I'll try that too. Thanks for mentioning it. Cheers, Amir
On Thu, 11 Dec 2025, 11:14 Michael Jeanson, <[email protected]> wrote: > On 12/11/25 10:51, Amir Najafi Zadeh wrote: > > Michael, Kienan, Thank you both for your replies. As you mentioned the > > cgroup namespace, it isn’t very helpful in some cases. Containers may > > share the same cgroup namespace, and the container runtime often avoids > > giving each container a private cgroup namespace for performance and > > security reasons. Because of this, the cgroup namespace can’t be used as > > a reliable or unique label for filtering trace logs. > > > > In my case, with container-d you can inspect a container, find its PID, > > and then check /proc/<pid>/ns/cgroup, but you’ll see that different > > containers often have the same cgroup namespace ID (e.g., in the > > following logs you can see the calico-node and kube-proxy containers > > sharing a cgroup ns). > > If you want to track containers, the pid namespace is the one used by > most container runtimes but I don't know specifically for container-d. > > > > > ``` > > Name: calico-node CID: > > b5624afe31b005725f4ba53c7b6fe758f3c09fabf013085231ff8b97588f6ace PID: > > 2243 cgroup_ns_inode: 4026531835 > > Name: kube-proxy CID: > > 52f3c12def7a680f61a925ac92dd5ebd5eba6cad17d671efbfd1d40db7dff624 PID: > > 1851 cgroup_ns_inode: 4026531835 > > >> MATCH FOUND: shares ns with container: > > b5624afe31b005725f4ba53c7b6fe758f3c09fabf013085231ff8b97588f6ace > > (calico-node) > > ``` > > > > Thanks again for your answers. I hope this feature appears in a future > > patch. > > > > Best, > > Amir > > > > On Thu, Dec 11, 2025 at 9:57 AM Michael Jeanson <[email protected] > > <mailto:[email protected]>> wrote: > > > > On 12/11/25 09:30, Kienan Stewart via lttng-dev wrote: > > > Hi Amir, > > > > > > On 12/10/25 9:40 PM, Amir Najafi Zadeh via lttng-dev wrote: > > >> Hello everyone, > > >> > > >> I hope you’re doing well. My name is Amir, and I’m a PhD student > in > > >> the Computer Science department at Stony Brook University, New > York. > > >> > > >> I have a question about the LTTng context that I haven’t been > > able to > > >> find an answer for in the docs or man pages. Does LTTng support > > adding > > >> the cgroup ID or cgroup path as a context field? I want to > > filter my > > >> trace results based on cgroups. > > >> > > > > > > I think you're looking for the `cgroup_ns` context which adds the > > inum > > > of the cgroup namespace as a context field. > > > > This will give you the ID of the cgroup namespace but we don't have > > contexts for cgroups themselves. It's probably something we would > like > > to have but there is no concrete plans on implementing this at the > > moment. > > > > > > > >> If this isn’t supported, are there any plans to add it in future > > >> versions, such as 2.14? > > >> > > >> For reference, I’m currently using LTTng 2.13 on Ubuntu 24.04 > with > > >> kernel 6.8.0-87-generic. > > >> > > >> Cheers, > > >> Amir > > >> -- > > >> *Amirhossein Najafizadeh* > > >> *PhD Student, Computer Science Department, Stony Brook > > University, N.Y. > > >> File systems and Storage Lab (FSL) > > > >
