run tests without adjusting rlimit about ebpf

[florianl]

Hi @eclipseo
Did you have a look at https://github.com/cilium/ebpf/blob/master/.semaphore/semaphore.yml? This file reflects the configuration for the CI/CD tests, that are triggered for every PR on this repository.

[lmb]

@eclipseo can you give details on the error you're seeing? FWIW, failing to increase the rlimit should only result in a warning, not an error:

	err := unix.Setrlimit(8, &unix.Rlimit{
		Cur: math.MaxUint64,
		Max: math.MaxUint64,
	})
	if err != nil {
		fmt.Println("WARNING: Failed to adjust rlimit, tests may fail")
	}

[eclipseo]

Here's what I get when I try running the tests:

Testing    in: /builddir/build/BUILD/ebpf-5d50e74ed36f0420ef5004e84ed2cdd3e739ad3f/_build/src
         PATH: /builddir/build/BUILD/ebpf-5d50e74ed36f0420ef5004e84ed2cdd3e739ad3f/_build/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/sbin
       GOPATH: /builddir/build/BUILD/ebpf-5d50e74ed36f0420ef5004e84ed2cdd3e739ad3f/_build:/usr/share/gocode
  GO111MODULE: off
      command: go test -buildmode pie -compiler gc -ldflags "-X github.com/cilium/ebpf/version.commit=5d50e74ed36f0420ef5004e84ed2cdd3e739ad3f -X github.com/cilium/ebpf/version=0 -extldflags '-Wl,-z,relro -Wl,--as-needed  -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld '"
      testing: github.com/cilium/ebpf
github.com/cilium/ebpf
WARNING: Failed to adjust rlimit, tests may fail
--- FAIL: TestCollectionSpecRewriteMaps (0.00s)
    collection_test.go:149: can't test program: can't run test: operation not permitted
--- FAIL: TestLoadCollectionSpec (0.00s)
    --- FAIL: TestLoadCollectionSpec/loader-clang-6.0.elf (0.00s)
        elf_reader_test.go:76: map hash_map: map create: operation not permitted
    --- FAIL: TestLoadCollectionSpec/loader-clang-7.elf (0.00s)
        elf_reader_test.go:76: map hash_map: map create: operation not permitted
    --- FAIL: TestLoadCollectionSpec/loader-clang-8.elf (0.00s)
        elf_reader_test.go:76: map hash_map: map create: operation not permitted
    --- FAIL: TestLoadCollectionSpec/loader-clang-9.elf (0.00s)
        elf_reader_test.go:76: map array_of_hash_map: map create: operation not permitted
--- FAIL: TestLink (0.00s)
    linker_test.go:35: 	0: MovReg dst: r0 src: r1
        	1: Call -1 <my_func>
        	2: Exit
        my_func:
        	3: LdImmDW dst: r0 imm: 1337
        	5: Exit
        
    linker_test.go:41: can't load program: operation not permitted
--- FAIL: TestMap (0.00s)
    map_test.go:33: map create: operation not permitted
--- FAIL: TestMapClose (0.00s)
    map_test.go:72: map create: operation not permitted
--- FAIL: TestMapPin (0.00s)
    map_test.go:99: map create: operation not permitted
--- FAIL: TestMapQueue (0.00s)
    map_test.go:162: map create: operation not permitted
--- FAIL: TestMapInMap (0.00s)
    --- FAIL: TestMapInMap/ArrayOfMaps (0.00s)
        map_test.go:226: map create: operation not permitted
    --- FAIL: TestMapInMap/HashOfMaps (0.00s)
        map_test.go:226: map create: operation not permitted
--- FAIL: TestNewMapInMapFromFD (0.00s)
    map_test.go:287: map create: operation not permitted
--- FAIL: TestPerfEventArray (0.00s)
    map_test.go:309: Can't create perf event array from PerfEventArray(keySize=0, valueSize=0, maxEntries=0, flags=0): map create: operation not permitted
    map_test.go:309: Can't create perf event array from PerfEventArray(keySize=4, valueSize=0, maxEntries=0, flags=0): map create: operation not permitted
    map_test.go:309: Can't create perf event array from PerfEventArray(keySize=0, valueSize=4, maxEntries=0, flags=0): map create: operation not permitted
--- FAIL: TestMapInMapValueSize (0.00s)
    map_test.go:356: map create: operation not permitted
--- FAIL: TestIterateEmptyMap (0.00s)
panic: map create: operation not permitted [recovered]
	panic: map create: operation not permitted
goroutine 45 [running]:
testing.tRunner.func1.1(0x56096849c1e0, 0xc000170800)
	/usr/lib/golang/src/testing/testing.go:942 +0x3d2
testing.tRunner.func1(0xc000174000)
	/usr/lib/golang/src/testing/testing.go:945 +0x3fb
panic(0x56096849c1e0, 0xc000170800)
	/usr/lib/golang/src/runtime/panic.go:967 +0x161
github.com/cilium/ebpf.createHash(0xc00016d5f0)
	/builddir/build/BUILD/ebpf-5d50e74ed36f0420ef5004e84ed2cdd3e739ad3f/_build/src/github.com/cilium/ebpf/map_test.go:879 +0xb9
github.com/cilium/ebpf.TestIterateEmptyMap(0xc000174000)
	/builddir/build/BUILD/ebpf-5d50e74ed36f0420ef5004e84ed2cdd3e739ad3f/_build/src/github.com/cilium/ebpf/map_test.go:374 +0x46
testing.tRunner(0xc000174000, 0x5609684c8c68)
	/usr/lib/golang/src/testing/testing.go:993 +0xde
created by testing.(*T).Run
	/usr/lib/golang/src/testing/testing.go:1044 +0x359
exit status 2
FAIL	github.com/cilium/ebpf	0.016s

[lmb]

linker_test.go:41: can't load program: operation not permitted

This error happens because loading an XDP program requires root. I'd have to look at the map errors, but I suspect they happen for a similar reason.

In general, it's not possible to run the tests without root, because a lot of eBPF is gated behind CAP_SYS_ADMIN. Is that what you are trying to do? If yes, you might be able to work around this using run-tests.sh, as Florian pointed outed. That requires that you have access to KVM if you want tests to run in a reasonable amount of time.

[eclipseo]

run-tests.sh requires network access which is not possible within our CI. Thanks anyway.

[florianl]

Instead of calling run-tests.sh you maybe can take it as source to configure your CI/CD tests and provide the required sources locally?

[lmb]

I'm open to fix run-tests.sh so that it works without network access if that is useful to you.

[lmb]

I'm closing this issue for now, feel free to re-open it if necessary.