API Template For Automation

Welcome to HCE’s GraphQL API template documentation

This contains the API templates to perform a chaos experiment in an automated way.

Table Of Content

Pre-requisites

Installed HCE: You should have an HCE installed from where you can prepare and run experiments from API calls.
Prepare Workflow: We can run a workflow using APIs in any automated pipeline but for that, we need to pre-create a workflow with the right tunables and attributes from HCE. This step will involve:
- Select the right set of experiments you want to include in the workflow
- Provide desired tunables in the experiment. At any point in time, you can change the tunables and save it - this won’t impact the overall API calls, infact this is correct method to update the tunables of the pre-created experiment for new runs.
Install ‘jq’: Make sure you have jq installed in your system if not, please install it as it is used in some APIs to filter path.
Derive Tunables: To derive tunables for preparing API commands check here.
Download ‘hce-api’ binary:
- Follow the below-mentioned steps to install ‘hce-api’ binary. It will be used to prepare the API commands based on the provided tunables.
- Download hce-api binary using this command, and replace <OS> and <ACRH> placeholder with your operating system (supports linux and darwin) and system arch (supports amd64 and arm64).
```
wget https://github.com/uditgaurav/hce-api-template/releases/download/0.1.0/hce-api-<OS>-<ARCH> -O hce-api
chmod +x hce-api
```
  If you have don’t have wget then you can also use curl command:
```
curl -L https://github.com/uditgaurav/hce-api-template/releases/download/0.1.0/hce-api-<OS>-<ARCH> -o hce-api
chmod +x hce-api
```

Derive Tunables

Derive the tunables for API calls. Login to your HCE dashboard.

Looking for details on ACCESS_KEY and ACCESS_ID?

On the HCE dashboard click on “Settings” and switch to the “Access Key” tab.

You will get this screen:

settings-image

Click on “Create Access Key” if you have lost the older one

Looking for details on PROJECT_ID and WORKFLOW_ID?

For Project ID:

On the HCE dashboard click on “Project” (as shown in point-1 on the image) and copy the “Project ID”. You can also get the project ID from the HCE URL at this place.

Checkout this screen:

projectid-img

For Workflow ID:

Click on “three dots” on the workflow and Navigate to the “View Manifest” option. You will get a screen like this:

workflow-id-img

It will give you the workflow id for the target workflow.

API to Launch Chaos Experiment

This contains the API to trigger the Chaos Experiment.

Tunables

ACCESS_KEY
ACCESS_ID
PROJECT_ID
WORKFLOW_ID
HCE_ENDPOINT

The above tunables are mandatory to provide. You need to replace it in the given API call.

Before getting started checkout the pre-requisite section and follow the steps to download hce-api binary.

Non-Interactive Mode:

Provide the values in the flags given below to get the API command in a file.

./hce-api generate --api launch-experiment --hce-endpoint=<HCE-ENDPOINT> \
--project-id <PROJECT-ID> --workflow-id <WORKFLOW-ID> \
--access-key <ACCESS-KEY> --access-id <ACCESS-ID> --file-name <FILE-NAME>

Example:

./hce-api generate --api launch-experiment --hce-endpoint=http://ae1a8f465611b4c07bbbc2e7d669f533-1139615104.us-east-2.elb.amazonaws.com:9091/ --project-id abceb5f4-4268-4467-9818-ad6e3b6bfd78 --workflow-id f4581780-efaf-4155-956e-6c379f24394b --access-key nEdGNDDrTFHyCnl --access-id adminNCWQu --file-name hce-api.sh

The default value for --file-name is hce-api.sh, all other variables are mandatory.

Interactive Mode:

Run the downloaded hce-api binary as shown below. It will not trigger the chaos but will prepare the launch command in a file:

$ ./hce-api


Provide the index number to create a file with the API command from the given options.
For Example to create an API that launches an experiment give 1 as input.

[1] API to Launch Chaos Experiment
[2] API to Monitor Chaos Experiment
[3] API to Validate Resilience Score
	
		
Select from the given options: 1
Provide the HCE endpoint: http://ae1a8f465611b4c07bbbc2e7d669f533-1139615104.us-east-2.elb.amazonaws.com:9091/
Provide the Project ID: abceb5f4-4268-4467-9818-ad6e3b6bfd78
Provide the Workflow ID: f4581780-efaf-4155-956e-6c379f24394b
Provide the HCE Access Key: nEdGNDDrTFHyCnl
Provide the HCE Access ID: adminNCWQu
Provide the File Name for API [Default is hce-api.sh]: hce-api.sh

Output:

The file containing the API command is created successfully

Check out the file hce-api.sh and get the launch command. To run the API execute bash hce-api.sh (replace file name for custom names).

API to Monitor Chaos Experiment

This contains the API to monitor the Chaos Experiment that is this API will help us to wait for the workflow completion.

Tunables

ACCESS_KEY
ACCESS_ID
PROJECT_ID
WORKFLOW_ID
HCE_ENDPOINT
Before getting started checkout the pre-requisite section and follow the steps to download hce-api binary.

Non-Interactive Mode:

Provide the values in the flags given below to get the API command in a file.

./hce-api generate --api monitor-experiment --hce-endpoint=<HCE-ENDPOINT> \
--project-id <PROJECT-ID> --workflow-id <WORKFLOW-ID> \
--access-key <ACCESS-KEY> --access-id <ACCESS-ID> --file-name <FILE-NAME>

Example:

./hce-api generate --api monitor-experiment --hce-endpoint=http://ae1a8f465611b4c07bbbc2e7d669f533-1139615104.us-east-2.elb.amazonaws.com:9091/ --project-id abceb5f4-4268-4467-9818-ad6e3b6bfd78 --workflow-id f4581780-efaf-4155-956e-6c379f24394b --access-key nEdGNDDrTFHyCnl --access-id adminNCWQu --file-name hce-api.sh

The default value for --file-name is hce-api.sh, all other variables are mandatory.

Interactive Mode:

Run the downloaded hce-api binary as shown below. It will not trigger the command but will prepare the monitor command in a given file:

$ ./hce-api


Provide the index number to create a file with the API command from the given options.
For Example to create an API that launches an experiment give 1 as input.

[1] API to Launch Chaos Experiment
[2] API to Monitor Chaos Experiment
[3] API to Validate Resilience Score
	
		
Select from the given options: 2
Provide the HCE endpoint: http://ae1a8f465611b4c07bbbc2e7d669f533-1139615104.us-east-2.elb.amazonaws.com:9091/
Provide the Project ID: abceb5f4-4268-4467-9818-ad6e3b6bfd78
Provide the Workflow ID: f4581780-efaf-4155-956e-6c379f24394b
Provide the HCE Access Key: nEdGNDDrTFHyCnl
Provide the HCE Access ID: adminNCWQu
Provide the File Name for API [Default is hce-api.sh]: hce-api.sh

Output:

The file containing the API command is created successfully

Check out the file hce-api.sh and get the chaos monitor command. To run the API run bash hce-api.sh (replace file name for custom names).

A sample bash script to monitor Chaos Experiment

In this sample script we will wait for the workflow completion with a delay of 2 seconds and 150 retries, you can adjust these values based on total chaos duration.

#!/bin/bash

set -e

# Tunables provide your values
DELAY=2
RETRY=150
fileName="hce-api.sh"

# Script execution logic
START=0
for (( i=$START; i<=$RETRY; i++ )); do
    echo
    res=$(sh $fileName)
    echo
    if [ "$res" == "Succeeded" ]; then
        echo "Experiment completed, CurrentState: $res"
        exit 0
    fi
    sleep $DELAY
    echo "Waiting for experiment completion... CurrentState: $res, retries left: $(($RETRY-$i))"
done

echo "[Error]: Timeout the workflows is not completed with DELAY: $DELAY and RETRY: $RETRY, CurrentState: $res"

exit 1

API to Validate Resilience Score

This contains the API to get the resilience score for a workflow run and validate against the expected probe success percentage.

Tunables

ACCESS_KEY
ACCESS_ID
PROJECT_ID
WORKFLOW_ID
HCE_ENDPOINT
Before getting started checkout the pre-requisite section and follow the steps to download hce-api binary.

Non-Interactive Mode:

Provide the values in the flags given below to get the API command in a file.

./hce-api generate --api validate-resilience-score --hce-endpoint=<HCE-ENDPOINT> \
--project-id <PROJECT-ID> --workflow-id <WORKFLOW-ID> \
--access-key <ACCESS-KEY> --access-id <ACCESS-ID> --file-name <FILE-NAME>

Example:

./hce-api generate --api validate-resilience-score --hce-endpoint=http://ae1a8f465611b4c07bbbc2e7d669f533-1139615104.us-east-2.elb.amazonaws.com:9091/ --project-id abceb5f4-4268-4467-9818-ad6e3b6bfd78 --workflow-id f4581780-efaf-4155-956e-6c379f24394b --access-key nEdGNDDrTFHyCnl --access-id adminNCWQu --file-name hce-api.sh

The default value for --file-name is hce-api.sh, all other variables are mandatory.

Interactive Mode:

Run the downloaded hce-api binary as shown below. It will not trigger the command but will prepare the monitor command in a given file:

$ ./hce-api


Provide the index number to create a file with the API command from the given options.
For Example to create an API that launches an experiment give 1 as input.

[1] API to Launch Chaos Experiment
[2] API to Monitor Chaos Experiment
[3] API to Validate Resilience Score
	
		
Select from the given options: 2
Provide the HCE endpoint: http://ae1a8f465611b4c07bbbc2e7d669f533-1139615104.us-east-2.elb.amazonaws.com:9091/
Provide the Project ID: abceb5f4-4268-4467-9818-ad6e3b6bfd78
Provide the Workflow ID: f4581780-efaf-4155-956e-6c379f24394b
Provide the HCE Access Key: nEdGNDDrTFHyCnl
Provide the HCE Access ID: adminNCWQu
Provide the File Name for API [Default is hce-api.sh]: hce-api.sh

Output:

The file containing the API command is created successfully

Check out the file hce-api.sh and get the validate-resilience-score command. To run the API run bash hce-api.sh (replace file name for custom names).

A sample bash script to validate the resiliency score

In this sample script you will get the probe success percentage for the last workflow run, you can make use of it to compare it with the expected probe success percentage.

#!/bin/bash

set -e

# Tunables provide your values
expectedProbeSuccessPercentage=100
fileName="hce-api.sh"

# Script execution logic
res=$(bash $fileName)
res=$(echo "$res" | tr -d '"')
echo
if [ "$res" != "$expectedProbeSuccessPercentage" ]; then
    echo "The probe success percentage is: $res, expected probe success percentage: $expectedProbeSuccessPercentage"
    exit 1
fi

echo "The probe success percentage is equal to the expected probe success percentage"
exit 0