Automated Performance Testing with Load Impact and AWS CodeBuild

Amazon Web Services CodeBuild Load Impact integrates nicely with AWS CodeBuild, a fully managed build service in the cloud. Using our robust and extensible APIs you can integrate Load Impact’s world-leading performance testing platform into your automated AWS CodeBuild build and test process.

Load Impact covers your back with everything you need for Web, API and application performance testing. And test scripting is simple.

To get started, try this sample of how to include performance testing in your AWS CodeBuild build setup.

This sample assumes you are familiar with AWS CodeBuild. We set up a new project with a simple build containing one build step to run the Load Impact performance test.

It also assumes you have a Load Impact account. If not, go get one – it’s free.

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We’ve broken down the integration process into four digestible steps, so let's get on with some automated performance testing!

1. Set up your AWS CodeBuild build

We created an AWS CodeBuild project which we named LI_CB_DEMO. It’s very simple, everything is just default.

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Name your build project, identify what you want to build by identifying your repository. In our example we use the github repository loadimpact/codebuildloadimpact which we have made public so you can get it all.

Set the build image to use Ubuntu and the build specification to use the buildspec.yml in the source code root directory.

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And this is the history when we have executed a couple of times.

What actually controls the build actions is the buildspec.yml file.

version: 0.1

environment_variables:
  plaintext:
    JAVA_HOME: "/usr/lib/jvm/java-8-openjdk-amd64"

phases:
  install:
    commands:
      - apt-get update -y
      - apt-get install -y curl
      - apt-get install -y jq
      - apt-get install -y bc
  pre_build:
    commands:
      - echo Nothing to do in the pre_build phase...
  build:
    commands:
      - bash cb_bash.sh
  post_build:
    commands:
      - echo Build completed on `date`
First phase, the install commands, we have added three necessary dependencies. Curl, jq and bc which are all needed.

The test command itself is added as a build comamnd. It just involves executing the cb\_bash.sh script in the repository. So the test script itself is also part of the repository.

You can get the code for the cb\_bash.sh script from github in the loadimpact/codebuildloadimpact repo where it is shared.

2. Integrate with the Load Impact API

Before we dive into the details – let’s get some essentials from your Load Impact account. We need the API key so you can access the API and a test to run.

You can find your API key when you are logged into your Load Impact account.

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Go to “Monitoring” on the left and click “Use REST API.”

Then copy it from the yellow text box.

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Just note that the API token is longer than the size of the box so make sure you get all of it!

Now you need to know which test to run. You can list your test configurations using the API or the CLI if you want to but the simplest way is to open it directly in your account and copy the id from the URL. Underlined in red.

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So now you have a test id for the test you want to run in your build and your API key.

All of the code is shared at GitHub for your download in the loadimpact/codebuildloadimpact repo!

3a. Edit the build settings to set the test Id and the API key

To avoid sticking sensitive information such as your test id and your API key into the script itself we use environment variables set in your build settings to hold these.

Set the environment variable LI_TEST_ID to hold your test id and the environment variable LI_API_KEY to hold your API key.

Just open your project settings and show the advanced settings at the bottom of the page.

You can just leave all the settings to default, or whatever setting makes sense for your particular build of course. As we don’t want to keep our Load Impact API key in the code in the repository we add it as an environment variable as well as the test id of the test we want to execute.

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Now, let us look into the script code itself that actually executes the tests.

The code has four parts, the initial and then three stages “Kickoff performance test”, “Performance test running” and “Show results”. If you are familiar with Codebuild you know the output from the execution is visible in the build log when you execute your build including the Load Impact performance test.

The initial part of the Bash code is where you set the test id and the API key.

#!/bin/bash
# Run Load Impact test from bash

# Load Impact test id
# env variable from Codebuild - LI_TEST_ID
testId="$LI_TEST_ID"

# API_KEY from your Load Impact account
# env variable from Codebuild - LI_API_KEY
API_KEY="$LI_API_KEY"

uri="https://api.loadimpact.com/v2/test-configs/$testId/start"

So make sure you set the LI_TEST_ID and LI_API_KEY environment variables!

3b. Kickoff a performance test

echo "Kickoff performance test"

OUT=$(curl -qSfsw "\n%{http_code}" -u $API_KEY: -X POST https://api.loadimpact.com/v2/test-configs/$testId/start)

status=`echo  "${OUT}" | tail -n1`

# Status 201 expected, 200 is just a current running test id
if [[ $status -ne 201 ]] ; then
  perc="Could not start test $testId : $status \n $resp.Content"
  echo "${perc}"
  exit 2
else
  tid=`echo "${OUT}" | head -n1 | jq '.id'`
fi

# Until 5 minutes timout or status is running 

t=0
status_text="\"NOT_YET\""
until [ $status_text == "\"Running\"" ]; do
  sleep 10s
  OUT=$(curl -qSfsw '\n%{http_code}' -u $API_KEY: -X GET https://api.loadimpact.com/v2/tests/$tid/)
  status_text=`echo  "${OUT}" | head -n1 | jq '.status_text'`
  ((t=t+10))

  if [[ $t -gt 300 ]] ; then
    echo "Timeout - test start > 5 min"
    exit 3
  fi
done

echo "Performance test running"
We kick off the performance test by gluing together the URI for the API to start the test and then write the status to stdout which can be seen in the CodeBuild log.

We use curl to make the API call to start the test and then specifically check for the expected 201 response.

If not there we will exit with an exit code of two (2) which will tell CodeBuild the test has failed.

If it is good, we parse the json response and extract the running test id.

Then we let it take a maximum of five minutes for the test to actually kickoff. Since it can take Load Impact a couple of minutes to acquire and allocate all the resources (mainly load agents) needed we take some time to let the test reach the status of “Running”. The bigger the test, the more resources needed and the longer it can take. But remember, it’s a couple of minutes.

We get that status of the test by calling the API and parsing the json response to check for the status in the response. If it takes too long we exit with exit code 3 to tell CodeBuild it failed.

The last thing we do is to write a message to stdout that the test is running.

3c. The test is running

# wait until completed

maxVULoadTime=0
percentage=0
until [[ $(echo "$percentage==100" | bc -l) == 1 ]]; do
  sleep 30s

  # Get percent completed
  OUT=$(curl -qSfs -u $API_KEY: -X GET https://api.loadimpact.com/v2/tests/$tid/results?ids=__li_progress_percent_total)

  percentage=`echo "${OUT}" | jq '.__li_progress_percent_total | max_by(.value)| .value'`

  echo  "Percentage completed $percentage"

  # Get VU Load Time
  OUT=$(curl -qSfs -u $API_KEY: -X GET https://api.loadimpact.com/v2/tests/$tid/results?ids=__li_user_load_time)

  maxVULoadTime=`echo "${OUT}" | jq '.__li_user_load_time | max_by(.value) | .value'`

  if [[ $(echo "$maxVULoadTime>1000" | bc -l) == 1 ]] ; then 
    perc="VU Load Time exceeded limit of 1 sec: $maxVULoadTime"
    echo "$perc"
    exit 4
  fi
done
So now your Load Impact performance test is running!

This time we wait until the test has completed, reached the percentage completed value of 100% with a slightly longer sleep between refreshing status calls.

We do this by calling the API for results and only requesting the percentage completed. The API returns all of the relevant data so we do some json parsing and just get the max percentage value from the result set.

All the results are available from the API so you can either use them or calculate new aggregate results to use as test thresholds for your test results.

We included an example of making a threshold from the Virtual User Load Time (please read the explanation of this value before using it).

We get the value by calling the same API as before but for the VU Load Time result, parse the json and get the max value by some jq magic.

If the value exceeds 1 second we exit the build step and fail it by setting the exit code to 4. This tells CodeBuild it failed and we also write a message on stdout.

3d. Show the results

#show results
echo "Show results"
echo "$maxVULoadTime"
echo "Max VU Load Time: $maxVULoadTime"
echo "Full results at https://app.loadimpact.com/test-runs/$tid"
Finally, we show the results and output the max VU Load Time. It can of course be any result but as a sample. You can use this result to decide on further actions in your build as well but that is outside the scope of this sample. And of course we tack on a direct link to the full results and analysis in Load Impact.

4. Executing the CodeBuild

As you start a build in Codebuild it will look like this.

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A couple of completed builds.

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Once the test is actually running Codebuild will have the output from the test in the log.

And looking into the details of the build log itself we see the steps and the individual messages.

There’s also a direct link to the full results and analysis in Load Impact where you can always find all the results of all your tests.

You can add/update/delete tests, user scenarios and data stores using the API and CLI, even stick all of it in your SCM of choice and let all of it be part of your build.

To dive deeper into using Load Impact from your CI/CD process (or for that matter any external usage) see our comprehensive API reference, and the accompanying CLI.

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Note: We’re happy to help you get started when integrating Load Impact into your development environment, but this article is not meant to imply full support of the integration.