[core] Improve logging in constraint.Attributes

Author: teo

core/scheduler.go

@@ -406,8 +406,9 @@ func resourceOffers(state *internalState, fidStore store.Singleton) events.Handl
 								    "constraints": descriptorConstraints[descriptor],
 								    "offerId": offer.ID.Value,
 								    "resources": remainingResources.String(),
+								    "attributes": offerAttributes.String(),
 								}).
-								Warn("descriptor constraints not satisfied by offer")
+								Warn("descriptor constraints not satisfied by offer attributes")
 						}
 						continue
 					}

core/task/constraint/attributes.go

@@ -24,10 +24,26 @@
 
 package constraint
 
-import "github.com/mesos/mesos-go/api/v1/lib"
+import (
+	"fmt"
+	"strings"
+
+	"github.com/mesos/mesos-go/api/v1/lib"
+)
 
 type Attributes []mesos.Attribute
 
+func (attrs Attributes) String() string {
+	if attrs == nil {
+		return "[]"
+	}
+	strs := make([]string, len(attrs))
+	for i, attr := range attrs {
+		strs[i] = attr.String()
+	}
+	return fmt.Sprintf("[%s]", strings.Join(strs, "; "))
+}
+
 func (attrs Attributes) Get(attributeName string) (value string, ok bool) {
 	for _, a := range attrs {
 		if a.Name == attributeName {

core/task/constraint/constraints.go

@@ -81,7 +81,7 @@ func (cts Constraints) String() string {
 	for i, ct := range cts {
 		strs[i] = ct.String()
 	}
-	return fmt.Sprintf("[%s]", strings.Join(strs, ", "))
+	return fmt.Sprintf("[%s]", strings.Join(strs, "; "))
 }
 
 func (cts Constraints) MergeParent(parentConstraints Constraints) (merged Constraints) {