docs-local.md

Local Workflow

Pre-requisites:

• node 18.x and npm installed

Install and Run the App

Install the dependencies:

npm install

Then you can run it:

npm start

If the log looks like this it's working:

> demo-node@1.0.0 start
> node index.js

demo-node listening on port 3000

Send Test Transactions

This will send calls port 3000 which is the default. These commands are expected to succeed, if they fail your environment may be misconfigured.

export PORT=3000
curl http://localhost:$PORT/
curl http://localhost:$PORT/nasa
curl http://localhost:$PORT/events
curl http://localhost:$PORT/bin

Capture

You need a Speedscale account and speedctl installed. If you already installed, make sure you are running the latest version:

speedctl update

And you will need certificates on your machine, so make sure they are created with this command:

speedctl create certs -o ~/.speedscale/certs

To quickly capture on your own local machine, you can capture the inbound and outbound traffic using speedctl with this command:

speedctl capture demo-node 3000

Now you need to configure your application to use the proxy, this is from the Speedscale Proxy Docs.

export GLOBAL_AGENT_HTTP_PROXY='http://127.0.0.1:4140'
export GLOBAL_AGENT_HTTPS_PROXY='http://127.0.0.1:4140'
export GLOBAL_AGENT_NO_PROXY='*127.0.0.1:12557'
export NODE_EXTRA_CA_CERTS=${HOME}/.speedscale/certs/tls.crt

Once that's done you are going to restart the application:

npm start

Now you're going to send the same test transactions, but the inbound port has changed to 4143:

export PORT=4143
curl http://localhost:$PORT/
curl http://localhost:$PORT/nasa
curl http://localhost:$PORT/events
curl http://localhost:$PORT/bin

As this is running you should get proper responses from the application, and you should also see the data in Speedscale traffic viewer.

Replay

The first step to replay is to create a snapshot. You should see the data like this in your traffic viewer:

The next step is to Save Tests/Mocks and follow the workflow using all the default values. The result should be a snapshot that looks like so:

Now you are going to replay that snapshot on your own machine using speedctl. Note that this example uses the standard test config you can make your own for a variety of different kinds of tests!

Note that this command will:

• Run the service mocks on port 4140
• Send calls to your app on port 3000

export SNAPSHOT_ID=MY_SNAPSHOT_ID
speedctl replay \
  $SNAPSHOT_ID \
  --test-config-id standard \
  --http-port 4140 \
  --custom-url http://localhost:3000

After running, you should see a Report in the Speedscale Reports list. It should have an 87.5% success rate like this.

The reason for the lower success rate is because the / endpoint includes a timestamp, and all the values in the JSON response are being compared. In this case you want to ignore the timestamp and just compare all the other fields.

You can customize your test config to ignore the ts value. You can test this immediately by hitting the 3 dots in the corner and selecting Edit Test Config. Then go to the Assertions tab and click on the HTTP Response Body assertion and add ts to the ignore list and Save. Then Save the entire test config and your report will be reanalyzed.

Your report should now show 100% and you can see the ts is ignored by opening up the assertion view.

Congrats, you completed all the capture and replay steps locally! Now is a great time to explore and check out other ways to run your tests for load, contract validation, chaos, or even start to integrate this into your CI/CD workflow.