Improve k0sctl init usefulness by accepting a list of addresses

.github/workflows/go.yml

@@ -223,3 +223,41 @@ jobs:
         env:
           LINUX_IMAGE: ${{ matrix.image }}
         run: make smoke-reset
+
+  smoke-init:
+    name: Init sub-command smoke test
+    needs: build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v2
+
+      - name: Set up Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.16
+
+      - name: Restore the compiled binary for smoke testing
+        uses: actions/cache@v2
+        id: restore-compiled-binary
+        with:
+          path: |
+            k0sctl
+          key: build-${{ github.run_id }}
+
+      - name: K0sctl cache
+        uses: actions/cache@v2
+        with:
+          path: |
+            /var/cache/k0sctl
+            ~/.k0sctl/cache
+            !*.log
+          key: k0sctl-cache
+
+      - name: Docker Layer Caching For Footloose
+        uses: satackey/action-docker-layer-caching@v0.0.11
+        continue-on-error: true
+
+      - name: Run init smoke test
+        run: make smoke-init

Makefile

@@ -57,7 +57,7 @@ upload-%: bin/% $(github_release)
 .PHONY: upload
 upload: $(addprefix upload-,$(bins) $(checksums))
 
-smoketests := smoke-basic smoke-upgrade smoke-reset smoke-os-override
+smoketests := smoke-basic smoke-upgrade smoke-reset smoke-os-override smoke-init
 .PHONY: $(smoketests)
 $(smoketests): k0sctl
 	$(MAKE) -C smoke-test $@

README.md

@@ -85,7 +85,25 @@ If the configuration cluster version `spec.k0s.version` is greater than the vers
 
 ### `k0sctl init`
 
-Generate a configuration template. Use `--k0s` to include an example `spec.k0s.config` k0s configuration block.
+Generate a configuration template. Use `--k0s` to include an example `spec.k0s.config` k0s configuration block. You can also supply a list of host addresses via arguments or stdin.
+
+Output a minimal configuration template:
+
+```sh
+$ k0sctl init > k0sctl.yaml
+```
+
+Output an example configuration with a default k0s config:
+
+```sh
+$ kosctl init --k0s > k0sctl.yaml
+```
+
+Create a configuration from a list of host addresses and pipe it to k0sctl apply:
+
+```sh
+$ k0sctl init 10.0.0.1 10.0.0.2 ubuntu@10.0.0.3:8022 | k0sctl apply --config -
+```
 
 ### `k0sctl reset`
 

cmd/apply.go

@@ -39,6 +39,7 @@ var applyCommand = &cli.Command{
 	Action: func(ctx *cli.Context) error {
 		start := time.Now()
 		content := ctx.String("config")
+		log.Debugf("Loaded configuration:\n%s", content)
 
 		c := config.Cluster{}
 		if err := yaml.UnmarshalStrict([]byte(content), &c); err != nil {

cmd/init.go

@@ -1,7 +1,10 @@
 package cmd
 
 import (
+	"bufio"
 	"os"
+	"strconv"
+	"strings"
 
 	"github.com/creasty/defaults"
 	"github.com/k0sproject/dig"
@@ -80,40 +83,159 @@ telemetry:
   enabled: true
 `)
 
+var defaultHosts = cluster.Hosts{
+	&cluster.Host{
+		Connection: rig.Connection{
+			SSH: &rig.SSH{
+				Address: "10.0.0.1",
+			},
+		},
+		Role: "controller",
+	},
+	&cluster.Host{
+		Connection: rig.Connection{
+			SSH: &rig.SSH{
+				Address: "10.0.0.2",
+			},
+		},
+		Role: "worker",
+	},
+}
+
+func hostFromAddress(addr, role, user, keypath string) *cluster.Host {
+	port := 22
+
+	if idx := strings.Index(addr, "@"); idx > 0 {
+		user = addr[:idx]
+		addr = addr[idx+1:]
+	}
+
+	if idx := strings.Index(addr, ":"); idx > 0 {
+		pstr := addr[idx+1:]
+		if p, err := strconv.Atoi(pstr); err == nil {
+			port = p
+		}
+		addr = addr[:idx]
+	}
+
+	host := &cluster.Host{
+		Connection: rig.Connection{
+			SSH: &rig.SSH{
+				Address: addr,
+				Port:    port,
+			},
+		},
+	}
+	if role != "" {
+		host.Role = role
+	} else {
+		host.Role = "worker"
+	}
+	if user != "" {
+		host.SSH.User = user
+	}
+	if keypath != "" {
+		host.SSH.KeyPath = keypath
+	}
+
+	_ = defaults.Set(host)
+
+	return host
+}
+
+func buildHosts(addresses []string, ccount int, user, keypath string) cluster.Hosts {
+	var hosts cluster.Hosts
+	role := "controller"
+	for _, a := range addresses {
+		// strip trailing comments
+		if idx := strings.Index(a, "#"); idx > 0 {
+			a = a[:idx]
+		}
+		a = strings.TrimSpace(a)
+		if a == "" || strings.HasPrefix(a, "#") {
+			// skip empty and comment lines
+			continue
+		}
+
+		if len(hosts) >= ccount {
+			role = "worker"
+		}
+
+		hosts = append(hosts, hostFromAddress(a, role, user, keypath))
+	}
+
+	if len(hosts) == 0 {
+		return defaultHosts
+	}
+
+	return hosts
+}
+
 var initCommand = &cli.Command{
-	Name:  "init",
-	Usage: "Create a configuration template",
+	Name:        "init",
+	Usage:       "Create a configuration template",
+	Description: "Outputs a new k0sctl configuration. When a list of addresses are provided, hosts are generated into the configuration. The list of addresses can also be provided via stdin.",
+	ArgsUsage:   "[[user@]address[:port] ...]",
 	Flags: []cli.Flag{
 		&cli.BoolFlag{
 			Name:  "k0s",
 			Usage: "Include a skeleton k0s config section",
 		},
+		&cli.StringFlag{
+			Name:    "cluster-name",
+			Usage:   "Cluster name",
+			Aliases: []string{"n"},
+			Value:   "k0s-cluster",
+		},
+		&cli.IntFlag{
+			Name:    "controller-count",
+			Usage:   "The number of controllers to create when addresses are given",
+			Aliases: []string{"C"},
+			Value:   1,
+		},
+		&cli.StringFlag{
+			Name:    "user",
+			Usage:   "Host user when addresses given",
+			Aliases: []string{"u"},
+		},
+		&cli.StringFlag{
+			Name:    "key-path",
+			Usage:   "Host key path when addresses given",
+			Aliases: []string{"i"},
+		},
 	},
 	Action: func(ctx *cli.Context) error {
+		var addresses []string
+
+		// Read addresses from stdin
+		stat, err := os.Stdin.Stat()
+		if err == nil {
+			if (stat.Mode() & os.ModeCharDevice) == 0 {
+				rd := bufio.NewReader(os.Stdin)
+				for {
+					row, _, err := rd.ReadLine()
+					if err != nil {
+						break
+					}
+					addresses = append(addresses, string(row))
+				}
+				if err != nil {
+					return err
+				}
+
+			}
+		}
+
+		// Read addresses from args
+		addresses = append(addresses, ctx.Args().Slice()...)
+
 		cfg := config.Cluster{
 			APIVersion: config.APIVersion,
 			Kind:       "Cluster",
-			Metadata:   &config.ClusterMetadata{},
+			Metadata:   &config.ClusterMetadata{Name: ctx.String("cluster-name")},
 			Spec: &cluster.Spec{
-				Hosts: cluster.Hosts{
-					&cluster.Host{
-						Connection: rig.Connection{
-							SSH: &rig.SSH{
-								Address: "10.0.0.1",
-							},
-						},
-						Role: "controller",
-					},
-					&cluster.Host{
-						Connection: rig.Connection{
-							SSH: &rig.SSH{
-								Address: "10.0.0.2",
-							},
-						},
-						Role: "worker",
-					},
-				},
-				K0s: cluster.K0s{},
+				Hosts: buildHosts(addresses, ctx.Int("controller-count"), ctx.String("user"), ctx.String("key-path")),
+				K0s:   cluster.K0s{},
 			},
 		}
 

cmd/init_test.go

@@ -0,0 +1,47 @@
+package cmd
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuildHosts(t *testing.T) {
+	addresses := []string{
+		"10.0.0.1",
+		"",
+		"10.0.0.2",
+		"10.0.0.3",
+	}
+	hosts := buildHosts(addresses, 1, "test", "foo")
+	require.Len(t, hosts, 3)
+	require.Len(t, hosts.Controllers(), 1)
+	require.Len(t, hosts.Workers(), 2)
+	require.Equal(t, "test", hosts.First().SSH.User)
+	require.Equal(t, "foo", hosts.First().SSH.KeyPath)
+
+	hosts = buildHosts(addresses, 2, "", "")
+	require.Len(t, hosts, 3)
+	require.Len(t, hosts.Controllers(), 2)
+	require.Len(t, hosts.Workers(), 1)
+	require.Equal(t, "root", hosts.First().SSH.User)
+	require.True(t, strings.HasSuffix(hosts.First().SSH.KeyPath, "/.ssh/id_rsa"))
+}
+
+func TestBuildHostsWithComments(t *testing.T) {
+	addresses := []string{
+		"# controllers",
+		"10.0.0.1",
+		"# workers",
+		"10.0.0.2# second worker",
+		"10.0.0.3 # last worker",
+	}
+	hosts := buildHosts(addresses, 1, "", "")
+	require.Len(t, hosts, 3)
+	require.Len(t, hosts.Controllers(), 1)
+	require.Len(t, hosts.Workers(), 2)
+	require.Equal(t, "10.0.0.1", hosts[0].Address())
+	require.Equal(t, "10.0.0.2", hosts[1].Address())
+	require.Equal(t, "10.0.0.3", hosts[2].Address())
+}

smoke-test/Makefile

@@ -19,6 +19,9 @@ id_rsa_k0s:
 smoke-basic: $(footloose) id_rsa_k0s
 	./smoke-basic.sh
 
+smoke-init: $(footloose) id_rsa_k0s
+	./smoke-init.sh
+
 smoke-upgrade: $(footloose) id_rsa_k0s
 	./smoke-upgrade.sh
 

smoke-test/smoke-basic.sh

@@ -9,6 +9,5 @@ trap cleanup EXIT
 
 deleteCluster
 createCluster
-../k0sctl init
 ../k0sctl apply --config ${K0SCTL_YAML} --debug
 ../k0sctl kubeconfig --config ${K0SCTL_YAML} | grep -v -- "-data"

smoke-test/smoke-init.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -e
+
+. ./smoke.common.sh
+trap cleanup EXIT
+
+deleteCluster
+createCluster
+../k0sctl init --key-path ./id_rsa_k0s 127.0.0.1:9022 root@127.0.0.1:9023 | ../k0sctl apply --config - --debug