drivers: make internal DisableLogCollection capability public

.changelog/17196.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+drivers: Add `DisableLogCollection` to task driver capabilities interface
+```

client/allocrunner/taskrunner/logmon_hook.go

@@ -19,7 +19,6 @@ import (
 	"github.com/hashicorp/nomad/helper/uuid"
 	"github.com/hashicorp/nomad/nomad/structs"
 	bstructs "github.com/hashicorp/nomad/plugins/base/structs"
-	"github.com/hashicorp/nomad/plugins/drivers"
 	pstructs "github.com/hashicorp/nomad/plugins/shared/structs"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
@@ -157,16 +156,8 @@ func (h *logmonHook) isLoggingDisabled() bool {
 		return true
 	}
 
-	// internal plugins have access to a capability to disable logging and
-	// metrics via a private interface; this is an "experimental" interface and
-	// currently only the docker driver exposes this to users.
-	ic, ok := h.runner.driver.(drivers.InternalCapabilitiesDriver)
-	if !ok {
-		return false
-	}
-
-	caps := ic.InternalCapabilities()
-	if caps.DisableLogCollection {
+	caps := h.runner.driverCapabilities
+	if caps != nil && caps.DisableLogCollection {
 		h.logger.Debug("log collection is disabled by driver")
 		return true
 	}

drivers/docker/config.go

@@ -793,13 +793,6 @@ func (d *Driver) TaskConfigSchema() (*hclspec.Spec, error) {
 // Capabilities is returned by the Capabilities RPC and indicates what optional
 // features this driver supports.
 func (d *Driver) Capabilities() (*drivers.Capabilities, error) {
+	driverCapabilities.DisableLogCollection = d.config != nil && d.config.DisableLogCollection
 	return driverCapabilities, nil
 }
-
-var _ drivers.InternalCapabilitiesDriver = (*Driver)(nil)
-
-func (d *Driver) InternalCapabilities() drivers.InternalCapabilities {
-	return drivers.InternalCapabilities{
-		DisableLogCollection: d.config != nil && d.config.DisableLogCollection,
-	}
-}

drivers/docker/config_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/hashicorp/nomad/ci"
 	"github.com/hashicorp/nomad/helper/pluginutils/hclutils"
 	"github.com/hashicorp/nomad/plugins/drivers"
+	"github.com/shoenig/test/must"
 	"github.com/stretchr/testify/require"
 )
 
@@ -621,28 +622,55 @@ func TestConfig_DriverConfig_GC(t *testing.T) {
 	}
 }
 
-func TestConfig_InternalCapabilities(t *testing.T) {
+func TestConfig_Capabilities(t *testing.T) {
 	ci.Parallel(t)
 
 	cases := []struct {
 		name     string
 		config   string
-		expected drivers.InternalCapabilities
+		expected *drivers.Capabilities
 	}{
 		{
-			name:     "pure default",
-			config:   `{}`,
-			expected: drivers.InternalCapabilities{},
+			name:   "pure default",
+			config: `{}`,
+			expected: &drivers.Capabilities{
+				SendSignals:          true,
+				Exec:                 true,
+				FSIsolation:          "image",
+				NetIsolationModes:    []drivers.NetIsolationMode{"host", "group", "task"},
+				MustInitiateNetwork:  true,
+				MountConfigs:         0,
+				RemoteTasks:          false,
+				DisableLogCollection: false,
+			},
 		},
 		{
-			name:     "disabled",
-			config:   `{ disable_log_collection = true }`,
-			expected: drivers.InternalCapabilities{DisableLogCollection: true},
+			name:   "disabled",
+			config: `{ disable_log_collection = true }`,
+			expected: &drivers.Capabilities{
+				SendSignals:          true,
+				Exec:                 true,
+				FSIsolation:          "image",
+				NetIsolationModes:    []drivers.NetIsolationMode{"host", "group", "task"},
+				MustInitiateNetwork:  true,
+				MountConfigs:         0,
+				RemoteTasks:          false,
+				DisableLogCollection: true,
+			},
 		},
 		{
-			name:     "enabled explicitly",
-			config:   `{ disable_log_collection = false }`,
-			expected: drivers.InternalCapabilities{},
+			name:   "enabled explicitly",
+			config: `{ disable_log_collection = false }`,
+			expected: &drivers.Capabilities{
+				SendSignals:          true,
+				Exec:                 true,
+				FSIsolation:          "image",
+				NetIsolationModes:    []drivers.NetIsolationMode{"host", "group", "task"},
+				MustInitiateNetwork:  true,
+				MountConfigs:         0,
+				RemoteTasks:          false,
+				DisableLogCollection: false,
+			},
 		},
 	}
 
@@ -652,7 +680,9 @@ func TestConfig_InternalCapabilities(t *testing.T) {
 			hclutils.NewConfigParser(configSpec).ParseHCL(t, "config "+c.config, &tc)
 
 			d := &Driver{config: &tc}
-			require.Equal(t, c.expected, d.InternalCapabilities())
+			caps, err := d.Capabilities()
+			must.NoError(t, err)
+			must.Eq(t, c.expected, caps)
 		})
 	}
 }

plugins/drivers/client.go

@@ -77,6 +77,7 @@ func (d *driverPluginClient) Capabilities() (*Capabilities, error) {
 
 		caps.MountConfigs = MountConfigSupport(resp.Capabilities.MountConfigs)
 		caps.RemoteTasks = resp.Capabilities.RemoteTasks
+		caps.DisableLogCollection = resp.Capabilities.DisableLogCollection
 	}
 
 	return caps, nil

plugins/drivers/driver.go

@@ -174,6 +174,10 @@ type Capabilities struct {
 	// adjust behavior such as propogating task handles between allocations
 	// to avoid downtime when a client is lost.
 	RemoteTasks bool
+
+	// DisableLogCollection indicates this driver has disabled log collection
+	// and the client should not start a logmon process.
+	DisableLogCollection bool
 }
 
 func (c *Capabilities) HasNetIsolationMode(m NetIsolationMode) bool {