cli: Add `json` and `-t` flags to `server members` command (#16444)

* cli: Add  and  flags to server members

* Update website/content/docs/commands/server/members.mdx

Co-authored-by: James Rasell <jrasell@users.noreply.github.com>

* Update website/content/docs/commands/server/members.mdx

Co-authored-by: James Rasell <jrasell@users.noreply.github.com>

* cli: update the server memebers tests to use must

* cli: add flags addition to changelog

---------

Co-authored-by: James Rasell <jrasell@users.noreply.github.com>

.changelog/16444.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+cli: Added `-json` and `-t` flag to `server members` command
+```

command/server_members.go

@@ -35,6 +35,12 @@ Server Members Options:
   -verbose
     Show detailed information about each member. This dumps a raw set of tags
     which shows more information than the default output format.
+
+ -json
+    Output the latest information about each member in a JSON format.
+
+  -t
+    Format and display latest information about each member using a Go template.
 `
 	return strings.TrimSpace(helpText)
 }
@@ -43,6 +49,9 @@ func (c *ServerMembersCommand) AutocompleteFlags() complete.Flags {
 	return mergeAutocompleteFlags(c.Meta.AutocompleteFlags(FlagSetClient),
 		complete.Flags{
 			"-detailed": complete.PredictNothing,
+			"-verbose":  complete.PredictNothing,
+			"-json":     complete.PredictNothing,
+			"-t":        complete.PredictAnything,
 		})
 }
 
@@ -57,12 +66,15 @@ func (c *ServerMembersCommand) Synopsis() string {
 func (c *ServerMembersCommand) Name() string { return "server members" }
 
 func (c *ServerMembersCommand) Run(args []string) int {
-	var detailed, verbose bool
+	var detailed, verbose, json bool
+	var tmpl string
 
 	flags := c.Meta.FlagSet(c.Name(), FlagSetClient)
 	flags.Usage = func() { c.Ui.Output(c.Help()) }
 	flags.BoolVar(&detailed, "detailed", false, "Show detailed output")
 	flags.BoolVar(&verbose, "verbose", false, "Show detailed output")
+	flags.BoolVar(&json, "json", false, "")
+	flags.StringVar(&tmpl, "t", "", "")
 
 	if err := flags.Parse(args); err != nil {
 		return 1
@@ -103,6 +115,17 @@ func (c *ServerMembersCommand) Run(args []string) int {
 	// Sort the members
 	sort.Sort(api.AgentMembersNameSort(srvMembers.Members))
 
+	if json || len(tmpl) > 0 {
+		out, err := Format(json, tmpl, srvMembers.Members)
+		if err != nil {
+			c.Ui.Error(err.Error())
+			return 1
+		}
+
+		c.Ui.Output(out)
+		return 0
+	}
+
 	// Determine the leaders per region.
 	leaders, leaderErr := regionLeaders(client, srvMembers.Members)
 

command/server_members_test.go

@@ -1,13 +1,16 @@
 package command
 
 import (
+	"encoding/json"
 	"fmt"
 	"strings"
 	"testing"
 
+	"github.com/hashicorp/nomad/api"
 	"github.com/hashicorp/nomad/ci"
 	"github.com/hashicorp/nomad/command/agent"
 	"github.com/mitchellh/cli"
+	"github.com/shoenig/test/must"
 )
 
 func TestServerMembersCommand_Implements(t *testing.T) {
@@ -25,30 +28,46 @@ func TestServerMembersCommand_Run(t *testing.T) {
 
 	// Get our own node name
 	name, err := client.Agent().NodeName()
-	if err != nil {
+	must.NoError(t, err)
-		t.Fatalf("err: %s", err)
-	}
 
 	// Query the members
-	if code := cmd.Run([]string{"-address=" + url}); code != 0 {
+	code := cmd.Run([]string{"-address=" + url})
-		t.Fatalf("expected exit 0, got: %d", code)
+
-	}
 	if out := ui.OutputWriter.String(); !strings.Contains(out, name) {
 		t.Fatalf("expected %q in output, got: %s", name, out)
 	}
 	ui.OutputWriter.Reset()
 
 	// Query members with verbose output
-	if code := cmd.Run([]string{"-address=" + url, "-verbose"}); code != 0 {
+	code = cmd.Run([]string{"-address=" + url, "-verbose"})
-		t.Fatalf("expected exit 0, got: %d", code)
+	must.Zero(t, code)
-	}
+
 	// Still support previous detailed flag
-	if code := cmd.Run([]string{"-address=" + url, "-detailed"}); code != 0 {
+	code = cmd.Run([]string{"-address=" + url, "-detailed"})
-		t.Fatalf("expected exit 0, got: %d", code)
+	must.Zero(t, code)
-	}
+
-	if out := ui.OutputWriter.String(); !strings.Contains(out, "Tags") {
+	must.StrContains(t, ui.OutputWriter.String(), "Tags")
-		t.Fatalf("expected tags in output, got: %s", out)
+
-	}
+	ui.OutputWriter.Reset()
+
+	// List json
+	code = cmd.Run([]string{"-address=" + url, "-json"})
+	must.Zero(t, code)
+
+	outJson := []api.AgentMember{}
+	err = json.Unmarshal(ui.OutputWriter.Bytes(), &outJson)
+	must.NoError(t, err)
+
+	ui.OutputWriter.Reset()
+
+	// Go template to format the output
+	code = cmd.Run([]string{"-address=" + url, "-t", "{{range .}}{{ .Status }}{{end}}"})
+	must.Zero(t, code)
+
+	out := ui.OutputWriter.String()
+	must.StrContains(t, out, "alive")
+
+	ui.ErrorWriter.Reset()
 }
 
 func TestMembersCommand_Fails(t *testing.T) {
@@ -57,21 +76,17 @@ func TestMembersCommand_Fails(t *testing.T) {
 	cmd := &ServerMembersCommand{Meta: Meta{Ui: ui}}
 
 	// Fails on misuse
-	if code := cmd.Run([]string{"some", "bad", "args"}); code != 1 {
+	code := cmd.Run([]string{"some", "bad", "args"})
-		t.Fatalf("expected exit code 1, got: %d", code)
+	must.One(t, code)
-	}
+
-	if out := ui.ErrorWriter.String(); !strings.Contains(out, commandErrorText(cmd)) {
+	must.StrContains(t, ui.ErrorWriter.String(), commandErrorText(cmd))
-		t.Fatalf("expected help output, got: %s", out)
-	}
 	ui.ErrorWriter.Reset()
 
 	// Fails on connection failure
-	if code := cmd.Run([]string{"-address=nope"}); code != 1 {
+	code = cmd.Run([]string{"-address=nope"})
-		t.Fatalf("expected exit code 1, got: %d", code)
+	must.One(t, code)
-	}
+
-	if out := ui.ErrorWriter.String(); !strings.Contains(out, "Error querying servers") {
+	must.StrContains(t, ui.ErrorWriter.String(), "Error querying servers")
-		t.Fatalf("expected failed query error, got: %s", out)
-	}
 }
 
 // Tests that a single server region that left should still
@@ -99,35 +114,29 @@ func TestServerMembersCommand_MultiRegion_Leave(t *testing.T) {
 	addr := fmt.Sprintf("127.0.0.1:%d",
 		srv1.Agent.Server().GetConfig().SerfConfig.MemberlistConfig.BindPort)
 
-	if _, err := srv2.Agent.Server().Join([]string{addr}); err != nil {
+	_, err := srv2.Agent.Server().Join([]string{addr})
-		t.Fatalf("Join err: %v", err)
+	must.NoError(t, err)
-	}
+
 	ui := cli.NewMockUi()
 	cmd := &ServerMembersCommand{Meta: Meta{Ui: ui}}
 
 	// Get our own node name
 	name, err := client1.Agent().NodeName()
-	if err != nil {
+	must.NoError(t, err)
-		t.Fatalf("err: %s", err)
-	}
 
 	// Query the members
-	if code := cmd.Run([]string{"-address=" + url}); code != 0 {
+	code := cmd.Run([]string{"-address=" + url})
-		t.Fatalf("expected exit 0, got: %d", code)
+	must.Zero(t, code)
-	}
+
-	if out := ui.OutputWriter.String(); !strings.Contains(out, name) {
+	must.StrContains(t, ui.OutputWriter.String(), name)
-		t.Fatalf("expected %q in output, got: %s", name, out)
-	}
 	ui.OutputWriter.Reset()
 
 	// Make one of the servers leave
 	srv2.Agent.Leave()
 
 	// Query again, should still contain expected output
-	if code := cmd.Run([]string{"-address=" + url}); code != 0 {
+	code = cmd.Run([]string{"-address=" + url})
-		t.Fatalf("expected exit 0, got: %d", code)
+	must.Zero(t, code)
-	}
+
-	if out := ui.OutputWriter.String(); !strings.Contains(out, name) {
+	must.StrContains(t, ui.OutputWriter.String(), name)
-		t.Fatalf("expected %q in output, got: %s", name, out)
-	}
 }

website/content/docs/commands/server/members.mdx

@@ -36,6 +36,10 @@ capability.
   for each member. This mode reveals additional information not displayed in
   the standard output format.
 
+- `-json`: Output the server memebers in its JSON format.
+
+- `-t`: Format and display the server memebers using a Go template.
+
 ## Examples
 
 Default view:
@@ -57,3 +61,44 @@ server-1.global  10.0.0.8   4648  alive   true    2         3             1.3.0
 server-2.global  10.0.0.9   4648  alive   false   2         3             1.3.0  dc1         global  id=04594bee-fec9-4cec-f308-eebe82025ae7,dc=dc1,expect=3,rpc_addr=10.0.0.9,raft_vsn=3,port=4647,role=nomad,region=global,build=1.3.0
 server-3.global  10.0.0.10  4648  alive   false   2         3             1.3.0  dc1         global  region=global,dc=dc1,rpc_addr=10.0.0.10,raft_vsn=3,build=1.3.0,expect=3,id=59542f6c-fb0e-50f1-4c9f-98bb593e9fe8,role=nomad,port=4647
 ```
+
+The `-json` flag can be used to get the latest server members information in json format:
+
+```shell-session
+$ nomad server members -json
+[
+    {
+        "Addr": "127.0.0.1",
+        "DelegateCur": 4,
+        "DelegateMax": 5,
+        "DelegateMin": 2,
+        "Name": "bacon-mac.global",
+        "Port": 4648,
+        "ProtocolCur": 2,
+        "ProtocolMax": 5,
+        "ProtocolMin": 1,
+        "Status": "alive",
+        "Tags": {
+            "build": "1.5.0",
+            "region": "global",
+            "rpc_addr": "127.0.0.1",
+            "role": "nomad",
+            "raft_vsn": "3",
+            "bootstrap": "1",
+            "expect": "1",
+            "dc": "dc1",
+            "port": "4647",
+            "revision": "fc40c491cacec3d8ec3f2f98cd82b9068a50797c",
+            "vsn": "1",
+            "id": "354fd9a8-4228-ca8e-8b93-3cf002514910"
+        }
+    }
+]
+  ```
+
+Or use the `-t` flag to format and display the server members information using a Go template:
+
+```shell-session
+$ nomad server members -t '{{range .}}{{printf "%s: %s" .Name .Status }}{{end}}'
+bacon-mac.global: alive
+```