Configuring Docker Scaler¶
Docker Scaler can be configured through Docker enivonment variables and/or by creating a new image based on thomasjpfan/docker-scaler
Service Scaling Environment Variables¶
Tip
The Docker Scaler container can be configured through envionment variables
The following environment variables can be used to configure the Docker Scaler relating to service scaling.
| Variable | Description |
|---|---|
| SERVER_PREFIX | Custom prefix for REST endpoint. Default: / |
| ALERT_SCALE_MIN | Send alert to alertmanager when trying to scale up service already at minimum replicas. Default: false |
| ALERT_SCALE_MAX | Send alert to alertmanager when trying to scale up service already at maximum replicas. Default: true |
| DEFAULT_MIN_REPLICAS | Default minimum number of replicas for a service. Default: 1 |
| DEFAULT_MAX_REPLICAS | Default maximum number of replicas for a service. Default: 5 |
| DEFAULT_SCALE_SERVICE_DOWN_BY | Default number of replicas to scale service down by. Default: 1 |
| DEFAULT_SCALE_SERVICE_UP_BY | Default number of replicas to scale service up by. Default: 1 |
| ALERTMANAGER_ADDRESS | Address for alertmanager. Default: `` |
| ALERT_TIMEOUT | Alert timeout duration (seconds). Default: 10 |
| RESCHEDULE_TICKER_INTERVAL | Duration to wait when checking for nodes to come up (seconds). Default: 60 |
| RESCHEDULE_TIMEOUT | Time to wait for nodes to come up during rescheduling (seconds). Default: 1000 |
| RESCHEDULE_ENV_KEY | Key for env variable when rescheduling services. Default: RESCHEDULE_DATE |
Node Scaling Environment Variables¶
The following environment variables can be used to configure the Docker Scaler relating to node scaling.
| Variable | Description |
|---|---|
| NODE_SCALER_BACKEND | Backend of node backend. Accepted Values: [aws] Default: "" |
| DEFAULT_MIN_MANAGER_NODES | Miniumum number of manager nodes. Default: 3 |
| DEFAULT_MAX_MANAGER_NODES | Maximum number of manager nodes. Default: 7 |
| DEFAULT_MIN_WORKER_NODES | Miniumum number of worker nodes. Default: 0 |
| DEFAULT_MAX_WORKER_NODES | Maximum number of worker nodes. Default: 5 |
| DEFAULT_SCALE_MANAGER_NODE_DOWN_BY | Default number of manager nodes to scale down by. Default: 1 |
| DEFAULT_SCALE_MANAGER_NODE_UP_BY | Default number of manager nodes to scale up by. Default: 1 |
| DEFAULT_SCALE_WORKER_NODE_DOWN_BY | Default number of worker nodes to scale down by. Default: 1 |
| DEFAULT_SCALE_WORKER_NODE_UP_BY | Default number of worker nodes to scale up by. Default: 1 |
| ALERT_NODE_MIN | Send alert to alertmanager when trying to scale up nodes already at minimum nodes. Default: true |
| ALERT_NODE_MAX | Send alert to alertmanager when trying to scale up nodes already at maximum nodes. Default: true |
AWS Node Scaling Envronment Variables¶
The following environment variables can be used to configure the Docker Scaler relating to AWS node scaling.
| Variable | Description |
|---|---|
| AWS_ENV_FILE | Location of AWS env file used when NODE_SCALER_BACKEND is sent to aws.Default: /run/secrets/aws |
| AWS_DEFAULT_REGION | Default AWS region. Default: us-east-1 |
| AWS_MANAGER_ASG | AWS autoscaling group name for manager nodes. |
| AWS_WORKER_ASG | AWS autoscaling group name for worker nodes. |
AWS Secrets file¶
AWS secret file defines the necessary environment variables to authenticate with AWS.
echo 'export AWS_ACCESS_KEY_ID=xxxx export AWS_SECRET_ACCESS_KEY=xxxx ' | docker secret create aws -
Changing the Default Labels¶
The service labels targets can be changed by setting the following environmental variables.
| Variable | Description |
|---|---|
| MIN_SCALE_LABEL | Service label key for the minimum number of replicas. Default: com.df.scaleMin |
| MAX_SCALE_LABEL | Service label key for the maximum number of replicas. Default: com.df.scaleMax |
| SCALE_DOWN_BY_LABEL | Service label key for the number of replicas to scale down by. Default: com.df.scaleDownBy |
| SCALE_UP_BY_LABEL | Service label key for the number of replicas to scale up by. Default: com.df.scaleUpBy |
| RESCHEDULE_FILTER_LABEL | Services with this label will be rescheduled after node scaling. Default: com.df.reschedule=true" |
| MIN_SCALE_MANAGER_NODE_LABEL | Service label for the minimum number of manager nodes. Default: com.df.scaleManagerNodeMin |
| MAX_SCALE_MANAGER_NODE_LABEL | Service label for the maximum number of manager nodes. Default: com.df.scaleManagerNodeMax |
| SCALE_MANAGER_NODE_DOWN_BY_LABEL | Service label for the number of manager nodes to scale down by. Default: com.df.scaleManagerNodeDownBy |
| SCALE_MANAGER_NODE_UP_BY_LABEL | Service label for the number of manager nodes to scale up by. Default: com.df.scaleManagerNodeUpBy |
| MIN_SCALE_WORKER_NODE_LABEL | Service label for the minimum number of worker nodes. Default: com.df.scaleWorkerNodeMin |
| MAX_SCALE_WORKER_NODE_LABEL | Service label for the maximum number of worker nodes. Default: com.df.scaleWorkerNodeMax |
| SCALE_WORKER_NODE_DOWN_BY_LABEL | Service label for the number of worker nodes to scale down by. Default: com.df.scaleWorkerNodeDownBy |
| SCALE_WORKER_NODE_UP_BY_LABEL | Service label for the number of worker nodes to scale up by. Default: com.df.scaleWorkerNodeUpBy |