Nomad Job Spec Builder

Nomad is a flexible workload orchestrator from HashiCorp. Unlike Kubernetes, it can schedule not just containers but also raw executables, Java applications, and VMs. It's simpler to operate than Kubernetes and integrates natively with Vault (secrets) and Consul (service mesh). Ideal for mixed workloads and teams transitioning to containers.

A job spec (job specification) is an HCL or JSON file that defines what to run, where, and how many instances. It includes the job type (service, batch, system), task groups (sets of co-located tasks), tasks (individual processes), resources (CPU/memory), network ports, and health checks. Submitted with `nomad job run job.hcl`.

Three types: (1) service — long-running services that Nomad restarts if they fail, like web servers. (2) batch — short-lived tasks that run to completion, like data pipelines. (3) system — runs one instance on every eligible node, like log collectors or monitoring agents. Service jobs are most common for web applications.

Nomad integrates with Consul for service registration. Each task with a `service` block automatically registers in Consul when healthy. Other services can discover it via Consul DNS (`service-name.service.consul`) or the Consul HTTP API. Nomad also supports Nomad-native service discovery without Consul for simpler setups.

Kubernetes is more feature-rich (CRDs, operators, extensive ecosystem) but complex to operate. Nomad is simpler, supports non-container workloads natively, has lower overhead, and is easier to self-host. Nomad excels in brownfield environments with mixed legacy apps. Kubernetes is better for greenfield, container-first teams with dedicated platform engineers.