fix: table align hosts file

Easy to read/parse the hosts file

Signed-off-by: Serge Logvinov <serge.logvinov@sinextra.dev>
Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>

internal/app/machined/pkg/controllers/k8s/extra_manifest.go

@@ -163,7 +163,7 @@ func (ctrl *ExtraManifestController) processURL(ctx context.Context, r controlle
 
 	// I wish we never used go-getter package, as it doesn't allow downloading into memory.
 	// But there's not much we can do about it right now, as it supports lots of magic
-	// users might rely upon now.
+	// users might rely upon.
 
 	// Disable netrc since we don't have getent installed, and most likely
 	// never will.

internal/app/machined/pkg/controllers/network/etcfile.go

@@ -8,8 +8,8 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"html/template"
 	"strings"
+	"text/tabwriter"
 
 	"github.com/cosi-project/runtime/pkg/controller"
 	"github.com/cosi-project/runtime/pkg/resource"
@@ -176,42 +176,36 @@ func (ctrl *EtcFileController) renderResolvConf(resolverStatus *network.Resolver
 	return buf.Bytes()
 }
 
-var hostsTemplate = template.Must(template.New("hosts").Parse(strings.TrimSpace(`
-127.0.0.1       localhost
-{{ .IP }}       {{ .Hostname }} {{ if ne .Hostname .Alias }}{{ .Alias }}{{ end }}
-::1             localhost ip6-localhost ip6-loopback
-ff02::1         ip6-allnodes
-ff02::2         ip6-allrouters
-
-{{- with .ExtraHosts }}
-{{ range . }}
-{{ .IP }} {{ range .Aliases }}{{.}} {{ end -}}
-{{ end -}}
-{{ end -}}
-`)))
-
 func (ctrl *EtcFileController) renderHosts(hostnameStatus *network.HostnameStatusSpec, nodeAddressStatus *network.NodeAddressSpec, cfgProvider talosconfig.Provider) ([]byte, error) {
 	var buf bytes.Buffer
 
-	extraHosts := []talosconfig.ExtraHost{}
+	tabW := tabwriter.NewWriter(&buf, 0, 0, 1, ' ', 0)
+
+	write := func(s string) {
+		tabW.Write([]byte(s)) //nolint:errcheck
+	}
+
+	write("127.0.0.1\tlocalhost\n")
+
+	write(fmt.Sprintf("%s\t%s", nodeAddressStatus.Addresses[0].IP(), hostnameStatus.FQDN()))
+
+	if hostnameStatus.Hostname != hostnameStatus.FQDN() {
+		write(" " + hostnameStatus.Hostname)
+	}
+
+	write("\n")
+
+	write("::1\tlocalhost ip6-localhost ip6-loopback\n")
+	write("ff02::1\tip6-allnodes\n")
+	write("ff02::2\tip6-allrouters\n")
 
 	if cfgProvider != nil {
-		extraHosts = cfgProvider.Machine().Network().ExtraHosts()
+		for _, extraHost := range cfgProvider.Machine().Network().ExtraHosts() {
+			write(fmt.Sprintf("%s\t%s\n", extraHost.IP(), strings.Join(extraHost.Aliases(), " ")))
+		}
 	}
 
-	data := struct {
+	if err := tabW.Flush(); err != nil {
-		IP         string
-		Hostname   string
-		Alias      string
-		ExtraHosts []talosconfig.ExtraHost
-	}{
-		IP:         nodeAddressStatus.Addresses[0].IP().String(),
-		Hostname:   hostnameStatus.FQDN(),
-		Alias:      hostnameStatus.Hostname,
-		ExtraHosts: extraHosts,
-	}
-
-	if err := hostsTemplate.Execute(&buf, data); err != nil {
 		return nil, err
 	}
 

internal/app/machined/pkg/controllers/network/etcfile_test.go

@@ -227,7 +227,7 @@ func (suite *EtcFileConfigSuite) TestComplete() {
 	suite.testFiles(
 		[]resource.Resource{suite.cfg, suite.defaultAddress, suite.hostnameStatus, suite.resolverStatus},
 		"nameserver 1.1.1.1\nnameserver 2.2.2.2\nnameserver 3.3.3.3\n\nsearch example.com\n",
-		"127.0.0.1       localhost\n33.11.22.44       foo.example.com foo\n::1             localhost ip6-localhost ip6-loopback\nff02::1         ip6-allnodes\nff02::2         ip6-allrouters\n\n10.0.0.1 a b \n10.0.0.2 c d ", //nolint:lll
+		"127.0.0.1   localhost\n33.11.22.44 foo.example.com foo\n::1         localhost ip6-localhost ip6-loopback\nff02::1     ip6-allnodes\nff02::2     ip6-allrouters\n10.0.0.1    a b\n10.0.0.2    c d\n", //nolint:lll
 	)
 }
 
@@ -235,7 +235,7 @@ func (suite *EtcFileConfigSuite) TestNoExtraHosts() {
 	suite.testFiles(
 		[]resource.Resource{suite.defaultAddress, suite.hostnameStatus, suite.resolverStatus},
 		"nameserver 1.1.1.1\nnameserver 2.2.2.2\nnameserver 3.3.3.3\n\nsearch example.com\n",
-		"127.0.0.1       localhost\n33.11.22.44       foo.example.com foo\n::1             localhost ip6-localhost ip6-loopback\nff02::1         ip6-allnodes\nff02::2         ip6-allrouters",
+		"127.0.0.1   localhost\n33.11.22.44 foo.example.com foo\n::1         localhost ip6-localhost ip6-loopback\nff02::1     ip6-allnodes\nff02::2     ip6-allrouters\n",
 	)
 }
 
@@ -253,7 +253,7 @@ func (suite *EtcFileConfigSuite) TestNoSearchDomain() {
 	suite.testFiles(
 		[]resource.Resource{cfg, suite.defaultAddress, suite.hostnameStatus, suite.resolverStatus},
 		"nameserver 1.1.1.1\nnameserver 2.2.2.2\nnameserver 3.3.3.3\n",
-		"127.0.0.1       localhost\n33.11.22.44       foo.example.com foo\n::1             localhost ip6-localhost ip6-loopback\nff02::1         ip6-allnodes\nff02::2         ip6-allrouters", //nolint:lll
+		"127.0.0.1   localhost\n33.11.22.44 foo.example.com foo\n::1         localhost ip6-localhost ip6-loopback\nff02::1     ip6-allnodes\nff02::2     ip6-allrouters\n", //nolint:lll
 	)
 }
 
@@ -263,7 +263,7 @@ func (suite *EtcFileConfigSuite) TestNoDomainname() {
 	suite.testFiles(
 		[]resource.Resource{suite.defaultAddress, suite.hostnameStatus, suite.resolverStatus},
 		"nameserver 1.1.1.1\nnameserver 2.2.2.2\nnameserver 3.3.3.3\n",
-		"127.0.0.1       localhost\n33.11.22.44       foo \n::1             localhost ip6-localhost ip6-loopback\nff02::1         ip6-allnodes\nff02::2         ip6-allrouters",
+		"127.0.0.1   localhost\n33.11.22.44 foo\n::1         localhost ip6-localhost ip6-loopback\nff02::1     ip6-allnodes\nff02::2     ip6-allrouters\n",
 	)
 }
 
@@ -279,7 +279,7 @@ func (suite *EtcFileConfigSuite) TestOnlyHostname() {
 	suite.testFiles(
 		[]resource.Resource{suite.defaultAddress, suite.hostnameStatus},
 		"",
-		"127.0.0.1       localhost\n33.11.22.44       foo.example.com foo\n::1             localhost ip6-localhost ip6-loopback\nff02::1         ip6-allnodes\nff02::2         ip6-allrouters",
+		"127.0.0.1   localhost\n33.11.22.44 foo.example.com foo\n::1         localhost ip6-localhost ip6-loopback\nff02::1     ip6-allnodes\nff02::2     ip6-allrouters\n",
 	)
 }