Add socket option to agent config for NGINX API

Author: dhurley

internal/config/config.go

@@ -501,6 +501,18 @@ func registerDataPlaneFlags(fs *flag.FlagSet) {
 		"Warning messages in the NGINX errors logs after a NGINX reload will be treated as an error.",
 	)
 
+	fs.String(
+		NginxApiURLKey,
+		"",
+		"The NGINX Plus API URL.",
+	)
+
+	fs.String(
+		NginxApiSocketKey,
+		"",
+		"The NGINX Plus API Unix socket path.",
+	)
+
 	fs.String(
 		NginxApiTlsCaKey,
 		DefNginxApiTlsCa,
@@ -1090,14 +1102,15 @@ func parseJSON(value string) interface{} {
 }
 
 func resolveDataPlaneConfig() *DataPlaneConfig {
-	return &DataPlaneConfig{
+	dataPlaneConfig := &DataPlaneConfig{
 		Nginx: &NginxDataPlaneConfig{
 			ReloadMonitoringPeriod: viperInstance.GetDuration(NginxReloadMonitoringPeriodKey),
 			TreatWarningsAsErrors:  viperInstance.GetBool(NginxTreatWarningsAsErrorsKey),
 			ExcludeLogs:            viperInstance.GetStringSlice(NginxExcludeLogsKey),
 			API: &NginxAPI{
-				URL: viperInstance.GetString(NginxApiURLKey),
-				TLS: TLSConfig{Ca: viperInstance.GetString(NginxApiTlsCaKey)},
+				URL:    viperInstance.GetString(NginxApiURLKey),
+				Socket: viperInstance.GetString(NginxApiSocketKey),
+				TLS:    TLSConfig{Ca: viperInstance.GetString(NginxApiTlsCaKey)},
 			},
 			ReloadBackoff: &BackOff{
 				InitialInterval:     viperInstance.GetDuration(NginxReloadBackoffInitialIntervalKey),
@@ -1108,6 +1121,12 @@ func resolveDataPlaneConfig() *DataPlaneConfig {
 			},
 		},
 	}
+
+	if dataPlaneConfig.Nginx.API.Socket != "" && !strings.HasPrefix(dataPlaneConfig.Nginx.API.Socket, "unix:") {
+		dataPlaneConfig.Nginx.API.Socket = "unix:" + dataPlaneConfig.Nginx.API.Socket
+	}
+
+	return dataPlaneConfig
 }
 
 func resolveClient() *Client {

internal/config/flags.go

@@ -139,6 +139,7 @@ var (
 	NginxExcludeLogsKey                      = pre(DataPlaneConfigRootKey, "nginx") + "exclude_logs"
 	NginxApiTlsCaKey                         = pre(DataPlaneConfigRootKey, "nginx") + "api_tls_ca"
 	NginxApiURLKey                           = pre(DataPlaneConfigRootKey, "nginx") + "api_url"
+	NginxApiSocketKey                        = pre(DataPlaneConfigRootKey, "nginx") + "api_socket"
 
 	SyslogServerPort = pre("syslog_server") + "port"
 

internal/config/types.go

@@ -74,8 +74,9 @@ type (
 	}
 
 	NginxAPI struct {
-		URL string    `yaml:"url" mapstructure:"url"`
-		TLS TLSConfig `yaml:"tls" mapstructure:"tls"`
+		URL    string    `yaml:"url"    mapstructure:"url"`
+		Socket string    `yaml:"socket" mapstructure:"socket"`
+		TLS    TLSConfig `yaml:"tls"    mapstructure:"tls"`
 	}
 
 	Client struct {
@@ -510,6 +511,14 @@ func (c *Config) IsNginxApiUrlConfigured() bool {
 	return c.DataPlaneConfig.Nginx.API.URL != ""
 }
 
+func (c *Config) IsNginxApiSocketConfigured() bool {
+	if !c.IsNginxApiConfigured() {
+		return false
+	}
+
+	return c.DataPlaneConfig.Nginx.API.Socket != ""
+}
+
 func (c *Config) IsNginxApiConfigured() bool {
 	if c.DataPlaneConfig == nil || c.DataPlaneConfig.Nginx == nil || c.DataPlaneConfig.Nginx.API == nil {
 		return false

internal/datasource/config/nginx_config_parser.go

@@ -330,6 +330,10 @@ func (ncp *NginxConfigParser) addApiToNginxConfigContext(
 		return nginxConfigContext
 	}
 
+	if ncp.agentConfig.IsNginxApiSocketConfigured() {
+		apiDetails.Listen = ncp.agentConfig.DataPlaneConfig.Nginx.API.Socket
+	}
+
 	if ncp.pingAPIEndpoint(ctx, apiDetails, stubStatusAPIDirective) {
 		nginxConfigContext.StubStatus = apiDetails
 	} else if ncp.pingAPIEndpoint(ctx, apiDetails, plusAPIDirective) {

internal/datasource/config/nginx_config_parser_test.go

@@ -9,6 +9,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"net"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -756,6 +757,23 @@ func TestNginxConfigParser_PlusAPIParse(t *testing.T) {
 	fakeServerUrl, err := url.Parse(fakeServer.URL)
 	require.NoError(t, err)
 
+	// Create a unix socket listener for testing unix socket
+	socketFile, err := os.CreateTemp("/tmp", "nginx-plus-api-*.sock")
+	require.NoError(t, err)
+	socket := socketFile.Name()
+	require.NoError(t, socketFile.Close())
+	require.NoError(t, os.Remove(socket))
+	defer os.Remove(socket)
+
+	listener, err := (&net.ListenConfig{}).Listen(t.Context(), "unix", socket)
+	require.NoError(t, err)
+	defer listener.Close()
+
+	server := httptest.NewUnstartedServer(handler)
+	server.Listener = listener
+	server.Start()
+	defer server.Close()
+
 	file := helpers.CreateFileWithErrorCheck(t, dir, "nginx-parse-config.conf")
 	defer helpers.RemoveFileWithErrorCheck(t, file.Name())
 
@@ -772,25 +790,40 @@ func TestNginxConfigParser_PlusAPIParse(t *testing.T) {
 	agentConfigWithOverride.DataPlaneConfig.Nginx.API = &config.NginxAPI{
 		URL: fmt.Sprintf("http://localhost:%s/api/", fakeServerUrl.Port()),
 	}
+	agentConfigWithUnixOverride := types.AgentConfig()
+	agentConfigWithUnixOverride.DataPlaneConfig.Nginx.API = &config.NginxAPI{
+		URL:    "http://localhost/api/",
+		Socket: "unix:" + socket,
+	}
 
 	tests := []struct {
 		agentConfig *config.Config
 		name        string
 		content     string
 		url         string
+		listen      string
 	}{
 		{
 			name:        "Test 1: No override of Plus API URL in agent config",
 			content:     testconfig.NginxConfigWithPlusAPI(fakeServerUrl.Port()),
 			url:         "http://localhost:" + fakeServerUrl.Port() + "/api/",
+			listen:      "localhost:" + fakeServerUrl.Port(),
 			agentConfig: types.AgentConfig(),
 		},
 		{
 			name:        "Test 2: Override Plus API URL in agent config",
 			content:     testconfig.NginxConfigWithPlusAPI("8080"),
 			url:         "http://localhost:" + fakeServerUrl.Port() + "/api/",
+			listen:      "localhost:" + fakeServerUrl.Port(),
 			agentConfig: agentConfigWithOverride,
 		},
+		{
+			name:        "Test 3: Override Plus API URL in agent config with unix socket",
+			content:     testconfig.NginxConfigWithPlusAPI("8080"),
+			url:         "http://localhost/api/",
+			listen:      "unix:" + socket,
+			agentConfig: agentConfigWithUnixOverride,
+		},
 	}
 
 	for _, test := range tests {
@@ -806,6 +839,8 @@ func TestNginxConfigParser_PlusAPIParse(t *testing.T) {
 			require.NoError(t, parseError)
 
 			assert.Equal(t, test.url, result.PlusAPI.URL)
+			assert.Equal(t, test.listen, result.PlusAPI.Listen)
+			assert.Equal(t, "/api/", result.PlusAPI.Location)
 		})
 	}
 }