Correct inabillity for appservice-discord to connect

[jgoerzen]

After recently updating my matrix-docker-ansible-deploy installation, matrix-appservice-discord would refuse to start, logging ECONNREFUSED to https://matrix.[mydomain]:443, which was resolving to 172.18.0.2 due to the --hostname in mailer grabbing that hostname.

Curious why the IRC bridge didn't have this issue, I looked into it, and it was connecting to http://matrix-synapse:8008. Correcting this one to that URL resolved the issue.

[spantaleev]

Interesting! What version of Docker is that on?

matrix.DOMAIN resolves to the public IP address of the instance for me, even though matrix-mailer does have a --hostname=matrix.DOMAIN argument.

I'm testing on CentOS 7:

# docker version

Client: Docker Engine - Community
 Version:           19.03.14
 API version:       1.40
 Go version:        go1.13.15
 Git commit:        5eb3275d40
 Built:             Tue Dec  1 19:20:42 2020
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.14
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.13.15
  Git commit:       5eb3275d40
  Built:            Tue Dec  1 19:19:17 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.3.9
  GitCommit:        ea765aba0d05254012b0b9e595e995c09186427f
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

In any case, it's better if we make them talk over the in-container network. Thank you! 👍

[jgoerzen]

Interesting, as I also upgraded my docker at the same time.

I'm finding that messages are making it from Discord to Matrix now, but not the other way anymore, and I wonder if this change is related. There was also an undocumented change to the config (relating to matrix_appservice_discord_auth_usePrivilegedIntents)... So three things changed (updated docker, upgraded matrix-docker-ansible-deploy, and a change to the Discord integration as a result of the latter).

The gateway now is receiving messages from Discord and sending them to Matrix, but is failing to send messages from Matrix to Discord, saying it can't find the channel. I am suspicious that maybe this change is to blame, though without it, it won't communicate at all. Looking at the upstream docs for the appservice, it says that this should be the public URL. So maybe this change should be reverted and the hostname removed from the mailer (I'm not sure why that's needed, in fact).

Client: Docker Engine - Community
 Version:           20.10.0
 API version:       1.41
 Go version:        go1.13.15
 Git commit:        7287ab3
 Built:             Tue Dec  8 18:59:49 2020
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.0
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.13.15
  Git commit:       eeddea2
  Built:            Tue Dec  8 18:57:58 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.4.3
  GitCommit:        269548fa27e0089a8b8278fc4fc781d7f65a939b
 runc:
  Version:          1.0.0-rc92
  GitCommit:        ff819c7e9184c13b7c2607fe6c30ae19403a7aff
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

[jgoerzen]

Also I have quite a few of Dec 10 08:31:09 matrix matrix-appservice-discord[23678]: WARNING: Error loading config file: .dockercfg: $HOME is not defined in my logs

[spantaleev]

I've upgraded to Docker 20.10.

Along with other breakage (see d08b277), it seems like: docker run --rm --network=matrix docker.io/alpine:3.12 nslookup matrix.DOMAIN resolves to the matrix-mailer's IP address (docker inspect matrix-mailer --format '{{.NetworkSettings.Networks.matrix.IPAddress}}').

This is probably some new Docker feature that we need to workaround. One way is to stop passing --hostname=matrix.DOMAIN to matrix-mailer. I think we do it for a reason right now though.. and we may need some special handling to work around it.

---

I'm also observing this error:

WARNING: Error loading config file: .dockercfg: $HOME is not defined

So far, it seems benign.

---

Your Discord bridge failures may also be related to us upgrading matrix-appservice-discord to v1.0.0 recently. See 05cecb5.

I still haven't verified that it works for me after the upgrade. I was running the old version of the bridge until today.

My Discord is fairly inactive, so I can't tell if it's broken yet.