[Elastic Agent] Golden files for program tests (#27862)

Currently it seems the expected config files for each program were manually generated. This makes adding a new test cumbersome and in case of small changes it means adjusting many files.

This changes the test that it is possible to run with `go test . -generate` and new golden files are generated. Ideally it also means most of the additional tests become obsolete like how many program files should be generated. To make sure no left over files exist, on -generate all the generated files are first cleaned up.

(cherry picked from commit d898e3d)

x-pack/elastic-agent/pkg/agent/program/program_test.go

@@ -5,6 +5,7 @@
 package program
 
 import (
+	"flag"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -21,6 +22,10 @@ import (
 	"github.com/elastic/beats/v7/x-pack/elastic-agent/pkg/agent/transpiler"
 )
 
+var (
+	generateFlag = flag.Bool("generate", false, "Write golden files")
+)
+
 func TestGroupBy(t *testing.T) {
 	t.Run("only named output", func(t *testing.T) {
 		sConfig := map[string]interface{}{
@@ -490,6 +495,81 @@ func TestConfiguration(t *testing.T) {
 	}
 }
 
+func TestUseCases(t *testing.T) {
+	defer os.Remove("fleet.yml")
+
+	useCasesPath := filepath.Join("testdata", "usecases")
+	useCases, err := filepath.Glob(filepath.Join(useCasesPath, "*.yml"))
+	require.NoError(t, err)
+
+	generatedFilesDir := filepath.Join(useCasesPath, "generated")
+
+	// Cleanup all generated files to make sure not having any left overs
+	if *generateFlag {
+		err := os.RemoveAll(generatedFilesDir)
+		require.NoError(t, err)
+	}
+
+	for _, usecase := range useCases {
+		t.Run(usecase, func(t *testing.T) {
+
+			useCaseName := strings.TrimSuffix(filepath.Base(usecase), ".yml")
+			singleConfig, err := ioutil.ReadFile(usecase)
+			require.NoError(t, err)
+
+			var m map[string]interface{}
+			err = yaml.Unmarshal(singleConfig, &m)
+			require.NoError(t, err)
+
+			ast, err := transpiler.NewAST(m)
+			require.NoError(t, err)
+
+			programs, err := Programs(&fakeAgentInfo{}, ast)
+			require.NoError(t, err)
+
+			require.Equal(t, 1, len(programs))
+
+			defPrograms, ok := programs["default"]
+			require.True(t, ok)
+
+			for _, program := range defPrograms {
+				generatedPath := filepath.Join(
+					useCasesPath, "generated",
+					useCaseName+"."+strings.ToLower(program.Spec.Cmd)+".golden.yml",
+				)
+
+				compareMap := &transpiler.MapVisitor{}
+				program.Config.Accept(compareMap)
+
+				// Generate new golden file for programm
+				if *generateFlag {
+					d, err := yaml.Marshal(&compareMap.Content)
+					require.NoError(t, err)
+
+					err = os.MkdirAll(generatedFilesDir, 0755)
+					require.NoError(t, err)
+					err = ioutil.WriteFile(generatedPath, d, 0644)
+					require.NoError(t, err)
+				}
+
+				programConfig, err := ioutil.ReadFile(generatedPath)
+				require.NoError(t, err)
+
+				var m map[string]interface{}
+				err = yamltest.FromYAML(programConfig, &m)
+				require.NoError(t, errors.Wrap(err, program.Cmd()))
+
+				if !assert.True(t, cmp.Equal(m, compareMap.Content)) {
+					diff := cmp.Diff(m, compareMap.Content)
+					if diff != "" {
+						t.Errorf("%s-%s mismatch (-want +got):\n%s", usecase, program.Spec.Name, diff)
+					}
+				}
+			}
+		})
+	}
+}
+
 type fakeAgentInfo struct{}
 
 func (*fakeAgentInfo) AgentID() string {

x-pack/elastic-agent/pkg/agent/program/testdata/usecases/enabled_output_true.yml

@@ -0,0 +1,17 @@
+inputs:
+  - type: event/file
+    streams:
+      - paths:
+          - /var/log/hello1.log
+          - /var/log/hello2.log
+management:
+  host: "localhost"
+config:
+  reload: 123
+outputs:
+  default:
+    type: elasticsearch
+    enabled: true
+    hosts: [127.0.0.1:9200, 127.0.0.1:9300]
+    username: elastic
+    password: changeme

x-pack/elastic-agent/pkg/agent/program/testdata/usecases/enabled_true.yml

@@ -0,0 +1,22 @@
+name:	Production Website DB Servers
+fleet:
+    kibana_url:		https://kibana.mydomain.com:5601
+    ca_hash:		7HIpactkIAq2Y49orFOOQKurWxmmSFZhBCoQYcRhJ3Y=
+    checkin_interval:	5m
+inputs:
+  - type: event/file
+    streams:
+      - enabled: true
+        paths:
+          - /var/log/hello1.log
+          - /var/log/hello2.log
+management:
+  host: "localhost"
+config:
+  reload: 123
+outputs:
+  default:
+    type: elasticsearch
+    hosts: [127.0.0.1:9200, 127.0.0.1:9300]
+    username: elastic
+    password: changeme

x-pack/elastic-agent/pkg/agent/program/testdata/usecases/endpoint_basic.yml

@@ -0,0 +1,115 @@
+revision: 5
+name: Endpoint Host
+fleet:
+  access_api_key: VuaCfGcBCdbkQm-e5aOx:ui2lp2axTNmsyakw9tvNnw
+  protocol: https
+  hosts: [ localhost:5601 ]
+  timeout: 30s
+  agent:
+    id: fleet-agent-id
+    logging.level: error
+  host:
+    id: host-agent-id
+
+outputs:
+  default:
+    type: elasticsearch
+    hosts: [127.0.0.1:9200, 127.0.0.1:9300]
+    username: elastic
+    password: changeme
+    api_key: TiNAGG4BaaMdaH1tRfuU:KnR6yE41RrSowb0kQ0HWoA
+    ca_sha256: 7HIpactkIAq2Y49orFOOQKurWxmmSFZhBCoQYcRhJ3Y=
+
+inputs:
+- id: endpoint-id
+  type: endpoint
+  name: endpoint-1
+  enabled: true
+  package:
+    name: endpoint
+    version: 0.3.0
+  data_stream:
+    namespace: default
+  artifact_manifest:
+    schema_version: v22
+    manifest_version: v21
+    artifacts:
+      - endpoint-allowlist-windows:
+          sha256: 1234
+          size: 2
+          url: /relative/path/to/endpoint-allowlist-windows
+      - endpoint-allowlist-macos:
+          sha256: 1234
+          size: 2
+          url: /relative/path/to/endpoint-allowlist-macos
+      - endpoint-allowlist-linux:
+          sha256: 1234
+          size: 2
+          url: /relative/path/to/endpoint-allowlist-linux
+  policy:
+    linux:
+      advanced:
+        free-form: free-form-value
+      indices:
+        network: logs-endpoint.events.network-default
+        file: logs-endpoint.events.file-default
+        process: logs-endpoint.events.process-default
+        metadata: metrics-endpoint.metadata-default
+        policy: metrics-endpoint.policy-default
+        telemetry: metrics-endpoint.telemetry-default
+      logging:
+        file: info
+        stdout: debug
+      events:
+        process: true
+        file: true
+        network: true
+    windows:
+      malware:
+        mode: prevent
+      advanced:
+        free-form: free-form-value
+      indices:
+        network: logs-endpoint.events.network-default
+        file: logs-endpoint.events.file-default
+        registry: logs-endpoint.events.registry-default
+        process: logs-endpoint.events.process-default
+        driver: logs-endpoint.events.driver-default
+        library: logs-endpoint.events.library-default
+        alerts: logs-endpoint.alerts-default
+        metadata: metrics-endpoint.metadata-default
+        policy: metrics-endpoint.policy-default
+        telemetry: metrics-endpoint.telemetry-default
+      logging:
+        file: info
+        stdout: debug
+      events:
+        registry: true
+        process: true
+        security: true
+        file: true
+        dns: false
+        dll_and_driver_load: false
+        network: true
+    mac:
+      malware:
+        mode: prevent
+      advanced:
+        free-form: free-form-value
+      indices:
+        network: logs-endpoint.events.network-default
+        file: logs-endpoint.events.file-default
+        process: logs-endpoint.events.process-default
+        alerts: logs-endpoint.alerts-default
+        metadata: metrics-endpoint.metadata-default
+        policy: metrics-endpoint.policy-default
+        telemetry: metrics-endpoint.telemetry-default
+      logging:
+        file: info
+        stdout: debug
+      events:
+        process: true
+        file: true
+        network: true
+runtime:
+  arch: x86_64

x-pack/elastic-agent/pkg/agent/program/testdata/usecases/fleet_server.yml

@@ -0,0 +1,51 @@
+name: Fleet Server Only
+fleet:
+  enabled: true
+  access_api_key: VuaCfGcBCdbkQm-e5aOx:ui2lp2axTNmsyakw9tvNnw
+  protocol: https
+  hosts: [ localhost:5601 ]
+  timeout: 30s
+  agent:
+    id: fleet-agent-id
+    logging.level: error
+  host:
+    id: host-agent-id
+  server:
+    host: 127.0.0.1
+    port: 8822
+    ssl:
+      verification_mode: none
+    policy:
+      id: copy-policy-id
+    output:
+      elasticsearch:
+        hosts: [ 127.0.0.1:9200, 127.0.0.1:9300 ]
+        username: fleet
+        password: fleetpassword
+
+outputs:
+  default:
+    type: elasticsearch
+    hosts: [127.0.0.1:9200, 127.0.0.1:9300]
+    username: elastic
+    password: changeme
+    api_key: TiNAGG4BaaMdaH1tRfuU:KnR6yE41RrSowb0kQ0HWoA
+    ca_sha256: 7HIpactkIAq2Y49orFOOQKurWxmmSFZhBCoQYcRhJ3Y=
+
+inputs:
+  - id: fleet-server-id
+    type: fleet-server
+    use_output: default
+    data_stream:
+      namespace: default
+    name: fleet_server-1
+    revision: 6
+    server:
+      host: 0.0.0.0
+      port: 8220
+      limits:
+        max_connections: 40
+      runtime:
+        gc_percent: 50
+      timeouts:
+        read: 5m

x-pack/elastic-agent/pkg/agent/program/testdata/usecases/generated/enabled_output_true.filebeat.golden.yml

@@ -0,0 +1,38 @@
+filebeat:
+  inputs:
+  - index: logs-generic-default
+    paths:
+    - /var/log/hello1.log
+    - /var/log/hello2.log
+    processors:
+    - add_fields:
+        fields:
+          dataset: generic
+          namespace: default
+          type: logs
+        target: data_stream
+    - add_fields:
+        fields:
+          dataset: generic
+        target: event
+    - add_fields:
+        fields:
+          id: agent-id
+          snapshot: false
+          version: 8.0.0
+        target: elastic_agent
+    - add_fields:
+        fields:
+          id: agent-id
+        target: agent
+    type: log
+output:
+  elasticsearch:
+    enabled: true
+    headers:
+      h1: test-header
+    hosts:
+    - 127.0.0.1:9200
+    - 127.0.0.1:9300
+    password: changeme
+    username: elastic

x-pack/elastic-agent/pkg/agent/program/testdata/usecases/generated/enabled_true.filebeat.golden.yml

@@ -0,0 +1,38 @@
+filebeat:
+  inputs:
+  - enabled: true
+    index: logs-generic-default
+    paths:
+    - /var/log/hello1.log
+    - /var/log/hello2.log
+    processors:
+    - add_fields:
+        fields:
+          dataset: generic
+          namespace: default
+          type: logs
+        target: data_stream
+    - add_fields:
+        fields:
+          dataset: generic
+        target: event
+    - add_fields:
+        fields:
+          id: agent-id
+          snapshot: false
+          version: 8.0.0
+        target: elastic_agent
+    - add_fields:
+        fields:
+          id: agent-id
+        target: agent
+    type: log
+output:
+  elasticsearch:
+    headers:
+      h1: test-header
+    hosts:
+    - 127.0.0.1:9200
+    - 127.0.0.1:9300
+    password: changeme
+    username: elastic