Nomad 1.8.0

We are pleased to announce the following Nomad updates.

Release highlights

• Long Term Support Release (Enterprise): Nomad 1.8 introduces a long term support release which provides extended maintenance (two years of critical fixes provided through minor releases and efficient upgrades (support for direct upgrades from one LTS release to the next).

• Exec2 Task Driver (beta): The exec2 driver is used to execute a command for a task. It offers a security model optimized for running 'ordinary' processes with very low startup times and minimal overhead in terms of CPU, disk, and memory utilization. The exec2 driver leverages kernel features such as the Landlock LSM, cgroups v2, and the unshare system utility. Due these enhancements, tasks no longer require leveraging filesystem isolation based on chroot, which provide an enhanced security profile and improved performance for the Nomad operator. Refer to Exec2 Task Driver for more details.

• Transparent proxy support for Consul service mesh: Transparent Proxy introduces a more seamless way of dialing upstream services when Consul service mesh is enabled. Users can configure services to use transparent proxy with a new transparent_proxy block. When a service is configured to use transparent proxy, workloads can now dial the service using a virtual IP Consul DNS name.

• Consul API Gateway for Nomad: Consul API Gateway on Nomad is now officially supported. A prescriptive job specification on hashicorp-guides/consul-api-gateway-on-nomad along with a supporting tutorial on how to securely deploy Consul API gateway on Nomad.

• Re-worked Jobs page in the web UI with live updates: Within the Jobs index page Nomad has made a few improvements:

  • Prioritize showing the current state over historical state for jobs: Previously, long-garbage-collected allocation placement failures, lost nodes, and other historical representations of job state were shown alongside currently running allocations. In self-healing jobs, this often meant that a healthy job looked like it had failures, when in fact Nomad had replaced or rescheduled those failures. Now, the jobs list tries to show accurate allocation information and meaningful statuses (like "Degraded", or "Recovering") to better illustrate the current state of a job.

  • Server-side pagination: For users with many thousands of jobs, the main landing page for the web UI will no longer have a noticeable delay on rendering. Users can control page length and filter paginated jobs appropriately.

  • Live updates: Previously, users had to manually refresh the page to see newly created jobs, or to hide jobs that had been stopped and garbage-collected. Now, the jobs list will update in real-time as jobs are created, updated, or removed. Further, any changes to allocations of jobs on-page will be reflected in the status of that job in real-time.

• Time based task execution (Enterprise) : Using a CRON-like syntax, operators can now schedule when tasks should execute and when they should stop. This provides governance for tasks executed from jobs, and allows operators to easily opt-in or opt-out of a schedule that governs when the task can run through the web based UI or through the CLI.

• Sentinel policy management in the Web UI (Enterprise): Enterprise users can manage Sentinel policies directly within the Nomad UI. Users can create a Sentinel policy based on a template provided from the UI or create policies directly using an editor for Sentinel policies. Refer to Sentinel policies to learn more about how to use Sentinel within Nomad.

• nomad-bench: Nomad now provides a testing framework through nomad-bench which provisions infrastructure used to run tests and benchmarks against Nomad test clusters. The infrastructure consists of Nomad test clusters that each have a set of servers with hundreds or thousands of simulated nodes created using nomad-nodesim. The Nomad server processes are not simulated and are expected to run on their own hosts, mimicking real-world deployments. Metrics are then gathered from the Nomad servers for use with benchmarking and load testing.

What's deprecated

• LXC Task driver: The Community LXC Task Driver is now deprecated. Official support will be removed and the repo will be archived when Nomad 1.9 is released. Users are encouraged to migrate their workloads to another task driver such as the built-in Docker task driver.

• ECS Task driver: The remote ECS Task Driver is now deprecated. Official support will be removed and the repo will be archived when Nomad 1.9 is released. Users are encouraged to migrate their workloads to Amazon ECS or to another Nomad task driver.

• stop_after_client_disconnect, max_client_disconnect, prevent_reschedule_on_lost: Nomad 1.8.0 introduces a disconnect block meant to group all the configuration options related to disconnected client's and server's behavior, causing the deprecation of the fields stop_after_client_disconnect, max_client_disconnect and prevent_reschedule_on_lost. This block also introduces new options for allocations reconciliation if the client regains connectivity.

• 32-bit builds: Support for 32-bit architectures is now deprecated. Nomad releases will no longer include binaries built for 32-bit platforms starting with Nomad 1.9.

What's removed

• raw_exec option no_cgroups: In Nomad 1.7.0 the raw_exec plugin option for no_cgroups became ineffective. Starting in Nomad 1.8.0 attempting to set the no_cgroups in raw_exec plugin configuration will result in an error when starting the agent.

Upgrading

For more detailed information, please refer to the upgrade details page and the changelogs.

Known issues

The following issues are known to exist in the v1.8.x releases:

Changelogs

The changelogs for this major release version and any maintenance versions are listed below.

• 1.8.0