The possible reason is that your container instance is not accessible outside because you do not expose it to the Internet. If you want to expose it to the Internet, the command should be like this:
az container create -g MyResourceGroup --name MyName --image MyImage --ports 80 --ip-address Public
For more details, see parameter --ip-address
in az container create
.
Or you can connect into the container instance through the CLI command az container exec -g MyResourceGroup --name mynginx --container-name nginx --exec-command "/bin/bash"
or exec the command in the portal.
In addition, it seems you run Jenkins in the container instance. I would not recommend you do this. Because the Container Instance is a light-weight service, if you run a server in it, then it won't be actually what it should be anymore. The VM is an appropriate host for the Jenkins server. See Jenkins in VM.