race in handleShutdown

[bgadrian]

Problem statement

When running the server with -race flag, and sending the intrerupt signal CTRL+C, an error occurs

Swagger specification

https://github.com/bgadrian/pseudoservice/blob/master/swagger.yaml

Steps to reproduce

Simple HTTP server, on port 8080, run local.

go run -race main.go CTRL+C

Environment

swagger version: 0.17.2
go version: 1.11.1
OS: Ubuntu 17

race:
Read: servers := *serversPtr
Write: servers = append(servers, httpServer)
2nd race:
Read: server := servers[i]
Write: servers = append(servers, httpServer)

^C2018/11/04 20:31:15 Shutting down... 
==================
WARNING: DATA RACE
Read at 0x00c000200020 by goroutine 16:
  github.com/bgadrian/pseudoservice/restapi.(*Server).handleShutdown()
      /srv/go/pseudoservice/restapi/server.go:418 +0xba

Previous write at 0x00c000200020 by main goroutine:
  github.com/bgadrian/pseudoservice/restapi.(*Server).Serve()
      /srv/go/pseudoservice/restapi/server.go:229 +0x1c4d
  main.main()
      /srv/go/pseudoservice/cmd/pseudo-service-server/main.go:53 +0x5a1

Goroutine 16 (running) created at:
  github.com/bgadrian/pseudoservice/restapi.(*Server).Serve()
      /srv/go/pseudoservice/restapi/server.go:178 +0x212
  main.main()
      /srv/go/pseudoservice/cmd/pseudo-service-server/main.go:53 +0x5a1
==================
==================
WARNING: DATA RACE
Read at 0x00c000260010 by goroutine 16:
  github.com/bgadrian/pseudoservice/restapi.(*Server).handleShutdown()
      /srv/go/pseudoservice/restapi/server.go:425 +0x1a5

Previous write at 0x00c000260010 by main goroutine:
  github.com/bgadrian/pseudoservice/restapi.(*Server).Serve()
      /srv/go/pseudoservice/restapi/server.go:229 +0x1c17
  main.main()
      /srv/go/pseudoservice/cmd/pseudo-service-server/main.go:53 +0x5a1

Goroutine 16 (running) created at:
  github.com/bgadrian/pseudoservice/restapi.(*Server).Serve()
      /srv/go/pseudoservice/restapi/server.go:178 +0x212
  main.main()
      /srv/go/pseudoservice/cmd/pseudo-service-server/main.go:53 +0x5a1
==================
2018/11/04 20:31:15 Stopped serving pseudo service at http://127.0.0.1:8080
Found 2 data race(s)
exit status 66

[fredbi]

Tested this. Moving the append(servers, ...) statements just before launching the go routines solves the issue.