Merge pull request #1027 from stealthybox/sops-gpg-batch

Improve SOPS GPG guide key management
pull/1025/head
Stefan Prodan 4 years ago committed by GitHub
commit 69f38b8c77
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GPG Key ID: 4AEE18F83AFDEB23

@ -11,7 +11,7 @@ toolkit controllers installed on it.
Please see the [get started guide](../get-started/index.md)
or the [installation guide](installation.md).
Install [gnupg](https://www.gnupg.org/) and [sops](https://github.com/mozilla/sops):
Install [gnupg](https://www.gnupg.org/) and [SOPS](https://github.com/mozilla/sops):
```sh
brew install gnupg sops
@ -19,71 +19,62 @@ brew install gnupg sops
## Generate a GPG key
Generate a GPG key with OpenPGP without specifying a passphrase:
Generate a GPG/OpenPGP key with no passphrase (`%no-protection`):
```console
$ gpg --full-generate-key
Real name: stefanprodan
Email address: stefanprodan@users.noreply.github.com
Comment:
You selected this USER-ID:
"stefanprodan <stefanprodan@users.noreply.github.com>"
```sh
export KEY_NAME="cluster0.yourdomain.com"
export KEY_COMMENT="flux secrets"
gpg --batch --full-generate-key <<EOF
%no-protection
Key-Type: 1
Key-Length: 4096
Subkey-Type: 1
Subkey-Length: 4096
Expire-Date: 0
Name-Comment: ${KEY_COMMENT}
Name-Real: ${KEY_NAME}
EOF
```
Retrieve the GPG key ID (second row of the sec column):
The above configuration creates an rsa4096 key that does not expire.
For a full list of options to consider for your environment, see [Unattended GPG key generation](https://www.gnupg.org/documentation/manuals/gnupg/Unattended-GPG-key-generation.html).
```console
$ gpg --list-secret-keys stefanprodan@users.noreply.github.com
Retrieve the GPG key fingerprint (second row of the sec column):
sec rsa3072 2020-09-06 [SC]
```sh
gpg --list-secret-keys "${KEY_NAME}"
sec rsa4096 2020-09-06 [SC]
1F3D1CED2F865F5E59CA564553241F147E7C5FA4
```
Store the key fingerprint as an environment variable:
```sh
export KEY_FP=1F3D1CED2F865F5E59CA564553241F147E7C5FA4
```
Export the public and private keypair from your local GPG keyring and
create a Kubernetes secret named `sops-gpg` in the `flux-system` namespace:
```sh
gpg --export-secret-keys \
--armor 1F3D1CED2F865F5E59CA564553241F147E7C5FA4 |
gpg --export-secret-keys --armor "${KEY_FP}" |
kubectl create secret generic sops-gpg \
--namespace=flux-system \
--from-file=sops.asc=/dev/stdin
```
## Encrypt secrets
Generate a Kubernetes secret manifest with kubectl:
```sh
kubectl -n default create secret generic basic-auth \
--from-literal=user=admin \
--from-literal=password=change-me \
--dry-run=client \
-o yaml > basic-auth.yaml
```
Encrypt the secret with sops using your GPG key:
It's a good idea to back up this secret-key/K8s-Secret with a password manager or offline storage.
Also consider deleting the secret decryption key from you machine:
```sh
sops --encrypt \
--pgp=1F3D1CED2F865F5E59CA564553241F147E7C5FA4 \
--encrypted-regex '^(data|stringData)$' \
--in-place basic-auth.yaml
gpg --delete-secret-keys "${KEY_FP}"
```
!!! hint
Note that you should encrypt only the `data` section. Encrypting the Kubernetes
secret metadata, kind or apiVersion is not supported by kustomize-controller.
You can now commit the encrypted secret to your Git repository.
!!! hint
Note that you shouldn't apply the encrypted secrets onto the cluster with kubectl. SOPS encrypted secrets are designed to be consumed by kustomize-controller.
## Configure secrets decryption
## Configure in-cluster secrets decryption
Registry the Git repository on your cluster:
Register the Git repository on your cluster:
```sh
flux create source git my-secrets \
@ -95,15 +86,100 @@ Create a kustomization for reconciling the secrets on the cluster:
```sh
flux create kustomization my-secrets \
--source=my-secrets \
--path=./clusters/cluster0 \
--prune=true \
--interval=10m \
--decryption-provider=sops \
--decryption-secret=sops-gpg
```
Note that the `sops-gpg` can contain more than one key, sops will try to decrypt the
Note that the `sops-gpg` can contain more than one key, SOPS will try to decrypt the
secrets by iterating over all the private keys until it finds one that works.
## Optional: Export the public key into the Git directory
Commit the public key to the repository so that team members who clone the repo can encrypt new files:
```sh
gpg --export --armor "${KEY_FP}" > ./clusters/cluster0/.sops.pub.asc
```
Check the file contents to ensure it's the public key before adding it to the repo and committing.
```sh
git add ./clusters/cluster0/.sops.pub.asc
git commit -am 'Share GPG public key for secrets generation'
```
Team members can then import this key when they pull the Git repository:
```sh
gpg --import ./clusters/cluster0/.sops.pub.asc
```
!!! hint
The public key is sufficient for creating brand new files.
The secret key is required for decrypting and editing existing files because SOPS computes a MAC on all values.
When using solely the public key to add or remove a field, the whole file should be deleted and recreated.
## Configure the Git directory for encryption
Write a [SOPS config file](https://github.com/mozilla/sops#using-sops-yaml-conf-to-select-kms-pgp-for-new-files) to the specific cluster or namespace directory used
to store encrypted objects with this particular GPG key's fingerprint.
```yaml
cat <<EOF > ./clusters/cluster0/.sops.yaml
creation_rules:
- path_regex: .*.yaml
encrypted_regex: ^(data|stringData)$
pgp: ${KEY_FP}
EOF
```
This config applies recursively to all sub-directories.
Multiple directories can use separate SOPS configs.
Contributors using the `sops` CLI to create and encrypt files
won't have to worry about specifying the proper key for the target cluster or namespace.
`encrypted_regex` helps encrypt the the proper `data` and `stringData` fields for Secrets.
You may wish to add other fields if you are encrypting other types of Objects.
!!! hint
Note that you should encrypt only the `data` or `stringData` section. Encrypting the Kubernetes
secret metadata, kind or apiVersion is not supported by kustomize-controller.
Ignore all `.sops.yaml` files in a [`.sourceignore`](../components/source/gitrepositories#excluding-files) file at the root of your repo.
```sh
touch .sourceignore
echo '**/.sops.yaml' >> .sourceignore
```
You can now commit your SOPS config.
## Encrypt secrets
Generate a Kubernetes secret manifest with kubectl:
```sh
kubectl -n default create secret generic basic-auth \
--from-literal=user=admin \
--from-literal=password=change-me \
--dry-run=client \
-o yaml > basic-auth.yaml
```
Encrypt the secret with SOPS using your GPG key:
```sh
sops --encrypt --in-place basic-auth.yaml
```
You can now commit the encrypted secret to your Git repository.
!!! hint
Note that you shouldn't apply the encrypted secrets onto the cluster with kubectl. SOPS encrypted secrets are designed to be consumed by kustomize-controller.
### Using various cloud providers
When using AWS/GCP KMS, you don't have to include the gpg `secretRef` under
@ -210,5 +286,5 @@ Once the manifests have been pushed to the Git repository, the following happens
* source-controller pulls the changes from Git
* kustomize-controller loads the GPG keys from the `sops-pgp` secret
* kustomize-controller decrypts the Kubernetes secrets with sops and applies them on the cluster
* kustomize-controller decrypts the Kubernetes secrets with SOPS and applies them on the cluster
* kubelet creates the pods and mounts the secret as a volume or env variable inside the app container

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