New enhanced runtime
The original Linux service manager for Migrate to Containers relied
sysv init and
systemd. The simplified Linux service manager
replaces it with a simplified, container friendly alternative.
This simplified Linux service manager adds functionality that lets you deploy your migrated container workloads to:
GKE Autopilot clusters
The simplified Linux service manager also resolves compatibility issues with Kubernetes plugins.
For example, the simplified Linux service manager removes the requirement of defining a
/sys/fs/cgroup in the
deployment_spec.yaml file and the need to create
Before you begin
- Migrate to Containers supplies a tool that you run on a VM workload to determine the fit of the workload for migration to a container. For more information, see Using the fit assessment tool.
About GKE Autopilot clusters
Autopilot is a mode of operation in Google Kubernetes Engine (GKE). Autopilot is designed to reduce the operational cost of managing clusters, optimize your clusters for production, and yield higher workload availability. In Autopilot mode, GKE provisions and manages the underlying infrastructure of the cluster, including nodes and node pools, giving you an optimized cluster with an automated experience.
See Autopilot overview for more details.
About Cloud Run
Cloud Run is a managed compute platform that enables you to run stateless containers that are invokable by web requests or Pub/Sub events. The simplified Linux service manager lets you deploy your migrated container workloads on Cloud Run.
Using workload identity with Migrate to Containers and GKE
Migrate to Containers and GKE let you deploy your migrated workloads to Anthos on bare metal. Sometimes, you might use the same cluster as both the processing cluster and the deployment cluster. If you have enabled workload identity on your deployment cluster, ensure that you configure your deployment environment to support Migrate to Containers and GKE.
Also, you must ensure that any services started as part of the init process are configured correctly for workload identity. The steps you perform depend on the service manager for your cluster. See Deploying a Linux workload to a target cluster for the configuration steps.
Changes from the existing runtime
To use the simplified Linux service manager, you should be aware of the following changes and limitations from the existing runtime.
New services-config.yaml artifact file added
If you enable the simplified Linux service manager, Migrate to Containers creates a new artifact file,
services-config.yaml, when you generate the migration artifacts. Use this file to control
application initialization on a deployed container. See Using services-config.yaml
for more information.
When using the current runtime, Migrate to Containers adds a readiness probe in
deployment_spec.yaml file. When you enable the simplified Linux service manager,
no readiness probe is added.
If you want to add a readiness probe, we recommend that you use an HTTP readiness probe. See Define readiness probes for more information.
readinessProbe: exec: command: - /.m4a/gamma status
However, this probe might return a false negative result.
The simplified Linux service manager creates a Unix socket at
/dev/log to support the syslog.
The simplified Linux service manager forwards these log messages to
stdout so that they are
recorded by Kubernetes as container logs.
You should be aware of the following limitations when using the simplified Linux service manager.
The simplified Linux service manager works best with the following types of workloads:
|Compute Engine Ubuntu 12.04||Ubuntu 12.04||apache2|
|Compute Engine Ubuntu 14.04||Ubuntu 14.04||redis, mysql, apache2|
|Compute Engine Ubuntu 18.04||Ubuntu 18.04||apache2, mysql, redis-server, tomcat|
|RHEL SAP 7.4||Red Hat||httpd|
|Compute Engine Memcached image||Debian 10.9||bitnami|
|Compute Engine Marketplace wordpress||Debian 9.13||apache2, mysql, php|
|Compute Engine Marketplace tomcat||Debian 9.13||tomcat8|
|Compute Engine Marketplace jenkins||Debian 10.9||apache2, jenkins|
|Compute Engine Marketplace moodle||Debian 9.13||apache2, mysql, php7.4 fpm, phpsessionclean|
|Compute Engine Marketplace Odoo||Debian 9.13||odoo, nginx|
|Compute Engine Marketplace Opencart||Debian 9.13||apache2, mysql, php7.0 fpm, supervisor, mariadb|
|Compute Engine Marketplace Erpnext||Debian 10.9||nginx, redis-server, supervisor, mariadb|
|Compute Engine Marketplace wildfly||Debian 10.10||wildfly, cron|
If you're using
systemd as your init system, be aware of the following limitations:
systemdservice types of
notifyare treated as
execservice. That means the service is considered started, when
Notify sockets are supported for
If needed, you can provide other readiness checks. For example, HTTP check or other types of check.
Socket type unit files are not supported. Sockets are not created and no environment variables are created.
Updates for version 1.9.0
The simplified Linux service manager for version 1.9.0 contains the following updates:
The Linux service manager has been released for general availability, and is no longer in Public Preview.
The procedure to Convert existing container workloads to support Autopilot has been changed. You now need to edit both the Dockerfile and the
deployment_spec.yamlfile for an existing migration to convert it.
config.yamlfile has been renamed to
Updates for version 1.8.1
The simplified Linux service manager was originally released in Public Preview as part of Migrate to Containers version 1.8. The simplified Linux service manager for version 1.8.1 contains the following updates:
You no longer set an annotation in the migration plan to enable the simplified Linux service manager. Instead, you now set
v2kServiceManager. See Deploy containers to Autopilot clusters for more.
The environment variable
HC_GAMMA_RUNTIMEhas been renamed to
poststartentries in the
services-config.yamlfile now automatically populated. See Using services-config.yaml for more.
Added support to the
services-config.yamlfile that lets you specify environment variables at the global level or at the application level. See Using services-config.yaml for more.
Added logging support that lets you customize log data written to Cloud Logging. See Customize log data written to Cloud Logging for more.