tests: Fixes DNS tests false positives

If dig fails to reach the DNS, it will output errors to stdout, which
can cause the test -n to falsely pass:

ubuntu@ubuntu:~$ dig +notcp +noall +answer +search kubernetes.default A
;; connection timed out; no servers could be reached
command terminated with exit code 9

ubuntu@ubuntu:~$ test -n "$(dig +notcp +noall +answer +search kubernetes.default A)" && echo OK
OK

This patch solves this issue by making sure the dig command actually succeeds
before checking its output.
This commit is contained in:
Claudiu Belu 2018-10-21 13:13:45 -07:00
parent f4bf0e8d33
commit fb8d2f7ef5

View File

@ -447,10 +447,10 @@ func createProbeCommand(namesToResolve []string, hostEntries []string, ptrLookup
}
fileName := fmt.Sprintf("%s_udp@%s", fileNamePrefix, name)
fileNames = append(fileNames, fileName)
probeCmd += fmt.Sprintf(`test -n "$$(dig +notcp +noall +answer +search %s %s)" && echo OK > /results/%s;`, name, lookup, fileName)
probeCmd += fmt.Sprintf(`check="$$(dig +notcp +noall +answer +search %s %s)" && test -n "$$check" && echo OK > /results/%s;`, name, lookup, fileName)
fileName = fmt.Sprintf("%s_tcp@%s", fileNamePrefix, name)
fileNames = append(fileNames, fileName)
probeCmd += fmt.Sprintf(`test -n "$$(dig +tcp +noall +answer +search %s %s)" && echo OK > /results/%s;`, name, lookup, fileName)
probeCmd += fmt.Sprintf(`check="$$(dig +tcp +noall +answer +search %s %s)" && test -n "$$check" && echo OK > /results/%s;`, name, lookup, fileName)
}
for _, name := range hostEntries {
@ -462,8 +462,8 @@ func createProbeCommand(namesToResolve []string, hostEntries []string, ptrLookup
podARecByUDPFileName := fmt.Sprintf("%s_udp@PodARecord", fileNamePrefix)
podARecByTCPFileName := fmt.Sprintf("%s_tcp@PodARecord", fileNamePrefix)
probeCmd += fmt.Sprintf(`podARec=$$(hostname -i| awk -F. '{print $$1"-"$$2"-"$$3"-"$$4".%s.pod.cluster.local"}');`, namespace)
probeCmd += fmt.Sprintf(`test -n "$$(dig +notcp +noall +answer +search $${podARec} A)" && echo OK > /results/%s;`, podARecByUDPFileName)
probeCmd += fmt.Sprintf(`test -n "$$(dig +tcp +noall +answer +search $${podARec} A)" && echo OK > /results/%s;`, podARecByTCPFileName)
probeCmd += fmt.Sprintf(`check="$$(dig +notcp +noall +answer +search $${podARec} A)" && test -n "$$check" && echo OK > /results/%s;`, podARecByUDPFileName)
probeCmd += fmt.Sprintf(`check="$$(dig +tcp +noall +answer +search $${podARec} A)" && test -n "$$check" && echo OK > /results/%s;`, podARecByTCPFileName)
fileNames = append(fileNames, podARecByUDPFileName)
fileNames = append(fileNames, podARecByTCPFileName)
@ -471,8 +471,8 @@ func createProbeCommand(namesToResolve []string, hostEntries []string, ptrLookup
ptrLookup := fmt.Sprintf("%s.in-addr.arpa.", strings.Join(reverseArray(strings.Split(ptrLookupIP, ".")), "."))
ptrRecByUDPFileName := fmt.Sprintf("%s_udp@PTR", ptrLookupIP)
ptrRecByTCPFileName := fmt.Sprintf("%s_tcp@PTR", ptrLookupIP)
probeCmd += fmt.Sprintf(`test -n "$$(dig +notcp +noall +answer +search %s PTR)" && echo OK > /results/%s;`, ptrLookup, ptrRecByUDPFileName)
probeCmd += fmt.Sprintf(`test -n "$$(dig +tcp +noall +answer +search %s PTR)" && echo OK > /results/%s;`, ptrLookup, ptrRecByTCPFileName)
probeCmd += fmt.Sprintf(`check="$$(dig +notcp +noall +answer +search %s PTR)" && test -n "$$check" && echo OK > /results/%s;`, ptrLookup, ptrRecByUDPFileName)
probeCmd += fmt.Sprintf(`check="$$(dig +tcp +noall +answer +search %s PTR)" && test -n "$$check" && echo OK > /results/%s;`, ptrLookup, ptrRecByTCPFileName)
fileNames = append(fileNames, ptrRecByUDPFileName)
fileNames = append(fileNames, ptrRecByTCPFileName)
}