How to get image classification prediction from GCP AIPlatform in ruby?

Question

I'm new with ruby and I want to use GCP AIPlatform but I'm struggeling with the payload.

So far, I have :

client = ::Google::Cloud::AIPlatform::V1::PredictionService::Client.new do |config|
  config.endpoint = "#{location}-aiplatform.googleapis.com"
end

img = File.open(imgPath, 'rb') do |img|
  'data:image/png;base64,' + Base64.strict_encode64(img.read)
end

instance = Instance.new(:content => img)

request = Google::Cloud::AIPlatform::V1::PredictRequest.new(
  endpoint: "projects/#{project}/locations/#{location}/endpoints/#{endpoint}",
  instances: [instance]
)

result = client.predict request
p result

Here is my proto

message Instance {
  required bytes content = 1;
};

But I have the following error : Invalid type Instance to assign to submessage field 'instances'

I read the documentation but for ruby SDK it's a bit light. The parameters are OK, the JS example here : https://github.com/googleapis/nodejs-ai-platform/blob/main/samples/predict-image-object-detection.js is working with those parameters

What am I doing wrong ?

Answer 1

I managed it

client = Google::Cloud::AIPlatform::V1::PredictionService::Client.new do |config|
  config.endpoint = "#{location}-aiplatform.googleapis.com"
end

img = File.open(imgPath, 'rb') do |img|
  Base64.strict_encode64(img.read)
end

instance = Google::Protobuf::Value.new(:struct_value => {:fields => {
  :content => {:string_value => img}
}})
endpoint = "projects/#{project}/locations/#{location}/endpoints/#{endpoint}"


request = Google::Cloud::AIPlatform::V1::PredictRequest.new(
  endpoint: endpoint,
  instances: [instance]
)

result = client.predict request
p result

The use of the Google::Protobuf::Value looks ugly to me but it works