Allow container runtime executable path to be specified

This change adds support for specifying the container runtime
executable path. This can be used if, for example, there are
two containerd executables and a specific one must be used.

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

cmd/nvidia-ctk-installer/container/container.go

@@ -38,6 +38,11 @@ const (
 type Options struct {
 	Config string
 	Socket string
+	// ExecutablePath specifies the path to the container runtime executable.
+	// This is used to extract the current config, for example.
+	// If a HostRootMount is specified, this path is relative to the host root
+	// mount.
+	ExecutablePath string
 	// EnabledCDI indicates whether CDI should be enabled.
 	EnableCDI     bool
 	RuntimeName   string

cmd/nvidia-ctk-installer/container/runtime/containerd/containerd.go

@@ -173,7 +173,7 @@ func getRuntimeConfig(o *container.Options, co *Options) (engine.Interface, erro
 		containerd.WithPath(o.Config),
 		containerd.WithConfigSource(
 			toml.LoadFirst(
-				containerd.CommandLineSource(o.HostRootMount),
+				containerd.CommandLineSource(o.HostRootMount, o.ExecutablePath),
 				toml.FromFile(o.Config),
 			),
 		),

cmd/nvidia-ctk-installer/container/runtime/runtime.go

@@ -53,6 +53,11 @@ func Flags(opts *Options) []cli.Flag {
 			Destination: &opts.Config,
 			EnvVars:     []string{"RUNTIME_CONFIG", "CONTAINERD_CONFIG", "DOCKER_CONFIG"},
 		},
+		&cli.StringFlag{
+			Name:        "container-runtime-executable-path",
+			Destination: &opts.ExecutablePath,
+			EnvVars:     []string{"RUNTIME_EXECUTABLE_PATH"},
+		},
 		&cli.StringFlag{
 			Name:        "socket",
 			Usage:       "Path to the runtime socket file",

cmd/nvidia-ctk/runtime/configure/configure.go

@@ -68,6 +68,7 @@ type config struct {
 	dryRun         bool
 	runtime        string
 	configFilePath string
+	executablePath string
 	configSource   string
 	mode           string
 	hookFilePath   string
@@ -120,6 +121,10 @@ func (m command) build() *cli.Command {
 			Usage:       "path to the config file for the target runtime",
 			Destination: &config.configFilePath,
 		},
+		&cli.StringFlag{
+			Name:        "executable-path",
+			Destination: &config.executablePath,
+		},
 		&cli.StringFlag{
 			Name:        "config-mode",
 			Usage:       "the config mode for runtimes that support multiple configuration mechanisms",
@@ -330,7 +335,7 @@ func (c *config) resolveConfigSource() (toml.Loader, error) {
 func (c *config) getCommandConfigSource() toml.Loader {
 	switch c.runtime {
 	case "containerd":
-		return containerd.CommandLineSource("")
+		return containerd.CommandLineSource("", c.executablePath)
 	case "crio":
 		return crio.CommandLineSource("")
 	}

pkg/config/engine/containerd/containerd.go

@@ -162,8 +162,11 @@ func (c *Config) GetRuntimeConfig(name string) (engine.RuntimeConfig, error) {
 }
 
 // CommandLineSource returns the CLI-based containerd config loader
-func CommandLineSource(hostRoot string) toml.Loader {
+func CommandLineSource(hostRoot string, executablePath string) toml.Loader {
-	return toml.FromCommandLine(chrootIfRequired(hostRoot, "containerd", "config", "dump")...)
+	if executablePath == "" {
+		executablePath = "containerd"
+	}
+	return toml.FromCommandLine(chrootIfRequired(hostRoot, executablePath, "config", "dump")...)
 }
 
 func chrootIfRequired(hostRoot string, commandLine ...string) []string {