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27 lines
844 B
Go
27 lines
844 B
Go
package portallocator
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import (
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"bufio"
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"fmt"
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"os"
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)
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func getDynamicPortRange() (start int, end int, err error) {
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const portRangeKernelParam = "/proc/sys/net/ipv4/ip_local_port_range"
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portRangeFallback := fmt.Sprintf("using fallback port range %d-%d", DefaultPortRangeStart, DefaultPortRangeEnd)
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file, err := os.Open(portRangeKernelParam)
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if err != nil {
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return 0, 0, fmt.Errorf("port allocator - %s due to error: %v", portRangeFallback, err)
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}
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defer file.Close()
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n, err := fmt.Fscanf(bufio.NewReader(file), "%d\t%d", &start, &end)
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if n != 2 || err != nil {
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if err == nil {
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err = fmt.Errorf("unexpected count of parsed numbers (%d)", n)
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}
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return 0, 0, fmt.Errorf("port allocator - failed to parse system ephemeral port range from %s - %s: %v", portRangeKernelParam, portRangeFallback, err)
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}
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return start, end, nil
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}
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