46 lines
1.0 KiB
Go
46 lines
1.0 KiB
Go
package runner
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import (
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"fmt"
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"net"
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"os"
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"time"
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)
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// GetFreePort queries the kernel for a free ephemeral port
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func GetFreePort() (int, error) {
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addr, err := net.ResolveTCPAddr("tcp", "127.0.0.1:0")
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if err != nil {
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return 0, err
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}
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l, err := net.ListenTCP("tcp", addr)
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if err != nil {
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return 0, err
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}
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defer l.Close()
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return l.Addr().(*net.TCPAddr).Port, nil
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}
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// WaitPortReady polls targetAddr until it accepts TCP connections or timeout occurs
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func WaitPortReady(addr string, timeout time.Duration) error {
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deadline := time.Now().Add(timeout)
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for time.Now().Before(deadline) {
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conn, err := net.DialTimeout("tcp", addr, 100*time.Millisecond)
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if err == nil {
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conn.Close()
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return nil
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}
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time.Sleep(20 * time.Millisecond)
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}
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return fmt.Errorf("timeout waiting for %s to bind", addr)
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}
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// FileExists checks whether path exists and is not a directory
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func FileExists(path string) bool {
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info, err := os.Stat(path)
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if os.IsNotExist(err) {
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return false
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}
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return err == nil && !info.IsDir()
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}
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