chore: adds publish data structures (#2564)

Adds data structures for new publish manifest change.

Addresses #2550 

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Author: xar-tol

internal/pkg/manifest/workload.go

@@ -450,6 +450,17 @@ type TaskConfig struct {
 	Storage        *Storage          `yaml:"storage"`
 }
 
+// PublishConfig represents the configurable options for setting up publishers.
+type PublishConfig struct {
+	Topics []Topic `yaml:"topics"`
+}
+
+// Topic represents the configurable options for setting up a SNS Topic.
+type Topic struct {
+	Name           *string  `yaml:"name"`
+	AllowedWorkers []string `yaml:"allowed_workers"`
+}
+
 // NetworkConfig represents options for network connection to AWS resources within a VPC.
 type NetworkConfig struct {
 	VPC *vpcConfig `yaml:"vpc"`

internal/pkg/manifest/workload_test.go

@@ -635,3 +635,63 @@ func TestDependency_UnmarshalYAML(t *testing.T) {
 		})
 	}
 }
+
+func TestUnmarshalPublish(t *testing.T) {
+	testCases := map[string]struct {
+		inContent     string
+		wantedPublish PublishConfig
+		wantedErr     error
+	}{
+		"Valid publish yaml": {
+			inContent: `topics:
+  - name: tests
+    allowed_workers:
+      - hello
+`,
+			wantedPublish: PublishConfig{
+				Topics: []Topic{
+					{
+						Name:           aws.String("tests"),
+						AllowedWorkers: []string{"hello"},
+					},
+				},
+			},
+		},
+		"Empty workers don't appear in topic": {
+			inContent: `topics:
+  - name: tests
+`,
+			wantedPublish: PublishConfig{
+				Topics: []Topic{
+					{
+						Name: aws.String("tests"),
+					},
+				},
+			},
+		},
+		"Error when unmarshalable": {
+			inContent: `topics:
+   - name: tests
+    allowed_workers:
+      - hello
+  - name: orders
+`,
+			wantedErr: errors.New("yaml: line 1: did not find expected '-' indicator"),
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			p := PublishConfig{}
+
+			err := yaml.Unmarshal([]byte(tc.inContent), &p)
+
+			if tc.wantedErr != nil {
+				require.EqualError(t, err, tc.wantedErr.Error())
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, tc.wantedPublish, p)
+			}
+		})
+	}
+}

internal/pkg/template/template_functions.go

@@ -131,3 +131,38 @@ func generateMountPointJSON(mountPoints []*MountPoint) string {
 	return string(out)
 
 }
+
+// generatePublisherJSON turns a list of Topics objects into a JSON string:
+// `{"myTopic": ["hello"], "mySecondTopic": ["hello","goodbye"]}`
+// This function must be called on an array of correctly constructed Topic objects.
+func generatePublishJSON(topics []*Topics) string {
+	publisherMap := make(map[string][]string)
+
+	for _, pb := range topics {
+		if aws.StringValue(pb.Name) == "" {
+			continue
+		}
+		publisherMap[aws.StringValue(pb.Name)] = aws.StringValueSlice(pb.AllowedWorkers)
+	}
+
+	out, ok := getJSONMap(publisherMap)
+	if !ok {
+		return "{}"
+	}
+
+	return string(out)
+}
+
+func getJSONMap(inMap map[string][]string) ([]byte, bool) {
+	// Check for empty maps
+	if len(inMap) == 0 {
+		return nil, false
+	}
+
+	out, err := json.Marshal(inMap)
+	if err != nil {
+		return nil, false
+	}
+
+	return out, true
+}

internal/pkg/template/template_functions_test.go

@@ -237,3 +237,18 @@ func TestGenerateMountPointJSON(t *testing.T) {
 	require.Equal(t, "{}", generateMountPointJSON([]*MountPoint{}), "nil list of arguments should render ")
 	require.Equal(t, "{}", generateMountPointJSON([]*MountPoint{{SourceVolume: aws.String("fromEFS")}}), "empty paths should not get injected")
 }
+
+func TestGeneratePublishJSON(t *testing.T) {
+	require.Equal(t, `{"tests":["testsWorker1","testsWorker2"]}`,
+		generatePublishJSON(
+			[]*Topics{
+				{
+					Name:           aws.String("tests"),
+					AllowedWorkers: aws.StringSlice([]string{"testsWorker1", "testsWorker2"}),
+				},
+			},
+		), "JSON should render correctly")
+
+	require.Equal(t, `{"tests":[]}`, generatePublishJSON([]*Topics{{Name: aws.String("tests")}}), "Topics with no workers show empty list")
+	require.Equal(t, "{}", generatePublishJSON([]*Topics{}), "nil list of arguments should render")
+}

internal/pkg/template/workload.go

@@ -202,6 +202,17 @@ type StateMachineOpts struct {
 	Retries *int
 }
 
+// PublishOpts holds configuration needed if the service has publishers.
+type PublishOpts struct {
+	Topics []*Topics
+}
+
+// Topics holds information needed to render a SNSTopic in a container definition.
+type Topics struct {
+	Name           *string
+	AllowedWorkers []*string
+}
+
 // NetworkOpts holds AWS networking configuration for the workloads.
 type NetworkOpts struct {
 	AssignPublicIP string
@@ -237,6 +248,7 @@ type WorkloadOpts struct {
 	DomainAlias        string
 	DockerLabels       map[string]string
 	DependsOn          map[string]string
+	Publish            *PublishOpts
 
 	// Additional options for service templates.
 	WorkloadType        string
@@ -333,6 +345,7 @@ func withSvcParsingFuncs() ParseOption {
 			"quoteSlice":          QuotePSliceFunc,
 			"randomUUID":          randomUUIDFunc,
 			"jsonMountPoints":     generateMountPointJSON,
+			"jsonPublishers":      generatePublishJSON,
 			"envControllerParams": envControllerParameters,
 		})
 	}