This PR adds a new data structure AppDefault which maps an app's vers…

…ion range to a release range and can be used to set the default release version(s) per app version(s).

This PR improves the handling of HTTP errors, especially the 404 not found, from the source URL.
This PR also bumps github.com/urfave/cli/v2 to v2.4.0 to fix the issue where the default value is not set for string slice flags.

README.md

@@ -9,6 +9,23 @@ The primary usecase for this project is currently Rancher's [system-upgrade-cont
 
 This service is in proudction for k3s here: https://update.k3s.io/v1-release/channels, which is driven by this config: https://github.com/rancher/k3s/blob/master/channel.yaml. Each channel's `self` link is the URL that will resolve to the latest GitHub release page for that channel.
 
+## Compile and Run 
+1. build the binary
+```
+go build . 
+```
+2. run the server
+```
+ ./channelserver --config-key k3s --path-prefix v1-release --channel-server-version v2.3.1
+```
+
+3. run the following curl command or open the url in the browser
+```
+curl 0.0.0.0:8080/v1-release/release 
+curl 0.0.0.0:8080/v1-release/channel 
+curl 0.0.0.0:8080/v1-release/appdefault
+```
+
 ## License
 Copyright (c) 2020 [Rancher Labs, Inc.](http://rancher.com)
 

channels.yaml

@@ -1,35 +1,49 @@
 # Example channels config
-channels:
-- name: stable
-  latest: v1.17.2+k3s1
-- name: latest
-  latestRegexp: .*
-  excludeRegexp: rc
-- name: testing
-  latestRegexp: .*
-- name: v1.16
-  latestRegexp: v1\.16\..*
-  excludeRegexp: rc
-- name: v1.16-testing
-  latestRegexp: v1\.16\.*
-- name: v1.17
-  latestRegexp: v1\.17\..*
-  excludeRegexp: rc
-- name: v1.17-testing
-  latestRegexp: v1\.17\..*
-- name: v1.0
-  latestRegexp: v1\.0\..*
-  excludeRegexp: rc
-- name: v1.0-testing
-  latestRegexp: v1\.0\..*
-releases:
-- version: v1.15.3+k3s2
-  minChannelServerVersion: v2.3.0
-  maxChannelServerVersion: v2.3.5
-- version: v1.17.4+k3s1
-  minChannelServerVersion: v2.4.0
-  maxChannelServerVersion: v2.4.5
-github:
-  owner: rancher
-  repo: k3s
-redirectBase: https://github.com/rancher/k3s/releases/tag/
+k3s:
+  channels:
+  - name: stable
+    latest: v1.17.2+k3s1
+  - name: latest
+    latestRegexp: .*
+    excludeRegexp: rc
+  - name: testing
+    latestRegexp: .*
+  - name: v1.16
+    latestRegexp: v1\.16\..*
+    excludeRegexp: rc
+  - name: v1.16-testing
+    latestRegexp: v1\.16\.*
+  - name: v1.17
+    latestRegexp: v1\.17\..*
+    excludeRegexp: rc
+  - name: v1.17-testing
+    latestRegexp: v1\.17\..*
+  - name: v1.0
+    latestRegexp: v1\.0\..*
+    excludeRegexp: rc
+  - name: v1.0-testing
+    latestRegexp: v1\.0\..*
+  releases:
+  - version: v1.15.3+k3s2
+    minChannelServerVersion: v2.3.0
+    maxChannelServerVersion: v2.3.5
+  - version: v1.17.4+k3s1
+    minChannelServerVersion: v2.4.0
+    maxChannelServerVersion: v2.4.5
+  appDefaults:
+    - appName: rancher
+      defaults:
+        - appVersion: '> 2.6.2-0 < 2.6.3-0'
+          defaultVersion: '1.20.x'
+        - appVersion: '> 2.6.2-0 < 2.6.4-0'
+          defaultVersion: '1.21.x'
+        - appVersion: '> 2.6.4-0'
+          defaultVersion: '1.22.x'
+    - appName: anotherApp
+      defaults:
+        - appVersion: '1.2.x'
+          defaultVersion: '1.19.5'
+  github:
+    owner: rancher
+    repo: k3s
+  redirectBase: https://github.com/rancher/k3s/releases/tag/

go.mod

@@ -13,6 +13,6 @@ require (
 	github.com/rancher/apiserver v0.0.0-20201023000256-1a0a904f9197
 	github.com/rancher/wrangler v0.8.11-0.20220120160420-18c996a8e956
 	github.com/sirupsen/logrus v1.6.0
-	github.com/urfave/cli/v2 v2.2.0
+	github.com/urfave/cli/v2 v2.4.0
 	sigs.k8s.io/yaml v1.2.0
 )

go.sum

@@ -80,9 +80,9 @@ github.com/coreos/pkg v0.0.0-20180108230652-97fdf19511ea/go.mod h1:E3G3o1h8I7cfc
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/cpuguy83/go-md2man v1.0.10 h1:BSKMNlYxDvnunlTymqtgONjNnaRV1sTpcovwwjF22jk=
 github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
-github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
-github.com/cpuguy83/go-md2man/v2 v2.0.0 h1:EoUDS0afbrsXAZ9YQ9jdu/mZ2sXgT1/2yyNng4PGlyM=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
+github.com/cpuguy83/go-md2man/v2 v2.0.1 h1:r/myEWzV9lfsM1tFLgDyu0atFtJ1fXn261LKYj/3DxU=
+github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
 github.com/davecgh/go-spew v0.0.0-20151105211317-5215b55f46b2/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -382,11 +382,11 @@ github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6So
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/russross/blackfriday v1.5.2 h1:HyvC0ARfnZBqnXwABFeSZHpKvJHJJfPz81GNueLj0oo=
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
-github.com/russross/blackfriday/v2 v2.0.1 h1:lPqVAte+HuHNfhJ/0LC98ESWRz8afy9tM/0RK8m9o+Q=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/sergi/go-diff v1.1.0/go.mod h1:STckp+ISIX8hZLjrqAeVduY0gWCT9IjLuqbuNXdaHfM=
-github.com/shurcooL/sanitized_anchor_name v1.0.0 h1:PdmoCO6wvbs+7yrJyMORt4/BmY5IYyJwS/kOiWx8mHo=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
@@ -427,8 +427,8 @@ github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGr
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/urfave/cli v1.20.0 h1:fDqGv3UG/4jbVl/QkFwEdddtEDjh/5Ov6X+0B/3bPaw=
 github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
-github.com/urfave/cli/v2 v2.2.0 h1:JTTnM6wKzdA0Jqodd966MVj4vWbbquZykeX1sKbe2C4=
-github.com/urfave/cli/v2 v2.2.0/go.mod h1:SE9GqnLQmjVa0iPEY0f1w3ygNIYcIJ0OKPMoW2caLfQ=
+github.com/urfave/cli/v2 v2.4.0 h1:m2pxjjDFgDxSPtO8WSdbndj17Wu2y8vOT86wE/tjr+I=
+github.com/urfave/cli/v2 v2.4.0/go.mod h1:NX9W0zmTvedE5oDoOMs2RTC8RvdK98NTYZE5LbaEYPg=
 github.com/vektah/gqlparser v1.1.2/go.mod h1:1ycwN7Ij5njmMkPPAOaRFY4rET2Enx7IkVv3vaXspKw=
 github.com/xiang90/probing v0.0.0-20160813154853-07dd2e8dfe18/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=

main.go

@@ -22,6 +22,7 @@ var (
 	SubKeys              cli.StringSlice
 	ChannelServerVersion string
 	PathPrefix           cli.StringSlice
+	AppName              string
 )
 
 func main() {
@@ -56,6 +57,12 @@ func main() {
 			EnvVars:     []string{"CHANNEL_SERVER_VERSION"},
 			Destination: &ChannelServerVersion,
 		},
+		&cli.StringFlag{
+			Name:        "app-name",
+			Usage:       "the app for which to retrieve the app default versions",
+			EnvVars:     []string{"APP_NAME"},
+			Destination: &AppName,
+		},
 		&cli.StringSliceFlag{
 			Name:        "path-prefix",
 			EnvVars:     []string{"PATH_PREFIX"},
@@ -91,7 +98,7 @@ func run(c *cli.Context) error {
 		sources = append(sources, config.StringSource(url))
 	}
 	for index, subkey := range SubKeys.Value() {
-		config := config.NewConfig(ctx, subkey, &config.DurationWait{Duration: intval}, ChannelServerVersion, sources)
+		config := config.NewConfig(ctx, subkey, &config.DurationWait{Duration: intval}, ChannelServerVersion, AppName, sources)
 		configs[PathPrefix.Value()[index]] = config
 	}
 	return server.ListenAndServe(ctx, ListenAddress, configs)

pkg/config/config.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"context"
+	"fmt"
 	"net/url"
 	"sync"
 	"time"
@@ -14,11 +15,12 @@ import (
 type Config struct {
 	sync.Mutex
 
-	url            string
-	redirect       *url.URL
-	gh             *github.Client
-	channelsConfig *model.ChannelsConfig
-	releasesConfig *model.ReleasesConfig
+	url               string
+	redirect          *url.URL
+	gh                *github.Client
+	channelsConfig    *model.ChannelsConfig
+	releasesConfig    *model.ReleasesConfig
+	appDefaultsConfig *model.AppDefaultsConfig
 }
 
 type Wait interface {
@@ -48,45 +50,51 @@ func (s StringSource) URL() string {
 	return string(s)
 }
 
-func NewConfig(ctx context.Context, subKey string, wait Wait, channelServerVersion string, urls []Source) *Config {
+func NewConfig(ctx context.Context, subKey string, wait Wait, channelServerVersion string, appName string, urls []Source) *Config {
 	c := &Config{
-		channelsConfig: &model.ChannelsConfig{},
-		releasesConfig: &model.ReleasesConfig{},
+		channelsConfig:    &model.ChannelsConfig{},
+		releasesConfig:    &model.ReleasesConfig{},
+		appDefaultsConfig: &model.AppDefaultsConfig{},
 	}
 
-	_, _ = c.loadConfig(ctx, subKey, channelServerVersion, urls...)
+	_, _ = c.loadConfig(ctx, subKey, channelServerVersion, appName, urls...)
 
 	go func() {
 		for wait.Wait(ctx) {
-			if index, err := c.loadConfig(ctx, subKey, channelServerVersion, urls...); err != nil {
-				logrus.Errorf("failed to reload configuration from %s: %v", urls, err)
+			if index, err := c.loadConfig(ctx, subKey, channelServerVersion, appName, urls...); err != nil {
+				logrus.Errorf("failed to reload configuration from %s: %v", urls[index].URL(), err)
 			} else {
 				urls = urls[:index+1]
-				logrus.Infof("Loaded configuration from %s in %v", urls[index], urls)
+				logrus.Infof("Loaded configuration from %s in %v", urls[index].URL(), urls)
 			}
 		}
 	}()
 
 	return c
 }
 
-func (c *Config) loadConfig(ctx context.Context, subKey string, channelServerVersion string, urls ...Source) (int, error) {
+func (c *Config) loadConfig(ctx context.Context, subKey string, channelServerVersion string, appName string, urls ...Source) (int, error) {
 	content, index, err := getURLs(ctx, urls...)
 	if err != nil {
-		return index, err
+		return index, fmt.Errorf("failed to get content from url %s: %v", urls[index].URL(), err)
 	}
 
 	config, err := GetChannelsConfig(ctx, content, subKey)
 	if err != nil {
-		return index, err
+		return index, fmt.Errorf("failed to get channel config: %v", err)
 	}
 
 	releases, err := GetReleasesConfig(content, channelServerVersion, subKey)
 	if err != nil {
-		return index, err
+		return index, fmt.Errorf("failed to get release config: %v", err)
 	}
 
-	return index, c.setConfig(ctx, channelServerVersion, config, releases)
+	appDefaultsConfig, err := GetAppDefaultsConfig(content, subKey, appName)
+	if err != nil {
+		return index, fmt.Errorf("failed to get app default config: %v", err)
+	}
+
+	return index, c.setConfig(ctx, channelServerVersion, config, releases, appDefaultsConfig)
 }
 
 func (c *Config) ghClient(config *model.ChannelsConfig) (*github.Client, error) {
@@ -103,7 +111,7 @@ func (c *Config) ghClient(config *model.ChannelsConfig) (*github.Client, error)
 	return c.gh, nil
 }
 
-func (c *Config) setConfig(ctx context.Context, channelServerVersion string, config *model.ChannelsConfig, releases *model.ReleasesConfig) error {
+func (c *Config) setConfig(ctx context.Context, channelServerVersion string, config *model.ChannelsConfig, releases *model.ReleasesConfig, appDefaultsConfig *model.AppDefaultsConfig) error {
 	gh, err := c.ghClient(config)
 	if err != nil {
 		return err
@@ -132,6 +140,7 @@ func (c *Config) setConfig(ctx context.Context, channelServerVersion string, con
 	c.channelsConfig = config
 	c.redirect = redirect
 	c.releasesConfig = releases
+	c.appDefaultsConfig = appDefaultsConfig
 	if config.GitHub != nil {
 		c.url = config.GitHub.APIURL
 	}
@@ -170,6 +179,12 @@ func (c *Config) ReleasesConfig() *model.ReleasesConfig {
 	return c.releasesConfig
 }
 
+func (c *Config) AppDefaultsConfig() *model.AppDefaultsConfig {
+	c.Lock()
+	defer c.Unlock()
+	return c.appDefaultsConfig
+}
+
 func (c *Config) Redirect(id string) (string, error) {
 	for _, channel := range c.channelsConfig.Channels {
 		if channel.Name == id && channel.Latest != "" {

pkg/config/get.go

@@ -47,6 +47,10 @@ func get(ctx context.Context, url Source) ([]byte, error) {
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("status %v", resp.Status)
+	}
+
 	return ioutil.ReadAll(resp.Body)
 }
 
@@ -146,3 +150,40 @@ func GetGHReleases(ctx context.Context, client *github.Client, owner, repo strin
 
 	return allReleases, nil
 }
+
+func GetAppDefaultsConfig(content []byte, subKey, appName string) (*model.AppDefaultsConfig, error) {
+	var (
+		data             map[string]interface{}
+		allConfigs       model.AppDefaultsConfig
+		availableConfigs model.AppDefaultsConfig
+	)
+
+	if subKey == "" {
+		if err := yaml.Unmarshal(content, &allConfigs); err != nil {
+			return nil, err
+		}
+	} else {
+		if err := yaml.Unmarshal(content, &data); err != nil {
+			return nil, err
+		}
+		subData, ok := data[subKey].(map[string]interface{})
+		if !ok {
+			return nil, fmt.Errorf("content at key %s expected to be map[string]interface{}, found %T instead", subKey, data[subKey])
+		}
+		if err := convert.ToObj(subData, &allConfigs); err != nil {
+			return nil, err
+		}
+	}
+
+	// no app name is specified, return all AppDefaultsConfigs
+	if appName == "" {
+		return &allConfigs, nil
+	}
+	for _, appDefault := range allConfigs.AppDefaults {
+		if appDefault.AppName == appName {
+			availableConfigs.AppDefaults = append(availableConfigs.AppDefaults, appDefault)
+			break
+		}
+	}
+	return &availableConfigs, nil
+}

pkg/model/config.go

@@ -39,3 +39,17 @@ type GitHub struct {
 	Owner  string `json:"owner,omitempty"`
 	Repo   string `json:"repo,omitempty"`
 }
+
+type AppDefaultsConfig struct {
+	AppDefaults []AppDefault `json:"appDefaults,omitempty"`
+}
+
+type AppDefault struct {
+	AppName  string    `json:"appName,omitempty"`
+	Defaults []Default `json:"defaults,omitempty"`
+}
+
+type Default struct {
+	AppVersion     string `json:"appVersion,omitempty"`
+	DefaultVersion string `json:"defaultVersion,omitempty"`
+}

pkg/server/server.go

@@ -15,6 +15,7 @@ import (
 	"github.com/rancher/channelserver/pkg/config"
 	"github.com/rancher/channelserver/pkg/model"
 	"github.com/rancher/channelserver/pkg/server/store"
+	"github.com/rancher/channelserver/pkg/server/store/appdefault"
 	"github.com/rancher/channelserver/pkg/server/store/release"
 )
 
@@ -46,6 +47,10 @@ func NewHandler(configs map[string]*config.Config) http.Handler {
 			schema.Store = release.New(config)
 			schema.CollectionMethods = []string{http.MethodGet}
 		})
+		server.Schemas.MustImportAndCustomize(model.AppDefault{}, func(schema *types.APISchema) {
+			schema.Store = appdefault.New(config)
+			schema.CollectionMethods = []string{http.MethodGet}
+		})
 		prefix = strings.Trim(prefix, "/")
 		apiroot.Register(server.Schemas, []string{prefix})
 		router.MatcherFunc(setType("apiRoot", prefix)).Path("/").Handler(server)