Add fleet-server to elastic-agent inspect output (#243)

* Add fleet-server to elastic-agent inspect output

Add the fleet-server input from the full filled config that is parsed
for programs in elastic-agent inspect output. This will show the policy
for fleet-server instead of the contents of fleet.yml

* Add unit test

* fix linter

CHANGELOG.next.asciidoc

@@ -98,6 +98,7 @@
 - Reduce Elastic Agent shut down time by stopping processes concurrently {pull}29650[29650]
 - Move `context cancelled` error from fleet gateway into debug level. {pull}187[187]
 - Update library containerd to 1.5.10. {pull}186[186]
+- Add fleet-server to output of elastic-agent inspect output command (and diagnostic bundle). {pull}243[243]
 
 ==== New features
 

internal/pkg/agent/cmd/inspect.go

@@ -299,9 +299,51 @@ func getProgramsFromConfig(log *logger.Logger, agentInfo *info.AgentInfo, cfg *c
 		return nil, err
 	}
 	composableWaiter.Wait()
+
+	// add the fleet-server input to default programs list
+	// this does not correspond to the actual config that fleet-server uses as it's in fleet.yml and not part of the assembled config (cfg)
+	fleetCFG, err := cfg.ToMapStr()
+	if err != nil {
+		return nil, err
+	}
+	if fleetInput := getFleetInput(fleetCFG); fleetInput != nil {
+		ast, err := transpiler.NewAST(fleetInput)
+		if err != nil {
+			return nil, err
+		}
+		router.programs["default"] = append(router.programs["default"], program.Program{
+			Spec: program.Spec{
+				Name: "fleet-server",
+				Cmd:  "fleet-server",
+			},
+			Config: ast,
+		})
+	}
+
 	return router.programs, nil
 }
 
+func getFleetInput(o map[string]interface{}) map[string]interface{} {
+	arr, ok := o["inputs"].([]interface{})
+	if !ok {
+		return nil
+	}
+	for _, iface := range arr {
+		input, ok := iface.(map[string]interface{})
+		if !ok {
+			continue
+		}
+		t, ok := input["type"]
+		if !ok {
+			continue
+		}
+		if t.(string) == "fleet-server" {
+			return input
+		}
+	}
+	return nil
+}
+
 type inmemRouter struct {
 	programs map[string][]program.Program
 }

internal/pkg/agent/cmd/inspect_test.go

@@ -0,0 +1,51 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License;
+// you may not use this file except in compliance with the Elastic License.
+
+package cmd
+
+import (
+	"testing"
+)
+
+func TestGetFleetInput(t *testing.T) {
+	tests := []struct {
+		name   string
+		input  map[string]interface{}
+		expect map[string]interface{}
+	}{{
+		name: "fleet-server input found",
+		input: map[string]interface{}{
+			"inputs": []map[string]interface{}{
+				map[string]interface{}{
+					"type": "fleet-server",
+				}},
+		},
+		expect: map[string]interface{}{
+			"type": "fleet-server",
+		},
+	}, {
+		name: "no fleet-server input",
+		input: map[string]interface{}{
+			"inputs": []map[string]interface{}{
+				map[string]interface{}{
+					"type": "test-server",
+				}},
+		},
+		expect: nil,
+	}, {
+		name: "wrong input formant",
+		input: map[string]interface{}{
+			"inputs": "example",
+		},
+		expect: nil,
+	}}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := getFleetInput(tt.input)
+			if tt.expect == nil && r != nil {
+				t.Error("expected nil")
+			}
+		})
+	}
+}