Rename kubernetes_node measurements in inputs.kube_inventory or inputs.kubernetes

[sjwang90]

Feature Request

Proposal:

The same measurement name causes conflicts for those users that have both inputs.kube_inventory and inputs.kubernetes plugins.

Current behavior:

kubernetes_node metric is emitted by both inputs.kube_inventory and inputs.kubernetes but each emit different field and tag keys. This causes problems and confusion when both input plugins are enabled.

Example query:

select capacity_cpu_cores, cpu_usage_core_nanoseconds / 1000000000 from kubernetes_node where time > now() - 12h group by kubernetes_cluster;

Resulting in output such as:

2021-03-15T20:41:30Z 32
2021-03-15T20:41:30Z 32
2021-03-15T20:41:30Z 1.200665496
2021-03-15T20:41:30Z 32
2021-03-15T20:41:30Z 32
2021-03-15T20:41:30Z 32
2021-03-15T20:41:30Z 32 1.275632175
2021-03-15T20:41:30Z 32
2021-03-15T20:41:30Z 32
2021-03-15T20:41:30Z 32

Desired behavior:

One of the metrics should be renamed.

Use case:

When the customer tries to query a kubernetes_node measurement, they get no or incorrect results results, and it seems there is a conflict preventing results from showing up. A Telegraf user in Kubernetes is likely to enable both plugins so this could be a common problem.

[chunleiz]

it could be achieved through configuration

[[inputs.kube_inventory]]
fieldpass = ["capacity_cpu_cores"]
[[inputs.kubernetes]]
fieldpass = ["cpu_usage_core_nanoseconds "]
[[processors.rename]]
[[processors.rename.replace]]
measurement = "kube_inventory"
dest = "kubernetes_node"
[[processors.rename.replace]]
measurement = "kubernetes"
dest = "kubernetes_node"

[sjwang90]

Thanks @chunleiz - is adding a processor sufficient for you? If it is we'll just have this as an item to add to plugin READMEs.

[sjwang90]

Current workaround:

• Use the rename processor to rename one of the kubernetes_node measurement names
• name_override won't work since it'll rename ALL measurement names

Proposed solutions:

Rename the inputs.kube_inventory measurement name since it's the newer plugin (release in 2019, inputs.kubernetes released in 2016)

• Add a config option to existing inputs.kube_inventory config to rename measurement when using both kubernetes and kube_inventory plugins
• BREAKING CHANGE (not until 2.0)
  • Permanently rename one of the measurements in one of the plugins
  • OR
  • Merge plugins together (might not be possible as kubernetes - performance focused, kube_inventory - state focused/metadata)

To-do:

• Determine new measurement name for kube_inventory. @Jayclifford345 take a look at the kube_inventory endpoint to see what the kubernetes_node should be renamed