refactor: separate workload class from placement driver

internal/runnerbootstrap/bootstrap.go

@@ -13,12 +13,13 @@ import (
 )
 
 const (
-	EnvAssignmentID = "CI_ASSIGNMENT_ID"
-	EnvCapability   = "CI_RUNNER_CAPABILITY"
-	EnvFacadeURL    = "CI_RUNNER_FACADE_URL"
-	EnvFacadeID     = "CI_RUNNER_FACADE_SPIFFE_ID"
-	EnvSPIFFEID     = "CI_SPIFFE_ID"
-	EnvBackend      = "CI_RUNNER_BACKEND"
+	EnvAssignmentID  = "CI_ASSIGNMENT_ID"
+	EnvCapability    = "CI_RUNNER_CAPABILITY"
+	EnvFacadeURL     = "CI_RUNNER_FACADE_URL"
+	EnvFacadeID      = "CI_RUNNER_FACADE_SPIFFE_ID"
+	EnvSPIFFEID      = "CI_SPIFFE_ID"
+	EnvWorkloadClass = "CI_WORKLOAD_CLASS"
+	EnvDriver        = "CI_WORKLOAD_DRIVER"
 )
 
 // Bootstrap emits assignment-scoped launch configuration. FacadeURL is the
@@ -48,7 +49,8 @@ func (b Bootstrap) Environment(assignment taskassignment.Assignment) (map[string
 		EnvFacadeURL:             b.FacadeURL,
 		EnvFacadeID:              b.FacadeSPIFFEID,
 		EnvSPIFFEID:              assignment.Identity.SPIFFEID,
-		EnvBackend:               string(assignment.Backend),
+		EnvWorkloadClass:         string(assignment.Placement.Class),
+		EnvDriver:                string(assignment.Placement.Driver),
 		"SPIFFE_ENDPOINT_SOCKET": b.WorkloadAPIAddr,
 	}, nil
 }
@@ -67,7 +69,7 @@ type Registration struct {
 	Ephemeral bool     `json:"ephemeral"`
 }
 
-func RegistrationJSON(assignmentID, capability, localProxyURL string, backend taskassignment.Backend) ([]byte, error) {
+func RegistrationJSON(assignmentID, capability, localProxyURL string, placement taskassignment.Placement) ([]byte, error) {
 	if assignmentID == "" || capability == "" {
 		return nil, errors.New("assignment ID and runner capability are required")
 	}
@@ -75,13 +77,13 @@ func RegistrationJSON(assignmentID, capability, localProxyURL string, backend ta
 	if err != nil || parsed.Scheme != "http" || parsed.Host == "" {
 		return nil, errors.New("local runner proxy URL must be an absolute http URL")
 	}
-	if backend != taskassignment.BackendPod && backend != taskassignment.BackendVM {
-		return nil, fmt.Errorf("unsupported runner backend %q", backend)
+	if err := placement.Validate(); err != nil {
+		return nil, err
 	}
 	registration := Registration{
 		Warning: "Generated for one preassigned task by gitea-dynamic-runner.",
 		UUID:    assignmentID, Name: assignmentID, Token: capability,
-		Address: localProxyURL, Labels: []string{"self-hosted", string(backend)}, Ephemeral: true,
+		Address: localProxyURL, Labels: []string{"self-hosted", string(placement.Class), string(placement.Driver)}, Ephemeral: true,
 	}
 	data, err := json.MarshalIndent(registration, "", "  ")
 	if err != nil {