The user mirrored the 4.11.0 release and attempted to use it to generate the the installation ISO in a completely disconnected environment.

When it was the turn for extracting the os image from machine-os-images, the agent based installer ran : oc adm release info --image-for=machine-os-images --insecure=true quay.io/openshift-release-dev/ocp-release@sha256:300bce8246cf880e792e106607925de0a404484637627edf5f517375517d54a4 --registry-config=/tmp/registry-config1141450352

This does not include the --icsp-file, and thus the image reference can be retrieved to perform the extraction.

https://github.com/openshift/installer/releases/tag/agent-installer-v4.11.0-dev-preview-2

100%

1. Mirroring the images of 4.11.0 using oc adm mirror command to the local registry.
2. Created install-config.yaml with mirror config
3. Created agent-config.yaml 
4. openshift-install-sep1 agent create image --dir kni-22

INFO[0001] Start configuring static network for 3 hosts  pkg=manifests
INFO[0002] Adding NMConnection file <bond0.nmconnection>  pkg=manifests
INFO[0002] Adding NMConnection file <eno49.nmconnection>  pkg=manifests
INFO[0002] Adding NMConnection file <eno50.nmconnection>  pkg=manifests
INFO[0003] Adding NMConnection file <bond0.nmconnection>  pkg=manifests
INFO[0003] Adding NMConnection file <eno49.nmconnection>  pkg=manifests
INFO[0003] Adding NMConnection file <eno50.nmconnection>  pkg=manifests
INFO[0004] Adding NMConnection file <bond0.nmconnection>  pkg=manifests
INFO[0004] Adding NMConnection file <eno49.nmconnection>  pkg=manifests
INFO[0004] Adding NMConnection file <eno50.nmconnection>  pkg=manifests
DEBUG   Fetching BaseIso Image...
DEBUG     Fetching Agent Manifests...
DEBUG     Reusing previously-fetched Agent Manifests
DEBUG     Fetching Install Config...
DEBUG     Reusing previously-fetched Install Config
DEBUG     Fetching Mirror Registries Config...
DEBUG     Reusing previously-fetched Mirror Registries Config
DEBUG   Generating BaseIso Image...
INFO[0004] Extracting base ISO from release payload
ERRO[0014] command 'oc adm release info --image-for=machine-os-images --insecure=true quay.io/openshift-release-dev/ocp-release@sha256:300bce8246cf880e792e106607925de0a404484637627edf5f517375517d54a4 --registry-config=/tmp/registry-config1141450352' exited with non-zero exit code 1:
error: unable to read image quay.io/openshift-release-dev/ocp-release@sha256:300bce8246cf880e792e106607925de0a404484637627edf5f517375517d54a4: Get "http://quay.io/v2/": dial tcp: lookup quay.io on 10.92.86.56:53: server misbehaving
WARN[0014] Failed to extract base ISO from release payload - check registry configuration
INFO[0014] Downloading base ISO
DEBUG Obtaining RHCOS image file from 'https://rhcos.mirror.openshift.com/art/storage/releases/rhcos-4.11/411.86.202207150124-0/x86_64/rhcos-411.86.202207150124-0-live.x86_64.iso'
ERROR failed to write asset (Agent Installer ISO) to disk: image reader not available
FATAL failed to fetch Agent Installer ISO: failed to fetch dependency of "Agent Installer ISO": failed to generate asset "BaseIso Image": failed to get base ISO image: command 'oc adm release info --image-for=machine-os-images --insecure=true quay.io/openshift-release-dev/ocp-release@sha256:300bce8246cf880e792e106607925de0a404484637627edf5f517375517d54a4 --registry-config=/tmp/registry-config1141450352' exited with non-zero exit code 1:
FATAL error: unable to read image quay.io/openshift-release-dev/ocp-release@sha256:300bce8246cf880e792e106607925de0a404484637627edf5f517375517d54a4: Get "http://quay.io/v2/": dial tcp: lookup quay.io on 10.92.86.56:53: server misbehaving
FATAL

Image correctly generated

Host OS: RHEL 8.4
NMstate version: nmstate-1.0.2-5.el8.noarch