Merge pull request #74 from ExternalReality/add_domain_request

#74

This PR adds `MAAS 2.0`'s `Domains` endpoint. The only thing one can do with a `Domain` right now is query its name since this is all `Juju` wants from it thus far.

controller.go

@@ -221,6 +221,23 @@ func (c *controller) Zones() ([]Zone, error) {
 	return result, nil
 }
 
+// Domains implements Controller
+func (c *controller) Domains() ([]Domain, error) {
+	source, err := c.get("domains")
+	if err != nil {
+		return nil, NewUnexpectedError(err)
+	}
+	domains, err := readDomains(c.apiVersion, source)
+	if err != nil {
+		return nil, errors.Trace(err)
+	}
+	var result []Domain
+	for _, domain := range domains {
+		result = append(result, domain)
+	}
+	return result, nil
+}
+
 // DevicesArgs is a argument struct for selecting Devices.
 // Only devices that match the specified criteria are returned.
 type DevicesArgs struct {

domain.go

@@ -0,0 +1,85 @@
+// Copyright 2018 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package gomaasapi
+
+import (
+	"github.com/juju/errors"
+	"github.com/juju/schema"
+	"github.com/juju/version"
+)
+
+type domain struct {
+	authoritative       bool
+	resourceRecordCount int
+	ttl                 *int
+	resourceURI         string
+	id                  int
+	name                string
+}
+
+// Name implements Domain interface
+func (domain *domain) Name() string {
+	return domain.name
+}
+
+func readDomains(controllerVersion version.Number, source interface{}) ([]*domain, error) {
+	checker := schema.List(schema.StringMap(schema.Any()))
+	coerced, err := checker.Coerce(source, nil)
+	if err != nil {
+		return nil, errors.Annotatef(err, "domain base schema check failed")
+	}
+	valid := coerced.([]interface{})
+	return readDomainList(valid)
+}
+
+func domain_(source map[string]interface{}) (*domain, error) {
+	fields := schema.Fields{
+		"authoritative":         schema.Bool(),
+		"resource_record_count": schema.ForceInt(),
+		"ttl":          schema.OneOf(schema.Nil("null"), schema.ForceInt()),
+		"resource_uri": schema.String(),
+		"id":           schema.ForceInt(),
+		"name":         schema.String(),
+	}
+	checker := schema.FieldMap(fields, nil) // no defaults
+	coerced, err := checker.Coerce(source, nil)
+	if err != nil {
+		return nil, errors.Annotatef(err, "domain schema check failed")
+	}
+	valid := coerced.(map[string]interface{})
+
+	var ttl *int = nil
+	if valid["ttl"] != nil {
+		i := valid["ttl"].(int)
+		ttl = &i
+	}
+
+	result := &domain{
+		authoritative:       valid["authoritative"].(bool),
+		id:                  valid["id"].(int),
+		name:                valid["name"].(string),
+		resourceRecordCount: valid["resource_record_count"].(int),
+		resourceURI:         valid["resource_uri"].(string),
+		ttl:                 ttl,
+	}
+
+	return result, nil
+}
+
+// readDomainList expects the values of the sourceList to be string maps.
+func readDomainList(sourceList []interface{}) ([]*domain, error) {
+	result := make([]*domain, 0, len(sourceList))
+	for i, value := range sourceList {
+		source, ok := value.(map[string]interface{})
+		if !ok {
+			return nil, errors.Errorf("unexpected value for domain %d, %T", i, value)
+		}
+		domain, err := domain_(source)
+		if err != nil {
+			return nil, errors.Annotatef(err, "domain %d", i)
+		}
+		result = append(result, domain)
+	}
+	return result, nil
+}

domain_test.go

@@ -0,0 +1,46 @@
+// Copyright 2018 Canonical Ltd.
+// Licensed under the LGPLv3, see LICENCE file for details.
+
+package gomaasapi
+
+import (
+	jc "github.com/juju/testing/checkers"
+	gc "gopkg.in/check.v1"
+)
+
+type domainSuite struct{}
+
+var _ = gc.Suite(&domainSuite{})
+
+func (*domainSuite) TestReadDomainsBadSchema(c *gc.C) {
+	_, err := readDomains(twoDotOh, "something")
+	c.Assert(err.Error(), gc.Equals, `domain base schema check failed: expected list, got string("something")`)
+}
+
+func (*domainSuite) TestReadDomains(c *gc.C) {
+	domains, err := readDomains(twoDotOh, parseJSON(c, domainResponse))
+	c.Assert(err, jc.ErrorIsNil)
+	c.Assert(domains, gc.HasLen, 2)
+	c.Assert(domains[0].Name(), gc.Equals, "maas")
+	c.Assert(domains[1].Name(), gc.Equals, "anotherDomain.com")
+}
+
+var domainResponse = `
+[
+    {
+        "authoritative": "true",
+        "resource_uri": "/MAAS/api/2.0/domains/0/",
+        "name": "maas",
+        "id": 0,
+        "ttl": null,
+        "resource_record_count": 3
+    }, {
+        "authoritative": "true",
+        "resource_uri": "/MAAS/api/2.0/domains/1/",
+        "name": "anotherDomain.com",
+        "id": 1,
+        "ttl": 10,
+        "resource_record_count": 3
+    }
+]
+`

interfaces.go

@@ -66,6 +66,9 @@ type Controller interface {
 	// file without sending the content of the file, we can return a File
 	// instance here too.
 	AddFile(AddFileArgs) error
+
+	// Returns the DNS Domain Managed By MAAS
+	Domains() ([]Domain, error)
 }
 
 // File represents a file stored in the MAAS controller.
@@ -142,6 +145,11 @@ type Zone interface {
 	Description() string
 }
 
+type Domain interface {
+	// The name of the Domain
+	Name() string
+}
+
 // BootResource is the bomb... find something to say here.
 type BootResource interface {
 	ID() int