topic Re: Dockerfile x HostGroup in Open Q&A

Dockerfile x HostGroup

RodrigoBiaggio — Wed, 16 Aug 2023 07:36:16 GMT

I have several fargate aws tasks in the environment. None of them have a host group configured. I'm trying to set --set-host-group inside my docker file, to make the deploy/run image with this information, but it's not working.

I made some tests, passing the parameter inside of entrypoint and inside of command (Tasks definition), none of them worked.

I spoke to chat and they told me it is not supported, or because I cannot set the host group of my AWS fargates tasks. Is correct?

If yes, does not have any workaround for this?

Re: Dockerfile x HostGroup

abraham_villega — Thu, 11 Nov 2021 16:07:13 GMT

Hi Rodrigo,

Setting host group in this case is not possible because the Oneagent is running in the container and not in full-stack.

We have a workaround that can help. You can use DT_CUSTOM_PROP environment variable to equal your host group. It will show on the processes, then you could use a auto tagging rule to propagate to the hosts.

Hope that helps.

Thanks,

Abraham

Re: Dockerfile x HostGroup

rodrigo_alvare1 — Thu, 11 Nov 2021 16:47:49 GMT

I agree with the solution provided by Abraham, had this issue in the past and the HOST_GROUP/--set-host-group flag was not supported on docker container

Im pretty sure that was listed as one of the limitations in this list but I cannot see it anymore (I'm also talking with docs team to update it) https://www.dynatrace.com/support/help/shortlink/oneagent-docker#limitations

The workaround I used was DT_TAGS and DT_CUSTOM_PROP environment variables

Re: Dockerfile x HostGroup

RodrigoBiaggio — Thu, 11 Nov 2021 16:57:13 GMT

Hi guys, thanks for the reply.

Just one more doubt.

Should I pass this parameter as an ARG in my dockerfile, like:
ARG DT_CUSTOM_PROP = "Platform"

Thanks

Re: Dockerfile x HostGroup

rodrigo_alvare1 — Thu, 11 Nov 2021 17:12:47 GMT

Cant remember if ENV or ARG (or if any of those will work), the syntax would be :

ENV DT_CUSTOM_PROP="myCustomProp"
ARG DT_CUSTOM_PROP="myCustomProp"

also you can pass it with key:value format:
DT_CUSTOM_PROP="App=springbootdemo"

and multiple values
DT_CUSTOM_PROP="App=springbootdemo Environment=Dev"

Re: Dockerfile x HostGroup

DanielS — Mon, 06 Mar 2023 17:41:45 GMT

Thanks, this is a great solution, I updated the image for tags because change a little.

Also when you choose "Custom metadata" choose the one for Process Group not host.

Re: Dockerfile x HostGroup

Scott_McMahon — Mon, 14 Aug 2023 16:04:59 GMT

Hey!

If you pass as ARG does that still work? I can't see how Dynatrace could detect the DT_CUSTOM_PROP values if ARG values are only available at runtime?

I was thinking it would be ENV DT_CUSTOM_PROP but my development team are unsure.

Re: Dockerfile x HostGroup

DanielS — Mon, 14 Aug 2023 16:30:32 GMT

Hello @Scott_McMahon please see this post.