You may need to switch your docker repo to private before docker push.

Thanks to the answer provided by Dean Wu and this comment by ses, before pushing, remember to log out, then log in from the command line to your docker hub account

# you may need log out first `docker logout` ref. https://stackoverflow.com/a/53835882/248616
docker login

According to the docs:

You need to include the namespace for Docker Hub to associate it with your account.
The namespace is the same as your Docker Hub account name.
You need to rename the image to YOUR_DOCKERHUB_NAME/docker-whale.

So, this means you have to tag your image before pushing:

docker tag firstimage YOUR_DOCKERHUB_NAME/firstimage

and then you should be able to push it.

docker push YOUR_DOCKERHUB_NAME/firstimage

I got the same issue while taking the docker beginner Course. I solved the issue by doing adocker login before the docker push call.

I had the same issue, but accepted answer given here did not work for me. I tried few steps and was able to get around to push it finally. Hope this helps someone.

Here are the steps worked for me :

1) Login to the docker.

docker login -u sirimalla

2) Tag your image build

my image name here is : mylocalimage and by default it has tag : latest
and my username is : sirimalla as registered with docker cloud, and I created a public repository named : dockerhub

so my personal repository becomes now : sirimalla/dockerhub and I want to push my image with tag : myfirstimagepush

I tagged as below :

docker tag mylocalimage:latest sirimalla/dockerhub:myfirstimagepush

3) Pushed the image to my personal docker repository as below

docker push sirimalla/dockerhub:myfirstimagepush

And it successfully pushed to my personal docker repo.