refactor config reader - also looks in additional search paths for config file unless NONE is specified

4 files changed, 69 insertions, 51 deletions

diff --git a/internal/config/args.go b/internal/config/args.go
index 89e4bc9..767cc65 100644
--- a/internal/config/args.go
+++ b/internal/config/args.go
@@ -16,6 +16,7 @@ type Args struct {
 	ConfigFile         string
 	ConnectionsPerCPU  int
 	Discovery          string
+	LogDir             string
 	LogLevel           string
 	Mode               omode.Mode
 	NoColor            bool
@@ -39,6 +40,8 @@ func (a *Args) String() string {
 	var sb strings.Builder
 
 	sb.WriteString("Args(")
+	// TODO: All commands should make use of this
+	sb.WriteString(fmt.Sprintf("%s:%s,", "LogDir", a.LogDir))
 	sb.WriteString(fmt.Sprintf("%s:%s,", "LogLevel", a.LogLevel))
 	sb.WriteString(fmt.Sprintf("%s:%v,", "Arguments", a.Arguments))
 	sb.WriteString(fmt.Sprintf("%s:%v,", "ConfigFile", a.ConfigFile))
@@ -66,16 +69,24 @@ func (a *Args) String() string {
 }
 
 // Based on the argument list, transform/manipulate some of the arguments.
-func (a *Args) transform(args []string) {
+func (a *Args) transformConfig(args []string, client *ClientConfig, server *ServerConfig, common *CommonConfig) (*ClientConfig, *ServerConfig, *CommonConfig) {
+	if a.LogDir != "" {
+		common.LogDir = a.LogDir
+		if common.LogStrategy == "" {
+			// TODO: Implement the other (not-daily) log strategy for the server.
+			common.LogStrategy = "daily"
+		}
+	}
+
 	if a.LogLevel != "" {
-		Common.LogLevel = a.LogLevel
+		common.LogLevel = a.LogLevel
 	}
 
-	if a.SSHPort != 2222 {
-		Common.SSHPort = a.SSHPort
+	if a.SSHPort != DefaultSSHPort {
+		common.SSHPort = a.SSHPort
 	}
 	if a.NoColor {
-		Client.TermColorsEnable = false
+		client.TermColorsEnable = false
 	}
 
 	if a.Spartan {
@@ -95,6 +106,8 @@ func (a *Args) transform(args []string) {
 		}
 		a.What = strings.Join(files, ",")
 	}
+
+	return client, server, common
 }
 
 // SerializeOptions returns a string ready to be sent over the wire to the server.
@@ -102,4 +115,4 @@ func (a *Args) SerializeOptions() string {
 	return fmt.Sprintf("quiet=%v:spartan=%v", a.Quiet, a.Spartan)
 }
 
-// TODO: Put the DeseializeOptions function here (move it away from the internal/server package)
+// NEXT: Put the DeseializeOptions function here (move it away from the internal/server package)
diff --git a/internal/config/common.go b/internal/config/common.go
index 7d45261..acc8e6a 100644
--- a/internal/config/common.go
+++ b/internal/config/common.go
@@ -23,7 +23,7 @@ type CommonConfig struct {
 // Create a new default configuration.
 func newDefaultCommonConfig() *CommonConfig {
 	return &CommonConfig{
-		SSHPort:                    2222,
+		SSHPort:                    DefaultSSHPort,
 		ExperimentalFeaturesEnable: false,
 		LogDir:                     "log",
 		CacheDir:                   "cache",
diff --git a/internal/config/config.go b/internal/config/config.go
index 2d77041..c9f411c 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -2,24 +2,26 @@ package config
 
 import (
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 )
 
-// ControlUser is used for various DTail specific operations.
-const ControlUser string = "DTAIL-CONTROL"
-
-// ScheduleUser is used for non-interactive scheduled mapreduce queries.
-const ScheduleUser string = "DTAIL-SCHEDULE"
-
-// ContinuousUser is used for non-interactive continuous mapreduce queries.
-const ContinuousUser string = "DTAIL-CONTINUOUS"
-
-// TestUser is used for unit tests and potentially also for integration tests.
-const TestUser string = "DTAIL-TEST"
-
-// InterruptTimeoutS is used to terminate DTail when Ctrl+C was pressed twice within a given interval.
-const InterruptTimeoutS int = 3
+const (
+	// ControlUser is used for various DTail specific operations.
+	ControlUser string = "DTAIL-CONTROL"
+	// ScheduleUser is used for non-interactive scheduled mapreduce queries.
+	ScheduleUser string = "DTAIL-SCHEDULE"
+	// ContinuousUser is used for non-interactive continuous mapreduce queries.
+	ContinuousUser string = "DTAIL-CONTINUOUS"
+	// InterruptTimeoutS is used to terminate DTail when Ctrl+C was pressed twice within a given interval.
+	InterruptTimeoutS int = 3
+	// ConnectionsPerCPU controls how many connections are established concurrently as a start (slow start)
+	DefaultConnectionsPerCPU int = 10
+	// DTailSSHServerDefaultPort is the default DServer port.
+	DefaultSSHPort int = 2222
+)
 
 // Client holds a DTail client configuration.
 var Client *ClientConfig
@@ -37,21 +39,42 @@ type configInitializer struct {
 	Client *ClientConfig
 }
 
-// Parse and read a given config file in JSON format.
-func (c *configInitializer) parseConfig(configFile string) {
+func (c *configInitializer) parseConfig(args *Args) {
+	if strings.ToUpper(args.ConfigFile) == "NONE" {
+		return
+	}
+
+	if args.ConfigFile != "" {
+		c.parseSpecificConfig(args.ConfigFile)
+		return
+	}
+
+	if homeDir, err := os.UserHomeDir(); err != nil {
+		var paths []string
+		paths = append(paths, fmt.Sprintf("%s/.config/dtail/dtail.conf", homeDir))
+		paths = append(paths, fmt.Sprintf("%s/.dtail.conf", homeDir))
+		for _, configPath := range paths {
+			if _, err := os.Stat(configPath); !os.IsNotExist(err) {
+				c.parseSpecificConfig(configPath)
+			}
+		}
+	}
+}
+
+func (c *configInitializer) parseSpecificConfig(configFile string) {
 	fd, err := os.Open(configFile)
 	if err != nil {
-		panic(err)
+		panic(fmt.Sprintf("Unable to read config file: %v", err))
 	}
 	defer fd.Close()
 
 	cfgBytes, err := ioutil.ReadAll(fd)
 	if err != nil {
-		panic(err)
+		panic(fmt.Sprintf("Unable to read config file %s: %v", configFile, err))
 	}
 
 	err = json.Unmarshal([]byte(cfgBytes), c)
 	if err != nil {
-		panic(err)
+		panic(fmt.Sprintf("Unable to parse config file %s: %v", configFile, err))
 	}
 }
diff --git a/internal/config/setup.go b/internal/config/setup.go
index 3c4bcc4..be8e867 100644
--- a/internal/config/setup.go
+++ b/internal/config/setup.go
@@ -1,11 +1,5 @@
 package config
 
-import (
-	"os"
-)
-
-const NoConfigFile string = "Don't read a config file - use defaults only"
-
 // Setup the DTail configuration.
 func Setup(args *Args, additionalArgs []string) {
 	initializer := configInitializer{
@@ -13,23 +7,11 @@ func Setup(args *Args, additionalArgs []string) {
 		Server: newDefaultServerConfig(),
 		Client: newDefaultClientConfig(),
 	}
-
-	if args.ConfigFile == "" {
-		// TODO: Search more paths for config file (e.g. in /etc and in ~/.config/...
-		args.ConfigFile = "./cfg/dtail.json"
-	}
-
-	if args.ConfigFile != NoConfigFile {
-		if _, err := os.Stat(args.ConfigFile); !os.IsNotExist(err) {
-			initializer.parseConfig(args.ConfigFile)
-		}
-	}
-
-	// Assign pointers to global variables, so that we can access the
-	// configuration from any place of the program.
-	Common = initializer.Common
-	Server = initializer.Server
-	Client = initializer.Client
-
-	args.transform(additionalArgs)
+	initializer.parseConfig(args)
+	Client, Server, Common = args.transformConfig(
+		additionalArgs,
+		initializer.Client,
+		initializer.Server,
+		initializer.Common,
+	)
 }