Implemented log rotator for exec based drivers

api/tasks.go

@@ -74,6 +74,12 @@ func (g *TaskGroup) AddTask(t *Task) *TaskGroup {
 	return g
 }
 
+// LogConfig provides configuration for log rotation
+type LogConfig struct {
+	MaxFiles      int `mapstructure:"max_files"`
+	MaxFileSizeMB int `mapstructure:"max_file_size"`
+}
+
 // Task is a single process in a task group.
 type Task struct {
 	Name        string
@@ -85,6 +91,7 @@ type Task struct {
 	Resources   *Resources
 	Meta        map[string]string
 	KillTimeout time.Duration
+	LogConfig   *LogConfig
 }
 
 // NewTask creates and initializes a new Task.

client/driver/exec.go

@@ -116,6 +116,7 @@ func (d *ExecDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle,
 		AllocDir:         ctx.AllocDir,
 		TaskName:         task.Name,
 		TaskResources:    task.Resources,
+		LogConfig:        task.LogConfig,
 		ResourceLimits:   true,
 		FSIsolation:      true,
 		UnprivilegedUser: true,

client/driver/executor/executor.go

@@ -2,6 +2,7 @@ package executor
 
 import (
 	"fmt"
+	"io"
 	"log"
 	"os"
 	"os/exec"
@@ -15,6 +16,7 @@ import (
 
 	"github.com/hashicorp/nomad/client/allocdir"
 	"github.com/hashicorp/nomad/client/driver/env"
+	"github.com/hashicorp/nomad/client/driver/logrotator"
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
@@ -25,6 +27,7 @@ type ExecutorContext struct {
 	AllocDir         *allocdir.AllocDir
 	TaskName         string
 	TaskResources    *structs.Resources
+	LogConfig        *structs.LogConfig
 	FSIsolation      bool
 	ResourceLimits   bool
 	UnprivilegedUser bool
@@ -94,19 +97,23 @@ func (e *UniversalExecutor) LaunchCmd(command *ExecCommand, ctx *ExecutorContext
 		}
 	}
 
-	stdoPath := filepath.Join(e.taskDir, allocdir.TaskLocal, fmt.Sprintf("%v.stdout", ctx.TaskName))
-	stdo, err := os.OpenFile(stdoPath, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0666)
-	if err != nil {
-		return nil, err
-	}
-	e.cmd.Stdout = stdo
+	logFileSize := int64(ctx.LogConfig.MaxFileSizeMB * 1024 * 1024)
 
-	stdePath := filepath.Join(e.taskDir, allocdir.TaskLocal, fmt.Sprintf("%v.stderr", ctx.TaskName))
-	stde, err := os.OpenFile(stdePath, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0666)
+	stdor, stdow := io.Pipe()
+	lro, err := logrotator.NewLogRotator(filepath.Join(e.taskDir, allocdir.TaskLocal), fmt.Sprintf("%v.stdout", ctx.TaskName), ctx.LogConfig.MaxFiles, logFileSize, e.logger)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error creating log rotator for stdout of task %v", err)
 	}
-	e.cmd.Stderr = stde
+	e.cmd.Stdout = stdow
+	go lro.Start(stdor)
+
+	stder, stdew := io.Pipe()
+	lre, err := logrotator.NewLogRotator(filepath.Join(e.taskDir, allocdir.TaskLocal), fmt.Sprintf("%v.stderr", ctx.TaskName), ctx.LogConfig.MaxFiles, logFileSize, e.logger)
+	if err != nil {
+		return nil, fmt.Errorf("error creating log rotator for stderr of task %v", err)
+	}
+	e.cmd.Stderr = stdew
+	go lre.Start(stder)
 
 	e.cmd.Env = ctx.TaskEnv.EnvList()
 

client/driver/java.go

@@ -162,6 +162,7 @@ func (d *JavaDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle,
 		AllocDir:      ctx.AllocDir,
 		TaskName:      task.Name,
 		TaskResources: task.Resources,
+		LogConfig:     task.LogConfig,
 	}
 	ps, err := exec.LaunchCmd(&executor.ExecCommand{Cmd: "java", Args: args}, executorCtx)
 	if err != nil {

client/driver/logrotator/logs.go

@@ -1,4 +1,4 @@
-package driver
+package logrotator
 
 import (
 	"fmt"

client/driver/logrotator/logs_test.go

@@ -1,4 +1,4 @@
-package driver
+package logrotator
 
 import (
 	"io"

client/driver/qemu.go

@@ -206,6 +206,7 @@ func (d *QemuDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle,
 		AllocDir:      ctx.AllocDir,
 		TaskName:      task.Name,
 		TaskResources: task.Resources,
+		LogConfig:     task.LogConfig,
 	}
 	ps, err := exec.LaunchCmd(&executor.ExecCommand{Cmd: args[0], Args: args[1:]}, executorCtx)
 	if err != nil {

client/driver/raw_exec.go

@@ -112,6 +112,7 @@ func (d *RawExecDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandl
 		AllocDir:      ctx.AllocDir,
 		TaskName:      task.Name,
 		TaskResources: task.Resources,
+		LogConfig:     task.LogConfig,
 	}
 	ps, err := exec.LaunchCmd(&executor.ExecCommand{Cmd: command, Args: driverConfig.Args}, executorCtx)
 	if err != nil {