agent/config/config.go
func environmentConfig() (Config, error) {
	dataDir := os.Getenv("ECS_DATADIR")

	steadyStateRate, burstRate := parseTaskMetadataThrottles()

	var errs []error
	instanceAttributes, errs := parseInstanceAttributes(errs)

	containerInstanceTags, errs := parseContainerInstanceTags(errs)

	additionalLocalRoutes, errs := parseAdditionalLocalRoutes(errs)

	var err error
	if len(errs) > 0 {
		err = apierrors.NewMultiError(errs...)
	}
	return Config{
		Cluster:                             os.Getenv("ECS_CLUSTER"),
		APIEndpoint:                         os.Getenv("ECS_BACKEND_HOST"),
		AWSRegion:                           os.Getenv("AWS_DEFAULT_REGION"),
		DockerEndpoint:                      os.Getenv("DOCKER_HOST"),
		ReservedPorts:                       parseReservedPorts("ECS_RESERVED_PORTS"),
		ReservedPortsUDP:                    parseReservedPorts("ECS_RESERVED_PORTS_UDP"),
		DataDir:                             dataDir,
		Checkpoint:                          parseCheckpoint(dataDir),
		EngineAuthType:                      os.Getenv("ECS_ENGINE_AUTH_TYPE"),
		EngineAuthData:                      NewSensitiveRawMessage([]byte(os.Getenv("ECS_ENGINE_AUTH_DATA"))),
		UpdatesEnabled:                      utils.ParseBool(os.Getenv("ECS_UPDATES_ENABLED"), false),
		UpdateDownloadDir:                   os.Getenv("ECS_UPDATE_DOWNLOAD_DIR"),
		DisableMetrics:                      utils.ParseBool(os.Getenv("ECS_DISABLE_METRICS"), false),
		ReservedMemory:                      parseEnvVariableUint16("ECS_RESERVED_MEMORY"),
		AvailableLoggingDrivers:             parseAvailableLoggingDrivers(),
		PrivilegedDisabled:                  utils.ParseBool(os.Getenv("ECS_DISABLE_PRIVILEGED"), false),
		SELinuxCapable:                      utils.ParseBool(os.Getenv("ECS_SELINUX_CAPABLE"), false),
		AppArmorCapable:                     utils.ParseBool(os.Getenv("ECS_APPARMOR_CAPABLE"), false),
		TaskCleanupWaitDuration:             parseEnvVariableDuration("ECS_ENGINE_TASK_CLEANUP_WAIT_DURATION"),
		TaskENIEnabled:                      utils.ParseBool(os.Getenv("ECS_ENABLE_TASK_ENI"), false),
		TaskIAMRoleEnabled:                  utils.ParseBool(os.Getenv("ECS_ENABLE_TASK_IAM_ROLE"), false),
		DeleteNonECSImagesEnabled:           utils.ParseBool(os.Getenv("ECS_ENABLE_UNTRACKED_IMAGE_CLEANUP"), false),
		TaskCPUMemLimit:                     parseTaskCPUMemLimitEnabled(),
		DockerStopTimeout:                   parseDockerStopTimeout(),
		ContainerStartTimeout:               parseContainerStartTimeout(),
		ImagePullInactivityTimeout:          parseImagePullInactivityTimeout(),
		CredentialsAuditLogFile:             os.Getenv("ECS_AUDIT_LOGFILE"),
		CredentialsAuditLogDisabled:         utils.ParseBool(os.Getenv("ECS_AUDIT_LOGFILE_DISABLED"), false),
		TaskIAMRoleEnabledForNetworkHost:    utils.ParseBool(os.Getenv("ECS_ENABLE_TASK_IAM_ROLE_NETWORK_HOST"), false),
		ImageCleanupDisabled:                utils.ParseBool(os.Getenv("ECS_DISABLE_IMAGE_CLEANUP"), false),
		MinimumImageDeletionAge:             parseEnvVariableDuration("ECS_IMAGE_MINIMUM_CLEANUP_AGE"),
		ImageCleanupInterval:                parseEnvVariableDuration("ECS_IMAGE_CLEANUP_INTERVAL"),
		NumImagesToDeletePerCycle:           parseNumImagesToDeletePerCycle(),
		NumNonECSContainersToDeletePerCycle: parseNumNonECSContainersToDeletePerCycle(),
		ImagePullBehavior:                   parseImagePullBehavior(),
		ImageCleanupExclusionList:           parseImageCleanupExclusionList("ECS_EXCLUDE_UNTRACKED_IMAGE"),
		InstanceAttributes:                  instanceAttributes,
		CNIPluginsPath:                      os.Getenv("ECS_CNI_PLUGINS_PATH"),
		AWSVPCBlockInstanceMetdata:          utils.ParseBool(os.Getenv("ECS_AWSVPC_BLOCK_IMDS"), false),
		AWSVPCAdditionalLocalRoutes:         additionalLocalRoutes,
		ContainerMetadataEnabled:            utils.ParseBool(os.Getenv("ECS_ENABLE_CONTAINER_METADATA"), false),
		DataDirOnHost:                       os.Getenv("ECS_HOST_DATA_DIR"),
		OverrideAWSLogsExecutionRole:        utils.ParseBool(os.Getenv("ECS_ENABLE_AWSLOGS_EXECUTIONROLE_OVERRIDE"), false),
		CgroupPath:                          os.Getenv("ECS_CGROUP_PATH"),
		TaskMetadataSteadyStateRate:         steadyStateRate,
		TaskMetadataBurstRate:               burstRate,
		SharedVolumeMatchFullConfig:         utils.ParseBool(os.Getenv("ECS_SHARED_VOLUME_MATCH_FULL_CONFIG"), false),
		ContainerInstanceTags:               containerInstanceTags,
		ContainerInstancePropagateTagsFrom:  parseContainerInstancePropagateTagsFrom(),
		PollMetrics:                         utils.ParseBool(os.Getenv("ECS_POLL_METRICS"), false),
		PollingMetricsWaitDuration:          parseEnvVariableDuration("ECS_POLLING_METRICS_WAIT_DURATION"),
		DisableDockerHealthCheck:            utils.ParseBool(os.Getenv("ECS_DISABLE_DOCKER_HEALTH_CHECK"), false),
		GPUSupportEnabled:                   utils.ParseBool(os.Getenv("ECS_ENABLE_GPU_SUPPORT"), false),
		NvidiaRuntime:                       os.Getenv("ECS_NVIDIA_RUNTIME"),
		TaskMetadataAZDisabled:              utils.ParseBool(os.Getenv("ECS_DISABLE_TASK_METADATA_AZ"), false),
	}, err
}
func environmentConfig() (Config, error) {
	dataDir := os.Getenv("ECS_DATADIR")

	steadyStateRate, burstRate := parseTaskMetadataThrottles()

	var errs []error
	instanceAttributes, errs := parseInstanceAttributes(errs)

	containerInstanceTags, errs := parseContainerInstanceTags(errs)

	additionalLocalRoutes, errs := parseAdditionalLocalRoutes(errs)

	var err error
	if len(errs) > 0 {
		err = apierrors.NewMultiError(errs...)
	}
	return Config{
		Cluster:                             os.Getenv("ECS_CLUSTER"),
		APIEndpoint:                         os.Getenv("ECS_BACKEND_HOST"),
		AWSRegion:                           os.Getenv("AWS_DEFAULT_REGION"),
		DockerEndpoint:                      os.Getenv("DOCKER_HOST"),
		ReservedPorts:                       parseReservedPorts("ECS_RESERVED_PORTS"),
		ReservedPortsUDP:                    parseReservedPorts("ECS_RESERVED_PORTS_UDP"),
		DataDir:                             dataDir,
		Checkpoint:                          parseCheckpoint(dataDir),
		EngineAuthType:                      os.Getenv("ECS_ENGINE_AUTH_TYPE"),
		EngineAuthData:                      NewSensitiveRawMessage([]byte(os.Getenv("ECS_ENGINE_AUTH_DATA"))),
		UpdatesEnabled:                      utils.ParseBool(os.Getenv("ECS_UPDATES_ENABLED"), false),
		UpdateDownloadDir:                   os.Getenv("ECS_UPDATE_DOWNLOAD_DIR"),
		DisableMetrics:                      utils.ParseBool(os.Getenv("ECS_DISABLE_METRICS"), false),
		ReservedMemory:                      parseEnvVariableUint16("ECS_RESERVED_MEMORY"),
		AvailableLoggingDrivers:             parseAvailableLoggingDrivers(),
		PrivilegedDisabled:                  utils.ParseBool(os.Getenv("ECS_DISABLE_PRIVILEGED"), false),
		SELinuxCapable:                      utils.ParseBool(os.Getenv("ECS_SELINUX_CAPABLE"), false),
		AppArmorCapable:                     utils.ParseBool(os.Getenv("ECS_APPARMOR_CAPABLE"), false),
		TaskCleanupWaitDuration:             parseEnvVariableDuration("ECS_ENGINE_TASK_CLEANUP_WAIT_DURATION"),
		TaskENIEnabled:                      utils.ParseBool(os.Getenv("ECS_ENABLE_TASK_ENI"), false),
		TaskIAMRoleEnabled:                  utils.ParseBool(os.Getenv("ECS_ENABLE_TASK_IAM_ROLE"), false),
		DeleteNonECSImagesEnabled:           utils.ParseBool(os.Getenv("ECS_ENABLE_UNTRACKED_IMAGE_CLEANUP"), false),
		TaskCPUMemLimit:                     parseTaskCPUMemLimitEnabled(),
		DockerStopTimeout:                   parseDockerStopTimeout(),
		ContainerStartTimeout:               parseContainerStartTimeout(),
		ImagePullInactivityTimeout:          parseImagePullInactivityTimeout(),
		CredentialsAuditLogFile:             os.Getenv("ECS_AUDIT_LOGFILE"),
		CredentialsAuditLogDisabled:         utils.ParseBool(os.Getenv("ECS_AUDIT_LOGFILE_DISABLED"), false),
		TaskIAMRoleEnabledForNetworkHost:    utils.ParseBool(os.Getenv("ECS_ENABLE_TASK_IAM_ROLE_NETWORK_HOST"), false),
		ImageCleanupDisabled:                utils.ParseBool(os.Getenv("ECS_DISABLE_IMAGE_CLEANUP"), false),
		MinimumImageDeletionAge:             parseEnvVariableDuration("ECS_IMAGE_MINIMUM_CLEANUP_AGE"),
		ImageCleanupInterval:                parseEnvVariableDuration("ECS_IMAGE_CLEANUP_INTERVAL"),
		NumImagesToDeletePerCycle:           parseNumImagesToDeletePerCycle(),
		NumNonECSContainersToDeletePerCycle: parseNumNonECSContainersToDeletePerCycle(),
		ImagePullBehavior:                   parseImagePullBehavior(),
		ImageCleanupExclusionList:           parseImageCleanupExclusionList("ECS_EXCLUDE_UNTRACKED_IMAGE"),
		InstanceAttributes:                  instanceAttributes,
		CNIPluginsPath:                      os.Getenv("ECS_CNI_PLUGINS_PATH"),
		AWSVPCBlockInstanceMetdata:          utils.ParseBool(os.Getenv("ECS_AWSVPC_BLOCK_IMDS"), false),
		AWSVPCAdditionalLocalRoutes:         additionalLocalRoutes,
		ContainerMetadataEnabled:            utils.ParseBool(os.Getenv("ECS_ENABLE_CONTAINER_METADATA"), false),
		DataDirOnHost:                       os.Getenv("ECS_HOST_DATA_DIR"),
		OverrideAWSLogsExecutionRole:        utils.ParseBool(os.Getenv("ECS_ENABLE_AWSLOGS_EXECUTIONROLE_OVERRIDE"), false),
		CgroupPath:                          os.Getenv("ECS_CGROUP_PATH"),
		TaskMetadataSteadyStateRate:         steadyStateRate,
		TaskMetadataBurstRate:               burstRate,
		SharedVolumeMatchFullConfig:         utils.ParseBool(os.Getenv("ECS_SHARED_VOLUME_MATCH_FULL_CONFIG"), false),
		ContainerInstanceTags:               containerInstanceTags,
		ContainerInstancePropagateTagsFrom:  parseContainerInstancePropagateTagsFrom(),
		PollMetrics:                         utils.ParseBool(os.Getenv("ECS_POLL_METRICS"), false),
		PollingMetricsWaitDuration:          parseEnvVariableDuration("ECS_POLLING_METRICS_WAIT_DURATION"),
		DisableDockerHealthCheck:            utils.ParseBool(os.Getenv("ECS_DISABLE_DOCKER_HEALTH_CHECK"), false),
		GPUSupportEnabled:                   utils.ParseBool(os.Getenv("ECS_ENABLE_GPU_SUPPORT"), false),
		NvidiaRuntime:                       os.Getenv("ECS_NVIDIA_RUNTIME"),
		TaskMetadataAZDisabled:              utils.ParseBool(os.Getenv("ECS_DISABLE_TASK_METADATA_AZ"), false),
	}, err
}
// environmentConfig reads the given configs from the environment and attempts
// to convert them to the given type