Gitlab Autoscaling not creating Docker-machines

Hi there, I am facing an issue.

I followed several docs, because I do have to implement private autoscaling runners using docker-machine. However, I am not able to achieve it.

I followed these docs :

also :
https://docs.gitlab.com/runner/executors/docker_machine.html

I got these errrors :
time=“2019-02-19T14:33:11Z” level=error msg="Docker machine “runner-nkcwyrce-vm01%!(EXTRA string=1550586790-ca92af9d)” does not exist. Use “docker-machine ls” to list machines. Use “docker-machine create” to add a new one." name=“runner-nkcwyrce-vm01%!(EXTRA string=1550586790-ca92af9d)” operation=provision #012

But for me it seems obvious, since I am creating ephemeral machines, to be destroyed after GITLAB CI Build. What I am missing here ?

Have you guys faced any issue related?

Really appreciate any help !!!

Find below my config.toml

concurrent = 20
check_interval = 0
log_level = “debug”

[[runners]]
name = “gitlab-multirunner”
url = “https://gitlab.com
token = “”
executor = “docker+machine”
limit = 10
[runners.docker]
tls_verify = false
image = “alpine”
privileged = true
disable_cache = false
volumes = ["/cache"]
shm_size = 0
[runners.machine]
IdleCount = 1
IdleTime = 600
MachineDriver = “google”
MachineName = “autoscaling-runner-”
MachineOptions = [
“google-project=my_project”,
“google-machine-type=n1-standard-2”,
“google-machine-image=debian-9-stretch-v20190213”,
“google-tags=docker+machine”,
“google-preemptible=true”,
“google-zone=us-east1-b”,
“google-use-internal-ip=true”,
]
OffPeakPeriods = [
“* * 0-7,20-23 * * mon-fri ",
"
* * * * sat,sun *”
]
OffPeakIdleCount = 0
OffPeakIdleTime = 1200
[runners.cache]
Type = “s3”
ServerAddress = “gitlab-multirunner-1:9000”
AccessKey = “WR9AD7I8JBMM6ZVCW0DC”
SecretKey = “UrFz9MuT3mRKgpoXTd8z++4mM1e8BUb2gyehMp8S”
BucketName = “gitlab-runner-cache”
Insecure = true
Shared = true

Regards,

ebsantos.com

Also got these errors… something to do with the VM machine hostname:
time=“2019-02-19T14:33:10Z” level=error msg=“Error creating machine: Invalid hostname specified. Allowed hostname chars are: 0-9a-zA-Z . -” driver=google name=“runner-nkcwyrce-vm01%!(EXTRA string=1550586790-ca92af9d)” operation=create

The example above, the Machine-name directive is set to = autoscaling-runner-