sciond socket file mode.

[juagargi]

sciond sets the file mode for both its Reliable and Unix socket files.
The file mode comes from the configuration value SocketFileMode,
specified in octal as a string.

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This change is 

[lukedirtwalker]

Reviewed 6 of 6 files at r1.
Reviewable status: all files reviewed, 4 unresolved discussions (waiting on @juagargi)

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go/sciond/internal/config/sample.go, line 28 at r1 (raw file):

Unix = "/run/shm/sciond/default-unix.sock"

# File permissions of both the Reliable and Unix socket files, in octal.

Add (default 0770) at the end.

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go/sciond/internal/config/sample.go, line 29 at r1 (raw file):

# File permissions of both the Reliable and Unix socket files, in octal.
SocketFileMode = "0755"

This should contain the default value, so that the test checks that the default and the sample match.

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go/sciond/internal/servers/server.go, line 106 at r1 (raw file):

func (srv *Server) listen() (net.Listener, error) {
	var listener net.Listener
	var error error

errors are always named err please also name it like that.

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go/sciond/internal/servers/server.go, line 119 at r1 (raw file):

		return nil, common.NewBasicError("unknown network", nil, "net", srv.network)
	}
	if error == nil {

usually we check the other way around:

if err != nil {
      return nil, err
}
if err := os.Chmod(....); err != nil {
....
}
return listener, nil

[juagargi]

Reviewable status: all files reviewed, 4 unresolved discussions (waiting on @lukedirtwalker)

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go/sciond/internal/config/sample.go, line 28 at r1 (raw file):

Previously, lukedirtwalker (Lukas Vogel) wrote…

Add (default 0770) at the end.

Done.

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go/sciond/internal/config/sample.go, line 29 at r1 (raw file):

Previously, lukedirtwalker (Lukas Vogel) wrote…

This should contain the default value, so that the test checks that the default and the sample match.

Done.

---

go/sciond/internal/servers/server.go, line 106 at r1 (raw file):

Previously, lukedirtwalker (Lukas Vogel) wrote…

errors are always named err please also name it like that.

Done.

---

go/sciond/internal/servers/server.go, line 119 at r1 (raw file):

Previously, lukedirtwalker (Lukas Vogel) wrote…

usually we check the other way around:

if err != nil {
      return nil, err
}
if err := os.Chmod(....); err != nil {
....
}
return listener, nil

Done.

[lukedirtwalker]

Reviewed 3 of 3 files at r2.
Reviewable status: complete! all files reviewed, all discussions resolved

[lukedirtwalker]

Reviewed 2 of 2 files at r3.
Reviewable status: complete! all files reviewed, all discussions resolved