Cray System Management Documentation > Cray System Management (CSM) Administration Guide > image management > Configure IMS to Validate RPMs

Configure IMS to Validate RPMs

Configuring the Image Management Service (IMS) to validate the GPG signatures of RPMs during IMS Build operations involves the following two steps:

Create and update IMS to use a new Kiwi-NG Image with the Signing Keys embedded.

NOTE The default IMS Kiwi-NG Image is already configured with the signing keys needed to validate HPE and SuSE RPMs and repositories.
Update IMS Recipes to require GPG verification of RPMs, repositories, or both.

Create and Update IMS to Use a New Kiwi-NG Image with an Embedded Signing Key

Create a temporary directory to perform the actions necessary to configure IMS to validate RPM signatures.
```
mkdir ims-validate
cd ims-validate/
```

Determine the container version for the IMS Kiwi-NG container.

kubectl -n services get cm cray-configmap-ims-v2-image-create-kiwi-ng -o yaml | grep cray-ims-kiwi-ng-opensuse-x86_64-builder

Example output:

  - image: cray/cray-ims-kiwi-ng-opensuse-x86_64-builder:0.4.7

If successful, make note of the version of the listed container. In this case, the version is 0.4.7.

Create a file containing the public portion of the Signing Key to be added to the IMS Kiwi-NG image.

cat my-signing-key.asc
-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----

Obtain a copy of the entrypoint.sh script from cray-ims-kiwi-ng-opensuse-x86_64-builder.

podman run -it --entrypoint "" --rm cray/cray-ims-kiwi-ng-opensuse-x86_64-builder:0.4.7 cat /scripts/entrypoint.sh | tee entrypoint.sh

Modify the entrypoint.sh script to pass the signing key to the kiwi-ng command.

cat entrypoint.sh

Example output:

[...]

# Call kiwi to build the image recipe. Note that the command line --add-bootstrap-package
# causes kiwi to install the cray-ca-cert RPM into the image root.
kiwi-ng $DEBUG_FLAGS --logfile=$PARAMETER_FILE_KIWI_LOGFILE --type tbz system build --description $RECIPE_ROOT_PARENT \
--target $IMAGE_ROOT_PARENT --add-bootstrap-package file:///mnt/ca-rpm/cray_ca_cert-1.0.1-1.x86_64.rpm \
--signing-key /signing-keys/my-signing-key.asc   # <--- ADD SIGNING-KEY FILE

[...]

Create a Dockerfile to create a new cray-ims-kiwi-ng-opensuse-x86_64-builder image.

cat Dockerfile
FROM registry.local/cray/cray-ims-kiwi-ng-opensuse-x86_64-builder:0.4.7

RUN mkdir /signing-keys
COPY my-signing-key.asc /signing-keys
COPY entrypoint.sh /scripts/entrypoint.sh
ENTRYPOINT ["/scripts/entrypoint.sh"]

NOTE Make sure that the version of the cray-ims-kiwi-ng-opensuse-x86_64-builder image in the FROM line matches the version of the image above.

Verify that the following files are in the temporary directory.
```
ls
Dockerfile  entrypoint.sh  my-signing-key.asc
```

Using the podman command, build and tag a new cray-ims-kiwi-ng-opensuse-x86_64-builder image.

podman build -t registry.local/cray/cray-ims-kiwi-ng-opensuse-x86_64-builder:0.4.7-validate .

STEP 1: FROM registry.local/cray/cray-ims-kiwi-ng-opensuse-x86_64-builder:0.4.7
STEP 2: RUN mkdir /signing-keys
--> Using cache 5d64aadcffd3f9f8f112cca75b886cecfccbfe903d4b0d4176882f0e78ccd4d0
--> 5d64aadcffd
STEP 3: COPY my-signing-key.asc /signing-keys
--> Using cache c10ffb877529bdbe855522af93827503f76d415e2e129d171a7fc927f896095a
--> c10ffb87752
STEP 4: COPY entrypoint.sh /scripts/entrypoint.sh
--> Using cache 6e388b60f42b6cd26df65ec1798ad771bdb835267126f16aa86e90aec78b0f32
--> 6e388b60f42
STEP 5: ENTRYPOINT ["/scripts/entrypoint.sh"]
--> Using cache 46c78827eb62c66c9f42aeba12333281b073dcc80212c4547c8cc806fe5519b3
STEP 6: COMMIT registry.local/cray/cray-ims-kiwi-ng-opensuse-x86_64-builder:0.4.7-validate
--> 46c78827eb6
46c78827eb62c66c9f42aeba12333281b073dcc80212c4547c8cc806fe5519b3

Obtain Nexus credentials.

NEXUS_USERNAME="$(kubectl -n nexus get secret nexus-admin-credential --template {{.data.username}} | base64 -d)"
NEXUS_PASSWORD="$(kubectl -n nexus get secret nexus-admin-credential --template {{.data.password}} | base64 -d)"

Push the new image to the Nexus image registry.

podman push registry.local/cray/cray-ims-kiwi-ng-opensuse-x86_64-builder:0.4.7-validate --creds="$NEXUS_USERNAME:$NEXUS_PASSWORD"

Update the IMS cray-configmap-ims-v2-image-create-kiwi-ng ConfigMap to use this new image.
```
kubectl -n services edit cm cray-configmap-ims-v2-image-create-kiwi-ng
```
Example output:
```
[...]

- image: cray/cray-ims-kiwi-ng-opensuse-x86_64-builder:0.4.7-validate

[...]
```
NOTE It may take several minutes for this change to take effect. Restarting IMS is not necessary.
Cleanup and remove the temporary directory
```
cd ..
rm -rfv ims-validate/
```

Update IMS Recipes to Require GPG Verification of RPMs/Repos

List the IMS recipes and determine which recipes need to be updated.

cray ims recipes list --format json

Example output:

[

  [...]

  {
    "created": "2021-06-29T21:50:38.319526+00:00",
    "id": "1aab3dbb-a654-4c84-b820-a293bd4ab2b4",
    "link": {
      "etag": "",
      "path": "s3://ims/recipes/1aab3dbb-a654-4c84-b820-a293bd4ab2b4/my_recipe.tgz",
      "type": "s3"
    },
    "linux_distribution": "sles15",
    "name": "cos-2.1.51-slingshot-1.2.1",
    "recipe_type": "kiwi-ng"
  },

[...]

]

Download the recipe archive for any recipe that will be updated.

cray artifacts get ims recipes/1aab3dbb-a654-4c84-b820-a293bd4ab2b4/recipe.tar.gz recipe.tar.gz

Uncompress the recipe archive into a temporary directory.

mkdir -v recipe
tar xvfz recipe.tar.gz -C recipe/
cd recipe/

Modify the recipe’s config.xml file and enable GPG validation on any repos that should be validated. To validate each package’s GPG signature, add package_gpgcheck="true". To validate the repository signature, add repository_gpgcheck="true".

<repository type="rpm-md" alias="..." priority="2" imageinclude="true" package_gpgcheck="true">
    ...
</repository>
<repository type="rpm-md" alias="..." priority="2" imageinclude="true" repository_gpgcheck="true">
    ...
</repository>

Create a new recipe tar file.
```
tar cvfz ../recipe-new.tgz .
```
Move to the parent directory.
```
cd ..
```

Create a new IMS recipe record.

cray ims recipes create --name "My Recipe" \
     --recipe-type kiwi-ng --linux-distribution sles15

Example output:

created = "2018-12-04T17:25:52.482514+00:00"
id = "2233c82a-5081-4f67-bec4-4b59a60017a6"
linux_distribution = "sles15"
name = "my_recipe.tgz"
recipe_type = "kiwi-ng"

If successful, create a variable for the id value in the returned data.

IMS_RECIPE_ID=2233c82a-5081-4f67-bec4-4b59a60017a6

Upload the customized recipe to S3.

It is suggested as a best practice that the S3 object name start with recipes/ and contain the IMS recipe ID to remove ambiguity.
```
cray artifacts create ims recipes/$IMS_RECIPE_ID/recipe.tgz recipe-new.tgz
```

Update the IMS recipe record with the S3 path to the recipe archive.

cray ims recipes update $IMS_RECIPE_ID \
          --link-type s3 \
          --link-path s3://ims/recipes/$IMS_RECIPE_ID/recipe.tgz

Example output:

id = "2233c82a-5081-4f67-bec4-4b59a60017a6"
recipe_type = "kiwi-ng"
linux_distribution = "sles15"
name = "my_recipe.tgz"
created = "2020-02-05T19:24:22.621448+00:00"

[link]
path = "s3://ims/recipes/2233c82a-5081-4f67-bec4-4b59a60017a6/my_recipe.tgz"
etag = ""
type = "s3"

Cleanup and remove the temporary directory.
```
cd ..
rm -rf recipe/
```