61 lines
1.8 KiB
Go
61 lines
1.8 KiB
Go
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package main
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import (
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"fmt"
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"github.com/mitchellh/panicwrap"
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"io"
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"os"
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"strings"
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)
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// This is output if a panic happens.
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const panicOutput = `
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!!!!!!!!!!!!!!!!!!!!!!!!!!! PACKER CRASH !!!!!!!!!!!!!!!!!!!!!!!!!!!!
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Packer crashed! This is always indicative of a bug within Packer.
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A crash log has been placed at "crash.log" relative to your current
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working directory. It would be immensely helpful if you could please
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report the crash with Packer[1] so that we can fix this.
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!!!!!!!!!!!!!!!!!!!!!!!!!!! PACKER CRASH !!!!!!!!!!!!!!!!!!!!!!!!!!!!
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`
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// panicHandler is what is called by panicwrap when a panic is encountered
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// within Packer. It is guaranteed to run after the resulting process has
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// exited so we can take the log file, add in the panic, and store it
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// somewhere locally.
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func panicHandler(logF *os.File) panicwrap.HandlerFunc {
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return func(m string) {
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// Write away just output this thing on stderr so that it gets
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// shown in case anything below fails.
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fmt.Fprintf(os.Stderr, fmt.Sprintf("%s\n", m))
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// Create the crash log file where we'll write the logs
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f, err := os.Create("crash.log")
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if err != nil {
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fmt.Fprintf(os.Stderr, "Failed to create crash log file: %s", err)
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return
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}
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defer f.Close()
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// Seek the log file back to the beginning
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if _, err = logF.Seek(0, 0); err != nil {
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fmt.Fprintf(os.Stderr, "Failed to seek log file for crash: %s", err)
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return
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}
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// Copy the contents to the crash file. This will include
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// the panic that just happened.
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if _, err = io.Copy(f, logF); err != nil {
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fmt.Fprintf(os.Stderr, "Failed to write crash log: %s", err)
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return
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}
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// Tell the user a crash occurred in some helpful way that
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// they'll hopefully notice.
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fmt.Printf("\n\n")
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fmt.Println(strings.TrimSpace(panicOutput))
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}
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}
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