syslog日志
Mar 13 08:42:41 xxx dockerd[30691]: time="2022-03-13T08:42:41.928436506Z" level=warning msg="Error getting v2 registry: Get https://docker.mirrors.ustc.edu.cn/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)"
Mar 13 08:42:41 xxx dockerd[30691]: time="2022-03-13T08:42:41.928568283Z" level=info msg="Attempting next endpoint for pull after error: Get https://docker.mirrors.ustc.edu.cn/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)"
終端表現
root@xxx:/data1/docker# docker pull redis
Using default tag: latest
Error response from daemon: Get https://registry-1.docker.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
排查記錄
1.根據網上的文檔，嘗試更換了各種地址，發現都無法拉取地址。於是開始自己排查。
2.測試域名解析是能正常解析的
root@xxx:/data1/docker# ping docker.mirrors.ustc.edu.cn
PING mirrors.ustc.edu.cn (202.141.160.110) 56(84) bytes of data.
3.嘗試telnet443端口，發現端口不通
root@xxx:/data1/docker# telnet docker.mirrors.ustc.edu.cn 443
Trying 202.141.160.110...
4.此時懷疑是網絡的問題，各種檢查，發現是這台有問題的機器到目標機器的網絡不通，但是內網別的機器正常，所以懷疑可能是防火牆、路由器、服務器路由問題
root@liuyi:/data1/docker# traceroute docker.mirrors.ustc.edu.cn
traceroute to docker.mirrors.ustc.edu.cn (202.141.160.110), 30 hops max, 60 byte packets
1 RT-AC86U-4680 (192.168.50.1) 1.707 ms 1.498 ms 1.403 ms
2 * * *
3 * * *
4 * * *
5 * * *
6 * * *
5.經過排查，發現是出問題的這台機器到路由器192.168.50.1的下一跳地址192.168.1.1不通。為什么我知道下一跳是這個IP呢，因為我用別的機器測了下。
root@liuyi:/data1/docker# ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
6.通過抓包發現只有發出去的包，沒有發回來的
root@liuyi:~# tcpdump -vvv|grep -i 192.168.1.1
tcpdump: listening on enp4s0, link-type EN10MB (Ethernet), capture size 262144 bytes
192.168.50.61 > 192.168.1.1: ICMP echo request, id 31374, seq 1, length 64
192.168.50.61 > 192.168.1.1: ICMP echo request, id 31374, seq 2, length 64
192.168.50.61 > 192.168.1.1: ICMP echo request, id 31374, seq 3, length 64
192.168.50.61 > 192.168.1.1: ICMP echo request, id 31374, seq 4, length 64
192.168.50.61 > 192.168.1.1: ICMP echo request, id 31374, seq 5, length 64
192.168.50.61 > 192.168.1.1: ICMP echo request, id 31374, seq 6, length 64
192.168.50.61 > 192.168.1.1: ICMP echo request, id 31374, seq 7, length 64**
解決方案
登錄路由器檢查，發現是路由器禁用了這台機器訪問網絡，解除限制后恢復正常。