Extend continuous integration tests by adding testing against various kernel
versions.
The code is based on vmtest CI scripts implemented by osandov@
for drgn [1] with the following modifications:
- The downloadables are stored in Amazon S3 cloud indexed in [2]
- `--setup-cmd` command line option is added to vmtest/run.sh so
setup commands run on VM boot can be set in e.g. `.travis.yml`
- Travis build matrix [2] is introduced for VM tests so VM tests are
followed by the existing CI tests. The matrix has `KERNEL` and
`VMTEST_SETUPCMD` dimensions.
- Minor style fixes.
The vmtest extention code is located in travis-ci/vmtest and contains
`run.sh` and `setup_example.sh`
- `run.sh` is responsible for the vmtest workflow: downloading vmlinux
and rootfs image from the cloud, fs mounting, syncing libbpf sources
to the image, setting up scripts run on VM boot, starting VM using
QEMU.
`run.sh` covers more use cases than a script for a job run in TravisCI,
e.g. int can build a kernel w/ `--build` option.
- `setup_example.sh` is an example of a script run in VM which can be
modified to e.g. run actual libbpf tests. A setup script should have
executable permission.
To set up a new kernel version for a test:
1) upload vmlinuz.* and vmlinux.*\.zst to Amazon S3 store
located at [4];
2) modify INDEX [2] file.
[1] https://github.com/osandov/drgn
[2] https://libbpf-vmtest.s3-us-west-1.amazonaws.com/x86_64/INDEX
[3] https://docs.travis-ci.com/user/build-matrix
[4] https://libbpf-vmtest.s3-us-west-1.amazonaws.com/
