Libraries/RW/Prometheus - Non-Raw transforms only apply to result.values

[Hashfyre]

Objective: Run RW.Prometheus based codebundle against a Prometheus endpoint with default transform Codebundle / Robot Script: Infracloudio/ifc-rw-codecollection/.../runbook.robot

Test Procedure:

• Dockerfile
• Run docker container as follow and we set RW_PATH_TO_ROBOT env

  docker run --rm -d -p 3000:3000 --name rds-codecollection \
  --network="host" \
  -e ENV_PROMETHEUS_HOST="http://af87d61af0d814b8d8e99d37987b291d-483479890.us-west-2.elb.amazonaws.com/prometheus/api/v1" \
  -e ENV_QUERY="aws_rds_database_connections_average{dimension_DBInstanceIdentifier=\"robotshopmysql\"} > 1" \
  -e MYSQL_USER="admin" \
  -e MYSQL_PASSWORD_ENV="<password>" \
  -e MYSQL_HOST="robotshopmysql.c9m6m4s8zo0.us-west-2.rds.amazonaws.com" \
  -e PROCESS_USER="shipping" \
  -e RW_PATH_TO_ROBOT="/app/codecollection/codebundles/rds-mysql-conn-count/runbook.robot" \
  runwhen:latest

  Note: Here we are not supplying the type of transform with -e TRANSFORM=Raw

and, in the corresponding sli.robot, if we do not input TRANSFORM as an USER VARIABLE:

Querying Prometheus Instance And Pushing Aggregated Data
    Log      ${ENV_QUERY}
    ${rsp}=    RW.Prometheus.Query Instant
    ...    api_url=${ENV_PROMETHEUS_HOST}
    ...    query=${ENV_QUERY}
    ...    step=${STEP}
    ...    target_service=${CURL_SERVICE}
    ${data}=    Set Variable    ${rsp["data"]}
    ${metric}=    RW.Prometheus.Transform Data
    ...    data=${data}
    ...    *** method=${TRANSFORM} *** <------ commented out TRANSFORM
    ...    no_result_overwrite=${NO_RESULT_OVERWRITE}
    ...    no_result_value=${NO_RESULT_VALUE}
    RW.Core.Push Metric    ${metric}

then RW.Prometheus.Transform Data call defaults to transform: Last, as seen here:

    RW.Core.Import User Variable    TRANSFORM
    ...    type=string
    ...    enum=[Raw,Max,Average,Minimum,Sum,First,Last]
    ...    description=What transform method to apply to the column data. First and Last are position relative, so Last is the most recent value. Use Raw to skip transform. 
    ...    default=Last
    ...    example=Last

While this can be controlled by the developer of sli.robot, the current logic creates an edge case where all transforms that only shuld apply to result.values:[][], can also be mistakenly called for result.value:[], resulting in the following error:

14:17:58.613    TRACE   Arguments: [ data={'resultType': 'vector',
 'result': [{'metric': {'__name__': 'aws_rds_database_connections_average',
                        'account_id': '590183940259',
                        'container': 'yet-another-cloudwatch-exporter',
                        'dimension_DBInstanceIdentifier': 'robotshopmysql',
                        'endpoint': 'http',
                        'instance': '192.168.164.136:5000',
                        'job': 'yace',
                        'name': 'arn:aws:rds:us-west-2:590183940259:db:robotshopmysql',
                        'namespace': 'monitoring',
                        'pod': 'yace-8b8bd5598-j2xps',
                        'region': 'us-west-2',
                        'service': 'yace'},
             'value': [1706172466.004, '30.2']}]} | method='Last' | no_result_overwrite=True | no_result_value=0.0 ]    
14:17:58.614    FAIL    TypeError: 'float' object is not subscriptable

This is because all transforms other than Raw can only apply to 2D matrices of [float][float], but here it gets applied to [float].

This PR intends to fix this issue, by only allowing non-Raw transforms on result.values[float][float]