Our CI tasks are run by CirrusCI in Docker containers in a Google
Compute Engine based Kubernetes environment. These containers have
limited capabilities - especially CAP_SYS_ADMIN is missing. See
https://github.com/bitcoin/bitcoin/issues/23296#issuecomment-1024920845
We need elevated privileges to hook into the USDT tracepoints. We use a
CirrusCI "compute_engine_instance" (a VM, not a container) where we have
the required privileges. The ubunut-mininmal-2204-lts was choosen with
debian-11 being an alternative. Both pack an outdated 'bpfcc-tools'
package (v0.18.0) from 2020. This version prints warnings to stderr
during BPF bytecode compilation, which causes our functional test runner
to fail. This is fixed in newer verison.
Until debian-12 or a newer Ubuntu release is avaliable as image in GCE
(https://cloud.google.com/compute/docs/images/os-details), we use a
third-party and untrusted PPA that releases up-to-date versions of the
package.
The official iovisor (authors of BCC) PPA is outdated too. An
alternative would be to compile BCC from source in the CI.
Co-authored-by: MacroFake <falke.marco@gmail.com>
