Bollard failing to parse docker system df JSON

[mac-chaffee]

Description
I'm getting this error when running docuum from source:

[2020-07-26 23:24:54 -04:00 ERROR] Unable to determine the disk space used by Docker images: Error { inner:

Failed to deserialize JSON: invalid type: string "2020-06-17T14:55:03.4970949Z", expected i64 at line 1 column 76799 }.

It's errorring on this bit of JSON (obtained by running curl --unix-socket /var/run/docker.sock http:/v1.40/system/df | jq | less)

{
      "ID": "rrc3gr2ks5mm41ntmlqsqu2k4",
      "Parent": "2tub3atjmssqqh0ji08jjc5oj",
      "Type": "regular",
      "Description": "fileop target",
      "InUse": false,
      "Shared": false,
      "Size": 353,
      "CreatedAt": "2020-06-17T14:55:03.5952988Z",
      "LastUsedAt": "2020-06-17T14:55:44.6490503Z",
      "UsageCount": 1
    }

I worry this might be a bollard bug where it doesn't expect some docker objects to still be reporting dates in iso8601 format.

Instructions to reproduce the bug
Ensure matching versions of docker, OS, docuum. Then:

git checkout v0.10.0
cargo run -- --threshold=50GB

System information:

• OS: macOS Catalina 10.15.6
• Docker version:

$ docker version
Client: Docker Engine - Community
 Version:           19.03.8
 API version:       1.40
 Go version:        go1.12.17
 Git commit:        afacb8b
 Built:             Wed Mar 11 01:21:11 2020
 OS/Arch:           darwin/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.8
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.12.17
  Git commit:       afacb8b
  Built:            Wed Mar 11 01:29:16 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          v1.2.13
  GitCommit:        7ad184331fa3e55e52b890ea95e65ba581ae3429
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

• Docuum version: 0.10.0

Additional context

Looks like starting bollard with Docker::connect_with_local_defaults() means it will try to use API version 1.40: https://docs.rs/bollard/0.7.1/src/bollard/docker.rs.html#72-75

Maybe we could experiment with an older API version. Or maybe docker just doesn't properly display old entries and I just need to do a docker system prune. Or we may just need to send this bug report to the bollard devs.

[stepchowfun]

Shoot. I was afraid something like this would happen with Bollard. I'll revert that PR tonight. Would you mind filing this bug with Bollard? If they fix it on their end, we can bring it back.

[stepchowfun]

Thank you for reporting this BTW!

The weird thing is... "it works on my machine"

[mac-chaffee]

Just adding a bit more info: think the blame rests on Docker itself, because their API docs seem to be literally lying lol: https://docs.docker.com/engine/api/v1.40/#operation/SystemDataUsage

^ that claims BuildCache objects use Integers for their CreatedAt dates

[stepchowfun]

Interesting. The weird thing is that on my machine I actually get an int64. I have the same version of Docker (19.03.8).

[mdonoughe]

That's very interesting. I looked at the code and it looks like it always uses the default handling of outputing an RFC 3339 string.

[stepchowfun]

Thanks @mdonoughe for reporting the issue upstream!

[mac-chaffee]

Thanks for handling this @stepchowfun @mdonoughe !

Looks like the inability to reproduce is due to my use of BuildKit. I should have known that would come back to bite me one day haha!

[stepchowfun]

I'm quite glad you had BuildKit enabled and discovered this! We should test with BuildKit both enabled and disabled as part of our release process.