Added a plugin logging configuration to specify defaults.

This is similar to https://github.com/hashicorp/nomad/pull/10156/files
and allows for a configuration like:

```
plugin "nomad-driver-podman" {
    config {
	extra_labels = ["job_name", "job_id", "task_group_name", "task_name", "namespace", "node_name", "node_id"]
	logging {
		driver = "journald"
		options = {
			tag = "{{index .Config.Labels \"com.hashicorp.nomad.alloc_id\" }}"
		}
	}
    }
}
```

README.md

@@ -188,6 +188,11 @@ plugin "nomad-driver-podman" {
 }
 ```
 
+* logging stanza:
+
+  * type - Defaults to `"nomad"`. See the task configuration for details.
+  * options - Defaults to `{}`. See the task configuration for details.
+
 * client_http_timeout (string) Defaults to `60s` default timeout used by http.Client requests
 
 ```hcl
@@ -342,11 +347,9 @@ Ensure you're running Podman 3.1.0 or higher because of bugs in older versions.
 config {
   logging = {
     driver = "journald"
-    options = [
-      {
-        "tag" = "redis"
-      }
-    ]
+    options = {
+      "tag" = "redis"
+    }
   }
 }
 ```

config.go

@@ -44,6 +44,16 @@ var (
 		),
 		// optional extra_labels to append to all tasks for observability. Globs supported
 		"extra_labels": hclspec.NewAttr("extra_labels", "list(string)", false),
+
+		// logging options
+		"logging": hclspec.NewDefault(hclspec.NewBlock("logging", false, hclspec.NewObject(map[string]*hclspec.Spec{
+			"driver":  hclspec.NewAttr("driver", "string", false),
+			"options": hclspec.NewBlockAttrs("options", "string", false),
+		})), hclspec.NewLiteral(`{
+			driver = "nomad"
+			options = {}
+		}`)),
+
 		// the path to the podman api socket
 		"socket_path": hclspec.NewAttr("socket_path", "string", false),
 		// disable_log_collection indicates whether nomad should collect logs of podman
@@ -123,8 +133,8 @@ type GCConfig struct {
 
 // LoggingConfig is the tasks logging configuration
 type LoggingConfig struct {
-	Driver  string             `codec:"driver"`
-	Options hclutils.MapStrStr `codec:"options"`
+	Driver  string            `codec:"driver"`
+	Options map[string]string `codec:"options"`
 }
 
 // VolumeConfig is the drivers volume specific configuration
@@ -148,6 +158,7 @@ type PluginConfig struct {
 	SocketPath           string           `codec:"socket_path"`
 	ClientHttpTimeout    string           `codec:"client_http_timeout"`
 	ExtraLabels          []string         `codec:"extra_labels"`
+	Logging              LoggingConfig    `codec:"logging"`
 }
 
 // LogWarnings will emit logs about known problematic configurations

driver.go

@@ -502,20 +502,34 @@ func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *drive
 	createOpts.ContainerBasicConfig.Labels = driverConfig.Labels
 
 	// Logging
-	switch driverConfig.Logging.Driver {
-	case "", LOG_DRIVER_NOMAD:
-		// Only modify container logging path if LogCollection is not disabled
-		if !d.config.DisableLogCollection {
-			createOpts.LogConfiguration.Driver = "k8s-file"
-
-			createOpts.ContainerBasicConfig.LogConfiguration.Path = cfg.StdoutPath
+	if driverConfig.Logging.Driver != "" {
+		switch driverConfig.Logging.Driver {
+		case LOG_DRIVER_NOMAD:
+			if !d.config.DisableLogCollection {
+				createOpts.LogConfiguration.Driver = "k8s-file"
+				createOpts.ContainerBasicConfig.LogConfiguration.Path = cfg.StdoutPath
+			}
+		case LOG_DRIVER_JOURNALD:
+			createOpts.LogConfiguration.Driver = "journald"
+		default:
+			return nil, nil, fmt.Errorf("Invalid task logging.driver option")
 		}
-	case LOG_DRIVER_JOURNALD:
-		createOpts.LogConfiguration.Driver = "journald"
-	default:
-		return nil, nil, fmt.Errorf("Invalid logging.driver option")
+		createOpts.ContainerBasicConfig.LogConfiguration.Options = driverConfig.Logging.Options
+	} else {
+		d.logger.Trace("no podman log driver provided, defaulting to plugin config")
+		switch d.config.Logging.Driver {
+		case LOG_DRIVER_NOMAD:
+			if !d.config.DisableLogCollection {
+				createOpts.LogConfiguration.Driver = "k8s-file"
+				createOpts.ContainerBasicConfig.LogConfiguration.Path = cfg.StdoutPath
+			}
+		case LOG_DRIVER_JOURNALD:
+			createOpts.LogConfiguration.Driver = "journald"
+		default:
+			return nil, nil, fmt.Errorf("Invalid plugin logging.driver option")
+		}
+		createOpts.ContainerBasicConfig.LogConfiguration.Options = d.config.Logging.Options
 	}
-	createOpts.ContainerBasicConfig.LogConfiguration.Options = driverConfig.Logging.Options
 
 	// Storage config options
 	createOpts.ContainerStorageConfig.Init = driverConfig.Init

driver_test.go

@@ -516,6 +516,55 @@ func TestPodmanDriver_logNomad(t *testing.T) {
 	must.StrContains(t, stdoutLog, stderrMagic)
 }
 
+// Check default plugin logger
+// TODO: Can we make this nicer?
+func TestPodmanDriver_logNomadDefault(t *testing.T) {
+	ci.Parallel(t)
+
+	stdoutMagic := uuid.Generate()
+	stderrMagic := uuid.Generate()
+
+	taskCfg := newTaskConfig("", []string{
+		"sh",
+		"-c",
+		fmt.Sprintf("echo %s; 1>&2 echo %s", stdoutMagic, stderrMagic),
+	})
+	task := &drivers.TaskConfig{
+		ID:        uuid.Generate(),
+		Name:      "logNomad",
+		AllocID:   uuid.Generate(),
+		Resources: createBasicResources(),
+	}
+	must.NoError(t, task.EncodeConcreteDriverConfig(&taskCfg))
+
+	d := podmanDriverHarness(t, nil)
+	cleanup := d.MkAllocDir(task, true)
+	defer cleanup()
+
+	_, _, err := d.StartTask(task)
+	must.NoError(t, err)
+
+	defer func() {
+		_ = d.DestroyTask(task.ID, true)
+	}()
+
+	// Attempt to wait
+	waitCh, err := d.WaitTask(context.Background(), task.ID)
+	must.NoError(t, err)
+
+	select {
+	case <-waitCh:
+	case <-time.After(10 * time.Second):
+		t.Fatalf("Container did not exit in time")
+	}
+
+	// log_driver=nomad combines both streams into stdout, so we will find both
+	// magic values in the same stream
+	stdoutLog := readStdoutLog(t, task)
+	must.StrContains(t, stdoutLog, stdoutMagic)
+	must.StrContains(t, stdoutLog, stderrMagic)
+}
+
 // check if extra labels make it into logs
 func TestPodmanDriver_ExtraLabels(t *testing.T) {
 	ci.Parallel(t)