ui: NMD-872-System jobs on node-pools scaled to 0 show up in UI as failed

[navyadas-dev]

Description

System jobs with no eligible nodes (e.g., when all nodes in a node pool are scaled to zero, or when constraints don't match any nodes) incorrectly display as "Failed" in both the jobs list and job details page. This is misleading because the job hasn't actually failed - it simply has no nodes to run on.

Reproduction Steps

I have used constraints instead of node pools as Node Pools Governance is an enterprise feature.

1. Start Nomad in dev mode:

./bin/nomad agent -dev

2. Start the UI.

USE_MIRAGE=false ember server --proxy http://127.0.0.1:4646

4. Submit the job:

nomad job run system-job-no-nodes.nomad.hcl

5. Use the following job file:

# System job for testing NMD-872 (OSS-compatible version)
# This job uses constraints that no nodes will match, simulating an empty node pool

job "test-system-job-no-nodes" {
  # System jobs run on every eligible node
  type = "system"

  # Constraint that will never match any node
  # This simulates having a node pool with 0 nodes
  constraint {
    attribute = "${node.class}"
    value     = "nonexistent-class-for-testing-nmd-872"
  }

  group "monitoring" {

    restart {
      attempts = 3
      delay    = "15s"
      interval = "5m"
      mode     = "delay"
    }

    task "agent" {
      driver = "raw_exec"

      config {
        command = "bash"

        args = [
          "-c",
          "echo 'System job running'; sleep 3600"
        ]
      }

      resources {
        cpu    = 100
        memory = 128
      }

      env {
        JOB_TYPE  = "system"
        TEST_CASE = "NMD-872"
      }
    }
  }
}

Changes:

ui/app/models/job.js (Jobs List Status)

• Added logic to check for failure signals (failed/lost/unplaced allocations) when totalAllocs === 0
• Fixed fallback condition to only return "Failed" when totalAllocs > 0 AND all allocations have failed
• Added fallback to "Scaled Down" for jobs with 0 allocations and no failures

ui/app/components/job-status/panel/steady.js (Job Details Page Status)

• Simplified early return for service jobs with 0 allocations
• Fixed fallback condition to prevent 0 === 0 bug
• Added fallback to "Scaled Down" for edge cases

ui/tests/acceptance/jobs-list-test.js (Test Update)

• Updated test expectation for ancient-system-job from "Failed" to "Scaled Down"

Testing & Reproduction steps

Before:
System job with no eligible nodes: "Failed" (red)

NMD-872-Before.mov

After:
System job with no eligible nodes: "Scaled Down" (neutral/gray)

NMD-872-After.mov

Job List view

Job details page

Links

https://hashicorp.atlassian.net/browse/NMD-872

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