COLLECTD_DOCKER_APP_ENV_TRIM_PREFIX COLLECTD_DOCKER_TASK_ENV_TRIM_PREFIX don't seem to work

[sokratisg]

I am trying to use this image in a Rancher environment. Outside the orchestration perspective, Rancher is just another Docker launching service except some special docker labels which greatly help identify resources running on the cluster.

I've been trying to use these resources (e.g: stack-name and/or container-name) to setup APP_LABEL_KEY & TASK_LABEL_KEY ENV variables but there seems to be an issue with the 63 chars limitation. Although I've raised the respective ENV variables to more than 63 chars, containers falling under the category of more than 63 chars cannot be monitored.

For example I have a container with the following ENV variables:
COLLECTD_DOCKER_APP_ENV_TRIM_PREFIX=128
COLLECTD_DOCKER_TASK_ENV_TRIM_PREFIX=128

And the following values for APP and TASK:
APP_LABEL_KEY="aaaaaaaa-aaaaaaaaa-aaaaaaaa"
TASK_LABEL_KEY="aaaaaaaa-aaaaaaaaa-aaaaaaaa-aaaaaaaa-aaaaaa-1"

Char lenght of string "<APP_LABEL_KEY>.<TASK_LABEL_KEY>" equals 74 so, I do not see a reason for this not to work as described in the README.

Could you help provide some info or any suggestion?

[sokratisg]

Also checked collectd/collectd@6fd0d25 which seems to be hardcoded into collectd-5.6.0. Do you happen to know if this refers to the whole graphite namespace (e.g: $PREFIX + $HOST + $APP + $TASK + metrics) or just the node part?

During all my tests I see that I do not get metrics at all for apps/tasks with a char length > 63. Do you trim those records or just ignore them?