minikube/docs/reusing_the_docker_daemon.md

Reusing the Docker daemon

Method 1: Without minikube registry addon

When using a single VM of Kubernetes it's really handy to reuse the Docker daemon inside the VM; as this means you don't have to build on your host machine and push the image into a docker registry - you can just build inside the same docker daemon as minikube which speeds up local experiments.

To be able to work with the docker daemon on your mac/linux host use the docker-env command in your shell:

eval $(minikube docker-env)

You should now be able to use docker on the command line on your host mac/linux machine talking to the docker daemon inside the minikube VM:

docker ps

Docker may report following forbidden error if you are using http proxy and the $(minikube ip) is not added to no_proxy/NO_PROXY:

error during connect: Get https://192.168.39.98:2376/v1.39/containers/json: Forbidden

On Centos 7, docker may report the following error:

Could not read CA certificate "/etc/docker/ca.pem": open /etc/docker/ca.pem: no such file or directory

The fix is to update /etc/sysconfig/docker to ensure that minikube's environment changes are respected:

< DOCKER_CERT_PATH=/etc/docker
---
> if [ -z "${DOCKER_CERT_PATH}" ]; then
>   DOCKER_CERT_PATH=/etc/docker
> fi

Remember to turn off the imagePullPolicy:Always, as otherwise Kubernetes won't use images you built locally.

Method 2: With minikube registry addon

Enable minikube registry addon and then push images directly into registry. Steps are as follows:

For illustration purpose, we will assume that minikube VM has one of the ip from 192.168.39.0/24 subnet. If you have not overridden these subnets as per networking guide, you can find out default subnet being used by minikube for a specific OS and driver combination here which is subject to change. Replace 192.168.39.0/24 with appropriate values for your environment wherever applicable.

Ensure that docker is configured to use 192.168.39.0/24 as insecure registry. Refer here for instructions.

Ensure that 192.168.39.0/24 is enabled as insecure registry in minikube. Refer here for instructions..

Enable minikube registry addon:

minikube addons enable registry

Build docker image and tag it appropriately:

docker build --tag $(minikube ip):5000/test-img .

Push docker image to minikube registry:

docker push $(minikube ip):5000/test-img

Now run it in minikube:

kubectl run test-img --image=$(minikube ip):5000/test-img

Or if 192.168.39.0/24 is not enabled as insecure registry in minikube, then:

kubectl run test-img --image=localhost:5000/test-img