Add clearer error for VPP token constraint failure

changes/21890-vpp-token-error

@@ -0,0 +1 @@
+- Improve messaging for VPP token constraint errors

server/datastore/mysql/vpp.go

@@ -16,6 +16,7 @@ import (
 	"github.com/fleetdm/fleet/v4/server/contexts/ctxerr"
 	"github.com/fleetdm/fleet/v4/server/fleet"
 	"github.com/fleetdm/fleet/v4/server/mdm/nanomdm/mdm"
+	"github.com/go-sql-driver/mysql"
 	"github.com/jmoiron/sqlx"
 )
 
@@ -780,6 +781,7 @@ TEAMLOOP:
 }
 
 func (ds *Datastore) UpdateVPPTokenTeams(ctx context.Context, id uint, teams []uint) (*fleet.VPPTokenDB, error) {
+	stmtTeamName := `SELECT name FROM teams WHERE id = ?`
 	stmtRemove := `DELETE FROM vpp_token_teams WHERE vpp_token_id = ?`
 	stmtInsert := `
 	INSERT INTO
@@ -858,6 +860,17 @@ func (ds *Datastore) UpdateVPPTokenTeams(ctx context.Context, id uint, teams []u
 	})
 
 	if err != nil {
+		var mysqlErr *mysql.MySQLError
+		// https://dev.mysql.com/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_dup_entry
+		if errors.As(err, &mysqlErr) && IsDuplicate(err) {
+			var dupeTeamID uint
+			var dupeTeamName string
+			fmt.Sscanf(mysqlErr.Message, "Duplicate entry '%d' for", &dupeTeamID)
+			if err := sqlx.GetContext(ctx, ds.reader(ctx), &dupeTeamName, stmtTeamName, dupeTeamID); err != nil {
+				return nil, ctxerr.Wrap(ctx, err, "getting team name for vpp token conflict error")
+			}
+			return nil, ctxerr.Wrap(ctx, fleet.ErrVPPTokenTeamConstraint{Name: dupeTeamName, ID: &dupeTeamID})
+		}
 		return nil, ctxerr.Wrap(ctx, err, "modifying vpp token team associations")
 	}
 
@@ -1127,7 +1140,7 @@ func checkVPPNullTeam(ctx context.Context, tx sqlx.ExtContext, currentID *uint,
 	}
 
 	if allTeamsFound && currentID != nil && *currentID != id {
-		return ctxerr.Wrap(ctx, errors.New("All teams token already exists"))
+		return ctxerr.Wrap(ctx, fleet.ErrVPPTokenTeamConstraint{Name: fleet.ReservedNameAllTeams})
 	}
 
 	if nullTeam != fleet.NullTeamNone {
@@ -1139,7 +1152,7 @@ func checkVPPNullTeam(ctx context.Context, tx sqlx.ExtContext, currentID *uint,
 			return ctxerr.Wrap(ctx, err, "scanning row in check vpp token null team")
 		}
 		if currentID == nil || *currentID != id {
-			return ctxerr.Errorf(ctx, "vpp token for team %s already exists", nullTeam)
+			return ctxerr.Wrap(ctx, fleet.ErrVPPTokenTeamConstraint{Name: nullTeam.PrettyName()})
 		}
 	}
 

server/datastore/mysql/vpp_test.go

@@ -981,8 +981,10 @@ func testVPPTokensCRUD(t *testing.T, ds *Datastore) {
 	assert.Error(t, err)
 	_, err = ds.UpdateVPPTokenTeams(ctx, tokBadConstraint.ID, []uint{team.ID})
 	assert.Error(t, err)
+	assert.ErrorContains(t, err, "\"Kritters\" team already has a VPP token.")
 	_, err = ds.UpdateVPPTokenTeams(ctx, tokBadConstraint.ID, []uint{0})
 	assert.Error(t, err)
+	assert.ErrorContains(t, err, "\"No team\" team already has a VPP token.")
 
 	toks, err = ds.ListVPPTokens(ctx)
 	assert.NoError(t, err)

server/fleet/mdm.go

@@ -801,6 +801,17 @@ const (
 	NullTeamNoTeam NullTeamType = "noteam"
 )
 
+func (n NullTeamType) PrettyName() string {
+	switch n {
+	case NullTeamAllTeams:
+		return ReservedNameAllTeams
+	case NullTeamNoTeam:
+		return ReservedNameNoTeam
+	default:
+		return string(n)
+	}
+}
+
 type AppleDevice int
 
 const (

server/fleet/vpp.go

@@ -1,6 +1,7 @@
 package fleet
 
 import (
+	"fmt"
 	"time"
 )
 
@@ -67,3 +68,12 @@ type VPPAppStatusSummary struct {
 	// Failed is the number of hosts that have the VPP app installation failed.
 	Failed uint `json:"failed" db:"failed"`
 }
+
+type ErrVPPTokenTeamConstraint struct {
+	Name string
+	ID   *uint
+}
+
+func (e ErrVPPTokenTeamConstraint) Error() string {
+	return fmt.Sprintf("Error: %q team already has a VPP token. Each team can only have one VPP token.", e.Name)
+}

server/service/appconfig.go

@@ -557,6 +557,10 @@ func (svc *Service) ModifyAppConfig(ctx context.Context, p []byte, applyOpts fle
 	if appConfig.MDM.VolumePurchasingProgram.Set && appConfig.MDM.VolumePurchasingProgram.Valid {
 		for tokenID, tokenTeams := range vppAssignments {
 			if _, err := svc.ds.UpdateVPPTokenTeams(ctx, tokenID, tokenTeams); err != nil {
+				var errTokConstraint fleet.ErrVPPTokenTeamConstraint
+				if errors.As(err, &errTokConstraint) {
+					return nil, ctxerr.Wrap(ctx, fleet.NewUserMessageError(errTokConstraint, http.StatusConflict))
+				}
 				return nil, ctxerr.Wrap(ctx, err, "saving ABM token assignments")
 			}
 		}