The check for image is now more robust

[potiuk]

The request to get manifest of the image in GitHub Packages
might randomly return either schma 1 response:

{
"schemaVersion": 1,
"name": "apache/airflow/master-python3.6-ci",
"tag": "470317521",
"architecture": "amd64",
"fsLayers": [
{

Or schema 2 response:

{
"schemaVersion": 2,
"mediaType": "application/vnd.docker.distribution.manifest.v2+json",
"config": {
"mediaType": "application/vnd.docker.container.image.v1+json",
"size": 56952,
"digest": "sha256:5c80e2ab289647802affafc5c1efc879fe4f5b559cb7a2a1215868e84b1d6424"
},

In order to check image more reliably we check the status code
of the curl response instead.

---

^ Add meaningful description above

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In case of fundamental code change, Airflow Improvement Proposal (AIP) is needed.
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In case of backwards incompatible changes please leave a note in UPDATING.md.

[potiuk]

Looks like the response of the API call to check if image is available (retrieving manifest) sometimes returns digest of the image and sometimes it does not :(

Example here: https://github.com/apache/airflow/pull/13409/checks?check_run_id=1665801504#step:5:239

Checking for quoted image tag should help.

[potiuk]

🤦 🤦
It turns out that sometime we get schema 2 answer:
https://github.com/apache/airflow/pull/13556/checks?check_run_id=1666011321#step:5:403

{
     "schemaVersion": 2,
     "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
     "config": {
        "mediaType": "application/vnd.docker.container.image.v1+json",
        "size": 56952,
        "digest": "sha256:5c80e2ab289647802affafc5c1efc879fe4f5b559cb7a2a1215868e84b1d6424"
     },

And sometimes schema 1 answer:
https://github.com/apache/airflow/runs/1665801504?check_suite_focus=true#step:5:240

  {
     "schemaVersion": 1,
     "name": "apache/airflow/master-python3.6-ci",
     "tag": "470317521",
     "architecture": "amd64",
     "fsLayers": [
        {

🤦 🤦 🤦 🤦 🤦 🤦 🤦 🤦 🤦

[potiuk]

Luckily in both cases same error:

{"errors":[{"code":"MANIFEST_UNKNOWN","message":"Docker image reference master-python3.6-ci:470415985 not found under repo \"apache\""}]}

[potiuk]

Looks red but it's quarantined test.

[github-actions]

The PR most likely needs to run full matrix of tests because it modifies parts of the core of Airflow. However, committers might decide to merge it quickly and take the risk. If they don't merge it quickly - please rebase it to the latest master at your convenience, or amend the last commit of the PR, and push it with --force-with-lease.