synced/coder
1
0
Fork 0
mirror of https://github.com/coder/coder.git synced 2025-07-03 16:13:58 +00:00
Code Issues Packages Projects Releases Wiki Activity

feat: implement scheduling mechanism for prebuilds (#18126)

Browse Source 
Closes https://github.com/coder/internal/issues/312
Depends on https://github.com/coder/terraform-provider-coder/pull/408

This PR adds support for defining an **autoscaling block** for
prebuilds, allowing number of desired instances to scale dynamically
based on a schedule.

Example usage:
```
data "coder_workspace_preset" "us-nix" {
  ...
  
  prebuilds = {
    instances = 0                  # default to 0 instances
    
    scheduling = {
      timezone = "UTC"             # a single timezone is used for simplicity
      
      # Scale to 3 instances during the work week
      schedule {
        cron = "* 8-18 * * 1-5"    # from 8AM–6:59PM, Mon–Fri, UTC
        instances = 3              # scale to 3 instances
      }
      
      # Scale to 1 instance on Saturdays for urgent support queries
      schedule {
        cron = "* 8-14 * * 6"      # from 8AM–2:59PM, Sat, UTC
        instances = 1              # scale to 1 instance
      }
    }
  }
}
```

### Behavior
- Multiple `schedule` blocks per `prebuilds` block are supported.
- If the current time matches any defined autoscaling schedule, the
corresponding number of instances is used.
- If no schedule matches, the **default instance count**
(`prebuilds.instances`) is used as a fallback.

### Why
This feature allows prebuild instance capacity to adapt to predictable
usage patterns, such as:
- Scaling up during business hours or high-demand periods
- Reducing capacity during off-hours to save resources

### Cron specification
The cron specification is interpreted as a **continuous time range.**

For example, the expression:

```
* 9-18 * * 1-5
```

is intended to represent a continuous range from **09:00 to 18:59**,
Monday through Friday.

However, due to minor implementation imprecision, it is currently
interpreted as a range from **08:59:00 to 18:58:59**, Monday through
Friday.

This slight discrepancy arises because the evaluation is based on
whether a specific **point in time** falls within the range, using the
`github.com/coder/coder/v2/coderd/schedule/cron` library, which performs
per-minute matching rather than strict range evaluation.

---------

Co-authored-by: Danny Kopping <danny@coder.com>
This commit is contained in:
Yevhenii Shcherbina
2025-06-19 11:08:48 -04:00
committed by GitHub
parent 511fd09582
commit 0f6ca55238
38 changed files with 2528 additions and 871 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
coderd/database/foreign_key_constraint.go
View File

@ -45,6 +45,7 @@ const (
ForeignKeyTailnetTunnelsCoordinatorID ForeignKeyConstraint = "tailnet_tunnels_coordinator_id_fkey" // ALTER TABLE ONLY tailnet_tunnels ADD CONSTRAINT tailnet_tunnels_coordinator_id_fkey FOREIGN KEY (coordinator_id) REFERENCES tailnet_coordinators(id) ON DELETE CASCADE;
ForeignKeyTemplateVersionParametersTemplateVersionID ForeignKeyConstraint = "template_version_parameters_template_version_id_fkey" // ALTER TABLE ONLY template_version_parameters ADD CONSTRAINT template_version_parameters_template_version_id_fkey FOREIGN KEY (template_version_id) REFERENCES template_versions(id) ON DELETE CASCADE;
ForeignKeyTemplateVersionPresetParametTemplateVersionPresetID ForeignKeyConstraint = "template_version_preset_paramet_template_version_preset_id_fkey" // ALTER TABLE ONLY template_version_preset_parameters ADD CONSTRAINT template_version_preset_paramet_template_version_preset_id_fkey FOREIGN KEY (template_version_preset_id) REFERENCES template_version_presets(id) ON DELETE CASCADE;
ForeignKeyTemplateVersionPresetPrebuildSchedulesPresetID ForeignKeyConstraint = "template_version_preset_prebuild_schedules_preset_id_fkey" // ALTER TABLE ONLY template_version_preset_prebuild_schedules ADD CONSTRAINT template_version_preset_prebuild_schedules_preset_id_fkey FOREIGN KEY (preset_id) REFERENCES template_version_presets(id) ON DELETE CASCADE;
ForeignKeyTemplateVersionPresetsTemplateVersionID ForeignKeyConstraint = "template_version_presets_template_version_id_fkey" // ALTER TABLE ONLY template_version_presets ADD CONSTRAINT template_version_presets_template_version_id_fkey FOREIGN KEY (template_version_id) REFERENCES template_versions(id) ON DELETE CASCADE;
ForeignKeyTemplateVersionTerraformValuesCachedModuleFiles ForeignKeyConstraint = "template_version_terraform_values_cached_module_files_fkey" // ALTER TABLE ONLY template_version_terraform_values ADD CONSTRAINT template_version_terraform_values_cached_module_files_fkey FOREIGN KEY (cached_module_files) REFERENCES files(id);
ForeignKeyTemplateVersionTerraformValuesTemplateVersionID ForeignKeyConstraint = "template_version_terraform_values_template_version_id_fkey" // ALTER TABLE ONLY template_version_terraform_values ADD CONSTRAINT template_version_terraform_values_template_version_id_fkey FOREIGN KEY (template_version_id) REFERENCES template_versions(id) ON DELETE CASCADE;