Support CDI devices as mounts

This change allows CDI devices to be requested as mounts in the
container. This enables their use in environments such as kind
where environment variables or annotations cannot be used.

Signed-off-by: Evan Lezar <elezar@nvidia.com>

internal/config/image/builder.go

@@ -19,10 +19,13 @@ package image
 import (
 	"fmt"
 	"strings"
+
+	"github.com/opencontainers/runtime-spec/specs-go"
 )
 
 type builder struct {
-	env            []string
+	env            map[string]string
+	mounts         []specs.Mount
 	disableRequire bool
 }
 
@@ -30,7 +33,12 @@ type builder struct {
 func New(opt ...Option) (CUDA, error) {
 	b := &builder{}
 	for _, o := range opt {
-		o(b)
+		if err := o(b); err != nil {
+			return CUDA{}, err
+		}
+	}
+	if b.env == nil {
+		b.env = make(map[string]string)
 	}
 
 	return b.build()
@@ -38,36 +46,57 @@ func New(opt ...Option) (CUDA, error) {
 
 // build creates a CUDA image from the builder.
 func (b builder) build() (CUDA, error) {
-	c := make(CUDA)
-
-	for _, e := range b.env {
-		parts := strings.SplitN(e, "=", 2)
-		if len(parts) != 2 {
-			return nil, fmt.Errorf("invalid environment variable: %v", e)
-		}
-		c[parts[0]] = parts[1]
-	}
-
 	if b.disableRequire {
-		c[envNVDisableRequire] = "true"
+		b.env[envNVDisableRequire] = "true"
 	}
 
+	c := CUDA{
+		env:    b.env,
+		mounts: b.mounts,
+	}
 	return c, nil
 }
 
 // Option is a functional option for creating a CUDA image.
-type Option func(*builder)
+type Option func(*builder) error
 
 // WithDisableRequire sets the disable require option.
 func WithDisableRequire(disableRequire bool) Option {
-	return func(b *builder) {
+	return func(b *builder) error {
 		b.disableRequire = disableRequire
+		return nil
 	}
 }
 
 // WithEnv sets the environment variables to use when creating the CUDA image.
+// Note that this also overwrites the values set with WithEnvMap.
 func WithEnv(env []string) Option {
-	return func(b *builder) {
-		b.env = env
+	return func(b *builder) error {
+		envmap := make(map[string]string)
+		for _, e := range env {
+			parts := strings.SplitN(e, "=", 2)
+			if len(parts) != 2 {
+				return fmt.Errorf("invalid environment variable: %v", e)
+			}
+			envmap[parts[0]] = parts[1]
+		}
+		return WithEnvMap(envmap)(b)
+	}
+}
+
+// WithEnvMap sets the environment variable map to use when creating the CUDA image.
+// Note that this also overwrites the values set with WithEnv.
+func WithEnvMap(env map[string]string) Option {
+	return func(b *builder) error {
+		b.env = env
+		return nil
+	}
+}
+
+// WithMounts sets the mounts associated with the CUDA image.
+func WithMounts(mounts []specs.Mount) Option {
+	return func(b *builder) error {
+		b.mounts = mounts
+		return nil
 	}
 }