Dogscaler was written to scale up autoscale groups based on the results of a datadog query.
Installation is easy just as any other gem:
gem install dogscaler
Within datadog, you need to generate an application key and also include your api key. You can find this information from Integrations -> Api
Create a set of credentials in IAM and give them access to: Autoscale -> DescribeAutoscaleGroups and Autoscale -> UpdateAutoscaleGroups
These permissions are used to lookup autoscale groups, check their size and updated the desired number of instances.
Create a dogscaler.yaml file with contents like:
datadog:
api_key: <KEYHERE>
application_key: <KEYHERE>
aws:
region: 'us-west-2'
profile: 'main' # This expects a .aws/credentials file with a section matching this name
slack:
channel: '#production'
api_token: 'token_here'
instances:
'mailer_prod':
queries:
- name: unsent_invites
query: max:mail.db.v3.unsent_invitations{*}
scale_up_threshhold: 1500
scale_down_threshhold: 20
transform: avg
- name: mailer load
query: avg:system.cpu.user{env:production,type:mailer}
scale_up_threshhold: 75
scale_down_threshhold: 20
transform: avg
asg_tag_filters:
Type: mailer
Environment: production
grow_by: 1
shrink_by: 1
cooldown_period: 240
'web_prod':
queries:
- name: web load
query: avg:system.cpu.user{env:production,type:web}
scale_up_threshhold: 75
scale_down_threshhold: 20
transform: avg
asg_tag_filters:
Type: web
Environment: production
grow_by: 2
shrink_by: 1
cooldown_period: 240
Below are some simple examples
Help output:
dogscaler help
Commands:
dogscaler apply # Scale the environment based on a query
dogscaler config # Generate a default configuration
dogscaler debug # testing command, describes the query it ran and the results
dogscaler help [COMMAND] # Describe available commands or one specific command
Options:
d, [--debug=Enable debug mode], [--no-debug]
r, [--region=AWS Region]
# Default: us-west-2
v, [--verbose=Verbose Output], [--no-verbose]
t, [--terse=Terse Output], [--no-terse]
[--dryrun=Do a dry run], [--no-dryrun]
[--config=Path to configuration file]The basic example - Apply the configuration.
$ dogscaler apply --config dogscaler.yaml
Test the configuration without making changes, with verbose output:
$ dogscaler apply --dryrun -v --config dogscaler.yaml
INFO -- : Value: 147.01052631578946 Threshold: 75.
INFO -- : Would scale up by 2 instances.
INFO -- : Value: 147.01052631578946 Threshold: 75.
INFO -- : Would scale up by 2 instances.
INFO -- : Updating autoscale group production
INFO -- : From current capacity: 1 to: 2
INFO -- : Not updating due to dry run mode
INFO -- : Value: 3.0 Threshold: 5.
INFO -- : Would scale down by 1 instances.
INFO -- : Would have reduced capacity of production-web but already at minimum.
INFO -- : Current desired: 3
INFO -- : Current min: 3And then in slack you'll see:
