I guess the hyperv isolation mode should also be exposed in toml config (@profnandaa @gabriel-samfira)

I guess the hyperv isolation mode should also be exposed in toml config

Should moby's Isolation type introduced into buildkit?

// Isolation modes for containers
const (
	IsolationEmpty   Isolation = ""        // IsolationEmpty is unspecified (same behavior as default)
	IsolationDefault Isolation = "default" // IsolationDefault is the default isolation mode on current daemon
	IsolationProcess Isolation = "process" // IsolationProcess is process isolation mode
	IsolationHyperV  Isolation = "hyperv"  // IsolationHyperV is HyperV isolation mode
)

I think I'd prefer if we add bool for hyperv isolation instead

I initially modified moby's vendor buildkit package to pass daemon's isolation type to buildkit executor, which just works like the boolean way, but with some more info (isolation mode string vs boolean).

However, since buildkit repository itself does not include github.com/moby/moby as dependency, if we want to introduce Isolation type we may find some other way.

Iiuc then in the containerd/oci level this is just passed with WithWindowsHyperV so looks like a bool to me. If moby has some extra definition for IsolationDefault then that can be left at moby side.

Isolation is a type with some test methods:

// Isolation represents the isolation technology of a container. The supported
// values are platform specific
type Isolation string

// Isolation modes for containers
const (
	IsolationEmpty   Isolation = ""        // IsolationEmpty is unspecified (same behavior as default)
	IsolationDefault Isolation = "default" // IsolationDefault is the default isolation mode on current daemon
	IsolationProcess Isolation = "process" // IsolationProcess is process isolation mode
	IsolationHyperV  Isolation = "hyperv"  // IsolationHyperV is HyperV isolation mode
)

// IsDefault indicates the default isolation technology of a container. On Linux this
// is the native driver. On Windows, this is a Windows Server Container.
func (i Isolation) IsDefault() bool {
	// TODO consider making isolation-mode strict (case-sensitive)
	v := Isolation(strings.ToLower(string(i)))
	return v == IsolationDefault || v == IsolationEmpty
}

// IsHyperV indicates the use of a Hyper-V partition for isolation
func (i Isolation) IsHyperV() bool {
	// TODO consider making isolation-mode strict (case-sensitive)
	return Isolation(strings.ToLower(string(i))) == IsolationHyperV
}

// IsProcess indicates the use of process isolation
func (i Isolation) IsProcess() bool {
	// TODO consider making isolation-mode strict (case-sensitive)
	return Isolation(strings.ToLower(string(i))) == IsolationProcess
}

IsolationDefault is only used in container creation that indicates daemon's default isolation mode should be used:
https://github.com/moby/moby/blob/af6d59ea486757853663bd1436d4c04dd549486f/daemon/create_windows.go#L15-L18

	if containertypes.Isolation.IsDefault(hostConfig.Isolation) {
		// Make sure the host config has the default daemon isolation if not specified by caller.
		hostConfig.Isolation = daemon.defaultIsolation
	}

In daemon's isolation mode there's only process and hyperv.

We shouldn't care about the extra wrapping or type definitions in Moby. If this is a bool in containerd then we should have a bool as well. We don't need to invent extra logic for this capability, just pass the value to containerd libs.

We shouldn't care about the extra wrapping or type definitions in Moby. If this is a bool in containerd then we should have a bool as well. We don't need to invent extra logic for this capability, just pass the value to containerd libs.

containerd uses a --isolated flag to enable Hyper-V mode in its ctr command. According to it I've opened another PR #6224 for isolation option implementation.