Docker Autoscaler executor (Experiment)
Introduced in GitLab Runner 15.11.0. This feature is an Experiment
The Docker Autoscaler executor is an autoscale-enabled Docker executor that creates instances on-demand to accommodate the jobs that the runner manager processes. It wraps the Docker executor so that all Docker executor options and features are supported.
The Docker Autoscaler uses fleeting plugins to autoscale. fleeting
is an abstraction for a group of autoscaled instances. It uses plugins that support different cloud providers,
like Google Cloud Platform (GCP), AWS, and Azure.
Install a fleeting plugin
To enable autoscaling for your target platform, install a fleeting plugin. You can install the AWS, GCP, or Azure fleeting plugin. These plugins are Experiments.
For other official plugins developed by GitLab, see the fleeting
project.
To install the plugin:
- Install the binary for your host platform:
- Ensure plugin binaries are discoverable through the
PATH
environment variable.
Configure Docker Autoscaler
The Docker Autoscaler executor wraps the Docker executor so that all Docker executor options and features are supported.
To configure the Docker Autoscaler, in the config.toml
:
- In the
[runners]
section, specify theexecutor
asdocker-autoscaler
. - In the following sections, configure the Docker Autoscaler based on your requirements:
Example: AWS autoscaling for 1 job per instance
Prerequisites:
- An AMI with Docker Engine installed.
- An AWS Autoscaling group. For the scaling policy use “none”, as Runner handles the scaling.
- An IAM Policy with the correct permissions
This configuration supports:
- A capacity per instance of 1
- A use count of 1
- An idle scale of 5
- An idle time of 20 minutes
- A maximum instance count of 10
By setting the capacity and use count to both 1, each job is given a secure ephemeral instance that cannot be affected by other jobs. As soon the job is complete the instance it was executed on is immediately deleted.
With an idle scale of 5, the runner tries to keep 5 whole instances (because the capacity per instance is 1) available for future demand. These instances stay for at least 20 minutes.
The runner concurrent
field is set to 10 (maximum number instances * capacity per instance).
concurrent = 10
[[runners]]
name = "docker autoscaler example"
url = "https://gitlab.com"
token = "<token>"
shell = "sh" # use powershell or pwsh for Windows AMIs
# uncomment for Windows AMIs when the Runner manager is hosted on Linux
# environment = ["FF_USE_POWERSHELL_PATH_RESOLVER=1"]
executor = "docker-autoscaler"
# Docker Executor config
[runners.docker]
image = "busybox:latest"
# Autoscaler config
[runners.autoscaler]
plugin = "fleeting-plugin-aws"
capacity_per_instance = 1
max_use_count = 1
max_instances = 10
[runners.autoscaler.plugin_config] # plugin specific configuration (see plugin documentation)
name = "my-docker-asg" # AWS Autoscaling Group name
profile = "default" # optional, default is 'default'
config_file = "/home/user/.aws/config" # optional, default is '~/.aws/config'
credentials_file = "/home/user/.aws/credentials" # optional, default is '~/.aws/credentials'
[runners.autoscaler.connector_config]
username = "ec2-user"
use_external_addr = true
[[runners.autoscaler.policy]]
idle_count = 5
idle_time = "20m0s"
Example: GCP instance group for 1 job per instance
Prerequisites:
- A VM image with Docker Engine installed, such as COS.
- An Instance group. For the “Autoscaling mode” select “do not autoscale”, as Runner handles the scaling.
- An IAM Policy with the correct permissions.
This configuration supports:
- A capacity per instance of 1
- A use count of 1
- An idle scale of 5
- An idle time of 20 minutes
- A maximum instance count of 10
By setting the capacity and use count to both 1, each job is given a secure ephemeral instance that cannot be affected by other jobs. As soon the job is complete the instance it was executed on is immediately deleted.
With an idle scale of 5, the runner tries to keep 5 whole instances (because the capacity per instance is 1) available for future demand. These instances stay for at least 20 minutes.
The runner concurrent
field is set to 10 (maximum number instances * capacity per instance).
concurrent = 10
[[runners]]
name = "docker autoscaler example"
url = "https://gitlab.com"
token = "<token>"
shell = "sh" # use powershell or pwsh for Windows Images
# uncomment for Windows Images when the Runner manager is hosted on Linux
# environment = ["FF_USE_POWERSHELL_PATH_RESOLVER=1"]
executor = "docker-autoscaler"
# Docker Executor config
[runners.docker]
image = "busybox:latest"
# Autoscaler config
[runners.autoscaler]
plugin = "fleeting-plugin-googlecompute"
capacity_per_instance = 1
max_use_count = 1
max_instances = 10
[runners.autoscaler.plugin_config] # plugin specific configuration (see plugin documentation)
name = "my-docker-instance-group" # GCP Instance Group name
project = "my-gcp-project"
zone = "europe-west1"
credentials_file = "/home/user/.config/gcloud/application_default_credentials.json" # optional, default is '~/.config/gcloud/application_default_credentials.json'
[runners.autoscaler.connector_config]
username = "runner"
use_external_addr = true
[[runners.autoscaler.policy]]
idle_count = 5
idle_time = "20m0s"