Support signed image metadata

environs/ec2/image.go

 // Copyright 2011, 2012, 2013 Canonical Ltd.
 // Licensed under the AGPLv3, see LICENCE file for details.
 
 package ec2
 
 import (
         "fmt"
         "launchpad.net/juju-core/environs/imagemetadata"
         "launchpad.net/juju-core/environs/instances"
 )
 
 // signedImageDataOnly is defined here to allow tests to override the content.
 // If true, only inline PGP signed image metadata will be used.
 var signedImageDataOnly = true
 
 // defaultCpuPower is larger the smallest instance's cpuPower, and no larger than
 // any other instance type's cpuPower. It is used when no explicit CpuPower
 // constraint exists, preventing the smallest instance from being chosen unless
 // the user has clearly indicated that they are willing to accept poor performance.
 const defaultCpuPower = 100
 
 // findInstanceSpec returns an InstanceSpec satisfying the supplied instanceConstraint.
 func findInstanceSpec(baseURLs []string, ic *instances.InstanceConstraint) (*instances.InstanceSpec, error) {
         if ic.Constraints.CpuPower == nil {
                 ic.Constraints.CpuPower = instances.CpuPower(defaultCpuPower)
         }
         ec2Region := allRegions[ic.Region]
-        imageConstraint := imagemetadata.NewImageConstraint(ic.Region, ec2Region.EC2Endpoint, ic.Series, ic.Arches, "")
-        ebs := ebsStorage
-        imageConstraint.Storage = &ebs
+        imageConstraint := imagemetadata.ImageConstraint{
+                CloudSpec: imagemetadata.CloudSpec{ic.Region, ec2Region.EC2Endpoint},
+                Series:    ic.Series,
+                Arches:    ic.Arches,
+        }
         matchingImages, err := imagemetadata.Fetch(
                 baseURLs, imagemetadata.DefaultIndexPath, &imageConstraint, signedImageDataOnly)
         if err != nil {
                 return nil, err
         }
         var images []instances.Image
         for _, imageMetadata := range matchingImages {
+                // For now, we only want images with "ebs" storage.
+                if imageMetadata.Storage != ebsStorage {
+                        continue
+                }
                 im := *imageMetadata
                 images = append(images, instances.Image{
                         Id:    im.Id,
                         VType: im.VType,
                         Arch:  im.Arch,
                 })
         }
 
         // Make a copy of the known EC2 instance types, filling in the cost for the specified region.
         regionCosts := allRegionCosts[ic.Region]
         if len(regionCosts) == 0 && len(allRegionCosts) > 0 {
                 return nil, fmt.Errorf("no instance types found in %s", ic.Region)
         }
 
         var itypesWithCosts []instances.InstanceType
         for _, itype := range allInstanceTypes {
                 cost, ok := regionCosts[itype.Name]
                 if !ok {
                         continue
                 }
                 itWithCost := itype
                 itWithCost.Cost = cost
                 itypesWithCosts = append(itypesWithCosts, itWithCost)
         }
-        spec, err := instances.FindInstanceSpec(images, ic, itypesWithCosts)
-        if err != nil {
-                return nil, err
-        }
-        return spec, nil
+        return instances.FindInstanceSpec(images, ic, itypesWithCosts)
 }