Load previous mixin feed data when generating

pkg/mixin/feed/feed.go

@@ -23,6 +23,7 @@ type MixinFeed struct {
 
 func NewMixinFeed(cxt *context.Context) *MixinFeed {
 	return &MixinFeed{
+		Index: make(map[string]map[string]*MixinFileset),
 		Context:cxt,
 	}
 }
@@ -39,7 +40,7 @@ func (feed *MixinFeed) Search(mixin string, version string) *MixinFileset {
 type MixinFileset struct {
 	Mixin   string
 	Version string
-	Files   []MixinFile
+	Files   []*MixinFile
 }
 
 func (f *MixinFileset) FindDownloadURL(os string, arch string) *url.URL {

pkg/mixin/feed/generate.go

@@ -53,9 +53,20 @@ func (o *GenerateOptions) ValidateTemplateFile(cxt *context.Context) error {
 }
 
 func (feed *MixinFeed) Generate(opts GenerateOptions) error {
+	// Check if the atom file already exists, and load in the existing data first
+	existingFeed, err := feed.FileSystem.Exists(opts.AtomFile)
+	if err != nil {
+		return err
+	}
+	if existingFeed {
+		err := feed.Load(opts.AtomFile)
+		if err != nil {
+			return err
+		}
+	}
+
 	mixinRegex := regexp.MustCompile(`(.*/)?(.+)/([a-z]+)-(linux|windows|darwin)-(amd64)(\.exe)?`)
 
-	feed.Index = make(map[string]map[string]*MixinFileset)
 	return feed.FileSystem.Walk(opts.SearchDirectory, func(path string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err
@@ -66,6 +77,7 @@ func (feed *MixinFeed) Generate(opts GenerateOptions) error {
 			version := matches[2]
 			mixin := matches[3]
 			filename := info.Name()
+			updated := info.ModTime()
 
 			versions, ok := feed.Index[mixin]
 			if !ok {
@@ -81,7 +93,17 @@ func (feed *MixinFeed) Generate(opts GenerateOptions) error {
 				}
 				versions[version] = fileset
 			}
-			fileset.Files = append(fileset.Files, MixinFile{File: filename, Updated: info.ModTime()})
+
+			// Check if the file is already in the feed
+			for _, file := range fileset.Files {
+				// The file is already in the feed, bump the timestamp and move on
+				if file.File == filename && file.Updated.After(updated) {
+					file.Updated = updated
+					return nil
+				}
+			}
+			// Add the file to the feed's index
+			fileset.Files = append(fileset.Files, &MixinFile{File: filename, Updated: updated})
 		}
 
 		return nil
@@ -105,6 +127,8 @@ func (feed *MixinFeed) Save(opts GenerateOptions) error {
 	}
 	sort.Sort(sort.Reverse(entries))
 
+	sort.Strings(mixins)
+
 	tmplData["Mixins"] = mixins
 	tmplData["Entries"] = entries
 	tmplData["Updated"] = entries[0].Updated()

pkg/mixin/feed/generate_test.go

@@ -66,24 +66,60 @@ func TestGenerate(t *testing.T) {
 	assert.Equal(t, wantXml, gotXml)
 }
 
+func TestGenerate_ExistingFeed(t *testing.T) {
+	tc := context.NewTestContext(t)
+	tc.AddTestFile("testdata/atom-template.xml", "template.xml")
+	tc.AddTestFile("testdata/atom-existing.xml", "atom.xml")
+
+	tc.FileSystem.Create("bin/v1.2.4/helm-darwin-amd64")
+	tc.FileSystem.Create("bin/v1.2.4/helm-linux-amd64")
+	tc.FileSystem.Create("bin/v1.2.4/helm-windows-amd64.exe")
+
+	up4, _ := time.Parse("2006-Jan-02", "2013-Feb-04")
+	tc.FileSystem.Chtimes("bin/v1.2.4/helm-darwin-amd64", up4, up4)
+	tc.FileSystem.Chtimes("bin/v1.2.4/helm-linux-amd64", up4, up4)
+	tc.FileSystem.Chtimes("bin/v1.2.4/helm-windows-amd64.exe", up4, up4)
+
+	opts := GenerateOptions{
+		AtomFile:        "atom.xml",
+		SearchDirectory: "bin",
+		TemplateFile:    "template.xml",
+	}
+	f := NewMixinFeed(tc.Context)
+	err := f.Generate(opts)
+	require.NoError(t, err)
+	err = f.Save(opts)
+	require.NoError(t, err)
+
+	b, err := tc.FileSystem.ReadFile("atom.xml")
+	require.NoError(t, err)
+	gotXml := string(b)
+
+	b, err = ioutil.ReadFile("testdata/atom.xml")
+	require.NoError(t, err)
+	wantXml := string(b)
+
+	assert.Equal(t, wantXml, gotXml)
+}
+
 func TestMixinEntries_Sort(t *testing.T) {
 	up2, _ := time.Parse("2006-Jan-02", "2013-Feb-02")
 	up3, _ := time.Parse("2006-Jan-02", "2013-Feb-03")
 	up4, _ := time.Parse("2006-Jan-02", "2013-Feb-04")
 
 	entries := MixinEntries{
 		{
-			Files: []MixinFile{
+			Files: []*MixinFile{
 				{Updated: up3},
 			},
 		},
 		{
-			Files: []MixinFile{
+			Files: []*MixinFile{
 				{Updated: up2},
 			},
 		},
 		{
-			Files: []MixinFile{
+			Files: []*MixinFile{
 				{Updated: up4},
 			},
 		},

pkg/mixin/feed/load.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"net/url"
+	"path"
 
 	"github.com/mmcdole/gofeed/atom"
 	"github.com/pkg/errors"
@@ -30,7 +31,6 @@ func (feed *MixinFeed) Load(file string) error {
 		feed.Mixins = append(feed.Mixins, category.Term)
 	}
 
-	feed.Index = make(map[string]map[string]*MixinFileset)
 	for _, entry := range atomFeed.Entries {
 		fileset := &MixinFileset{}
 
@@ -56,7 +56,7 @@ func (feed *MixinFeed) Load(file string) error {
 			continue
 		}
 
-		fileset.Files = make([]MixinFile, 0, len(entry.Links))
+		fileset.Files = make([]*MixinFile, 0, len(entry.Links))
 		for _, link := range entry.Links {
 			if link.Rel == "download" {
 				if entry.UpdatedParsed == nil {
@@ -74,9 +74,10 @@ func (feed *MixinFeed) Load(file string) error {
 					continue
 				}
 
-				file := MixinFile{
+				file := &MixinFile{
 					URL:     parsedUrl,
 					Updated: *entry.UpdatedParsed,
+					File: path.Base(parsedUrl.Path),
 				}
 				fileset.Files = append(fileset.Files, file)
 			}

pkg/mixin/feed/testdata/atom-existing.xml

@@ -0,0 +1,32 @@
+<feed xmlns="http://www.w3.org/2005/Atom">
+    <id>https://porter.sh/mixins</id>
+    <title>DeisLabs Mixins</title>
+    <updated>2013-02-03T00:00:00Z</updated>
+    <link rel="self" href="https://porter.sh/mixins/atom.xml"/>
+    <author>
+        <name>DeisLabs</name>
+        <uri>https://deislabs.io</uri>
+    </author>
+    <category term="exec"/>
+    <category term="helm"/>
+    <entry>
+        <id>https://porter.sh/mixins/v1.2.3/helm</id>
+        <title>helm @ v1.2.3</title>
+        <updated>2013-02-03T00:00:00Z</updated>
+        <category term="helm"/>
+        <content>v1.2.3</content>
+        <link rel="download" href="https://porter.sh/mixins/v1.2.3/helm-darwin-amd64" />
+        <link rel="download" href="https://porter.sh/mixins/v1.2.3/helm-linux-amd64" />
+        <link rel="download" href="https://porter.sh/mixins/v1.2.3/helm-windows-amd64.exe" />
+    </entry>
+    <entry>
+        <id>https://porter.sh/mixins/v1.2.3/exec</id>
+        <title>exec @ v1.2.3</title>
+        <updated>2013-02-02T00:00:00Z</updated>
+        <category term="exec"/>
+        <content>v1.2.3</content>
+        <link rel="download" href="https://porter.sh/mixins/v1.2.3/exec-darwin-amd64" />
+        <link rel="download" href="https://porter.sh/mixins/v1.2.3/exec-linux-amd64" />
+        <link rel="download" href="https://porter.sh/mixins/v1.2.3/exec-windows-amd64.exe" />
+    </entry>
+</feed>

pkg/porter/mixins.go

@@ -61,12 +61,14 @@ func (p *Porter) InstallMixin(opts mixin.InstallOptions) error {
 }
 
 func (p *Porter) GenerateMixinFeed(opts feed.GenerateOptions) error {
-	f := feed.MixinFeed{}
-	err := f.Generate(opts, p.Context)
+	f := feed.NewMixinFeed(p.Context)
+
+	err := f.Generate(opts)
 	if err != nil {
 		return err
 	}
-	return f.Save(opts, p.Context)
+
+	return f.Save(opts)
 }
 
 func (p *Porter) CreateMixinFeedTemplate() error {