bug: Parameters hidden by default have their values reset to default when unrelated parameter value modified on existing workspace #20257
Description
Is there an existing issue for this?
- I have searched the existing issues
Current Behavior
Reported by customer on ticket 4452.
If a workspace is built from a template which contains a parameter like volume_size which is hidden by default and the user chooses a non default value for the volume_size value (note that mutable = true), then once the workspace is built they attempt to change an unrelated parameter such as instance_type_amd or user_shell the value for volume_size will be reset to the default 300GB value. This results in the workspace then entering a failed state as it cannot shrink the volume. If the volume_size parameter is NOT hidden by default, i.e. count is removed, then the issue does not occur.
Reported by customer running 2.25.3, confirmed still present on 2.26.1 and 2.27.0.
data "coder_parameter" "advanced_opts" {
name = "advanced_opts"
display_name = "Show Advanced Options"
order = 100
form_type = "checkbox"
type = "bool"
mutable = true
default = false
}
data "coder_parameter" "volume_size" {
count = data.coder_parameter.advanced_opts.value == "true" ? 1 : 0
name = "volume_size"
display_name = "Volume Size (GiB)"
description = "Size of the home volume in GiB"
type = "string"
mutable = true
order = 100
form_type = "dropdown"
default = "300"
option {
name = "300 GiB"
value = "300"
}
option {
name = "400 GiB"
value = "400"
}
option {
name = "500 GiB"
value = "500"
}
}
data "coder_parameter" "instance_arch" {
name = "instance_arch"
display_name = "Arch"
description = "Which chip architecture?"
type = "string"
mutable = false
order = 1
form_type = "dropdown"
default = "amd64"
option {
name = "64-bit (x86)"
value = "amd64"
}
option {
name = "64-bit (Arm)"
value = "arm64"
}
}
data "coder_parameter" "instance_type_amd" {
count = data.coder_parameter.instance_arch.value == "amd64" ? 1 : 0
name = "instance_type_amd"
display_name = "Instance Type"
description = "What instance type should your workspace use?"
type = "string"
mutable = true
order = 2
form_type = "dropdown"
default = "c6a.4xlarge"
option {
name = "x86_64 - 8 vCPU, 16 GiB RAM"
value = "c6a.2xlarge"
}
option {
name = "x86_64 - 16 vCPU, 32 GiB RAM"
value = "c6a.4xlarge"
}
option {
name = "x86_64 - 32 vCPU, 64 GiB RAM"
value = "c6a.8xlarge"
}
option {
name = "x86_64 - 32 vCPU, 72 GiB RAM"
value = "c5.9xlarge"
}
}
Screen.Recording.2025-10-10.at.10.23.36.am.mov
Reproduced on MacOS with Chrome and Firefox. No network calls or console errors are observed.
Relevant Log Output
Expected Behavior
Any parameter which is hidden by default is not reset to the default value when an unrelated parameter value is changed.
Steps to Reproduce
- Build a workspace with the template contents shared above, ensuring
volume_sizeis set to a non default value. - Open the workspace settings screen
- Modify the value of an unrelated setting
- Observe the value for
volume_sizeis reset to default value of 300GB
Environment
- Host OS: Kubernetes
- Coder version: 2.25.3, 2.26.1, 2.27.0
Additional Context
The issue occurs consistently, I have tested this on the latest version, The issue happens on multiple deployments