Now that we enter the container namespace to fetch IPs for every
container, there is no need to have 'weave ps' do it.
This does mean we lose Weave MAC addresses, but that is a rather
idiosyncratic feature anyway.
With c75700fe04 we added code to detect
Ubuntu Xenial kernels with a regression in the eBPF subsystem in order
to gently fallback to procfs scanning on such systems (and not crash the
host system by running eBPF code).
With the latest kernel update for Ubuntu Xenial, the bug was fixed:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1763454
Therefore we can update the added check with an upper limit and make
sure that eBPF connection tracking only is disabled on kernels within
the range having the bug.
xref: https://github.com/weaveworks/scope/issues/3131
* Sentence cased text everywhere
Follows Weave Cloud's direction of sentence case on most things.
* More space between sorter caret and label
* Use full topology name for table header
The Ubuntu Xenial update to kernel 4.4.0-119.143 from 4.4.0-116.140 did
include a regression in the eBPF code. A basic `bpf_map_lookup_elem`
call as found in the tcptracer-bpf library used by Scope leads to a
kernel panic. As a result, Scope / the system crashes during startup
when the tcptracer is initialized. The Scope bug report can be found
here:
https://github.com/weaveworks/scope/issues/3131
To avoid crashes and gently fallback to procfs (as Scope already does
for systems not supporting eBPF), update `isKernelSupported()` and
explicitly check for Ubuntu Kernel versions with the problem.
Once the bug is fixed and an update published, the `abiNumber` check in
`isKernelSupported()` can and should be updated with an upper limit.
The Ubuntu bug report can be found here:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1763454
* Refactor: func has already access to probeID
* Allow controls for more k8s topologies
Controls for nodes generally need to know about the probe that is in
control of them.
This PR appends the probe ID info to k8s topologies CronJob, DaemonSet,
Service, and StatefulSet. Therefore allowing plugins to append controls.
* Remove superfluous error check
* Add some tests to verify controls allowance
* Add topology.ReplaceNode() for efficiency
In some places AddNode() was called after adding to an existing node,
in which case the Merge() is just a waste of time.
Reflectors are created and run within the same function, asynchronously from the main thread.
Creating reflectors may require calls to the kubernetes api, which can return errors.
API errors are not handled in the main thread, but are handled asynchronously by retries.
Upgraded from 99c19923, branch release-3.0.
This required fetching or upgrading the following:
* k8s.io/api to kubernetes-1.9.1
* k8s.io/apimachinery to kubernetes-1.9.1
* github.com/juju/ratelimit to 1.0.1
* github.com/spf13/pflag to 4c012f6d
Also, update Scope's imports/function calls to be compatible with the new client.
`isResourceSupported` checks whether a kubernetes resource is supported by the api server.
This ensures that, if the probe is unable to communicate with the api server, the call is retried until a true/false response.
If `isResourceSupported` returns false, `ListAndWatch` is not called and `runReflectorUntil` just exits.
This change makes the underlying reader set their corresponding `eof` slot to true on termination.
This make the overall logReadCloser converge to EOF in case of errors of the underlying readers, therefore prevent spinning on read.
`bufio.Reader.ReadBytes` may not return io.EOF when `Close()` closes the underlying reader.
For instance, closing logReadCloser from the Scope App makes `bufio.Reader.ReadBytes` produce the following error: `http2: response body closed`.
This is achieved by issuing an http request for each container to kubernetes' API, which yields one Reader for the corresponding container.
`logReadCloser' then reads from the above readers in parallel as data is available, buffering when necessary, forwarding it to clients by implementing the io.ReadCloser interface.
...which is useful if we want to disable periodic fetching of all
objects.
Previously the interval was also used to set the initial backoff of
the reconnect logic. A zero value there would result in _no_
backoff. So instead we now just use the default, which is 10s which
also happens to be the default probe.kubernetes.interval, so there is
no change in behaviour for the stock settings.
Having 6 lists of topolgies in the same file is a bit much:
1. consts for topology names
2. Report type definition
3. MakeReport() Report initialisation
4. Report.Topology(name) lookup
5. Report.TopologyMap() mapping of names to topology references
6. Report.WalkPairedTopologies() iterator over topology references
We get rid of 5 and 6 by introducing a topologyNames slice. So we
are down to 5.
We replace Report.TopologyMap() with a new function,
WalkNamedTopologies, that uses topologyNames. WalkPairedTopologies()
is updated to operate in a similar fashion. Likewise for
WalkTopologies() and Topologies() - these were previously calling
Walk[Paired]Topologies, but it is clearer to simply implement them
directly.
