feat: add mongodb plugin

[vmarchaud]

Plugin ported from OC: https://github.com/census-instrumentation/opencensus-node/tree/master/packages/opencensus-instrumentation-mongodb

[codecov-io]

Codecov Report

Merging #205 into master will increase coverage by 0.11%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #205      +/-   ##
==========================================
+ Coverage   92.33%   92.44%   +0.11%     
==========================================
  Files         146      145       -1     
  Lines        7047     7111      +64     
  Branches      621      621              
==========================================
+ Hits         6507     6574      +67     
+ Misses        540      537       -3

Impacted Files	Coverage Δ
packages/opentelemetry-tracing/src/config.ts	100% <0%> (ø)	⬆️
packages/opentelemetry-tracing/src/utility.ts	100% <0%> (ø)	⬆️
...ry-tracing/test/export/SimpleSpanProcessor.test.ts	100% <0%> (ø)	⬆️
...try-node/test/instrumentation/PluginLoader.test.ts	100% <0%> (ø)	⬆️
...pe-async-hooks/test/AsyncHooksScopeManager.test.ts	100% <0%> (ø)	⬆️
...ry-tracing/test/export/ConsoleSpanExporter.test.ts	100% <0%> (ø)	⬆️
...ntelemetry-tracing/test/MultiSpanProcessor.test.ts	100% <0%> (ø)	⬆️
packages/opentelemetry-web/src/WebTracer.ts	100% <0%> (ø)	⬆️
...telemetry-scope-base/test/NoopScopeManager.test.ts	100% <0%> (ø)	⬆️
...y-tracing/test/export/InMemorySpanExporter.test.ts	100% <0%> (ø)	⬆️
... and 5 more

[mayurkale22]

Added initial comments, what are the version are the supported versions? I think we should target 1-3. Also, we should have unit tests for all supported versions. WDYT?

[mayurkale22]

Why CanonicalCode.UNKNOWN?

[vmarchaud]

Because it hard to set the correct code depending on the mongodb error, and simpler to just set it as unknown. I don't think it would bring a lot of value to parse the error from mongodb to set the correct error code.

[OlivierAlbertini]

PR look good. Added comments.

[OlivierAlbertini]

Also we should prefix private properties with "_"

[vmarchaud]

Note that the plugin is currently not working, i will make the pr ready for review when it will be

[vmarchaud]

Some update on this: I have started to port opencensus code without success for now, i'm still checking if it should patch mongodb or mongodb-core. I didn't have too much time to look into it in September but it should be better in October (so i'm pretty sure this will not be part of the alpha releases).

[vmarchaud]

Initial implementation is working, feel free to review it althrough i didn't finish yet, as @mayurkale22 said we need to add some tags on each span.

The instrumentation is actually done against mongobdb-core which the lowest level package used by everyone however the maintainers actually merged it with the mongodb package recently so we will need to find a solution to make it work for both.

[OlivierAlbertini]

should use supportedVersions from BasePlugin and add tests in order to be sure that plugin is not loaded for other versions (if possible)

[vmarchaud]

I changed it to use supportedVersions but i don't think we need to test that it behave correctly in the plugin, it would argue that it need to be done only where the behavior is implemented (ie. in PluginLoader)

[vmarchaud]

First round of review has been taken into account ! Here are the attributes i add to each span:

{ 'peer.hostname': 'localhost',
  'peer.port': '27017',
  'db.instance': 'opentelemetry-tests.test',
  'db.type': 'mongodb',
  component: 'mongodb-core',
  'db.statement': '{"a":"?"}' }

[vmarchaud]

I can't reproduce the linting issue in local, for me everything is fine.

[dyladan]

@vmarchaud after doing a lerna clean do rm packages/*/**/yarn.lock then do lerna bootstrap. There's a version issue. One of the linting related packages must have updated a patch version that was not in fact backwards compatible.

[vmarchaud]

@mayurkale22 Rebased, should be good to merge !

[dyladan]

@vmarchaud do I understand correctly that this only instruments mongodb-core and that the mongodb package is still not instrumented as it no longer depends on mongodb-core?

Looks like it was removed in mongodb/node-mongodb-native@16f9a1c#diff-b9cfc7f2cdf78a7f4b91a753d10865a2L20

[vmarchaud]

@dyladan Yeah indeed, i didn't knew when i started the plugin that it was dropped from mongodb. In the future we will need to decide if we replace this plugin by a mongodb one that will support all versions.

[vmarchaud]

I've rebased & addressed comments from @dyladan @markwolff, please review again ! thanks

[obecny]

lgtm, just 2 minor questions

[obecny]

all tsconfig.ts has "test" too, what's the reason of removing it ?

[vmarchaud]

I've got a typescript issue when compiling:

Argument of type 'SimpleSpanProcessor' is not assignable to parameter of type 'SpanProcessor'.
  Types of property 'onStart' are incompatible.
    Type '(span: import("/home/vmarchaud/opentelemetry/opentelemetry-js/packages/opentelemetry-plugin-mongodb-core/node_modules/@opentelemetry/tracing/build/src/Span").Span) => void' is not assignable to type '(span: import("/home/vmarchaud/opentelemetry/opentelemetry-js/packages/opentelemetry-types/build/src/trace/span").Span) => void'.
      Types of parameters 'span' and 'span' are incompatible.
        Type 'Span' is missing the following properties from type 'Span': _tracer, spanContext, kind, attributes, and 17 more.ts(2345)

Which makes no sense since i had the same setup as other plugins then i found out that compiling the test aren't useful since we run them using ts-mocha which was working, i believe we could remove that from all other packages too.

[mayurkale22]

Merging PR now, please open an issue to discuss this separately.