I would like to employ Prometheus' relabeling for adding a label hostname, which should be a more concise version of instance as provided by targets. This should allow more compact legends in Grafana dashboards.
For instance, when __address__ has been set to myhost.mydomain.com:8080, hostname should be set to myhost. I am using __address__ rather than instance as source_label, because the second is apparently not yet set when relabeling occurs.
The relevant excerpt of my prometheus.yaml looks as follows (it is meant to employ a lazy regular expression):
- job_name: 'node_exporter'
static_configs:
- targets: ['myhost1.mydomain.com:8080',
'myhost2.mydomain.com:8080']
relabel_configs:
- source_labels: ['__address__']
regex: '^([^\.:]+?)'
replacement: ${1}
target_label: 'hostname'
The expected new label hostname is not yet added. What could be wrong in my setup?
