In union option groups, the list of selected ids is encoded as a comma-delimited string.
For example, if 'foo' and 'bar' are selected, the value 'foo,bar' is sent, ie ["foo", "bar"] -> "foo,bar"
Under this scheme, with nothing selected, the empty string should be sent, ie. [] -> ""
Before this change, the frontend code called the "none option" by id 'none'.
There were several issues with this:
* The frontend would send 'none' when nothing was selected, not ''. The backend ignored this as it ignores
junk values in the options, treating them as though they hadn't been given.
* The backend would attempt to set the default value of an option to "nothing selected", ie. [], by sending ''.
The frontend would interpret this as nothing selected, *not even the 'none' option*, which caused a visual bug.
* Everything would break if one of the legitimate options had the id 'none', which could easily happen eg.
if a user had a 'none' k8s namespace. This is perhaps an unusual name, but our code shouldn't break when
a particular arbitary string is used as an input.
With this change, the none option is called '', which fixes all the above problems:
* The frontend encodes [''] as ''
* The frontend decodes '' as [''], and therefore shows the '' option as selected
* The string '' is not a valid k8s namespace name and is a reasonable "prohibited value" for all other use cases.
The backend already couldn't handle a value with this id correctly prior to this change anyway.
The rendering code checks whether endpoint IPs are part of
cluster-local networks. Due to the prevalence of endpoints - medium
sized reports can contain many thousands of endpoints - this is
performance critical. Alas the existing code performs the check via a
linear scan of a list of networks. That is slow when there are more
than a few, which will be the case in the context of k8s, since there
the probes register service IPs as local /32 networks.
Here we change representation of the set of networks to a prefix
tree (aka trie), which is well-suited for IP network membership checks
since networks are in fact a bitstring prefixes.
The specific representation is a crit-bit tree, but that choice was
purely based on implementation convenience - the chosen library is the
only one I could find that directly supports IP networks.
The rendering code checks whether endpoint IPs are part of
cluster-local networks. Due to the prevalence of endpoints - medium
sized reports can contain many thousands of endpoints - this is
performance critical. Alas the existing code performs the check via a
linear scan of a list of networks. That is slow when there are more
than a few. Unfortunately in some common k8s network setups, e.g. on
AWS, a cluster can contain hundreds of networks, due to /32 networks
derived from interfaces with multiple IPs.
Here we change representation of the set of networks to a prefix
tree (aka trie), which is well-suited for IP network membership checks
since networks are in fact a bitstring prefixes.
The specific representation is a crit-bit tree, but that choice was
purely based on implementation convenience - the chosen library is the
only one I could find that directly supports IP networks.
...by removing them. It was a ridiculous amount of contorted code to
test some utterly trivial functionality that is largely provided by
the golang stdlib.
* Node details fetching reports at proper timestamp.
* Corrected all the relevant timestamps in the UI.
* Renamed some state variables.
* Time travel works for topologies list.
* Added a whole screen overlay for time travel.
* Polished the backend.
* Make time travel work also with the Resource View.
* Fixed the jest tests.
* Fixed the empty view message for resource view.
* Some naming polishing.
* Addressed the comments.
Pins d3-transition and d3-drag dependencies which were previously
pulled in as deps from d3zoom as version 1.1.0 each. This broke
the zoom feature for `npm start`.
Fixes#2545
* Hacky working prototype.
* Operate with time.Duration offset instead of fixed timestamp.
* Polished the backend code.
* Made a nicer UI component.
* Small refactorings of the websockets code.
* Fixed the backend tests.
* Better websocketing and smoother transitions
* Small styling refactoring.
* Detecting empty topologies.
* Improved error messaging.
* Addressed some of David's comments.
* Moved nodesDeltaBuffer to a global state to fix the paused status rendering bug.
* Small styling changes
* Changed the websocket global state variables a bit.
* Polishing & refactoring.
* More polishing.
* Final refactoring.
* Addressed a couple of bugs.
* Hidden the timeline control behind Cloud context and a feature flag.
* Addressed most of @davkal's comments.
* Added mixpanel tracking.
the information is constant and already present in the id, so we can
extract it from there.
That reduces the report size and improves report encoding/decoding
performance. It should reduce memory usage too and improve report
merging performance too.
NB: Probes with this change are incompatible with old apps.
