Traefik Bug

Summary

The Traefik logs contain an error, which matches the message captured in this bug report on Github. The issue seems to be fixed in the new version of Traefik.

Context/Logs

Error Log:

time="2020-11-12T08:58:37+01:00" level=error msg="Stack: goroutine 98049 [running]:
github.com/containous/traefik/v2/pkg/middlewares/recovery.recoverFunc(0x2ec3a60, 0xc000d87da0, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53800)
    /go/src/github.com/containous/traefik/pkg/middlewares/recovery/recovery.go:47 +0x1db
panic(0x24c0be0, 0xc00099c270)
    /usr/local/go/src/runtime/panic.go:969 +0x166
github.com/containous/traefik/v2/pkg/middlewares/pipelining.(*writerWithoutCloseNotify).Hijack(0xc000b27510, 0x7fa8856fb9e0, 0xc0009950e0, 0x2eb97a0, 0xc0009950e0, 0x1)
    /go/src/github.com/containous/traefik/pkg/middlewares/pipelining/pipelining.go:69 +0x47
net/http/httputil.(*ReverseProxy).handleUpgradeResponse(0xc0005ec640, 0x2ea76a0, 0xc000b27510, 0xc000a53e00, 0xc000475200)
    /usr/local/go/src/net/http/httputil/reverseproxy.go:530 +0x309
net/http/httputil.(*ReverseProxy).ServeHTTP(0xc0005ec640, 0x2ea76a0, 0xc000b27510, 0xc000a53d00)
    /usr/local/go/src/net/http/httputil/reverseproxy.go:268 +0xf07
github.com/containous/traefik/v2/pkg/middlewares/pipelining.(*pipelining).ServeHTTP(0xc000b7a6d0, 0x2ea7660, 0xc000879f40, 0xc000a53d00)
    /go/src/github.com/containous/traefik/pkg/middlewares/pipelining/pipelining.go:36 +0xe7
github.com/containous/traefik/v2/pkg/middlewares/accesslog.(*FieldHandler).ServeHTTP(0xc000724c40, 0x2ea7660, 0xc000879f40, 0xc000a53d00)
    /go/src/github.com/containous/traefik/pkg/middlewares/accesslog/field_middleware.go:29 +0x18d
github.com/vulcand/oxy/roundrobin.(*RoundRobin).ServeHTTP(0xc00025ebd0, 0x2ea7660, 0xc000879f40, 0xc000a53c00)
    /go/pkg/mod/github.com/vulcand/oxy@v1.1.0/roundrobin/rr.go:147 +0x13d
github.com/containous/traefik/v2/pkg/middlewares/emptybackendhandler.(*emptyBackend).ServeHTTP(0xc000b7a700, 0x2ea7660, 0xc000879f40, 0xc000a53c00)
    /go/src/github.com/containous/traefik/pkg/middlewares/emptybackendhandler/empty_backend_handler.go:31 +0x168
github.com/containous/traefik/v2/pkg/middlewares/tracing.(*forwarderMiddleware).ServeHTTP(0xc0006598f0, 0x2ea7660, 0xc000879f40, 0xc000a53c00)
    /go/src/github.com/containous/traefik/pkg/middlewares/tracing/forwarder.go:38 +0x609
github.com/containous/traefik/v2/pkg/middlewares/headers.secureHeader.ServeHTTP.func1(0x2ea7660, 0xc000879ef0, 0xc000a53c00)
    /go/src/github.com/containous/traefik/pkg/middlewares/headers/secure.go:52 +0xea
github.com/unrolled/secure.(*Secure).HandlerFuncWithNextForRequestOnly(0xc000541b80, 0x2ea7660, 0xc000879ef0, 0xc000a53b00, 0xc000f08a80)
    /go/pkg/mod/github.com/unrolled/secure@v1.0.7/secure.go:228 +0x201
github.com/containous/traefik/v2/pkg/middlewares/headers.secureHeader.ServeHTTP(0x2e5a460, 0xc0006598f0, 0xc000541b80, 0xc0007d7860, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
    /go/src/github.com/containous/traefik/pkg/middlewares/headers/secure.go:51 +0x7a
github.com/containous/traefik/v2/pkg/middlewares/headers.(*Header).ServeHTTP(0xc00083dd80, 0x2ea7660, 0xc000879ea0, 0xc000a53b00)
    /go/src/github.com/containous/traefik/pkg/middlewares/headers/header.go:51 +0x133
github.com/containous/traefik/v2/pkg/middlewares/headers.(*headers).ServeHTTP(0xc00083dda0, 0x2ea7660, 0xc000879ea0, 0xc000a53b00)
    /go/src/github.com/containous/traefik/pkg/middlewares/headers/headers.go:75 +0x52
github.com/containous/traefik/v2/pkg/middlewares/tracing.(*Wrapper).ServeHTTP(0xc000659c50, 0x2ea7660, 0xc000879ea0, 0xc000a53b00)
    /go/src/github.com/containous/traefik/pkg/middlewares/tracing/wrapper.go:57 +0x16a
github.com/containous/traefik/v2/pkg/middlewares/headers.secureHeader.ServeHTTP.func1(0x2eb97e0, 0xc0002fa8c0, 0xc000a53b00)
    /go/src/github.com/containous/traefik/pkg/middlewares/headers/secure.go:52 +0xea
github.com/unrolled/secure.(*Secure).HandlerFuncWithNextForRequestOnly(0xc000541e00, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53a00, 0xc000f08fc8)
    /go/pkg/mod/github.com/unrolled/secure@v1.0.7/secure.go:228 +0x201
github.com/containous/traefik/v2/pkg/middlewares/headers.secureHeader.ServeHTTP(0x2e5a420, 0xc000659c50, 0xc000541e00, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
    /go/src/github.com/containous/traefik/pkg/middlewares/headers/secure.go:51 +0x7a
github.com/containous/traefik/v2/pkg/middlewares/headers.(*headers).ServeHTTP(0xc00083de20, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53a00)
    /go/src/github.com/containous/traefik/pkg/middlewares/headers/headers.go:75 +0x52
github.com/containous/traefik/v2/pkg/middlewares/tracing.(*Wrapper).ServeHTTP(0xc000659e30, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53a00)
    /go/src/github.com/containous/traefik/pkg/middlewares/tracing/wrapper.go:57 +0x16a
github.com/containous/traefik/v2/pkg/middlewares/accesslog.(*FieldHandler).ServeHTTP(0xc000724c80, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53a00)
    /go/src/github.com/containous/traefik/pkg/middlewares/accesslog/field_middleware.go:29 +0x18d
github.com/gorilla/mux.(*Router).ServeHTTP(0xc000b96d80, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53800)
    /go/pkg/mod/github.com/containous/mux@v0.0.0-20181024131434-c33f32e26898/mux.go:133 +0x112
github.com/containous/traefik/v2/pkg/middlewares/recovery.(*recovery).ServeHTTP(0xc000b02da0, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53800)
    /go/src/github.com/containous/traefik/pkg/middlewares/recovery/recovery.go:33 +0x104
github.com/containous/traefik/v2/pkg/middlewares/accesslog.(*FieldHandler).ServeHTTP(0xc000725300, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53800)
    /go/src/github.com/containous/traefik/pkg/middlewares/accesslog/field_middleware.go:29 +0x18d
github.com/containous/traefik/v2/pkg/middlewares/requestdecorator.(*RequestDecorator).ServeHTTP(0xc0003e6ee8, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53700, 0xc000f09768)
    /go/src/github.com/containous/traefik/pkg/middlewares/requestdecorator/request_decorator.go:47 +0x37d
github.com/containous/traefik/v2/pkg/middlewares/requestdecorator.WrapHandler.func1.1(0x2eb97e0, 0xc0002fa8c0, 0xc000a53700)
    /go/src/github.com/containous/traefik/pkg/middlewares/requestdecorator/request_decorator.go:84 +0x83
net/http.HandlerFunc.ServeHTTP(0xc000b03340, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53700)
    /usr/local/go/src/net/http/server.go:2041 +0x44
github.com/containous/traefik/v2/pkg/server/router/tcp.(*Manager).buildEntryPointHandler.func1(0x2eb97e0, 0xc0002fa8c0, 0xc000a53700)
    /go/src/github.com/containous/traefik/pkg/server/router/tcp/router.go:194 +0x16f
net/http.HandlerFunc.ServeHTTP(0xc000b03760, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53700)
    /usr/local/go/src/net/http/server.go:2041 +0x44
github.com/containous/traefik/v2/pkg/middlewares.(*HTTPHandlerSwitcher).ServeHTTP(0xc0003e6ea8, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53700)
    /go/src/github.com/containous/traefik/pkg/middlewares/handler_switcher.go:23 +0x70
github.com/containous/traefik/v2/pkg/middlewares/forwardedheaders.(*XForwarded).ServeHTTP(0xc000626410, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53700)
    /go/src/github.com/containous/traefik/pkg/middlewares/forwardedheaders/forwarded_header.go:173 +0x10b
net/http.serverHandler.ServeHTTP(0xc0002fa1c0, 0x2eb97e0, 0xc0002fa8c0, 0xc000a53700)
    /usr/local/go/src/net/http/server.go:2836 +0xa3
net/http.(*conn).serve(0xc000a26320, 0x2ec39a0, 0xc0002539c0)
    /usr/local/go/src/net/http/server.go:1924 +0x86c
created by net/http.(*Server).Serve
    /usr/local/go/src/net/http/server.go:2962 +0x35c
" middlewareName=traefik-internal-recovery middlewareType=Recovery

Possible Solution

Deploy the new Traefik version 2.3.2.