Pulling an Image from a Private Registry
This page shows how to create a Pod that uses a Secret to pull an image from a private Docker registry or repository.
- Before you begin
- Logging in to Docker
- Creating a Secret that holds your authorization token
- Understanding your Secret
- Creating a Pod that uses your Secret
- What’s next
Before you begin
-
You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using Minikube.
-
To do this exercise, you need a Docker ID and password.
Logging in to Docker
docker login
When prompted, enter your Docker username and password.
The login process creates or updates a config.json file that holds an
authorization token.
View the configfile.json file:
cat ~/.docker/config.json
The output contains a section similar to this:
{
"auths": {
"https://index.docker.io/v1/": {
"auth": "c3RldmU1MzpTdGV2ZURvY2tAIzE2"
}
}
}
Creating a Secret that holds your authorization token
Create a Secret named regsecret:
kubectl create secret docker-registry regsecret --docker-username=<your-name> --docker-password=<your-pword> --docker-email=<your-email>
where:
<your-name>is your Docker username.<your-pword>is your Docker password.<your-email>is your Docker email.
Understanding your Secret
To understand what’s in the Secret you just created, start by viewing the Secret in YAML format:
kubectl get secret regsecret --output=yaml
The output is similar to this:
apiVersion: v1
data:
.dockercfg: eyJodHRwczovL2luZGV4L ... J0QUl6RTIifX0=
kind: Secret
metadata:
...
name: regsecret
...
type: kubernetes.io/dockercfg
The value of the .dockercfg field is a base64 representation of your secret data.
Copy the base64 representation of the secret data into a file named secret64.
Important: Make sure there are no line breaks in your secret64 file.
To understand what is in the .dockercfg field, convert the secret data to a
readable format:
base64 -d secret64
The output is similar to this:
{"https://index.docker.io/v1/":{"username":"janedoe","password":"xxxxxxxxxxx","email":"jdoe@example.com","auth":"c3RldmU1MzpTdGV2ZURvY2tAIzE2"}}
Notice that the secret data contains the authorization token from your
config.json file.
Creating a Pod that uses your Secret
Here is a configuration file for a Pod that needs access to your secret data:
private-reg-pod.yaml
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Copy the contents of private-reg-pod.yaml to your own file named
my-private-reg-pod.yaml. In your file, replace <your-private-image> with
the path to an image in a private repository.
Example Docker Hub private image:
janedoe/jdoe-private:v1
To pull the image from the private repository, Kubernetes needs credentials. The
imagePullSecrets field in the configuration file specifies that Kubernetes
should get the credentials from a Secret named
regsecret.
Create a Pod that uses your Secret, and verify that the Pod is running:
kubectl create -f my-private-reg-pod.yaml
kubectl get pod private-reg
What’s next
- Learn more about Secrets.
- Learn more about using a private registry.
- See kubectl create secret docker-registry.
- See Secret
- See the
imagePullSecretsfield of PodSpec.