Allow DD initialization from the native side using DdSdkConfiguration

[ddiachkov]

Feature description

Hello! We have an app with a lot of native code that initializes before the JS side and runs in the background. The native code needs the ability to send logs to DD, and so the SDK must be initialized on application start.

Recently dd-sdk-reactnative added the new DdSdkNativeInitialization.initFromNative API to load configuration from JSON file. Unfortunately, it is a bit limiting since JSON configurations need to be stored in the repo, and it doesn't support environment variables or build environments.

Proposed solution

It would be nice to be able to init dd-sdk-reactnative with just DdSdkConfiguration instance. That would fix the limitations since we can generate it in the runtime using BuildConfig for tokens.

Here is the patch I ended up with:

diff --git a/node_modules/@datadog/mobile-react-native/android/src/main/kotlin/com/datadog/reactnative/DdSdkNativeInitialization.kt b/node_modules/@datadog/mobile-react-native/android/src/main/kotlin/com/datadog/reactnative/DdSdkNativeInitialization.kt
index 1b352a1..d6e6028 100644
--- a/node_modules/@datadog/mobile-react-native/android/src/main/kotlin/com/datadog/reactnative/DdSdkNativeInitialization.kt
+++ b/node_modules/@datadog/mobile-react-native/android/src/main/kotlin/com/datadog/reactnative/DdSdkNativeInitialization.kt
@@ -345,6 +345,24 @@ class DdSdkNativeInitialization internal constructor(
                 )
             }
         }
+
+        /**
+         * Initializes the Datadog React Native SDK using the provided configuration.
+         */
+        @JvmStatic
+        fun initFromNative(appContext: Context, ddSdkConfiguration: DdSdkConfiguration) {
+            val nativeInitialization = DdSdkNativeInitialization(appContext.applicationContext)
+            try {
+                nativeInitialization.initialize(ddSdkConfiguration)
+            } catch (@Suppress("TooGenericExceptionCaught") error: Exception) {
+                Log.w(
+                    DdSdkNativeInitialization::class.java.canonicalName,
+                    "Failed to initialize the Datadog SDK: $error"
+                )
+            }
+        }
     }
 }

Alternatively, making internal constructor public also works.

Other relevant information

For more context, this is how my whole setup works:

1. On application start, I initialize a new DdSdkConfiguration with settings based on runtime / build environment.
2. Then I initialize dd-sdk-reactnative via DdSdkNativeInitialization.initFromNative with DdSdkConfiguration.
3. I also have a native module that provides access to the current DdSdkConfiguration to the JS side (it generates datadog-configuration.json from DdSdkConfiguration).
4. When JS side starts, I initialize DatadogProvider like this:

const config = new FileBasedConfiguration({
    configuration: NativeModules.Telemetry.datadogConfiguration(),
});

<DatadogProvider configuration={config}>{children}</DatadogProvider>

[marco-saia-datadog]

Hey @ddiachkov, thank you for your great feedback!

I agree that we should allow passing a configuration to the native initialiser, as it can be useful in many different use cases.

We will evaluate this feature soon to work on a solid solution.

At first glance, I believe that we should allow you to retrieve the configuration from our SDK module itself, so that you can use it on the JS side if you have to. On the other hand, I would also consider refactoring the current implementation to avoid having to maintain two configurations, as it would be counterintuitive and possibly unsafe.

We will look into this and keep you updated on this thread.

Thank you again for your contribution!

[kagrawal98]

+1
it will be really helpful to have this support added

[kagrawal98]

@marco-saia-datadog is support added for this in the latest version of the datadog react native SDK ?

[wcastand]

i would argue we should always init native side by default, main reason for always wanting this is not missing app crashes at the start of the app before the JS bundle is done. I currently have this issue where some crash goes unnoticed because they are at start up before the JS bundle init and Datadog too. I made a ticket in the support already to ask if it would be possible to make it the default since i would assume no one wants to miss crashes report

[wcastand]

is there any news on that front?
is it planned at some point to make datadog init on the native side before the react-native init the default or an expo plugin to let us setup that? or a tutorial for the expo-plugins.

also same for the config being a json instead of a dynamic config etc?

missing all the log for crash at start up is really annoying and makes datadog kind of useless for debugging :/

[wcastand]

i tried to do a plugin on expo on my own and i manage to get it to work on android but on ios, without error or anything i still can't get any session on datadog to show up.

in the AppDelegate i do this, had to convert your doc in to swift but maybe i missed something because even if no error on build or running the app, i get no session on datadog showing up :/

import DatadogSDKReactNative

public override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
  ) -> Bool {
    DdSdk.initFromNative()
...

i also added the datadog config to the project

EDIT:

looks like init on ios side log errors but not directly linked to datadog that's why i didn't realize right away (they disappear when i remove the initFromNative). I logged my config and it's the right one, the one use and that works on android and JS

[kagrawal98]

@wcastand were you able to fix errors in the IOS flow ? Also, have you been using resourceEventMapper config .If yes, did you find some way to implement that using configuration.json file ?

[wcastand]

Couldn't fix iOS so far and I'm not using the mapper sorry

[kagrawal98]

Thanks @wcastand , I have few questions based on your implementation in android -

• what extra goodness are you able to capture from the native initialisation ?
• Do you think when doing init on native and then doing init again on JS with any config changes on the JS side overrrides the DD config which was used on native ? (nothing is mentioned about this in the docs)
• Also, the datadog-configuration.json does not support overriding all the config. So, wanted to check are there any such config that you are using that cannot be overridden by the config.json ? If yes, are you doing init on native or JS side?

[wcastand]

in theory initializing on native side first let you capture crashes that occurs at startup before the JS bundle is init or at JS bundle startup, which you won't get in normal cases since datadog is not init yet. In practice i didn't have enough time to test it works properly yet.

In practice also, i still don't have the sourcemaps after a 1+ year ticket about it so you know, not sure when we get proper datadog config on native side or even init on native side by default :) that's why i tried to do it myself to help move faster on it and work out the issues but yeah on ios it's internal issue since we get no error msg as far as i know.

for the rest i have no clue, not being part of datadog team so i'm clueless as you on this one, my best guess is they have 2 differents config and they don't interact with each other but i could be wrong.

and i don't think i use config that don't exist on both side and my config are the same.

[wcastand]

little update for those interested, i made an expo plugin to do this if it can help build this into the repo. Still quite new so if any problem arise from it on prod, i let you know but so far so good.

https://gist.github.com/wcastand/71623f28a185d1b1066380047b3973ac