Weave Net

Troubleshooting Weave Net

Basic Diagnostics

Check the version of Weave Net you are running using:

weave version

If it is not the latest version, as shown in the list of releases, then it is recommended you upgrade using the installation instructions.

To check the Weave Net container logs:

docker logs weave

A reasonable amount of information, and all errors, get logged there.

The log verbosity may be increased by using the --log-level=debug option during weave launch. To log information on a per-packet basis use --pktdebug - but be warned, as this can produce a lot of output.

Another useful debugging technique is to attach standard packet capture and analysis tools, such as tcpdump and wireshark, to the weave network bridge on the host.

Status Reporting

A status summary can be obtained using weave status:

$ weave status

        Version: 1.1.0 (up to date; next check at 2016/04/06 12:30:00)

        Service: router
       Protocol: weave 1..2
           Name: 4a:0f:f6:ec:1c:93(host1)
     Encryption: disabled
  PeerDiscovery: enabled
        Targets: [192.168.48.14 192.168.48.15]
    Connections: 5 (1 established, 1 pending, 1 retrying, 1 failed, 1 connecting)
          Peers: 3 (with 5 established, 1 pending connections)
 TrustedSubnets: none

        Service: ipam
         Status: ready
          Range: 10.32.0.0-10.47.255.255
  DefaultSubnet: 10.32.0.0/12

        Service: dns
         Domain: weave.local.
            TTL: 1
        Entries: 9

        Service: proxy
        Address: tcp://127.0.0.1:12375

       Service: plugin (legacy)
    DriverName: weave

The terms used here are explained further at How Weave Net Works.

List Connections

Connections between Weave Net peers carry control traffic over TCP and data traffic over UDP. For a connection to be fully established, the TCP connection and UDP datapath must be able to transmit information in both directions. Weave Net routers check this regularly with heartbeats. Failed connections are automatically retried, with an exponential back-off.

To view detailed information on the local Weave Net router’s type weave status connections:

$ weave status connections
<- 192.168.48.12:33866   established unencrypted fastdp 7e:21:4a:70:2f:45(host2) mtu=1410
<- 192.168.48.13:60773   pending     encrypted   fastdp 7e:ae:cd:d5:23:8d(host3)
-> 192.168.48.14:6783    retrying    dial tcp4 192.168.48.14:6783: no route to host
-> 192.168.48.15:6783    failed      dial tcp4 192.168.48.15:6783: no route to host, retry: 2015-08-06 18:55:38.246910357 +0000 UTC
-> 192.168.48.16:6783    connecting

The columns are as follows:

Specific error messages:

List Peers

Detailed information on peers can be obtained with weave status peers:

$ weave status peers
ce:31:e0:06:45:1a(host1)
   <- 192.168.48.12:39634   ea:2d:b2:e6:e4:f5(host2)         established
   <- 192.168.48.13:49619   ee:38:33:a7:d9:71(host3)         established
ea:2d:b2:e6:e4:f5(host2)
   -> 192.168.48.11:6783    ce:31:e0:06:45:1a(host1)         established
   <- 192.168.48.13:58181   ee:38:33:a7:d9:71(host3)         established
ee:38:33:a7:d9:71(host3)
   -> 192.168.48.12:6783    ea:2d:b2:e6:e4:f5(host2)         established
   -> 192.168.48.11:6783    ce:31:e0:06:45:1a(host1)         established

This lists all peers known to this router, including itself. Each peer is shown with its name and nickname, then each line thereafter shows another peer that it is connected to, with the direction, IP address and port number of the connection. In the above example, host3 has connected to host1 at 192.168.48.11:6783; host1 sees the host3 end of the same connection as 192.168.48.13:49619.

Listing DNS Entries

Detailed information on DNS registrations can be obtained with weave status dns:

$ weave status dns
one          10.32.0.1       eebd81120ee4 4a:0f:f6:ec:1c:93
one          10.43.255.255   4fcec78d2a9b 66:c4:47:c6:65:bf
one          10.40.0.0       bab69d305cba ba:98:d0:37:4f:1c
three        10.32.0.3       7615b6537f74 4a:0f:f6:ec:1c:93
three        10.44.0.1       c0b39dc52f8d 66:c4:47:c6:65:bf
three        10.40.0.2       8a9c2e2ef00f ba:98:d0:37:4f:1c
two          10.32.0.2       83689b8f34e0 4a:0f:f6:ec:1c:93
two          10.44.0.0       7edc306cb668 66:c4:47:c6:65:bf
two          10.40.0.1       68a5e9c2641b ba:98:d0:37:4f:1c

The columns are as follows:

Producing a JSON Report

weave report

Produces a comprehensive dump of the internal state of the router, IPAM and DNS services in JSON format, including all the information available from the weave status commands. You can also supply a Golang text template to weave report in a similar fashion to docker inspect:

$ weave report -f '{{.DNS.Domain}}' weave.local.

Weave Net adds a template function, json, which can be applied to get results in JSON format.

$ weave report -f '{{json .DNS}}'
{"Domain":"weave.local.","Upstream":["8.8.8.8","8.8.4.4"],"Address":"172.17.0.1:53","TTL":1,"Entries":null}

Listing Attached Containers

weave ps

Produces a list of all containers running on this host that are connected to the Weave network, like this:

weave:expose 7a:c4:8b:a1:e6:ad 10.2.5.2/24
b07565b06c53 ae:e3:07:9c:8c:d4
5245643870f1 ce:15:34:a9:b5:6d 10.2.5.1/24
e32a7d37a93a 7a:61:a2:49:4b:91 10.2.8.3/24
caa1d4ee2570 ba:8c:b9:dc:e1:c9 10.2.1.1/24 10.2.2.1/24

On each line are the container ID, its MAC address, then the list of IP address/routing prefix length (CIDR notation) assigned on the Weave network. The special container name weave:expose displays the Weave bridge MAC and any IP addresses added to it via the weave expose command.

You can also supply a list of container IDs/names to weave ps, like this:

$ weave ps able baker
able ce:15:34:a9:b5:6d 10.2.5.1/24
baker 7a:61:a2:49:4b:91 10.2.8.3/24

Stopping Weave Net

To stop Weave Net, if you have configured your environment to use the Weave Docker API Proxy, e.g. by running eval $(weave env) in your shell, you must first restore the environment using:

eval $(weave env --restore)

Then run:

weave stop

Note that this leaves the local application container network intact. Containers on the local host can continue to communicate, whereas communication with containers on different hosts, as well as service export/import, is disrupted but resumes once Weave is relaunched.

To stop Weave Net and to completely remove all traces of the Weave network on the local host, run:

weave reset

Any running application containers permanently lose connectivity with the Weave network and will have to be restarted in order to re-connect.

Reboots

All the containers started by weave launch are configured with the Docker restart policy --restart=always, so they will come back again on reboot. This can be disabled via:

weave launch --no-restart

Note that the Weave Net router creates the weave network bridge if necessary when it restarts. The Weave Net Docker API Proxy then re-attaches any application containers that it originally attached to the Weave network when they restart.

Troubleshooting the V2 plugin

If Weave Net is installed via docker plugin install, download the weave script to run weave status, weave ps or weave report as above. Install Weave Net by following the install instructions.

Docker “v2” plugins do run as containers, but at a lower level within the Docker environment. Because of this, you cannot view them with docker ps, docker inspect, etc.

Do not run weave launch, weave stop or similar commands when using this plugin; use the docker plugin commands instead. You can run weave reset, but only after disabling the plugin via docker plugin disable.

Diagnostic logs from the plugin go to the same place as the Docker daemon, which will depend on your Linux install. For example, if it uses systemd, then do this to view the Docker and plugin logs:

sudo journalctl -u docker

Snapshot Releases

Snapshot releases are published at times to provide previews of new features, assist in the validation of bug fixes, etc. One can install the latest snapshot release using:

sudo curl -L git.io/weave-snapshot -o /usr/local/bin/weave
sudo chmod a+x /usr/local/bin/weave
weave setup

Snapshot releases report the script version as “unreleased”, and the container image versions as git hashes.

See Also