badouralix/linux-headers
Toolbox to run eBPF programs on Docker Desktop
733
badouralix/linux-headers repository overview
linux-headers
This Dockerfile builds a toolbox for running eBPF programs on Docker Desktop.
Watch https://youtu.be/bGAVrtb_tFs for a quick introduction to eBPF tracing.
See the repo on Docker Hub.
Usage
Make sure to use the correct kernel release, because eBPF requires the exact kernel headers without BTF.
export DOCKER_DESKTOP_KERNEL_RELEASE=$(docker run --rm alpine uname -r) # For instance 5.15.49-linuxkit
docker run -it --rm --cap-add=SYS_ADMIN --cap-add=SYSLOG badouralix/linux-headers:$DOCKER_DESKTOP_KERNEL_RELEASE
Frequently Asked Questions
Why CAP_SYS_ADMIN ?
Not using --cap-add=SYS_ADMIN in the docker run command results immediately in the following error :
mount: /sys/kernel/debug: permission denied.
Why CAP_SYSLOG ?
Not using --cap-add=SYSLOG in the docker run command results in the following error when running execsnoop-bpfcc :
cannot attach kprobe, probe entry may not exist
Traceback (most recent call last):
File "/usr/sbin/execsnoop-bpfcc", line 245, in <module>
b.attach_kprobe(event=execve_fnname, fn_name="syscall__execve")
File "/usr/lib/python3/dist-packages/bcc/__init__.py", line 845, in attach_kprobe
raise Exception("Failed to attach BPF program %s to kprobe %s"
Exception: Failed to attach BPF program b'syscall__execve' to kprobe b'sys_execve', it's not traceable (either non-existing, inlined, or marked as "notrace")
See https://stackoverflow.com/a/55592796 and https://github.com/iovisor/bcc/issues/2670.
Why linux headers ?
In order to build eBPF programs, compilers need the local kernel headers. With Docker Desktop, it means the kernel headers of the underlying virtual machine. These headers are available in https://hub.docker.com/r/docker/for-desktop-kernel as shown by dive.
dive docker/for-desktop-kernel:5.15.49-13422a825f833d125942948cf8a8688cef721ead
┃ ● Layers ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Cmp Size Command
350 MB FROM e7f5e092709a618
│ Layer Details ├───────────────────────────────────────────────────────────────────────
Tags: (unavailable)
Id: e7f5e092709a61807859d5669414c448ec9d7b1cfaa959782596b5eb34555cd2
Digest: sha256:234146d432fbf071cb2308baf94bcd19fe266e8453ca1f628913665b178e9f5e
Command:
COPY /out/* / # buildkit
│ Image Details ├───────────────────────────────────────────────────────────────────────
Image name: docker/for-desktop-kernel:5.15.49-13422a825f833d125942948cf8a8688cef721ead
Total Image size: 350 MB
Potential wasted space: 0 B
Image efficiency score: 100 %
Count Total Space Path
│ Aggregated Layer Contents ├───────────────────────────────────────────────────────────
Permission UID:GID Size Filetree
-rw-r--r-- 0:0 6.0 MB ├── System.map
-rw-r--r-- 0:0 1.7 kB ├── intel-ucode-license.txt
-rw-r--r-- 0:0 4.7 MB ├── intel-ucode.cpio
-rw-r--r-- 0:0 9.2 MB ├── kernel
-rw-r--r-- 0:0 56 B ├── kernel-builder
-rw-r--r-- 0:0 84 MB ├── kernel-dev.tar
-rw-r--r-- 0:0 6.5 MB ├── kernel-headers.tar
-rw-r--r-- 0:0 80 B ├── kernel-source-info
-rw-r--r-- 0:0 110 MB ├── kernel.tar
-rw-r--r-- 0:0 129 MB └── linux.tar.xz
Why not using BTF ?
Having to install linux headers is quite an overhead and heavily reduces the portability of eBPF programs. This topic is discussed in details in https://nakryiko.com/posts/bpf-portability-and-co-re. An alternative is to use BTF. Unfortunately, this is not supported by the Docker Desktop kernel yet : https://github.com/docker/for-mac/issues/6800.
License
Unless expressly stated otherwise, all contents licensed under the MIT License.
Tag summary
Content type
Image
Digest
sha256:a13831ec2…
Size
483 MB
Last updated
over 3 years ago
docker pull badouralix/linux-headers:5.15.49-linuxkit-pr