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Diagnose why exercise in "multi-host networking" isn't working?


(Davidmichaelkarr) #1

As an aside, I find it odd that the “production” documentation is presently for 1.12 even though that appears to only be available as an RC.

Anyway, I was stepping through the docs, doing exercises when it made sense. I was going through the “multi-host networking” page at https://docs.docker.com/engine/userguide/networking/get-started-overlay/ .

I got into “Step 4: Run an application on your Network”, and apparently successfully did sub-step 3, to run the nginx server.

However, running sub-step 4, to get the contents of the home page, it fails with the following:
[localhost ~]$ docker run -it --rm --net=my-net --env="constraint:node==mhs-demo1" busybox wget -O- http://web Connecting to web (10.0.9.2:80) wget: can't connect to remote host (10.0.9.2): No route to host

Ok, that seems odd. I then did the following:
[localhost ~]$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a5d6d27de093 nginx "nginx -g 'daemon off" 10 minutes ago Up 6 minutes 80/tcp, 443/tcp mhs-demo0/web

And the following, for more info:
[localhost ~]$ docker info Containers: 4 Running: 4 Paused: 0 Stopped: 0 Images: 4 Server Version: swarm/1.2.3 Role: primary Strategy: spread Filters: health, port, containerslots, dependency, affinity, constraint Nodes: 2 mhs-demo0: 192.168.99.101:2376 └ ID: OA2B:HOF2:ZIF5:BPUU:MGLB:LLE6:ZYGG:JQY4:G7SN:E6AY:3OTT:5254 └ Status: Healthy └ Containers: 3 └ Reserved CPUs: 0 / 1 └ Reserved Memory: 0 B / 1.021 GiB └ Labels: executiondriver=, kernelversion=4.4.12-boot2docker, operatingsystem=Boot2Docker 1.11.2 (TCL 7.1); HEAD : a6645c3 - Wed Jun 1 22:59:51 UTC 2016, provider=virtualbox, storagedriver=aufs └ UpdatedAt: 2016-06-22T21:26:42Z └ ServerVersion: 1.11.2 mhs-demo1: 192.168.99.105:2376 └ ID: DF2L:GFUM:T6A2:WYCX:YFP7:INS6:6RYA:APK5:WXNX:JSW5:WCYP:2OMT └ Status: Healthy └ Containers: 1 └ Reserved CPUs: 0 / 1 └ Reserved Memory: 0 B / 1.021 GiB └ Labels: executiondriver=, kernelversion=4.4.12-boot2docker, operatingsystem=Boot2Docker 1.11.2 (TCL 7.1); HEAD : a6645c3 - Wed Jun 1 22:59:51 UTC 2016, provider=virtualbox, storagedriver=aufs └ UpdatedAt: 2016-06-22T21:26:40Z └ ServerVersion: 1.11.2 Plugins: Volume: Network: Kernel Version: 4.4.12-boot2docker Operating System: linux Architecture: amd64 CPUs: 2 Total Memory: 2.042 GiB Name: 9c9adfdec0c1 Docker Root Dir: Debug mode (client): false Debug mode (server): false WARNING: No kernel memory limit support

What else can I do to troubleshoot this?