Merge pull request cri-o#8754 from MarSik/runtime-inherit

RuntimeHandler inheritance

docs/crio.conf.5.md

@@ -345,6 +345,9 @@ Root directory used to store runtime data
 **runtime_type**="oci"
 Type of the runtime used for this runtime handler. "oci", "vm"
 
+**inherit_default_runtime**=false
+Override the runtime path, runtime config path, runtime root and runtime type from the default runtime on load.
+
 **runtime_config_path**=""
 Path to the runtime configuration file, should only be used with VM runtime types
 

pkg/config/config.go

@@ -264,6 +264,10 @@ type RuntimeHandler struct {
 	// Output of the "features" subcommand.
 	// This is populated dynamically and not read from config.
 	features runtimeHandlerFeatures
+
+	// Inheritance request
+	// Fill in the Runtime information (paths and type) from the default runtime
+	InheritDefaultRuntime bool `toml:"inherit_default_runtime,omitempty"`
 }
 
 // Multiple runtime Handlers in a map.

pkg/config/config_test.go

@@ -1503,6 +1503,20 @@ var _ = t.Describe("Config", func() {
 			// Then
 			Expect(err).ToNot(HaveOccurred())
 		})
+
+		It("should succeed with empty runtime type and runtime_config_path when inheriting from default", func() {
+			// Given
+			sut.Runtimes["inherited"] = &config.RuntimeHandler{
+				RuntimeConfigPath: invalidPath, RuntimeType: "invalid", InheritDefaultRuntime: true,
+			}
+			err := sut.ReloadRuntimes(sut)
+			Expect(err).ToNot(HaveOccurred())
+
+			// When
+			err = sut.Validate(false)
+			// Then
+			Expect(err).ToNot(HaveOccurred())
+		})
 	})
 
 	t.Describe("RuntimeHandlerFeatures", func() {

pkg/config/reload.go

@@ -285,6 +285,16 @@ func (c *Config) ReloadRuntimes(newConfig *Config) error {
 		return nil
 	}
 
+	// Update the default runtime paths in all runtimes that are asking for inheritance
+	for _, runtime := range c.Runtimes {
+		if runtime.InheritDefaultRuntime {
+			runtime.RuntimePath = c.Runtimes[c.DefaultRuntime].RuntimePath
+			runtime.RuntimeType = c.Runtimes[c.DefaultRuntime].RuntimeType
+			runtime.RuntimeConfigPath = c.Runtimes[c.DefaultRuntime].RuntimeConfigPath
+			runtime.RuntimeRoot = c.Runtimes[c.DefaultRuntime].RuntimeRoot
+		}
+	}
+
 	if err := c.ValidateRuntimes(); err != nil {
 		return fmt.Errorf("unabled to reload runtimes: %w", err)
 	}

pkg/config/reload_test.go

@@ -428,6 +428,30 @@ var _ = t.Describe("Config", func() {
 			Expect(sut.Runtimes).To(HaveKeyWithValue("existing", newRuntime))
 			Expect(sut.Runtimes["existing"].PrivilegedWithoutHostDevices).To(BeTrue())
 		})
+
+		It("should inherit runtime config", func() {
+			// Given
+			newRuntime := &config.RuntimeHandler{
+				RuntimePath:           invalidPath,
+				InheritDefaultRuntime: true,
+			}
+			defaultRuntime := &config.RuntimeHandler{
+				RuntimePath: existingRuntimePath,
+			}
+			newConfig := &config.Config{}
+			newConfig.DefaultRuntime = "default"
+			newConfig.Runtimes = make(config.Runtimes)
+			newConfig.Runtimes["default"] = defaultRuntime
+			newConfig.Runtimes["new"] = newRuntime
+
+			// When
+			err := sut.ReloadRuntimes(newConfig)
+
+			// Then
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sut.Runtimes).To(HaveKeyWithValue("new", newRuntime))
+			Expect(sut.Runtimes["new"].RuntimePath).To(Equal(existingRuntimePath))
+		})
 	})
 
 	t.Describe("ReloadPinnedImages", func() {

pkg/config/template.go

@@ -1230,6 +1230,7 @@ const templateStringCrioRuntimeRuntimesRuntimeHandler = `# The "crio.runtime.run
 # runtime_path = "/path/to/the/executable"
 # runtime_type = "oci"
 # runtime_root = "/path/to/the/root"
+# inherit_default_runtime = false
 # monitor_path = "/path/to/container/monitor"
 # monitor_cgroup = "/cgroup/path"
 # monitor_exec_cgroup = "/cgroup/path"
@@ -1250,6 +1251,9 @@ const templateStringCrioRuntimeRuntimesRuntimeHandler = `# The "crio.runtime.run
 #   state.
 # - runtime_config_path (optional, string): the path for the runtime configuration
 #   file. This can only be used with when using the VM runtime_type.
+# - inherit_default_runtime (optional, bool): when true the runtime_path,
+#   runtime_type, runtime_root and runtime_config_path will be replaced by
+#   the values from the default runtime on load time.
 # - privileged_without_host_devices (optional, bool): an option for restricting
 #   host devices from being passed to privileged containers.
 # - allowed_annotations (optional, array of strings): an option for specifying
@@ -1320,6 +1324,7 @@ const templateStringCrioRuntimeRuntimesRuntimeHandler = `# The "crio.runtime.run
 {{ $.Comment }}runtime_path = "{{ $runtime_handler.RuntimePath }}"
 {{ $.Comment }}runtime_type = "{{ $runtime_handler.RuntimeType }}"
 {{ $.Comment }}runtime_root = "{{ $runtime_handler.RuntimeRoot }}"
+{{ $.Comment }}inherit_default_runtime = {{ $runtime_handler.InheritDefaultRuntime }}
 {{ $.Comment }}runtime_config_path = "{{ $runtime_handler.RuntimeConfigPath }}"
 {{ $.Comment }}container_min_memory = "{{ $runtime_handler.ContainerMinMemory }}"
 {{ $.Comment }}monitor_path = "{{ $runtime_handler.MonitorPath }}"