I have installed anchore-engine using docker-compose in RHEL. Then, I tried to add a docker image for scanning purpose but I'm getting the following error.
[xxx@xxx aevolume]$ docker-compose exec engine-api anchore-cli system wait
Starting checks to wait for anchore-engine to be available timeout=-1.0 interval=5.0
API availability: Checking anchore-engine URL (http://localhost:8228)...
API availability: Success.
Service availability: Checking for service set (catalog,apiext,policy_engine,simplequeue,analyzer)...
Service availability: Success.
Feed sync: Checking sync completion for feed set (vulnerabilities)...
Feed sync: Success.
[xxx@xxx aevolume]$ docker-compose exec engine-api anchore-cli image add docker.io/library/debian:7
Error: cannot fetch image digest/manifest from registry
HTTP Code: 400
Detail: {'error_codes': ['SKOPEO_UNKNOWN_ERROR'], 'raw_exception_message': 'Error encountered in skopeo operation. cmd=/bin/sh -c skopeo inspect --raw --tls-verify=false docker://docker.io/library/debian:7, rc=1, stdout=None, stderr=b\'time="2020-04-15T05:19:42Z" level=fatal msg="Error parsing image name \\\\"docker://docker.io/library/debian:7\\\\": error pinging docker registry registry-1.docker.io: Get http://registry-1.docker.io/v2/: dial tcp: lookup registry-1.docker.io on 127.0.0.11:53: read udp 127.0.0.1:55548->127.0.0.11:53: i/o timeout"\\n\', error_code=SKOPEO_UNKNOWN_ERROR'}
It seems like a proxy issue. So, I've created a file ~/.docker/config.json in docker client that too didn't work.
I've followed this doc for anchore-engine installation.