magento2 make image base via REST API

Question

How can I make an image of a product the base image ? I tought setting the position would be enough but that's not true.

I create my products via the REST api , this works fine.

The images are uploaded correct.

But I don't know how to tag an image as the base image. When I have multiple images it is always the last images that is tagged as base automaticly, I don't want that. How could I set that in my array?

$product = [
    "sku" => str_replace(' ', '-', $data['name']),
    "name" => $data['name'],
    "type_id" => 'configurable',
    "price" => 0,
    'attribute_set_id' => 9, // default
    "extension_attributes" => [],
    "custom_attributes" => [],
    'media_gallery_entries' => $this->getMediaGalleryEntries($data)
];

function getMediaGalleryEntries($data)
{
    $image = 'path/to/my/image';

    $entries[] = [
        'position' => $iterator,
        'media_type' => 'image',
        'disabled' => false,
        'label' => '',
        'types' => ['image', 'small_image', 'thumbnail'],
        'content' => [
            'type' => 'image/jpeg',
            'name' => pathinfo($image,PATHINFO_FILENAME).'.'.pathinfo($image, PATHINFO_EXTENSION),
            'base64_encoded_data' => base64_encode(file_get_contents($image)),
        ]
    ];

    return $entries;
}

Answer 1

I've solved it like this:

 foreach($images as $image) {
    $entries[] = [
        'position' => $iterator,
        'media_type' => 'image',
        'disabled' => false,
        'label' => '',
        'types' => ($iterator == 1 ? ['image','small_image','thumbnail'] : []),
        'content' => [
            'type' => 'image/jpeg',
            'name' => pathinfo($image,PATHINFO_FILENAME).'.'.pathinfo($image, PATHINFO_EXTENSION),
            'base64_encoded_data' => base64_encode(file_get_contents($image)),
        ]
    ];
    $iterator++;
}

Types should only be assigned to the first image.This is the image I want as base image.

Answer 2

In Magento1, you would have set the image attribute on the product object to the image you have created in a media object.

Looking at your Import Data it seems to be the types array in the gallery object which defines what the image is used for (image, small_image or thumbnail) while image should be the base image.

This also explains why always the last image is the base image when you import all images with all three types