Inject metadata into events.json

- Extract JSON fetching into a separate method, so it can
  follow the same logic as other endpoints.

[#20]

Signed-off-by: Jacques Chester <[email protected]>

README.md

@@ -53,10 +53,12 @@ Will produce a number of files in the resource directory.
 * `job.json`: the Job structure
 * `versioned_resource_types.json`: information about non-core resource types used in the build. This covers things
    added to a pipeline using `resource_types:`, but not core resources like `git-resource`.
-* `events.json`: an array of JSON objects from the Job, based on the eventstream sent to `fly` or the web UI.
+* `events.json`: contains an array of JSON objects based on the eventstream sent to `fly` or the web UI.
 * `events.log`: the rendered logs from the Job, as they would appear in `fly` or the web UI.
 
-Use `events.log` if you just want to slurp text output.
+Use `events.log` if you just want to slurp text output. The `events.json` file is not a literal transcription of
+the eventstream. Instead an object is constructed containing an array of event objects, as well as injected
+metadata.
 
 ### The original resources with information encoded in the filename
 

pkg/in/in.go

@@ -30,6 +30,10 @@ type versionedResourceTypesWrapper struct {
 	VersionedResourceTypes atc.VersionedResourceTypes `json:"versioned_resource_types"`
 }
 
+type eventsWrapper struct {
+	Events []atc.Event `json:"events"`
+}
+
 type inner struct {
 	inRequest              *config.InRequest
 	concourseClient        gc.Client
@@ -40,6 +44,7 @@ type inner struct {
 	plan                   atc.PublicBuildPlan
 	job                    atc.Job
 	versionedResourceTypes versionedResourceTypesWrapper
+	events                 eventsWrapper
 	buildId                int
 }
 
@@ -113,8 +118,25 @@ func (i inner) In() (*config.InResponse, error) {
 		return nil, err
 	}
 
-	// events
-	err = i.writeEventsLogAndJson()
+	// Events need to be fetched twice: once for the .json, once for the .log.
+	// The json follows the same basic logic as other endpoints. The log file however
+	// requires me to use a Concourse package to render it. This has clever EOFing
+	// stuff that I don't feel comfortable trying to reverse engineer, hence the
+	// double-handling of events.
+
+	// events part 1: JSON
+	err = i.getEventsForJson()
+	if err != nil {
+		return nil, err
+	}
+
+	err = i.writeJsonFile("events", i.events)
+	if err != nil {
+		return nil, err
+	}
+
+	// events part 2: rendering to pretty text
+	err = i.getAndWriteRenderedEventLog()
 	if err != nil {
 		return nil, err
 	}
@@ -253,12 +275,36 @@ func (i *inner) getVersionedResourceTypes() error {
 	return nil
 }
 
-// This method is gross because it needs to fetch events twice: once for the .log, once for the .json.
-// This has to do with the clever way events are handled by Concourse and also to do with my unwillingness
-// to completely and properly tease apart a smarter way to do this.
-func (i *inner) writeEventsLogAndJson() error {
-	//////////////////////// Rendered log ////////////////////////
+func (i *inner) getEventsForJson() error {
+	eventsForJsonFile, err := i.concourseClient.BuildEvents(i.inRequest.Version.BuildId)
+	if err != nil && err.Error() == "not authorized" {
+		log.Printf("was unauthorized to fetch events for build '%s', no event JSON will be written.", i.inRequest.Version.BuildId)
+		return nil
+	}
+	if err != nil {
+		return fmt.Errorf("error while fetching events for build '%s': '%s", i.inRequest.Version.BuildId, err.Error())
+	}
+	defer eventsForJsonFile.Close()
+
+	eventsArr := make([]atc.Event, 0)
+	for {
+		ev, err := eventsForJsonFile.NextEvent()
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+
+		eventsArr = append(eventsArr, ev)
+	}
+
+	i.events = eventsWrapper{Events: eventsArr}
+
+	return nil
+}
 
+func (i *inner) getAndWriteRenderedEventLog() error {
 	eventsForLogFile, err := i.concourseClient.BuildEvents(i.inRequest.Version.BuildId)
 	// first, check if we are even authorised
 	if err != nil && err.Error() == "not authorized" {
@@ -291,47 +337,6 @@ func (i *inner) writeEventsLogAndJson() error {
 		return err
 	}
 
-	//////////////////////// JSON ////////////////////////
-
-	eventsForJsonFile, err := i.concourseClient.BuildEvents(i.inRequest.Version.BuildId)
-	defer eventsForJsonFile.Close()
-
-	jsonBuilder := &strings.Builder{}
-	jsonEnc := json.NewEncoder(jsonBuilder)
-	for {
-		ev, err := eventsForJsonFile.NextEvent()
-		if err != nil {
-			if err == io.EOF {
-				break
-			}
-			return err
-		}
-
-		err = jsonEnc.Encode(ev)
-		if err != nil {
-			return err
-		}
-		jsonBuilder.WriteString(",")
-	}
-	jsonStr := fmt.Sprintf("[%s]", strings.TrimSuffix(jsonBuilder.String(), ","))
-	unadornedJsonPath := filepath.Join(i.inRequest.WorkingDirectory, "events.json")
-	err = ioutil.WriteFile(unadornedJsonPath, []byte(jsonStr), os.ModePerm)
-	if err != nil {
-		return err
-	}
-
-	detailedJsonPath := filepath.Join(i.inRequest.WorkingDirectory, fmt.Sprintf("%s.json", i.addDetailedPostfixTo("events")))
-	_, err = fileutils.CopyFile(unadornedJsonPath, detailedJsonPath)
-	if err != nil {
-		return err
-	}
-
-	numberedJsonPath := filepath.Join(i.inRequest.WorkingDirectory, fmt.Sprintf("%s.json", i.addBuildNumberPostfixTo("events")))
-	_, err = fileutils.CopyFile(unadornedJsonPath, numberedJsonPath)
-	if err != nil {
-		return err
-	}
-
 	return nil
 }
 

pkg/in/in_test.go

@@ -162,6 +162,7 @@ func TestInPkg(t *testing.T) {
 					gt.Expect(AFileExistsContaining("build/plan.json", `"concourse_build_resource":{"release":"v0.99.11","git_ref":"abcdef1234567890","get_timestamp":1234567890,"concourse_version":"3.99.11","get_uuid":"96d7128f-bacf-4f60-9ffd-1a9ca4c9e1d7"},`, gt)).To(gomega.BeTrue())
 					gt.Expect(AFileExistsContaining("build/resources.json", `"concourse_build_resource":{"release":"v0.99.11","git_ref":"abcdef1234567890","get_timestamp":1234567890,"concourse_version":"3.99.11","get_uuid":"96d7128f-bacf-4f60-9ffd-1a9ca4c9e1d7"},`, gt)).To(gomega.BeTrue())
 					gt.Expect(AFileExistsContaining("build/job.json", `"concourse_build_resource":{"release":"v0.99.11","git_ref":"abcdef1234567890","get_timestamp":1234567890,"concourse_version":"3.99.11","get_uuid":"96d7128f-bacf-4f60-9ffd-1a9ca4c9e1d7"},`, gt)).To(gomega.BeTrue())
+					gt.Expect(AFileExistsContaining("build/events.json", `"concourse_build_resource":{"release":"v0.99.11","git_ref":"abcdef1234567890","get_timestamp":1234567890,"concourse_version":"3.99.11","get_uuid":"96d7128f-bacf-4f60-9ffd-1a9ca4c9e1d7"},`, gt)).To(gomega.BeTrue())
 				})
 
 				it("writes out a concourse_build_resource_release file", func() {