add ECS_EBSTA_SUPPORTED envvar to advertise ebsta capabilities

Author: prateekchaudhry

README.md

@@ -267,6 +267,7 @@ Additionally, the following environment variable(s) can be used to configure the
 | `ECS_OFFHOST_INTROSPECTION_INTERFACE_NAME` | `eth0` | Primary network interface name to be used for blocking offhost agent introspection port access. By default, this value is `eth0` | `eth0` |
 | `ECS_AGENT_LABELS` | `{"test.label.1":"value1","test.label.2":"value2"}` | The labels to add to the ECS Agent container. | |
 | `ECS_AGENT_APPARMOR_PROFILE` | `unconfined` | Specifies the name of the AppArmor profile to run the ecs-agent container under. This only applies to AppArmor-enabled systems, such as Ubuntu, Debian, and SUSE. If unset, defaults to the profile written out by ecs-init (ecs-agent-default). | `ecs-agent-default` |
+| `ECS_EBSTA_SUPPORTED` | `true` | Whether to use the container instance with EBS Task Attach support. ecs-init sets this variable for the ECS Agent if the instance support can support mounting EBS volumes or not. | `false` | `false` |
 
 
 

agent/app/agent_capability.go

@@ -295,8 +295,10 @@ func (agent *ecsAgent) capabilities() ([]*ecs.Attribute, error) {
 	// add service-connect capabilities if applicable
 	capabilities = agent.appendServiceConnectCapabilities(capabilities)
 
-	// add ebs-task-attach attribute if applicable
-	capabilities = agent.appendEBSTaskAttachCapabilities(capabilities)
+	if agent.cfg.EBSTASupportEnabled {
+		// add ebs-task-attach attribute if applicable
+		capabilities = agent.appendEBSTaskAttachCapabilities(capabilities)
+	}
 
 	if agent.cfg.External.Enabled() {
 		// Add external specific capability; remove external unsupported capabilities.

agent/config/config.go

@@ -582,6 +582,7 @@ func environmentConfig() (Config, error) {
 		PollingMetricsWaitDuration:          parseEnvVariableDuration("ECS_POLLING_METRICS_WAIT_DURATION"),
 		DisableDockerHealthCheck:            parseBooleanDefaultFalseConfig("ECS_DISABLE_DOCKER_HEALTH_CHECK"),
 		GPUSupportEnabled:                   utils.ParseBool(os.Getenv("ECS_ENABLE_GPU_SUPPORT"), false),
+		EBSTASupportEnabled:                 utils.ParseBool(os.Getenv("ECS_EBSTA_SUPPORTED"), false),
 		InferentiaSupportEnabled:            utils.ParseBool(os.Getenv("ECS_ENABLE_INF_SUPPORT"), false),
 		NvidiaRuntime:                       os.Getenv("ECS_NVIDIA_RUNTIME"),
 		TaskMetadataAZDisabled:              utils.ParseBool(os.Getenv("ECS_DISABLE_TASK_METADATA_AZ"), false),

agent/config/types.go

@@ -301,6 +301,9 @@ type Config struct {
 
 	// GPUSupportEnabled specifies if the Agent is capable of launching GPU tasks
 	GPUSupportEnabled bool
+
+	// EBSTASupportEnabled specifies if the Agent can support tasks needing EBS Task Attach
+	EBSTASupportEnabled bool
 	// InferentiaSupportEnabled specifies whether the built-in support for inferentia task is enabled.
 	InferentiaSupportEnabled bool
 

ecs-init/docker/docker.go

@@ -327,6 +327,13 @@ func (c *client) getContainerConfig(envVarsFromFiles map[string]string) *godocke
 		envVariables["ECS_ENABLE_TASK_ENI"] = "false"
 	}
 
+	if config.RunningInExternal() || !isPathValid(config.MountDirectoryEBS(), true) {
+		// EBS Task Attach (EBSTA) is not supported for external instances
+		// If EBS mount directory fails to get created, tasks requiring EBSTA can not be supported
+		// Disable EBSTA Support for these cases
+		envVariables["ECS_EBSTA_SUPPORTED"] = "false"
+	}
+
 	var env []string
 	for envKey, envValue := range envVariables {
 		env = append(env, envKey+"="+envValue)

ecs-init/engine/engine.go

@@ -142,13 +142,12 @@ func (e *Engine) PreStart() error {
 	if err != nil {
 		return engineError("could not create route to the credentials proxy", err)
 	}
-	// Add the EBS Task Attach host mount point
-	// Skip for External, EBS Task Attach is not supported for External launch type
-	if !config.RunningInExternal() {
-		err = os.MkdirAll(config.MountDirectoryEBS(), mountFilePermission)
-		if err != nil {
-			return engineError("could not create EBS mount directory", err)
-		}
+
+	err = os.MkdirAll(config.MountDirectoryEBS(), mountFilePermission)
+	if err != nil {
+		// Log error and continue
+		// If directory creation fails, set ECS_EBSTA_SUPPORTED=false in docker/docker.go
+		log.Error("could not create EBS mount directory", err)
 	}
 
 	docker, err := getDockerClient()