Adding TCP proxy server

The daemon now serves as a proxy to the X-Ray SDK for API calls that are
related to sampling rules. The proxy runs on TCP port 2000 and relays
calls to get sampling rules and report sampling statistics to X-Ray.

CHANGELOG.md

@@ -1,11 +1,17 @@
 # Change Log
 All notable changes to this project will be documented in this file.
 
+## 3.0.0 (2018-08-28)
+- The daemon now serves as a proxy to the X-Ray SDK for API calls that are related to sampling rules. The proxy runs on TCP port 2000 and relays calls to get sampling rules and report sampling statistics to X-Ray. The TCP proxy server address can be configured from command line using `t` flag or by using `cfg.yaml` version `2` file.
+- `cfg.yaml` file version is changed to `2` and has an extra attribute. The daemon supports version `1` of cfg.yaml:
 
-## 2.1.3 (2018-06-13)
-- Updated AWS SDK dependency version to `1.14.1`
-- Refactored `MockTimerClient`
-- Moving version number variable to `cfg` package
+```
+  Socket:
+  # Change the address and port on which the daemon listens for HTTP requests to proxy to AWS X-Ray.
+  TCPAddress: "127.0.0.1:2000"
+```
+- Adds timestamp header `X-Amzn-Xray-Timestamp` to PutTraceSegments API calls made by the daemon
+- Adding support for configuring `ProxyAddress` through command line: PR [#10](https://github.com/aws/aws-xray-daemon/pull/10)
 
 ## 2.1.2 (2018-05-14)
 - SystemD service file updates for Debian and Linux binaries: PR [#3](https://github.com/aws/aws-xray-daemon/pull/3)

README.md

@@ -46,15 +46,16 @@ Usage: X-Ray [options]
 1. -a  --resource-arn Amazon Resource Name (ARN) of the AWS resource running the daemon.    
 2. -o  --local-mode   Don't check for EC2 instance metadata.    
 3. -m  --buffer-memory    Change the amount of memory in MB that buffers can use (minimum 3).    
-4. -n  --region   Send segments to the X-Ray service in a specific region.    
-5. -b  --bind    Overrides default UDP address (127.0.0.1:2000).    
-6. -r  --role-arn Assume the specified IAM role to upload segments to a different account.    
-7. -c  --config   Load a configuration file from the specified path.    
-8. -f  --log-file Output logs to the specified file path.    
-9. -l  --log-level    Log level, from most verbose to least: dev, debug, info, warn, error, prod (default).    
-10. -p --proxy-address  Proxy address through which to upload segments.
-11. -v --version  Show AWS X-Ray daemon version.
-12. -h --help    Show this screen
+4. -n  --region   Send segments to X-Ray service in a specific region.    
+5. -b  --bind    Overrides default UDP address (127.0.0.1:2000).  
+6. -t  --bind-tcp	Overrides default TCP address (127.0.0.1:2000).  
+7. -r  --role-arn Assume the specified IAM role to upload segments to a different account.    
+8. -c  --config   Load a configuration file from the specified path.    
+9. -f  --log-file Output logs to the specified file path.    
+10. -l  --log-level    Log level, from most verbose to least: dev, debug, info, warn, error, prod (default).    
+11. -p --proxy-address  Proxy address through which to upload segments.
+12. -v --version  Show AWS X-Ray daemon version.
+13. -h --help    Show this screen
 
 ## Build  
 

VERSION

@@ -1 +1 @@
-2.1.3
+3.0.0

daemon/cfg.yaml

@@ -9,6 +9,8 @@ Endpoint: ""
 Socket:
   # Change the address and port on which the daemon listens for UDP packets containing segment documents.
   UDPAddress: "127.0.0.1:2000"
+  # Change the address and port on which the daemon listens for HTTP requests to proxy to AWS X-Ray.
+  TCPAddress: "127.0.0.1:2000"
 Logging:
   LogRotation: true
   # Change the log level, from most verbose to least: dev, debug, info, warn, error, prod (default).
@@ -26,4 +28,4 @@ NoVerifySSL: false
 # Upload segments to AWS X-Ray through a proxy.
 ProxyAddress: ""
 # Daemon configuration file format version.
-Version: 1
+Version: 2

daemon/cfg/cfg.go

@@ -17,13 +17,16 @@ import (
 	"reflect"
 
 	"github.com/aws/aws-xray-daemon/daemon/util"
+
 	"gopkg.in/yaml.v2"
 
 	log "github.com/cihub/seelog"
 )
 
 // Version number of the X-Ray daemon.
-const Version = "2.1.3"
+const Version = "3.0.0"
+
+var cfgFileVersions = [...]int{1, 2} // Supported versions of cfg.yaml file.
 
 var configLocations = []string{
 	"/etc/amazon/xray/cfg.yaml",
@@ -54,8 +57,15 @@ type Config struct {
 	Socket struct {
 		// Address and port on which the daemon listens for UDP packets containing segment documents.
 		UDPAddress string `yaml:"UDPAddress"`
+		TCPAddress string `yaml:"TCPAddress"`
 	} `yaml:"Socket"`
 
+	ProxyServer struct {
+		IdleConnTimeout     int
+		MaxIdleConnsPerHost int
+		MaxIdleConns        int
+	}
+
 	// Structure for logging.
 	Logging struct {
 		// LogRotation, if true, will rotate log after 50 MB size of current log file.
@@ -94,8 +104,20 @@ func DefaultConfig() *Config {
 		Region:            "",
 		Socket: struct {
 			UDPAddress string `yaml:"UDPAddress"`
+			TCPAddress string `yaml:"TCPAddress"`
 		}{
 			UDPAddress: "127.0.0.1:2000",
+			TCPAddress: "127.0.0.1:2000",
+		},
+		ProxyServer: struct {
+			IdleConnTimeout     int
+			MaxIdleConnsPerHost int
+			MaxIdleConns        int
+		}{
+
+			IdleConnTimeout:     30,
+			MaxIdleConnsPerHost: 2,
+			MaxIdleConns:        0,
 		},
 		Logging: struct {
 			LogRotation *bool  `yaml:"LogRotation"`
@@ -321,11 +343,23 @@ func contains(s []string, e string) bool {
 
 func merge(configFile string) *Config {
 	userConfig := loadConfigFromFile(configFile)
-	if userConfig.Version != 1 {
+	versionMatch := false
+	for i := 0; i < len(cfgFileVersions); i++ {
+		if cfgFileVersions[i] == userConfig.Version {
+			versionMatch = true
+			break
+		}
+	}
+
+	if !versionMatch {
 		errorAndExit("Config Version Setting is not correct. Use X-Ray Daemon Config Migration Script to update the config file. Please refer to AWS X-Ray Documentation for more information.", nil)
 	}
 
 	userConfig.Socket.UDPAddress = getStringValue(userConfig.Socket.UDPAddress, DefaultConfig().Socket.UDPAddress)
+	userConfig.Socket.TCPAddress = getStringValue(userConfig.Socket.TCPAddress, DefaultConfig().Socket.TCPAddress)
+	userConfig.ProxyServer.IdleConnTimeout = DefaultConfig().ProxyServer.IdleConnTimeout
+	userConfig.ProxyServer.MaxIdleConnsPerHost = DefaultConfig().ProxyServer.MaxIdleConnsPerHost
+	userConfig.ProxyServer.MaxIdleConns = DefaultConfig().ProxyServer.MaxIdleConns
 	userConfig.TotalBufferSizeMB = getIntValue(userConfig.TotalBufferSizeMB, DefaultConfig().TotalBufferSizeMB)
 	userConfig.ResourceARN = getStringValue(userConfig.ResourceARN, DefaultConfig().ResourceARN)
 	userConfig.RoleARN = getStringValue(userConfig.RoleARN, DefaultConfig().RoleARN)