func migrateToMostRecentSequence()

in main/cmds.go [81:111]

• 15 lines of code
• 3 McCabe index (conditional complexity)

func migrateToMostRecentSequence(ctx *log.Context, h HandlerEnvironment, seqNum int) {
	// The status folder is used instead of the settings because the settings file is written
	// by the agent before install is called.  As a result, the extension cannot determine if this
	// is a new install or an upgrade.
	//
	// If this is an upgrade there will be a status file. The agent will re-write the last status
	// file to indicate that the upgrade happened successfully. The extension uses the last status
	// sequence number to determine the last settings file that was executed.
	//
	// The agent helpfully copies mrseq every time an extension is upgraded thereby preserving the
	// most recent executed sequence. If extensions use mrseq they benefit from this mechanism, and
	// do not have invent another method.  The CustomScript extension should have been using this
	// from the beginning, but it was not.
	//
	computedSeqNum, err := FindSeqNumStatus(h.HandlerEnvironment.StatusFolder)
	if err != nil {
		// If there was an error, the sequence number is zero.
		ctx.Log("event", "migrate to mrseq", "error", err)
		return
	}

	fout, err := os.Create(mostRecentSequence)
	if err != nil {
		ctx.Log("event", "migrate to mrseq", "error", err)
		return
	}
	defer fout.Close()

	ctx.Log("event", "migrate to mrseq", "message", fmt.Sprintf("migrated mrseq to %v", computedSeqNum))
	fout.WriteString(fmt.Sprintf("%v", computedSeqNum))
}