No credentials found and service=\"registry.docker.io\"" status="401 Unauthorized"

[kingzleshe]

what could cause this situation?
I never encountered it before.

2021-07-24T17:39:57Z [D] Trying to load authentication credentials.
                         container: /prowlarr
                         image: linuxserver/prowlarr:develop
2021-07-24T17:39:57Z [D] No credentials for linuxserver found
                         config_file: /config.json
2021-07-24T17:39:57Z [D] Got image name: linuxserver/prowlarr:develop
2021-07-24T17:39:57Z [D] Checking if pull is needed
                         container: /prowlarr
                         image: linuxserver/prowlarr:develop
2021-07-24T17:39:57Z [D] Building challenge URL
                         URL: https://index.docker.io/v2/
2021-07-24T17:40:03Z [D] Got response to challenge request
                         header: Bearer realm="https://auth.docker.io/token",service="registry.docker.io"
                         status: 401 Unauthorized
2021-07-24T17:40:03Z [D] Checking challenge header content
                         realm: https://auth.docker.io/token
                         service: registry.docker.io
2021-07-24T17:40:03Z [D] Setting scope for auth token
                         image: linuxserver/prowlarr
                         scope: repository:linuxserver/prowlarr:pull
2021-07-24T17:40:03Z [D] No credentials found.
2021-07-24T17:40:10Z [D] Parsing image ref
                         host: index.docker.io
                         image: linuxserver/prowlarr
                         normalized: docker.io/linuxserver/prowlarr:develop
                         tag: develop
2021-07-24T17:40:10Z [D] Doing a HEAD request to fetch a digest
                         url: https://index.docker.io/v2/linuxserver/prowlarr/manifests/develop
2021-07-24T17:40:16Z [D] Found a remote digest to compare with
                         remote: sha256:c3865542a2519fceae3c37760ebdf4b32b060af59e3b87fde4b4d883566c5622
2021-07-24T17:40:16Z [D] Comparing
                         local: sha256:c3865542a2519fceae3c37760ebdf4b32b060af59e3b87fde4b4d883566c5622
                         remote: sha256:c3865542a2519fceae3c37760ebdf4b32b060af59e3b87fde4b4d883566c5622
2021-07-24T17:40:16Z [D] Found a match
2021-07-24T17:40:16Z [D] No pull needed. Skipping image.
2021-07-24T17:40:16Z [D] No new images found for /prowlarr
2021-07-24T17:40:16Z [D] Trying to load authentication credentials.
                         container: /portainer
                         image: portainer/portainer-ce:latest
2021-07-24T17:40:16Z [D] No credentials for portainer found
                         config_file: /config.json
2021-07-24T17:40:16Z [D] Got image name: portainer/portainer-ce:latest
2021-07-24T17:40:16Z [D] Checking if pull is needed
                         container: /portainer
                         image: portainer/portainer-ce:latest
2021-07-24T17:40:16Z [D] Building challenge URL
                         URL: https://index.docker.io/v2/
2021-07-24T17:40:22Z [D] Got response to challenge request
                         header: Bearer realm="https://auth.docker.io/token",service="registry.docker.io"
                         status: 401 Unauthorized
2021-07-24T17:40:22Z [D] Checking challenge header content
                         realm: https://auth.docker.io/token
                         service: registry.docker.io
2021-07-24T17:40:22Z [D] Setting scope for auth token
                         image: portainer/portainer-ce
                         scope: repository:portainer/portainer-ce:pull
2021-07-24T17:40:22Z [D] No credentials found.
[...]
2021-07-24T17:40:53Z [D] No pull needed. Skipping image.
2021-07-24T17:40:53Z [D] No new images found for /adguardhome
2021-07-24T17:40:53Z [D] Session done: 20 scanned, 0 updated, 0 failed

[piksel]

Those are just debug messages. You can leave out the --debug if you want to hide them.

This instance is just the normal way to do authentication over HTTP. First, you make a request without any credentials and check the server response for what types of authentication they require/supports. Then you set up your HTTP headers to match those requirements on subsequent requests.