlab and Gitlab Runners support this, see: https://docs.gitlab.com/runner/configuration/advanced-configuration.html#use-a-private-container-registry
On older Gitlab I've solved this with copying an auth key into ~/.docker/config.json
{
"auths": {
"my.docker.registry.url": {
"auth": "dmlsbW9zLm5hZ3k6VGZWNTM2WmhC"
}
}
}
I've logged into this container from my computer and copied this auth key into the Gitlab Runner's docker container.
What version of docker do you run on Gitlab ?
Also for a v2 registry, you have to explicitly allow insecure registry with a command line switch, or secure your registry using a certificate.
Otherwise Docker fallback to the v1 registry if it gets a security exception.