Docker machine fails to create machine

`bad certificate`

This usually means that the certificates in /root/.docker/machine/certs has expired and we are facing https://gitlab.com/gitlab-org/gitlab-runner/-/issues/3676.

Verify the certs were recently created.

sudo ls -lah /root/.docker/machine/certs/
total 24K
drwx------ 2 root root 4.0K May 20 07:31 .
drwxr-xr-x 4 root root 4.0K May 20 07:31 ..
-rw------- 1 root root 1.7K May 20 07:31 ca-key.pem
-rw-r--r-- 1 root root 1.1K May 20 07:31 ca.pem
-rw-r--r-- 1 root root 1.1K May 20 07:31 cert.pem
-rw------- 1 root root 1.7K May 20 07:31 key.pem

Stop gitlab-runner which shouldn’t be running any jobs.
Terminal window
```
sudo /root/runner_upgrade.sh stop
```

Delete idle machines

sudo ls /root/.docker/machine/machines | xargs -P100 -n1 sudo -H docker-machine rm -f

Move old certificates to another directory just in case.
Terminal window
```
sudo mv /root/.docker/machine/certs/ /tmp/certs.bak
```

Run docker-machine create to force certificate creation. To look at what flags to pass you can look at /etc/gitlab-runner/config.toml to see what flags are defined.

sudo -H docker-machine create --driver google \
    --google-project xx \
    --google-username=xx \
    --google-use-internal-ip --google-zone=xx \
    --google-service-account=xxx \
    --google-machine-image=xx \
    --google-subnetwork=xx --google-network=xx \
    vm01

Start gitlab-runner
Terminal window
```
sudo /root/runner_upgrade.sh
```