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>
* coder list: adds information about next start / stop to available columns (not default)
* coder schedule: show now essentially coder list with a different set of columns
* Updates cli schedule unit tests to use new dbfake
Co-authored-by: Mathias Fredriksson <mafredri@gmail.com>
This removes an indirect import of `coderd/database` from the CLI and
results in a logical separation between server related and generalized
schedule.
No size change (yet).
Ref: #9380
