Marathon discovery - panic: runtime error: index out of range

[rohit01]

Stacktrace:

panic: runtime error: index out of range

goroutine 219 [running]:
panic(0xd864c0, 0xc820010030)
    /usr/local/go/src/runtime/panic.go:481 +0x3e6
github.com/prometheus/prometheus/retrieval/discovery/marathon.targetForTask(0xc83e5e38e0, 0x0, 0x0)
    /go/src/github.com/prometheus/prometheus/retrieval/discovery/marathon/marathon.go:229 +0x1cf
github.com/prometheus/prometheus/retrieval/discovery/marathon.targetsForApp(0xc83e5e3b48, 0x0, 0x0, 0x0)
    /go/src/github.com/prometheus/prometheus/retrieval/discovery/marathon/marathon.go:219 +0x18b
github.com/prometheus/prometheus/retrieval/discovery/marathon.createTargetGroup(0xc83e5e3b48, 0xc83b2d9aa0)
    /go/src/github.com/prometheus/prometheus/retrieval/discovery/marathon/marathon.go:195 +0x33
github.com/prometheus/prometheus/retrieval/discovery/marathon.AppsToTargetGroups(0xc826630640, 0x56)
    /go/src/github.com/prometheus/prometheus/retrieval/discovery/marathon/marathon.go:187 +0xe0
github.com/prometheus/prometheus/retrieval/discovery/marathon.(*Discovery).fetchTargetGroups(0xc8393e00c0, 0xc8393ce3b8, 0x0, 0x0)
    /go/src/github.com/prometheus/prometheus/retrieval/discovery/marathon/marathon.go:113 +0xb1
github.com/prometheus/prometheus/retrieval/discovery/marathon.(*Discovery).updateServices(0xc8393e00c0, 0x7f0857028650, 0xc8393a7480, 0xc8393ce3c0, 0x0, 0x0)
    /go/src/github.com/prometheus/prometheus/retrieval/discovery/marathon/marathon.go:73 +0x50
github.com/prometheus/prometheus/retrieval/discovery/marathon.(*Discovery).Run(0xc8393e00c0, 0x7f0857028650, 0xc8393a7480, 0xc8393ce3c0)
    /go/src/github.com/prometheus/prometheus/retrieval/discovery/marathon/marathon.go:64 +0x177
created by github.com/prometheus/prometheus/retrieval.(*targetSet).runProviders
    /go/src/github.com/prometheus/prometheus/retrieval/targetmanager.go:328 +0x308

What did you do?
Using service discovery with marathon.

What did you expect to see?
Services running under marathon in targets.

What did you see instead? Under which circumstances?
Exception in logs. Index out of range.

Environment
OS: ubuntu 14.04 64bit server.

• System information:
  Linux 4.2.0-36-generic x86_64
• Prometheus version:
  Tested with prometheus 16.2, 19.2 and master branch.

[rohit01]

marathon service discovery calls URL: /v2/apps/?embed=apps.tasks

There can be valid applications in marathon with zero tasks.

[fabxc]

This is fixed in https://github.com/prometheus/prometheus/releases/tag/0.19.3

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.