skopeo/registries.conf

# For more information on this configuration file, see containers-registries.conf(5).
#
# There are multiple versions of the configuration syntax available, where the
# second iteration is backwards compatible to the first one. Mixing up both
# formats will result in an runtime error.
#
# The initial configuration format looks like this:
#
# Registries to search for images that are not fully-qualified.
# i.e. foobar.com/my_image:latest vs my_image:latest
[registries.search]
registries = ['docker.io', 'registry.fedoraproject.org', 'registry.access.redhat.com', 'registry.centos.org', 'quay.io']

# Registries that do not use TLS when pulling images or uses self-signed
# certificates.
[registries.insecure]
registries = []

# Blocked Registries, blocks the `docker daemon` from pulling from the blocked registry.  If you specify
# "*", then the docker daemon will only be allowed to pull from registries listed above in the search
# registries.  Blocked Registries is deprecated because other container runtimes and tools will not use it.
# It is recommended that you use the trust policy file /etc/containers/policy.json to control which
# registries you want to allow users to pull and push from.  policy.json gives greater flexibility, and
# supports all container runtimes and tools including the docker daemon, cri-o, buildah ...
# The atomic CLI `atomic trust` can be used to easily configure the policy.json file.
[registries.block]
registries = []

# The second version of the configuration format allows to specify registry
# mirrors:
#
# # An array of host[:port] registries to try when pulling an unqualified image, in order.
# unqualified-search-registries = ["example.com"]
#
# [[registry]]
# # The "prefix" field is used to choose the relevant [[registry]] TOML table;
# # (only) the TOML table with the longest match for the input image name
# # (taking into account namespace/repo/tag/digest separators) is used.
# #
# # If the prefix field is missing, it defaults to be the same as the "location" field.
# prefix = "example.com/foo"
#
# # If true, unencrypted HTTP as well as TLS connections with untrusted
# # certificates are allowed.
# insecure = false
#
# # If true, pulling images with matching names is forbidden.
# blocked = false
#
# # The physical location of the "prefix"-rooted namespace.
# #
# # By default, this equal to "prefix" (in which case "prefix" can be omitted
# # and the [[registry]] TOML table can only specify "location").
# #
# # Example: Given
# #   prefix = "example.com/foo"
# #   location = "internal-registry-for-example.net/bar"
# # requests for the image example.com/foo/myimage:latest will actually work with the
# # internal-registry-for-example.net/bar/myimage:latest image.
# location = internal-registry-for-example.com/bar"
#
# # (Possibly-partial) mirrors for the "prefix"-rooted namespace.
# #
# # The mirrors are attempted in the specified order; the first one that can be
# # contacted and contains the image will be used (and if none of the mirrors contains the image,
# # the primary location specified by the "registry.location" field, or using the unmodified
# # user-specified reference, is tried last).
# #
# # Each TOML table in the "mirror" array can contain the following fields, with the same semantics
# # as if specified in the [[registry]] TOML table directly:
# # - location
# # - insecure
# [[registry.mirror]]
# location = "example-mirror-0.local/mirror-for-foo"
# [[registry.mirror]]
# location = "example-mirror-1.local/mirrors/foo"
# insecure = true
# # Given the above, a pull of example.com/foo/image:latest will try:
# # 1. example-mirror-0.local/mirror-for-foo/image:latest
# # 2. example-mirror-1.local/mirrors/foo/image:latest
# # 3. internal-registry-for-example.net/bar/myimage:latest
# # in order, and use the first one that exists.