This allows to make a 17% smaller runc binary by not compiling in
checkpoint/restore support.
It turns out that google.golang.org/protobuf package, used by go-criu,
is quite big, and go linker can't drop unused stuff if reflection is
used anywhere in the code.
Currently there's no alternative to using protobuf in go-criu, and since
not all users use c/r, let's provide them an option for a smaller
binary.
For the reference, here's top10 biggest vendored packages, as reported
by gsa[1]:
$ gsa runc | grep vendor | head
│ 8.59% │ google.golang.org/protobuf │ 1.3 MB │ vendor │
│ 5.76% │ github.com/opencontainers/runc │ 865 kB │ vendor │
│ 4.05% │ github.com/cilium/ebpf │ 608 kB │ vendor │
│ 2.86% │ github.com/godbus/dbus/v5 │ 429 kB │ vendor │
│ 1.25% │ github.com/urfave/cli │ 188 kB │ vendor │
│ 0.90% │ github.com/vishvananda/netlink │ 135 kB │ vendor │
│ 0.59% │ github.com/sirupsen/logrus │ 89 kB │ vendor │
│ 0.56% │ github.com/checkpoint-restore/go-criu/v6 │ 84 kB │ vendor │
│ 0.51% │ golang.org/x/sys │ 76 kB │ vendor │
│ 0.47% │ github.com/seccomp/libseccomp-golang │ 71 kB │ vendor │
And here is a total binary size saving when `runc_nocriu` is used.
For non-stripped binaries:
$ gsa runc-cr runc-nocr | tail -3
│ -17.04% │ runc-cr │ 15 MB │ 12 MB │ -2.6 MB │
│ │ runc-nocr │ │ │ │
└─────────┴──────────────────────────────────────────┴──────────┴──────────┴─────────┘
And for stripped binaries:
│ -17.01% │ runc-cr-stripped │ 11 MB │ 8.8 MB │ -1.8 MB │
│ │ runc-nocr-stripped │ │ │ │
└─────────┴──────────────────────────────────────────┴──────────┴──────────┴─────────┘
[1]: https://github.com/Zxilly/go-size-analyzer
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin