Can't grab instances that service.Name include "."

[curry7313]

Consul include two services：

consul
go.micro.api.greeter

Configuration

Consul Template configuration file(app.ctmpl):

{{range services}}
 	 upstream {{.Name}} {
    	 {{range service .Name}}
   	     server {{.Address}}:{{.Port}};
	 {{end}}
    }
{{end}}

Shell

consul-template -template "app.ctmpl:nginx.conf" -once

nginx.conf

upstream consul { 
   	     server 127.0.0.1:8300; 
    }   
 upstream go.micro.api.greeter {	 
   }

why instances of "go.micro.api.greeter" is not be found?

[eikenb]

To reproduce this I created a small config file for the service...

$ cat greeter.json
{
  "Service": {
    "Name": "go.micro.api.greeter",
    "Address": "localhost",
    "Port": 99
  }
}

Registered it...

$ consul services register greeter.json

Then ran consul-template and got the same results as you...

$ consul-template -once -dry -template ./app.ctmpl
(output same as you list)

If I switch the dots to dashes though, it works.

$ cat greeter-dashes.json
{
  "Service": {
    "Name": "go-micro-api-greeter",
    "Address": "localhost", 
    "Port": 99
  }
}

Registered it like above, and ran the template and it worked...
consul-template -once -template ./app.tmpl -dry

upstream consul {
    server 127.0.0.1:8300;
}

upstream go-micro-api-greeter {
    server localhost:99;
}

I know consul's DNS interface doesn't like service names with dots in them and it might be related. Haven't dug into the code yet, just wanted to note how I reproduced it at this point.

[eikenb]

I'm labeling as a bug for the moment but if it ends up that it is using consul in a way that it is hitting this DNS limitation then it will probably change to a documentation issue.

[eikenb]

Found the problem and I think this is going to change to a documentation issue. Names with dots/periods ('.') in them won't work properly with the template format as it uses the dot for a separator. Snipped from the service api functions section in the readme...

Query Consul for services based on their health.

{{ service "<TAG>.<NAME>@<DATACENTER>~<NEAR>|<FILTER>" }}

Notice the dot between the tag and name, <TAG>.<NAME>. That is matching against the service name with the dots in it and interprets it as with the TAG being 'go.micro.api' and the name being just 'greeter'. So the service api lookup call fails to find a match.

There is no way to fix this in the code with that delimiter being what it is, so I'm going to make this issue a documentation issue to make sure to call that out.