Add CLI arg to set dynamic config path

hugo/content/configuration-overview.md

@@ -28,7 +28,7 @@ The following sections explain how to configure the NGINX Agent using configurat
 
 ### Configure with Config Files
 
-The configuration files for the NGINX Agent are `/etc/nginx-agent/nginx-agent.conf` and `/var/lib/nginx-agent/agent-dynamic.conf`. The `agent-dynamic.conf` file location is different for FreeBSD which is located `/var/db/nginx-agent/agent-dynamic.conf`. These files have comments at the top indicating their purpose.
+The default locations of configuration files for the NGINX Agent are `/etc/nginx-agent/nginx-agent.conf` and `/var/lib/nginx-agent/agent-dynamic.conf`. The `agent-dynamic.conf` file default location is different for FreeBSD which is located `/var/db/nginx-agent/agent-dynamic.conf`. These files have comments at the top indicating their purpose.
 
 Examples of the configuration files are provided below:
 
@@ -111,11 +111,13 @@ nginx_app_protect:
 <details open>
     <summary>example dynamic-agent.conf</summary>
 
+{{<note>}}
+Default location in Linux environments: `/var/lib/nginx-agent/agent-dynamic.conf`
+
+Default location in FreeBSD environments: `/var/db/nginx-agent/agent-dynamic.conf`
+{{</note>}}
+
 ```yaml
-#
-# /var/lib/nginx-agent/agent-dynamic.conf
-# On FreeBSD /var/db/nginx-agent/agent-dynamic.conf
-#
 # Dynamic configuration file for NGINX Agent.
 #
 # The purpose of this file is to track agent configuration
@@ -163,6 +165,7 @@ Flags:
       --dataplane-report-interval duration               The amount of time the agent will report on the dataplane. After this period of time it will send a snapshot of the dataplane information. (default 24h0m0s)
       --dataplane-status-poll-interval duration          The frequency the agent will check the dataplane for changes. Used as a "heartbeat" to keep the gRPC connections alive. (default 30s)
       --display-name string                              The instance's 'name' value.
+      --dynamic-config-path string                       Defines the path of the Agent dynamic config file. (default "/var/lib/nginx-agent/agent-dynamic.conf")
       --features strings                                 A comma-separated list of features enabled for the agent. (default [registration,nginx-config-async,nginx-ssl-config,nginx-counting,metrics,dataplane-status,process-watcher,file-watcher,activity-events,agent-api])
   -h, --help                                             help for nginx-agent
       --ignore-directives strings                        A comma-separated list of ignoring directives which contain sensitive info.
@@ -203,6 +206,14 @@ The NGINX Agent follows NGINX configuration directives to file paths outside the
 
 - [`ssl_certificate`](https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate)
 
+#### NGINX Agent Dynamic Config Path Option
+
+Use the `--dynamic-config-path` command-line option to set the location of the dynamic config file. This setting also requires you to move your dynamic config to the new path, or create a new dynamic config file at the specified location.
+
+Default location in Linux environments: `/var/lib/nginx-agent/agent-dynamic.conf`
+
+Default location in FreeBSD environments: `/var/db/nginx-agent/agent-dynamic.conf`
+
 ### NGINX Agent Environment Variables
 
 This section displays the configurable options for the NGINX Agent that can be set with environment variables. A list of the configurable environment variables can be seen below:

hugo/content/getting-started.md

@@ -45,12 +45,18 @@ sudo mkdir /etc/nginx-agent
 sudo cp <project_root_directory>/nginx-agent.conf /etc/nginx-agent/
 ```
 
-Create the `agent-dynamic.conf` file in the `/var/lib/nginx-agent/` directory, which is required for NGINX Agent to run. 
+Create the `agent-dynamic.conf` file, which is required for NGINX Agent to run. 
 
+In Linux environments:
 ```shell
 sudo touch /var/lib/nginx-agent/agent-dynamic.conf
 ```
 
+In FreeBSD environments:
+```shell
+sudo touch /var/db/nginx-agent/agent-dynamic.conf
+```
+
 ### Enable the gRPC interface
 
 Add the the following settings to `/etc/nginx-agent/nginx-agent.conf`:

main.go

@@ -13,7 +13,6 @@ import (
 	"strconv"
 
 	"github.com/nginx/agent/sdk/v2/agent/events"
-
 	sdkGRPC "github.com/nginx/agent/sdk/v2/grpc"
 	"github.com/nginx/agent/v2/src/core"
 	"github.com/nginx/agent/v2/src/core/config"
@@ -31,12 +30,12 @@ var (
 	env     = &core.EnvironmentType{}
 )
 
-func init() {
-	config.InitConfiguration(version, commit)
-}
-
 func main() {
+	config.InitFlags(version, commit)
+
 	config.RegisterRunner(func(cmd *cobra.Command, _ []string) {
+		config.InitConfigurationFiles()
+
 		ctx, cancel := context.WithCancel(context.Background())
 		defer cancel()
 

src/core/config/config.go

@@ -17,7 +17,6 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
-	"runtime"
 	"sort"
 	"strings"
 	"time"
@@ -32,10 +31,7 @@ import (
 )
 
 const (
-	dynamicConfigUsageComment = `#
-# /etc/nginx-agent/dynamic-agent.conf
-#
-# Dynamic configuration file for NGINX Agent.
+	dynamicConfigUsageComment = `# Dynamic configuration file for NGINX Agent.
 #
 # The purpose of this file is to track agent configuration
 # values that can be dynamically changed via the API and the agent install script.
@@ -63,15 +59,19 @@ func Execute() error {
 	return ROOT_COMMAND.Execute()
 }
 
-func InitConfiguration(version, commit string) {
+func InitFlags(version, commit string) {
 	SetVersion(version, commit)
 	SetDefaults()
 	RegisterFlags()
-	dynamicConfigPath := DynamicConfigFileAbsPath
-	if runtime.GOOS == "freebsd" {
-		dynamicConfigPath = DynamicConfigFileAbsFreeBsdPath
+}
+
+func InitConfigurationFiles() {
+	dynamicConfFilePath := Viper.GetString(DynamicConfigPathKey)
+	if dynamicConfFilePath == "" {
+		dynamicConfFilePath = getDefaultDynamicConfPath()
 	}
-	configPath, err := RegisterConfigFile(dynamicConfigPath, ConfigFileName, ConfigFilePaths()...)
+
+	configPath, err := RegisterConfigFile(dynamicConfFilePath, ConfigFileName, ConfigFilePaths()...)
 	if err != nil {
 		log.Fatalf("Failed to load configuration file: %v", err)
 	}
@@ -104,13 +104,15 @@ func SetDefaults() {
 	Viper.SetDefault(NginxClientVersion, Defaults.Nginx.NginxClientVersion)
 	Viper.SetDefault(NginxConfigReloadMonitoringPeriod, Defaults.Nginx.ConfigReloadMonitoringPeriod)
 
+	// NGINX AGENT DEFAULTS
+	Viper.SetDefault(DynamicConfigPathKey, Defaults.DynamicConfigPath)
 	Viper.SetDefault(QueueSizeKey, Defaults.QueueSize)
 }
 
 func setFlagDeprecated(name string, usageMessage string) {
 	err := ROOT_COMMAND.Flags().MarkDeprecated(name, usageMessage)
 	if err != nil {
-		log.Warnf("error occurred deprecating flag %s: %v", name, err)
+		log.Warnf("Error occurred deprecating flag %s: %v", name, err)
 	}
 }
 
@@ -149,7 +151,7 @@ func RegisterFlags() {
 		}
 		err := Viper.BindEnv(flag.Name)
 		if err != nil {
-			log.Warnf("error occurred binding env %s: %v", flag.Name, err)
+			log.Warnf("Error occurred binding env %s: %v", flag.Name, err)
 		}
 	})
 }
@@ -160,7 +162,7 @@ func RegisterConfigFile(dynamicConfFilePath string, confFileName string, confPat
 		return cfg, err
 	}
 
-	SetDynamicConfigFileAbsPath(dynamicConfFilePath)
+	setDynamicConfigFileAbsPath(dynamicConfFilePath)
 	if err := LoadPropertiesFromFile(cfg); err != nil {
 		log.Fatalf("Unable to load properties from config files (%s, %s) - %v", cfg, dynamicConfFilePath, err)
 	}
@@ -270,11 +272,7 @@ func UpdateAgentConfig(systemId string, updateTags []string, updateFeatures []st
 	// already set.
 	dynamicCfgPath := Viper.GetString(DynamicConfigPathKey)
 	if dynamicCfgPath == "" {
-		if runtime.GOOS == "freebsd" {
-			dynamicCfgPath = DynamicConfigFileAbsFreeBsdPath
-		} else {
-			dynamicCfgPath = DynamicConfigFileAbsPath
-		}
+		dynamicCfgPath = getDefaultDynamicConfPath()
 	}
 
 	// Overwrite existing nginx-agent.conf with updated config
@@ -385,11 +383,7 @@ func LoadPropertiesFromFile(cfg string) error {
 	// already set.
 	dynamicCfgPath := Viper.GetString(DynamicConfigPathKey)
 	if dynamicCfgPath == "" {
-		if runtime.GOOS == "freebsd" {
-			dynamicCfgPath = DynamicConfigFileAbsFreeBsdPath
-		} else {
-			dynamicCfgPath = DynamicConfigFileAbsPath
-		}
+		dynamicCfgPath = getDefaultDynamicConfPath()
 	}
 
 	dynamicCfgDir, dynamicCfgFile := filepath.Split(dynamicCfgPath)
@@ -484,7 +478,7 @@ func removeFeatures(readFile io.Reader) (bool, []byte, error) {
 	return featuresSet, buf.Bytes(), nil
 }
 
-func SetDynamicConfigFileAbsPath(dynamicCfgPath string) {
+func setDynamicConfigFileAbsPath(dynamicCfgPath string) {
 	Viper.Set(DynamicConfigPathKey, dynamicCfgPath)
 	log.Debugf("Set dynamic agent config file: %s", dynamicCfgPath)
 }
@@ -493,7 +487,7 @@ func wordSepNormalizeFunc(f *flag.FlagSet, name string) flag.NormalizedName {
 	from := []string{"_", "."}
 	to := "-"
 	for _, sep := range from {
-		name = strings.Replace(name, sep, to, -1)
+		name = strings.ReplaceAll(name, sep, to)
 	}
 	return flag.NormalizedName(name)
 }