CONNECTION_TIMEOUT cicd network_error ai_generated true

Error: Failed to connect to github.com port 443: Connection timed out

ID: cicd/github-actions-connect-timeout

Also available as: JSON · Markdown · 中文
80%Fix Rate
85%Confidence
1Evidence
2023-05-12First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
GitHub Actions Runner 2.308.0 active — — —
Ubuntu 22.04 active — — —
Windows Server 2022 active — — —

Root Cause

GitHub Actions runner cannot reach github.com due to DNS resolution failures, firewall rules, or proxy misconfiguration in the runner environment.

generic

中文

GitHub Actions 运行器无法访问 github.com，原因是运行器环境中的 DNS 解析失败、防火墙规则或代理配置错误。

Official Documentation

https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners/about-self-hosted-runners#communication-between-self-hosted-runners-and-github

Workarounds

  1. 85% success Configure proxy environment variables on the runner: export http_proxy=http://proxy.example.com:8080; export https_proxy=http://proxy.example.com:8080; export no_proxy=localhost,127.0.0.1 
    Configure proxy environment variables on the runner: export http_proxy=http://proxy.example.com:8080; export https_proxy=http://proxy.example.com:8080; export no_proxy=localhost,127.0.0.1
  2. 75% success Update DNS resolver on the runner host: echo 'nameserver 8.8.8.8' > /etc/resolv.conf 
    Update DNS resolver on the runner host: echo 'nameserver 8.8.8.8' > /etc/resolv.conf
  3. 80% success Check firewall rules to allow outbound HTTPS (port 443) to github.com IP ranges: nslookup github.com; sudo ufw allow out on eth0 to any port 443 proto tcp 
    Check firewall rules to allow outbound HTTPS (port 443) to github.com IP ranges: nslookup github.com; sudo ufw allow out on eth0 to any port 443 proto tcp

中文步骤

  1. Configure proxy environment variables on the runner: export http_proxy=http://proxy.example.com:8080; export https_proxy=http://proxy.example.com:8080; export no_proxy=localhost,127.0.0.1
  2. Update DNS resolver on the runner host: echo 'nameserver 8.8.8.8' > /etc/resolv.conf
  3. Check firewall rules to allow outbound HTTPS (port 443) to github.com IP ranges: nslookup github.com; sudo ufw allow out on eth0 to any port 443 proto tcp

Dead Ends

Common approaches that don't work:

  1. Restarting the runner service without checking network connectivity 95% fail

    The underlying network issue persists after restart; runner will hit the same timeout on next job.

  2. Adding more retries via workflow configuration (e.g., 'retry-on-error: true') 90% fail

    GitHub Actions retries only the step, not the underlying TCP connection; connection timeout is fatal and not recoverable by retrying the step.

  3. Clearing runner cache and reinstalling the runner agent 85% fail

    The runner agent itself is functional; the issue is at the network layer, not the agent software.