How to pipe a github secret variable into a file - kubectl

Question

I have a github pipeline and im piping a github sercret variable into a file but i get the following error.
/home/runner/work/_temp/c6144b9a-c8e3-489a-ae97-795f592c57f0.sh: line 6: /config: Permission denied
echo: write error: Broken pipe
name: pipeline
on: [ push ]
env:
KUBECONFIG_B64DATA: ${{ secrets.KUBECONFIG_B64DATA }}
deploy:
name: Deploy
# if: startsWith(github.ref, 'refs/tags/')
runs-on: ubuntu-latest
steps:
- name: Checkout
uses: actions/checkout#master
- name: Setup Kubectl
run: |
sudo apt-get -y install curl
curl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectl
chmod +x ./kubectl
sudo mv ./kubectl /usr/local/bin/kubectl
sudo echo $KUBECONFIG_B64DATA | base64 --decode > /config
sudo mkdir -p ~/.kube
sudo mv config /root/.kube/
EDIT:
I use a different folder to get passed permissions isuses (/tmp/config)
However i still struggle to pipe a github secret variable into a file because github masks the secret and im returned with an error.
base64: invalid input
I believe this is because when you echo a secret you simply get **** instead of the actual value

Answer 1

I spent 4 hours on this issue. Then found the solution which was actually hidden in the comments.
As pointed out by #Kay, this was caused by the white space. Doing echo "${KUBECONFIG_B64DATA// /}" | base64 --decode > /tmp/config fixed the problem for me.
Just posting this as an official answer, so that it becomes easier for someone to find it later.

Answer 2

Change this line:
sudo echo $KUBECONFIG_B64DATA | base64 --decode > /config
To
sudo bash -c 'base64 --decode <<< "$KUBECONFIG_B64DATA" > /config'
Or
sudo tee /config > /dev/null < <(base64 --decode <<< "$KUBECONFIG_B64DATA")