feat: fetch K3s image tag from channelserver on latest/stable/+min.ma…

…jor (#841)

cmd/cluster/clusterCreate.go

@@ -291,7 +291,7 @@ func NewCmdClusterCreate() *cobra.Command {
 
 	cmd.Flags().StringP("image", "i", "", "Specify k3s image that you want to use for the nodes")
 	_ = cfgViper.BindPFlag("image", cmd.Flags().Lookup("image"))
-	cfgViper.SetDefault("image", fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.GetK3sVersion(false)))
+	cfgViper.SetDefault("image", fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.K3sVersion))
 
 	cmd.Flags().String("network", "", "Join an existing network")
 	_ = cfgViper.BindPFlag("network", cmd.Flags().Lookup("network"))

cmd/node/nodeCreate.go

@@ -77,7 +77,7 @@ func NewCmdNodeCreate() *cobra.Command {
 		l.Log().Fatalln("Failed to register flag completion for '--cluster'", err)
 	}
 
-	cmd.Flags().StringP("image", "i", fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.GetK3sVersion(false)), "Specify k3s image used for the node(s)")
+	cmd.Flags().StringP("image", "i", fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.K3sVersion), "Specify k3s image used for the node(s)")
 	cmd.Flags().String("memory", "", "Memory limit imposed on the node [From docker]")
 
 	cmd.Flags().BoolVar(&createNodeOpts.Wait, "wait", true, "Wait for the node(s) to be ready before returning.")

go.mod

@@ -15,7 +15,6 @@ require (
 	github.com/docker/go-units v0.4.0
 	github.com/fvbommel/sortorder v1.0.2 // indirect
 	github.com/go-test/deep v1.0.7
-	github.com/heroku/docker-registry-client v0.0.0-20190909225348-afc9e1acc3d5
 	github.com/imdario/mergo v0.3.12
 	github.com/liggitt/tabwriter v0.0.0-20181228230101-89fcab3d43de
 	github.com/mitchellh/copystructure v1.2.0
@@ -50,7 +49,6 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/docker/distribution v2.7.1+incompatible // indirect
 	github.com/docker/go v1.5.1-1.0.20160303222718-d30aec9fd63c // indirect
-	github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 // indirect
 	github.com/fsnotify/fsnotify v1.4.9 // indirect
 	github.com/go-logr/logr v0.4.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect

pkg/config/transform.go

@@ -56,9 +56,18 @@ func TransformSimpleToClusterConfig(ctx context.Context, runtime runtimes.Runtim
 		simpleConfig.Name = k3d.DefaultClusterName
 	}
 
-	// fetch latest image
-	if simpleConfig.Image == "latest" {
-		simpleConfig.Image = version.GetK3sVersion(true)
+	/* Special cases for Image:
+	 * - "latest" / "stable": get latest / stable channel image
+	 * - starts with "+": get channel following the "+"
+	 */
+	if simpleConfig.Image == "latest" || simpleConfig.Image == "stable" || strings.HasPrefix(simpleConfig.Image, "+") {
+		searchChannel := strings.TrimPrefix(simpleConfig.Image, "+")
+		v, err := version.GetK3sVersion(searchChannel)
+		if err != nil {
+			return nil, err
+		}
+		l.Log().Debugf("Using fetched K3s version %s", v)
+		simpleConfig.Image = fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, v)
 	}
 
 	clusterNetwork := k3d.ClusterNetwork{}

pkg/config/v1alpha2/types.go

@@ -53,7 +53,7 @@ var DefaultConfig = fmt.Sprintf(
 	DefaultConfigTpl,
 	ApiVersion,
 	k3d.DefaultClusterName,
-	fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.GetK3sVersion(false)),
+	fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.K3sVersion),
 )
 
 type VolumeWithNodeFilters struct {

pkg/config/v1alpha3/types.go

@@ -53,7 +53,7 @@ image: %s
 var DefaultConfig = fmt.Sprintf(
 	DefaultConfigTpl,
 	k3d.DefaultClusterName,
-	fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.GetK3sVersion(false)),
+	fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.K3sVersion),
 )
 
 type VolumeWithNodeFilters struct {

pkg/types/k3s/channel.go

@@ -0,0 +1,54 @@
+/*
+Copyright © 2020-2021 The k3d Author(s)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+package k3s
+
+const K3sChannelServerURL string = "https://update.k3s.io/v1-release/channels"
+
+// Source: https://github.com/rancher/channelserver/blob/b084228bfc14d280e524ad132311d8cfcebd1271/pkg/model/config.go#L15-L20
+type Channel struct {
+	Name          string `json:"name,omitempty"`
+	Latest        string `json:"latest,omitempty"`
+	LatestRegexp  string `json:"latestRegexp,omitempty"`
+	ExcludeRegexp string `json:"excludeRegexp,omitempty"`
+}
+
+type ChannelServerResponse struct {
+	Channels []struct {
+		Channel `json:,squash`
+	} `json:"data"`
+}
+
+/*
+{
+
+    "type": "collection",
+    "links": {
+        "self": "…/v1-release/channels"
+    },
+    "actions": { },
+    "resourceType": "channels",
+    "data": [ 13 items
+        {
+            "id": "stable",
+            "type": "channel",
+            "links": { … },
+*/