No ETag in response from Amazon Appstore

Question

As part of the transition in my team from manual uploads to automatic uploads I'm trying to implement the flow of replacing apk in Amazon Appsotre.
I wrote the code based on the example that Amazon published for this flow.

'''

# Get the current list of APKs
get_apks_path = f"v1/applications/{app_id}/edits/{edit_id}/apks"
get_apks_url = '/'.join([BASE_URL, get_apks_path])
apks = requests.get(get_apks_url, headers=token)
apks_json = apks.json()
if 'Message' in apks_json:
    print(apks.content)
    sys.exit(1)
else:
    if apks_json.headers['ETag'] is None:
        print("No Etag found")
        sys.exit(1)
    else:
        etag = apks.headers['Etag']
    firstapk = apks_json[0]
    apk_id = firstapk['id']
    replace_apk_path = f"v1/applications/{app_id}/edits/{edit_id}/apks/{apk_id}/replace"
    # Open the apk file on your local machine
    local_apk = open(apk_location, 'rb').read()
    replace_apk_url = '/'.join([BASE_URL, replace_apk_path])
    all_headers = {
           'Content-Type': 'application/vnd.android.package-archive',
           'If-Match': etag
       }
    all_headers.update(token)
    replace_apk_response = requests.put(replace_apk_url,  data=local_apk, headers=all_headers)
    print(replace_apk_response.content)

'''

The problem is that when I'm reading the response for the GET request I don't see ETag, which is mandatory in order to complete flow.
Am I missing something?
Links for the explanation about the ETag and example:
https://developer.amazon.com/docs/app-submission-api/flows.html#about-etags
https://developer.amazon.com/docs/app-submission-api/python-example.html

Answer 1

I ran into the same issue. In order to get the eTag of the apk you want to upload you first need to do a GET request to the apk endpoint.

get_apk_path = '/v1/applications/%s/edits/%s/apks/%s' % (app_id, edit_id, androidApkId)
get_apk_url = BASE_URL + get_apk_path
apk_response = requests.get(get_apk_url, headers=auth_token_header)

etagApk = apk_response.headers['Etag']
print("Etag of the apk: " + etagApk)