Unsafe defer of
.Close method GO-S2307Deferring unsafe method "Close" on type "*os.File"
433 if err != nil {
434 return err
435 }
436 defer certOut.Close()437
438 if _, err := certOut.Write(getServerCA(server)); err != nil {
439 return errDeferring unsafe method "Close" on type "*os.File"
95 if err != nil {
96 return err
97 }
98 defer output.Close() 99
100 return kubeconfigTemplate.Execute(output, &data)
101}Deferring unsafe method "Close" on type "*os.File"
272 if err != nil {
273 return false
274 }
275 defer file.Close()276
277 nameserver := regexp.MustCompile(`^nameserver\s+([^\s]*)`)
278 scanner := bufio.NewScanner(file)Deferring unsafe method "Close" on type "io.ReadCloser"
128 if err != nil {
129 return nil, err
130 }
131 defer resp.Body.Close()132 }
133 }
134Deferring unsafe method "Close" on type "io.ReadCloser"
116 if err != nil {
117 return nil, err
118 }
119 defer resp.Body.Close()120
121 // If we got a 401 Unauthorized response when using client certs, try again without client cert auth.
122 // This allows us to fall back from node identity to token when the node resource is deleted.
Description
Calling Close() method may return an error, and ignoring the same
might result in a data loss. This is similar to many more Close methods.
For example, on POSIX systems, os.Close uses the close system call underneath,
which may return an EIO:
A previously-uncommitted write(2) encountered an input/output error.
This means that the data written by os.Write hasn't been written to the disk,
which results in a data loss. It is recommended to handle the error returned
by the os.Close call or call os.Sync if available to force the OS to write
the data to the disk.
Bad practice
package main
import (
"fmt"
"os"
)
func foo() error {
f, err := os.Create("/tmp/test.txt")
if err != nil {
return err
}
defer f.Close()
return fmt.Fprint(f, "Hello World")
}
Recommended
package main
import (
"fmt"
"os"
)
func foo() error {
f, err := os.Create("/tmp/test.txt")
if err != nil {
return err
}
err = fmt.Fprint(f, "Hello World")
if err != nil {
return err
}
return f.Close()
}
package main
import (
"fmt"
"os"
)
func foo() error {
f, err := os.Create("/tmp/test.txt")
if err != nil {
return err
}
defer f.Close()
err = fmt.Fprint(f, "Hello World")
if err != nil {
return err
}
return f.Sync()
}