feat: add AgentAPI using DRPC (#10811)

Co-authored-by: Spike Curtis <spike@coder.com>

coderd/agentapi/apps.go

@@ -0,0 +1,98 @@
+package agentapi
+
+import (
+	"context"
+
+	"github.com/google/uuid"
+	"golang.org/x/xerrors"
+
+	"cdr.dev/slog"
+	agentproto "github.com/coder/coder/v2/agent/proto"
+	"github.com/coder/coder/v2/coderd/database"
+)
+
+type AppsAPI struct {
+	AgentFn                  func(context.Context) (database.WorkspaceAgent, error)
+	Database                 database.Store
+	Log                      slog.Logger
+	PublishWorkspaceUpdateFn func(context.Context, *database.WorkspaceAgent) error
+}
+
+func (a *AppsAPI) BatchUpdateAppHealths(ctx context.Context, req *agentproto.BatchUpdateAppHealthRequest) (*agentproto.BatchUpdateAppHealthResponse, error) {
+	workspaceAgent, err := a.AgentFn(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(req.Updates) == 0 {
+		return &agentproto.BatchUpdateAppHealthResponse{}, nil
+	}
+
+	apps, err := a.Database.GetWorkspaceAppsByAgentID(ctx, workspaceAgent.ID)
+	if err != nil {
+		return nil, xerrors.Errorf("get workspace apps by agent ID %q: %w", workspaceAgent.ID, err)
+	}
+
+	var newApps []database.WorkspaceApp
+	for _, update := range req.Updates {
+		updateID, err := uuid.FromBytes(update.Id)
+		if err != nil {
+			return nil, xerrors.Errorf("parse workspace app ID %q: %w", update.Id, err)
+		}
+
+		old := func() *database.WorkspaceApp {
+			for _, app := range apps {
+				if app.ID == updateID {
+					return &app
+				}
+			}
+
+			return nil
+		}()
+		if old == nil {
+			return nil, xerrors.Errorf("workspace app ID %q not found", updateID)
+		}
+
+		if old.HealthcheckUrl == "" {
+			return nil, xerrors.Errorf("workspace app %q (%q) does not have healthchecks enabled", updateID, old.Slug)
+		}
+
+		var newHealth database.WorkspaceAppHealth
+		switch update.Health {
+		case agentproto.AppHealth_DISABLED:
+			newHealth = database.WorkspaceAppHealthDisabled
+		case agentproto.AppHealth_INITIALIZING:
+			newHealth = database.WorkspaceAppHealthInitializing
+		case agentproto.AppHealth_HEALTHY:
+			newHealth = database.WorkspaceAppHealthHealthy
+		case agentproto.AppHealth_UNHEALTHY:
+			newHealth = database.WorkspaceAppHealthUnhealthy
+		default:
+			return nil, xerrors.Errorf("unknown health status %q for app %q (%q)", update.Health, updateID, old.Slug)
+		}
+
+		// Don't bother updating if the value hasn't changed.
+		if old.Health == newHealth {
+			continue
+		}
+		old.Health = newHealth
+
+		newApps = append(newApps, *old)
+	}
+
+	for _, app := range newApps {
+		err = a.Database.UpdateWorkspaceAppHealthByID(ctx, database.UpdateWorkspaceAppHealthByIDParams{
+			ID:     app.ID,
+			Health: app.Health,
+		})
+		if err != nil {
+			return nil, xerrors.Errorf("update workspace app health for app %q (%q): %w", err, app.ID, app.Slug)
+		}
+	}
+
+	err = a.PublishWorkspaceUpdateFn(ctx, &workspaceAgent)
+	if err != nil {
+		return nil, xerrors.Errorf("publish workspace update: %w", err)
+	}
+	return &agentproto.BatchUpdateAppHealthResponse{}, nil
+}