Logging tags (rancher-specific)

1

I am trying to log some events in a remote syslog logging server (elk stack with syslog plugin).

I have managed to create docker specific tags as follows:

logging:
  driver: syslog
  options:
    syslog-address: "tcp://someserver:someport"
    tag: '{{.Name}},{{.ImageName}}'

Is this an analogy for rancher tags?

The following syntax does not seem to work:

logging:
  driver: syslog
  options:
    syslog-address: "tcp://someserver:someport"
    tag: '{{ index .ContainerLabels "io.rancher.stack.name" }}'

The error I am getting for example in this approach is:

found unexpected end of stream

The following seems to cause no template specific errors but logs <no value>

tag: '{{ .io.rancher.stack.name }}'

Any suggestion if such a thing is feasible and what is the correct syntax?

UPDATE1: The following variable seems to provide the stack name: {{ Stack.Name }}.

What other variables are available? {{ Service.Name }} does not seem to work for example.

UPDATE2: Docker variables do not seem to be available in a rancher environment, i.e. the following

   tag: '{{.Stack.Name}},{{.Name}},{{.ImageName}}'

will expand to:

mystack,<no value>,<no value>

UPDATE2: any idea why the following produces

yaml error: unexpected end of stream

logging:
  driver: syslog
  options:
    syslog-address: "tcp://my-logging-server:my-logging-port
    tag: '{{ index .ContainerLabels "io.rancher.stack.name" }}'
2

Using the exact same file, and ssh-ing into rancher server and executing

rancher-compose -f thefile.yml up

works!

Could this imply some encoding related issues that mix up the file when uploading it via the rancher-ui?

edit: filed as a bug