After this patch, circleci builds the traffic control plugin image and
pushes it on docker hub. Rename traffic control plugin docker image
to "weaveworks/scope-traffic-control-plugin".
Use string for delay and packet loss parameter, code refactoring,
improved error messages, fix typos, add empty status representation,
fix namesapce ID representation.
To avoid to run `tc` every tic to get the qdisc status, we cache it.
The cache is updated every time a value is changed via the control interface.
NOTE: This will keep track only of the changes by done the plugins interface,
if the qdisc parameters are changed by another applcation or by the user
via terminal, such changes will not be caught.
This patch sends the delay and packet loss values along with
the container metadata. In this way the user has a direct feedback
about the traffic control plugin status.
As it is an initial implementation, it only controls latency of the
outgoing (egress) traffic. There is also a TODO to turn this plugin
into something more serious. Also, at some point we may consider
moving this plugin outside of "example" directory.
This allows plugins to add controls to nodes that already have some
controls set by other plugin. Previously only the last plugin that
sets the controls in the node would have its controls visible. That
was because of NodeControls' Merge function that actually weren't
merging data from two inputs, but rather returning data that was newer
and discarding the older one.
It exposes a button that allows switching between showing an iowait
statistics and an idle statistics. When the button is pressed it
should be replaced with other button. The button is shown in the host
node.
This is a rather nasty case as it shows several problems:
- Button control races
- The way the NodeControl currently works creates races between
plugins adding buttons to the same node. This is because
NodeControls are not really merged, but rather one of the two are
chosen based on a NodeControls' timestamps, so the older one is
thrown away entirely. In the end GUI can switch randomly between
showing controls from one plugin or from another.
- Showing outdated statistics
- When pressing the button to switch to show the other statistics,
the old ones are still shown for several seconds.
- Slowness of the updates in GUI
- Pressing the button yields no immediate reaction. Changes happen
after several seconds. Probably related to the previous point.
* Check that the protocol is TCP
* Support all HTTP methods
* Clear out tasks from table when they exit (required using task ids as table
keys). A nice side effect of this is that we can tell apart tasks receiving 0
req/second (i.e. tasks which currently aren't receiving any requests but were
receiving requests at some point) from tasks which don't exist anymore.
We report metrics fro the former.
* Simplify hash table key (no need to use a struct)
