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// -*- Mode: Go; indent-tabs-mode: t -*-
//go:build faultinject
/*
* Copyright (C) 2021 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package osutil_test
import (
"bytes"
"os"
"path/filepath"
. "gopkg.in/check.v1"
"github.com/snapcore/snapd/osutil"
"github.com/snapcore/snapd/testutil"
)
type testhelperFaultInjectionSuite struct {
testutil.BaseTest
sysroot string
}
var _ = Suite(&testhelperFaultInjectionSuite{})
func (s *testhelperFaultInjectionSuite) SetUpTest(c *C) {
s.BaseTest.SetUpTest(c)
s.sysroot = c.MkDir()
restore := osutil.MockInjectSysroot(s.sysroot)
s.AddCleanup(restore)
oldSnappyTesting := os.Getenv("SNAPPY_TESTING")
s.AddCleanup(func() { os.Setenv("SNAPPY_TESTING", oldSnappyTesting) })
s.AddCleanup(func() { os.Unsetenv("SNAPD_FAULT_INJECT") })
}
func (s *testhelperFaultInjectionSuite) TestFaultInject(c *C) {
foreverLoopCalls := 0
restore := osutil.MockForeverLoop(func() {
foreverLoopCalls++
})
defer restore()
os.Setenv("SNAPPY_TESTING", "1")
stderrBuf := &bytes.Buffer{}
restore = osutil.MockStderr(stderrBuf)
defer restore()
sysrqFile := filepath.Join(s.sysroot, "/proc/sysrq-trigger")
c.Assert(os.MkdirAll(filepath.Dir(sysrqFile), 0755), IsNil)
os.Setenv("SNAPD_FAULT_INJECT", "tag:reboot,othertag:panic,funtag:reboot")
c.Assert(os.WriteFile(sysrqFile, nil, 0644), IsNil)
osutil.MaybeInjectFault("tag")
c.Assert(filepath.Join(s.sysroot, "/proc/sysrq-trigger"), testutil.FileEquals, "b\n")
c.Check(foreverLoopCalls, Equals, 1)
c.Check(filepath.Join(s.sysroot, "/var/lib/snapd/faults/tag:reboot"), testutil.FilePresent)
c.Check(stderrBuf.String(), Equals, "injecting \"reboot\" fault for tag \"tag\"\n")
// trying to inject a tag again does nothing as long as the stamp file is present
c.Assert(os.WriteFile(sysrqFile, nil, 0644), IsNil)
stderrBuf.Reset()
osutil.MaybeInjectFault("tag")
c.Check(foreverLoopCalls, Equals, 1)
c.Check(stderrBuf.String(), Equals, "")
// remove the tag now
c.Assert(os.Remove(filepath.Join(s.sysroot, "/var/lib/snapd/faults/tag:reboot")), IsNil)
osutil.MaybeInjectFault("tag")
// and the fault was injected
c.Check(filepath.Join(s.sysroot, "/var/lib/snapd/faults/tag:reboot"), testutil.FilePresent)
c.Check(foreverLoopCalls, Equals, 2)
c.Check(stderrBuf.String(), Equals, "injecting \"reboot\" fault for tag \"tag\"\n")
// try another tag that triggers reboot
c.Assert(os.WriteFile(sysrqFile, nil, 0644), IsNil)
stderrBuf.Reset()
osutil.MaybeInjectFault("funtag")
c.Assert(filepath.Join(s.sysroot, "/proc/sysrq-trigger"), testutil.FileEquals, "b\n")
c.Check(foreverLoopCalls, Equals, 3)
c.Check(stderrBuf.String(), Equals, "injecting \"reboot\" fault for tag \"funtag\"\n")
c.Check(filepath.Join(s.sysroot, "/var/lib/snapd/faults/funtag:reboot"), testutil.FilePresent)
// clear sysrq-trigger file
c.Assert(os.WriteFile(sysrqFile, nil, 0644), IsNil)
stderrBuf.Reset()
c.Assert(func() {
osutil.MaybeInjectFault("othertag")
}, PanicMatches, `fault "othertag:panic"`)
c.Check(stderrBuf.String(), Equals, "injecting \"panic\" fault for tag \"othertag\"\n")
// we have a stamp file
c.Check(filepath.Join(s.sysroot, "/var/lib/snapd/faults/othertag:panic"), testutil.FilePresent)
// nothing was written to the sysrq file
c.Assert(filepath.Join(s.sysroot, "/proc/sysrq-trigger"), testutil.FileEquals, "")
c.Check(foreverLoopCalls, Equals, 3)
// nothing happens until the stamp file is present
stderrBuf.Reset()
osutil.MaybeInjectFault("othertag")
c.Check(stderrBuf.String(), Equals, "")
// remove it
c.Check(os.Remove(filepath.Join(s.sysroot, "/var/lib/snapd/faults/othertag:panic")), IsNil)
// and the fault can be triggered
c.Assert(func() {
osutil.MaybeInjectFault("othertag")
}, PanicMatches, `fault "othertag:panic"`)
c.Check(stderrBuf.String(), Equals, "injecting \"panic\" fault for tag \"othertag\"\n")
// now a tag that is not set
osutil.MaybeInjectFault("unset")
c.Assert(filepath.Join(s.sysroot, "/proc/sysrq-trigger"), testutil.FileEquals, "")
osutil.MaybeInjectFault("otherunsertag")
c.Assert(filepath.Join(s.sysroot, "/proc/sysrq-trigger"), testutil.FileEquals, "")
c.Check(foreverLoopCalls, Equals, 3)
}
func (s *testhelperFaultInjectionSuite) TestFaultInjectDisabledNoSnappyTesting(c *C) {
// with SNAPPY_TESTING disabled, fault injection is disabled as well
c.Assert(os.Unsetenv("SNAPPY_TESTING"), IsNil)
restore := osutil.MockForeverLoop(func() {
c.Fatalf("unexpected call")
})
defer restore()
sysrqFile := filepath.Join(s.sysroot, "/proc/sysrq-trigger")
os.Setenv("SNAPD_FAULT_INJECT", "tag:reboot,othertag:panic")
osutil.MaybeInjectFault("tag")
c.Check(sysrqFile, testutil.FileAbsent)
c.Check(filepath.Join(s.sysroot, "/var/lib/snapd/faults/tag:reboot"), testutil.FileAbsent)
osutil.MaybeInjectFault("othertag")
c.Check(sysrqFile, testutil.FileAbsent)
c.Check(filepath.Join(s.sysroot, "/var/lib/snapd/faults/othertag:panic"), testutil.FileAbsent)
}
func (s *testhelperFaultInjectionSuite) TestFaultInjectDisabledNoTags(c *C) {
os.Setenv("SNAPPY_TESTING", "1")
// no fault injection tags
os.Setenv("SNAPD_FAULT_INJECT", "")
restore := osutil.MockForeverLoop(func() {
c.Fatalf("unexpected call")
})
defer restore()
// and nothing happens
osutil.MaybeInjectFault("tag")
osutil.MaybeInjectFault("othertag")
}
func (s *testhelperFaultInjectionSuite) TestFaultInjectInvalidTags(c *C) {
os.Setenv("SNAPPY_TESTING", "1")
// no fault injection tags
os.Setenv("SNAPD_FAULT_INJECT", "tag:panic,bad/tag:reboot")
restore := osutil.MockForeverLoop(func() {
c.Fatalf("unexpected call")
})
defer restore()
stderrBuf := &bytes.Buffer{}
restore = osutil.MockStderr(stderrBuf)
defer restore()
// SNAPD_FAULT_INJECT is invalid
osutil.MaybeInjectFault("tag")
c.Check(stderrBuf.String(), Equals, "invalid fault tags \"tag:panic,bad/tag:reboot\"\n")
stderrBuf.Reset()
// invalid tag
os.Setenv("SNAPD_FAULT_INJECT", "tag::bad,othertag:reboot")
osutil.MaybeInjectFault("tag")
c.Check(stderrBuf.String(), Equals, "incorrect fault tag: \"tag::bad\"\n")
stderrBuf.Reset()
// another invalid tag
os.Setenv("SNAPD_FAULT_INJECT", "tag,othertag:reboot")
osutil.MaybeInjectFault("tag")
c.Check(stderrBuf.String(), Equals, "")
}
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