解决：Docker——No route to host) while connecting to upstream

解决：Docker——No route to host) while connecting to upstream

According to the error message: the situation is that there is no route to the specified hosts

problem analysis

View log file

The error message is as shown:

Actual situation: Can be routed to port 8080 but not routed to port 8081 and 8082

After analysis, judge: This is probably the reason for the firewall

So check the open ports by the following method

firewall-cmd --permanent --zone=public --list-ports

Found that port 8081 and port 8082 are not open

Solution

Use the following command to open the port to be routed

firewall-cmd --permanent --zone=public --add-port=8081/tcp

Restart firewall

firewall-cmd --reload 

You can refer to the following blog:

Linux firewall open/close designated port

to sum up

When there is a problem with nginx, you can first look at the log file information without any ideas, there will be error messages, which can tell you which aspect may be wrong, and then look for specific solutions.