Get unique tags

[hoffoo]

I would like to list all tags and create groups of hosts based on them. The issue is that I only want one group per tag, even if multiple services in the Catalog have the same tag. Right now when I range by service im getting duplicate tags (which makes perfect sense).

I tried various things i read trough but cannot come up with a workaround for me (If only I could use a map in a template or just add a function on the fly).

Any ideas would be super helpful!

[sethvargo]

Hi @hoffoo

This is a duplicate of #33. Right now this is not possible because Consul does not provide a way to query on just a tag. Your case is interesting because you need to invert the result from services (i.e. map[tag]services instead of map[service]tags). Unfortunately this is not something that is currently possible due to the upstream bug in Consul. You can read more information on the linked issue. Sorry about that.

[hoffoo]

no problem thanks a lot for clarifying!

[sielaq]

Hi @hoffoo,

We have workaround it like this,

{{range services}}
  {{range $tag, $services := service .Name|byTag}}
    #{{$tag}}
    {{$service_name := (index $services 0).Name}}
    {{$service_name}}
    {{range $services}}
      {{.Node}} {{.Port}} {{.Address}}
    {{end}}
  {{end}}
{{end}}

or you can ensure only specific Tags like:

{{range services}}
  {{range $tag, $services := service .Name|byTag}}
    {{if or (eq $tag "YOUR_TAG_1") (eq $tag "YOUR_TAG_2")}}
      #{{$tag}}
      {{$service_name := (index $services 0).Name}}
      {{$service_name}}
      {{range $services}}
        {{.Node}} {{.Port}} {{.Address}}
      {{end}}
    {{end}}
  {{end}}
{{end}}

I'm not sure if this would also help for you.

[scalp42]

@sielaq in your example the if or acts as a AND operation. How can we query YOUR_TAG_1 OR YOUR_TAG_2 ?

[sielaq]

Actually it behaves like logical OR , if any appearance of YOUR_TAG_1 or YOUR_TAG_2 exists in tags, then service is generated. Might be you are setting tags not properly (for ex. you have only one big tag).

see our HAproxy set up in PaaS project which works already
https://github.com/eBayClassifiedsGroup/PanteraS/blob/master/infrastructure/template.conf