build, linter, errcheck: lint tests/libstorage

Signed-off-by: Miguel Duarte Barroso <[email protected]>

nogo_config.json

@@ -150,7 +150,6 @@
       "cmd/": "KubeVirt binaries do not pass errcheck yet",
       "tools/": "KubeVirt tools do not pass errcheck yet",
       "tests/console": "tests/console does not pass errcheck yet",
-      "tests/libstorage/": "tests/libstorage does not pass errcheck yet",
       "tests/monitoring/": "tests/monitoring does not pass errcheck yet",
       "tests/network/": "tests/network/ pkg does not pass errcheck yet",
       "tests/reporter/": "tests/reporter pkg does not pass errcheck yet",

tests/errorhandling/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["closing_files.go"],
+    importpath = "kubevirt.io/kubevirt/tests/errorhandling",
+    visibility = ["//visibility:public"],
+    deps = ["//vendor/golang.org/x/sys/unix:go_default_library"],
+)

tests/errorhandling/closing_files.go

@@ -0,0 +1,23 @@
+package errorhandling
+
+import (
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+func SafelyCloseFile(f *os.File) {
+	if err := f.Close(); err != nil {
+		panicIfNotReadOnlyFile(f)
+	}
+}
+
+func panicIfNotReadOnlyFile(f *os.File) {
+	fileFlags, err := unix.FcntlInt(f.Fd(), unix.F_GETFD, 0)
+	if err != nil {
+		panic("could not access file's FD flags")
+	}
+	if fileFlags&(unix.O_WRONLY|unix.O_APPEND|unix.O_RDWR) != 0 {
+		panic("this is not a read-only fd")
+	}
+}

tests/libstorage/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "//pkg/util/net/ip:go_default_library",
         "//staging/src/kubevirt.io/api/core/v1:go_default_library",
         "//staging/src/kubevirt.io/client-go/kubecli:go_default_library",
+        "//tests/errorhandling:go_default_library",
         "//tests/flags:go_default_library",
         "//tests/framework/cleanup:go_default_library",
         "//tests/libnode:go_default_library",

tests/libstorage/config.go

@@ -24,6 +24,7 @@ import (
 	"io/ioutil"
 	"os"
 
+	"kubevirt.io/kubevirt/tests/errorhandling"
 	"kubevirt.io/kubevirt/tests/flags"
 )
 
@@ -56,7 +57,7 @@ func LoadConfig() (*KubeVirtTestsConfiguration, error) {
 		return nil, err
 	}
 
-	defer jsonFile.Close()
+	defer errorhandling.SafelyCloseFile(jsonFile)
 
 	// read the configuration file as a byte array
 	byteValue, _ := ioutil.ReadAll(jsonFile)