Address already in use error when binding ipv6 addresses in 2.95

[lewisl9029]

Describe the bug

I've been running the chrislusf/seaweedfs container at 2.94 for a while now, and recently attempted to upgrade to 3.00, when I ran into the following error:

reflame-storage | F0427 22:17:12     1 master.go:141] Master startup error: listen tcp 127.0.0.1:9333: bind: address already in use
reflame-storage | goroutine 56 [running]:
reflame-storage | github.com/chrislusf/seaweedfs/weed/glog.stacks(0x0)        
reflame-storage |       /go/src/github.com/chrislusf/seaweedfs/weed/glog/glog.go:767 +0x8a
reflame-storage | github.com/chrislusf/seaweedfs/weed/glog.(*loggingT).output(0x3ccebc0, 0x3, 0xc0003f8000, {0x2e99990, 0xc000593df0}, 0x1, 0x0)
reflame-storage |       /go/src/github.com/chrislusf/seaweedfs/weed/glog/glog.go:718 +0x3ab
reflame-storage | github.com/chrislusf/seaweedfs/weed/glog.(*loggingT).printf(0x7fff3b836f36, 0x9, {0x23f2519, 0x18}, {0xc000593df0, 0x1, 0x1})
reflame-storage |       /go/src/github.com/chrislusf/seaweedfs/weed/glog/glog.go:656 +0x110
reflame-storage | github.com/chrislusf/seaweedfs/weed/glog.Fatalf(...)        
reflame-storage |       /go/src/github.com/chrislusf/seaweedfs/weed/glog/glog.go:1149
reflame-storage | github.com/chrislusf/seaweedfs/weed/command.startMaster({0xc000146fb8, 0xc000146fd0, 0xc0005ee2a0, 0xc0005ee2c0, 0xc0005eed70, 0xc0009b4d00, 0xc000146fd8, 0xc000146fed, 0xc0005eed90, 0xc000146ff8, ...}, ...)
reflame-storage |       /go/src/github.com/chrislusf/seaweedfs/weed/command/master.go:141 +0x2fc
reflame-storage | created by github.com/chrislusf/seaweedfs/weed/command.runServer
reflame-storage |       /go/src/github.com/chrislusf/seaweedfs/weed/command/server.go:288 +0x68d

I went backwards and found that the error started occurring at 2.95, and from the changelog, this line seemed like the most obvious culprit:

Master, Filer, S3, IAM also bind to localhost, in addition to -ip.bind. This should avoid exposing to all network interfaces while make most common use cases easy.

I need to bind to ipv6 for proper networking on https://fly.io/, so this is blocking my upgrade. Let me know if there's something wrong with my configuration, and if you're aware of any workarounds. Thanks!

System Setup

Here's a dockerfile to reproduce:

FROM chrislusf/seaweedfs:2.95

EXPOSE 58088

WORKDIR /app

COPY filer.toml /app/filer.toml

ENTRYPOINT [ "weed", "server", "-ip.bind=[::]", "-dir=/data", "-filer=true", "-filer.port=8888", "-master.port=9333", "-volume.port=8080" ]

Here's the content of filer.toml:

[leveldb3]
enabled = true
dir = "/data/filer-leveldb3"		

Expected behavior
Seaweed starts without errors.

Other than this small glitch, seaweed has been working like a dream! Thank you so much for your work on it!

[chrislusf]

Thanks! Added a fix.