Resource Checks Cannot Reach Internet

I’m trying to get concourse ci working at home but cannot seem to get the worker to function properly.

When I start the worker or restart it, for some time I see this in concourse’s web UI:

Backend error: Exit status: 500, message: {"Type":"","Message":"exit status 2","Handle":"","ProcessID":"","Binary":""}

After some time I see errors indicating it cannot reach, for example, gitlab.com

resource script '/opt/resource/check []' failed: exit status 128

stderr:
Cloning into '/tmp/git-resource-repo-cache'...
fatal: unable to access 'https://gitlab.com/[REDACTED].git/': Failed to connect to gitlab.com port 443: Connection timed out

Any ideas? I have a similar setup at the office that seems to function just fine.

I’m using Concourse 5.5.0, with Consul & Docker on the same machine.

Forgot to mention, I intercepted the check and tried to use APT to install some tools to help debug, but APT could not reach any external addresses…

Update After testing with CURL, I can reach the host machine, and it’s web server by IP, but it looks like DNS is failing.
Although, when I run apt update, the IPs for apt seem to resolve to IPs but cannot connect.

Err:1 https://packagecloud.io/github/git-lfs/ubuntu bionic InRelease
  Cannot initiate the connection to packagecloud.io:443 (2600:1f1c:2e5:6900:5174:4b7e:e606:ac27). - connect (101: Network is unreachable) Cannot initiate the connection to packagecloud.io:443 (2600:1f1c:2e5:6901:bcb8:2b4a:6e8d:142b). - connect (101: Network is unreachable) Could not connect to packagecloud.io:443 (54.183.241.58), connection timed out Could not connect to packagecloud.io:443 (52.8.147.134), connection timed out
Err:2 http://archive.ubuntu.com/ubuntu bionic InRelease
Cannot initiate the connection to archive.ubuntu.com:80 (2001:67c:1360:8001::21). - connect (101: Network is unreachable) Cannot initiate the connection to archive.ubuntu.com:80 (2001:67c:1360:8001::17). - connect (101: Network is unreachable) Cannot initiate the connection to archive.ubuntu.com:80 (2001:67c:1560:8001::14). - connect (101: Network is unreachable) Cannot initiate the connection to archive.ubuntu.com:80 (2001:67c:1560:8001::11). - connect (101: Network is unreachable) Could not connect to archive.ubuntu.com:80 (91.189.88.162), connection timed out Could not connect to archive.ubuntu.com:80 (91.189.88.149), connection timed out Could not connect to archive.ubuntu.com:80 (91.189.88.31), connection timed out Could not connect to archive.ubuntu.com:80 (91.189.88.24), connection timed out Could not connect to archive.ubuntu.com:80 (91.189.88.174), connection timed out Could not connect to archive.ubuntu.com:80 (91.189.88.173), connection timed out

UPDATE Further checks show the DNS failure is not an issue with my DNS config, but an issue with reaching a DNS server, so I’m back to square one. No outgoing connections can be made, but I can reach the host’s web server for some reason.

Looks like the issue exists in the quickstart version via docker-compose as well.