X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/5836e576fe0b78c50383cf56e1c4fb4521daeca1..73ad2ee9af3b97c46293bdfc9e2925a67726b786:/lib/dispatchcloud/node_size.go

diff --git a/lib/dispatchcloud/node_size.go b/lib/dispatchcloud/node_size.go
index f145901c32..b5fd0262a8 100644
--- a/lib/dispatchcloud/node_size.go
+++ b/lib/dispatchcloud/node_size.go
@@ -8,6 +8,7 @@ import (
 	"errors"
 	"log"
 	"os/exec"
+	"sort"
 	"strings"
 	"time"
 
@@ -15,11 +16,17 @@ import (
 )
 
 var (
-	ErrConstraintsNotSatisfiable  = errors.New("constraints not satisfiable by any configured instance type")
 	ErrInstanceTypesNotConfigured = errors.New("site configuration does not list any instance types")
 	discountConfiguredRAMPercent  = 5
 )
 
+// ConstraintsNotSatisfiableError includes a list of available instance types
+// to be reported back to the user.
+type ConstraintsNotSatisfiableError struct {
+	error
+	AvailableTypes []arvados.InstanceType
+}
+
 // ChooseInstanceType returns the cheapest available
 // arvados.InstanceType big enough to run ctr.
 func ChooseInstanceType(cc *arvados.Cluster, ctr *arvados.Container) (best arvados.InstanceType, err error) {
@@ -40,7 +47,15 @@ func ChooseInstanceType(cc *arvados.Cluster, ctr *arvados.Container) (best arvad
 	needRAM := ctr.RuntimeConstraints.RAM + ctr.RuntimeConstraints.KeepCacheRAM
 	needRAM = (needRAM * 100) / int64(100-discountConfiguredRAMPercent)
 
-	err = ErrConstraintsNotSatisfiable
+	availableTypes := make([]arvados.InstanceType, len(cc.InstanceTypes))
+	copy(availableTypes, cc.InstanceTypes)
+	sort.Slice(availableTypes, func(a, b int) bool {
+		return availableTypes[a].Price < availableTypes[b].Price
+	})
+	err = ConstraintsNotSatisfiableError{
+		errors.New("constraints not satisfiable by any configured instance type"),
+		availableTypes,
+	}
 	for _, it := range cc.InstanceTypes {
 		switch {
 		case err == nil && it.Price > best.Price: