Problem: "I can manage all my K8s config in git, except Secrets."
Solution: Encrypt your Secret into a SealedSecret, which is safe to store - even inside a public repository. The SealedSecret can be decrypted only by the controller running in the target cluster and nobody else (not even the original author) is able to obtain the original Secret from the SealedSecret.
-
- Will you still be able to decrypt if you no longer have access to your cluster?
- How can I do a backup of my SealedSecrets?
- Can I decrypt my secrets offline with a backup key?
- What flags are available for kubeseal?
- How do I update parts of JSON/YAML/TOML/.. file encrypted with sealed secrets?
- Can I bring my own (pre-generated) certificates?
- How to use kubeseal if the controller is not running within the
kube-system
namespace? - How to verify the images?
- How to use one controller for a subset of namespaces
Sealed Secrets is composed of two parts:
- A cluster-side controller / operator
- A client-side utility:
kubeseal
The kubeseal
utility uses asymmetric crypto to encrypt secrets that only the controller can decrypt.
These encrypted secrets are encoded in a SealedSecret
resource, which you can see as a recipe for creating
a secret. Here is how it looks:
apiVersion: bitnami.com/v1alpha1
kind: SealedSecret
metadata:
name: mysecret
namespace: mynamespace
spec:
encryptedData:
foo: AgBy3i4OJSWK+PiTySYZZA9rO43cGDEq.....
Once unsealed this will produce a secret equivalent to this:
apiVersion: v1
kind: Secret
metadata:
name: mysecret
namespace: mynamespace
data:
foo: YmFy # <- base64 encoded "bar"
This normal kubernetes secret will appear in the cluster
after a few seconds you can use it as you would use any secret that you would have created directly (e.g. reference it from a Pod
).
Jump to the Installation section to get up and running.
The Usage section explores in more detail how you craft SealedSecret
resources.
The previous example only focused on the encrypted secret items themselves, but the relationship between a SealedSecret
custom resource and the Secret
it unseals into is similar in many ways (but not in all of them) to the familiar Deployment
vs Pod
.
In particular, the annotations and labels of a SealedSecret
resource are not the same as the annotations of the Secret
that gets generated out of it.
To capture this distinction, the SealedSecret
object has a template
section which encodes all the fields you want the controller to put in the unsealed Secret
.
The Sprig function library is available in addition to the default Go Text Template functions.
The metadata
block is copied as is (the ownerReference
field will be updated unless disabled).
Other secret fields are handled individually. The type
and immutable
fields are copied, and the data
field can be used to template complex values on the Secret
. All other fields are currently ignored.
apiVersion: bitnami.com/v1alpha1
kind: SealedSecret
metadata:
name: mysecret
namespace: mynamespace
annotations:
"kubectl.kubernetes.io/last-applied-configuration": ....
spec:
encryptedData:
.dockerconfigjson: AgBy3i4OJSWK+PiTySYZZA9rO43cGDEq.....
template:
type: kubernetes.io/dockerconfigjson
immutable: true
# this is an example of labels and annotations that will be added to the output secret
metadata:
labels:
"jenkins.io/credentials-type": usernamePassword
annotations:
"jenkins.io/credentials-description": credentials from Kubernetes
The controller would unseal that into something like:
apiVersion: v1
kind: Secret
metadata:
name: mysecret
namespace: mynamespace
labels:
"jenkins.io/credentials-type": usernamePassword
annotations:
"jenkins.io/credentials-description": credentials from Kubernetes
ownerReferences:
- apiVersion: bitnami.com/v1alpha1
controller: true
kind: SealedSecret
name: mysecret
uid: 5caff6a0-c9ac-11e9-881e-42010aac003e
type: kubernetes.io/dockerconfigjson
immutable: true
data:
.dockerconfigjson: ewogICJjcmVk...
As you can see, the generated Secret
resource is a "dependent object" of the SealedSecret
and as such
it will be updated and deleted whenever the SealedSecret
object gets updated or deleted.
The key certificate (public key portion) is used for sealing secrets,
and needs to be available wherever kubeseal
is going to be
used. The certificate is not secret information, although you need to
ensure you are using the correct one.
kubeseal
will fetch the certificate from the controller at runtime
(requires secure access to the Kubernetes API server), which is
convenient for interactive use, but it's known to be brittle when users
have clusters with special configurations such as private GKE clusters that have
firewalls between control plane and nodes.
An alternative workflow
is to store the certificate somewhere (e.g. local disk) with
kubeseal --fetch-cert >mycert.pem
,
and use it offline with kubeseal --cert mycert.pem
.
The certificate is also printed to the controller log on startup.
Since v0.9.x certificates get automatically renewed every 30 days. It's good practice that you and your team
update your offline certificate periodically. To help you with that, since v0.9.2 kubeseal
accepts URLs too. You can set up your internal automation to publish certificates somewhere you trust.
kubeseal --cert https://your.intranet.company.com/sealed-secrets/your-cluster.cert
It also recognizes the SEALED_SECRETS_CERT
env var. (pro-tip: see also direnv).
NOTE: we are working on providing key management mechanisms that offload the encryption to HSM based modules or managed cloud crypto solutions such as KMS.
SealedSecrets are from the POV of an end user a "write only" device.
The idea is that the SealedSecret can be decrypted only by the controller running in the target cluster and nobody else (not even the original author) is able to obtain the original Secret from the SealedSecret.
The user may or may not have direct access to the target cluster. More specifically, the user might or might not have access to the Secret unsealed by the controller.
There are many ways to configure RBAC on k8s, but it's quite common to forbid low-privilege users from reading Secrets. It's also common to give users one or more namespaces where they have higher privileges, which would allow them to create and read secrets (and/or create deployments that can reference those secrets).
Encrypted SealedSecret
resources are designed to be safe to be looked at without gaining any knowledge about the secrets it conceals. This implies that we cannot allow users to read a SealedSecret meant for a namespace they wouldn't have access to
and just push a copy of it in a namespace where they can read secrets from.
Sealed-secrets thus behaves as if each namespace had its own independent encryption key and thus once you seal a secret for a namespace, it cannot be moved in another namespace and decrypted there.
We don't technically use an independent private key for each namespace, but instead we include the namespace name during the encryption process, effectively achieving the same result.
Furthermore, namespaces are not the only level at which RBAC configurations can decide who can see which secret. In fact, it's possible that users can access a secret called foo
in a given namespace but not any other secret in the same namespace. We cannot thus by default let users freely rename SealedSecret
resources otherwise a malicious user would be able to decrypt any SealedSecret for that namespace by just renaming it to overwrite the one secret user does have access to. We use the same mechanism used to include the namespace in the encryption key to also include the secret name.
That said, there are many scenarios where you might not care about this level of protection. For example, the only people who have access to your clusters are either admins or they cannot read any Secret
resource at all. You might have a use case for moving a sealed secret to other namespaces (e.g. you might not know the namespace name upfront), or you might not know the name of the secret (e.g. it could contain a unique suffix based on the hash of the contents etc).
These are the possible scopes:
strict
(default): the secret must be sealed with exactly the same name and namespace. These attributes become part of the encrypted data and thus changing name and/or namespace would lead to "decryption error".namespace-wide
: you can freely rename the sealed secret within a given namespace.cluster-wide
: the secret can be unsealed in any namespace and can be given any name.
In contrast to the restrictions of name and namespace, secret items (i.e. JSON object keys like spec.encryptedData.my-key
) can be renamed at will without losing the ability to decrypt the sealed secret.
The scope is selected with the --scope
flag:
kubeseal --scope cluster-wide <secret.yaml >sealed-secret.json
It's also possible to request a scope via annotations in the input secret you pass to kubeseal
:
sealedsecrets.bitnami.com/namespace-wide: "true"
-> fornamespace-wide
sealedsecrets.bitnami.com/cluster-wide: "true"
-> forcluster-wide
The lack of any of such annotations means strict
mode. If both are set, cluster-wide
takes precedence.
NOTE: Next release will consolidate this into a single
sealedsecrets.bitnami.com/scope
annotation.
See https://github.com/bitnami-labs/sealed-secrets/releases for the latest release and detailed installation instructions.
Cloud platform specific notes and instructions:
Once you deploy the manifest it will create the SealedSecret
resource
and install the controller into kube-system
namespace, create a service
account and necessary RBAC roles.
After a few moments, the controller will start, generate a key pair, and be ready for operation. If it does not, check the controller logs.
The official controller manifest installation mechanism is just a YAML file.
In some cases you might need to apply your own customizations, like set a custom namespace or set some env variables.
kubectl
has native support for that, see kustomize.
The Sealed Secrets helm chart is now officially supported and hosted in this GitHub repo.
helm repo add sealed-secrets https://bitnami-labs.github.io/sealed-secrets
NOTE: The versioning scheme of the helm chart differs from the versioning scheme of the sealed secrets project itself.
Originally the helm chart was maintained by the community and the first version adopted a major version of 1 while the sealed secrets project itself is still at major 0. This is ok because the version of the helm chart itself is not meant to be necessarily the version of the app itself. However this is confusing, so our current versioning rule is:
- The
SealedSecret
controller version scheme: 0.X.Y - The helm chart version scheme: 1.X.Y-rZ
There can be thus multiple revisions of the helm chart, with fixes that apply only to the helm chart without affecting the static YAML manifests or the controller image itself.
NOTE: The helm chart readme still contains a deprecation notice, but it no longer reflects reality and will be removed upon the next release.
NOTE: The helm chart by default installs the controller with the name
sealed-secrets
, while thekubeseal
command line interface (CLI) tries to access the controller with the namesealed-secrets-controller
. You can explicitly pass--controller-name
to the CLI:
kubeseal --controller-name sealed-secrets <args>
Alternatively, you can set fullnameOverride
when installing the chart to override the name. Note also that kubeseal
assumes that the controller is installed within the kube-system
namespace by default. So if you want to use the kubeseal
CLI without having to pass the expected controller name and namespace you should install the Helm Chart like this:
helm install sealed-secrets -n kube-system --set-string fullnameOverride=sealed-secrets-controller sealed-secrets/sealed-secrets
In some companies you might be given access only to a single namespace, not a full cluster.
One of the most restrictive environments you can encounter is:
- A
namespace
was allocated to you with someservice account
. - You do not have access to the rest of the cluster, not even cluster CRDs.
- You may not even be able to create further service accounts or roles in your namespace.
- You are required to include resource limits in all your deployments.
Even with these restrictions you can still install the sealed secrets Helm Chart, there is only one pre-requisite:
- The cluster must already have the sealed secrets CRDs installed.
Once your admins installed the CRDs, if they were not there already, you can install the chart by preparing a YAML config file such as this:
serviceAccount:
create: false
name: {allocated-service-account}
rbac:
create: false
clusterRole: false
resources:
limits:
cpu: 150m
memory: 256Mi
Note that:
- No service accounts are created, instead the one allocated to you will be used.
{allocated-service-account}
is the name of theservice account
you were allocated on the cluster.
- No RBAC roles are created neither in the namespace nor the cluster.
- Resource limits must be specified.
- The limits are samples that should work, but you might want to review them in your particular setup.
Once that file is ready, if you named it config.yaml
you now can install the sealed secrets Helm Chart like this:
helm install sealed-secrets -n {allocated-namespace} sealed-secrets/sealed-secrets --skip-crds -f config.yaml
Where {allocated-namespace}
is the name of the namespace
you were allocated in the cluster.
The kubeseal
client is also available on homebrew:
brew install kubeseal
The kubeseal
client is also available on MacPorts:
port install kubeseal
The kubeseal
client is also available on Nixpkgs: (DISCLAIMER: Not maintained by bitnami-labs)
nix-env -iA nixpkgs.kubeseal
The kubeseal
client can be installed on Linux, using the below commands:
KUBESEAL_VERSION='' # Set this to, for example, KUBESEAL_VERSION='0.23.0'
curl -OL "https://github.com/bitnami-labs/sealed-secrets/releases/download/v${KUBESEAL_VERSION:?}/kubeseal-${KUBESEAL_VERSION:?}-linux-amd64.tar.gz"
tar -xvzf kubeseal-${KUBESEAL_VERSION:?}-linux-amd64.tar.gz kubeseal
sudo install -m 755 kubeseal /usr/local/bin/kubeseal
If you have curl
and jq
installed on your machine, you can get the version dynamically this way. This can be useful for environments used in automation and such.
# Fetch the latest sealed-secrets version using GitHub API
KUBESEAL_VERSION=$(curl -s https://api.github.com/repos/bitnami-labs/sealed-secrets/tags | jq -r '.[0].name' | cut -c 2-)
# Check if the version was fetched successfully
if [ -z "$KUBESEAL_VERSION" ]; then
echo "Failed to fetch the latest KUBESEAL_VERSION"
exit 1
fi
curl -OL "https://github.com/bitnami-labs/sealed-secrets/releases/download/v${KUBESEAL_VERSION}/kubeseal-${KUBESEAL_VERSION}-linux-amd64.tar.gz"
tar -xvzf kubeseal-${KUBESEAL_VERSION}-linux-amd64.tar.gz kubeseal
sudo install -m 755 kubeseal /usr/local/bin/kubeseal
where KUBESEAL_VERSION
is the version tag of the kubeseal release you want to use. For example: v0.18.0
.
If you just want the latest client tool, it can be installed into
$GOPATH/bin
with:
go install github.com/bitnami-labs/sealed-secrets/cmd/kubeseal@main
You can specify a release tag or a commit SHA instead of main
.
The go install
command will place the kubeseal
binary at $GOPATH/bin
:
$(go env GOPATH)/bin/kubeseal
Don't forget to check the release notes for guidance about possible breaking changes when you upgrade the client tool and/or the controller.
Currently, only the latest version of Sealed Secrets is supported for production environments.
The Sealed Secrets controller ensures compatibility with different versions of Kubernetes by relying on a stable Kubernetes API. Typically, Kubernetes versions above 1.16 are considered compatible. However, we officially support the currently recommended Kubernetes versions. Additionally, versions above 1.24 undergo thorough verification through our CI process with every release.
# Create a json/yaml-encoded Secret somehow:
# (note use of `--dry-run` - this is just a local file!)
echo -n bar | kubectl create secret generic mysecret --dry-run=client --from-file=foo=/dev/stdin -o json >mysecret.json
# This is the important bit:
kubeseal -f mysecret.json -w mysealedsecret.json
# At this point mysealedsecret.json is safe to upload to Github,
# post on Twitter, etc.
# Eventually:
kubectl create -f mysealedsecret.json
# Profit!
kubectl get secret mysecret
Note the SealedSecret
and Secret
must have the same namespace and
name. This is a feature to prevent other users on the same cluster
from re-using your sealed secrets. See the Scopes section for more info.
kubeseal
reads the namespace from the input secret, accepts an explicit --namespace
argument, and uses
the kubectl
default namespace (in that order). Any labels,
annotations, etc on the original Secret
are preserved, but not
automatically reflected in the SealedSecret
.
By design, this scheme does not authenticate the user. In other
words, anyone can create a SealedSecret
containing any Secret
they like (provided the namespace/name matches). It is up to your
existing config management workflow, cluster RBAC rules, etc to ensure
that only the intended SealedSecret
is uploaded to the cluster. The
only change from existing Kubernetes is that the contents of the
Secret
are now hidden while outside the cluster.
If you want the Sealed Secrets controller to manage an existing Secret
, you can annotate your Secret
with the sealedsecrets.bitnami.com/managed: "true"
annotation. The existing Secret
will be overwritten when unsealing a SealedSecret
with the same name and namespace, and the SealedSecret
will take ownership of the Secret
(so that when the SealedSecret
is deleted the Secret
will also be deleted).
New in v0.23.0
There are some use cases in which you don't want to replace the whole Secret
but just add or modify some keys from the existing Secret
. For this, you can annotate your Secret
with sealedsecrets.bitnami.com/patch: "true"
. Using this annotation will make sure that secret keys, labels and annotations in the Secret
that are not present in the SealedSecret
won't be deleted, and those present in the SealedSecret
will be added to the Secret
(secret keys, labels and annotations that exist both in the Secret
and the SealedSecret
will be modified by the SealedSecret
).
This annotation does not make the SealedSecret
take ownership of the Secret
. You can add both the patch
and managed
annotations to obtain the patching behavior while also taking ownership of the Secret
.
If you want SealedSecret
and the Secret
to be independent, which mean when you delete the SealedSecret
the Secret
won't disappear with it, then you have to annotate that Secret with the annotation sealedsecrets.bitnami.com/skip-set-owner-references: "true"
ahead of applying the Usage steps. You still may also add sealedsecrets.bitnami.com/managed: "true"
to your Secret
so that your secret will be updated when SealedSecret
is updated.
If you want to add or update existing sealed secrets without having the cleartext for the other items, you can just copy&paste the new encrypted data items and merge it into an existing sealed secret.
You must take care of sealing the updated items with a compatible name and namespace (see note about scopes above).
You can use the --merge-into
command to update an existing sealed secrets if you don't want to copy&paste:
echo -n bar | kubectl create secret generic mysecret --dry-run=client --from-file=foo=/dev/stdin -o json \
| kubeseal > mysealedsecret.json
echo -n baz | kubectl create secret generic mysecret --dry-run=client --from-file=bar=/dev/stdin -o json \
| kubeseal --merge-into mysealedsecret.json
Creating temporary Secret with the kubectl
command, only to throw it away once piped to kubeseal
can
be a quite unfriendly user experience. We're working on an overhaul of the CLI experience. In the meantime,
we offer an alternative mode where kubeseal only cares about encrypting a value to stdout, and it's your responsibility to put it inside a SealedSecret
resource (not unlike any of the other k8s resources).
It can also be useful as a building block for editor/IDE integrations.
The downside is that you have to be careful to be consistent with the sealing scope, the namespace and the name.
See Scopes
strict
scope (default):
$ echo -n foo | kubeseal --raw --namespace bar --name mysecret
AgBChHUWLMx...
namespace-wide
scope:
$ echo -n foo | kubeseal --raw --namespace bar --scope namespace-wide
AgAbbFNkM54...
Include the sealedsecrets.bitnami.com/namespace-wide
annotation in the SealedSecret
metadata:
annotations:
sealedsecrets.bitnami.com/namespace-wide: "true"
cluster-wide
scope:
$ echo -n foo | kubeseal --raw --scope cluster-wide
AgAjLKpIYV+...
Include the sealedsecrets.bitnami.com/cluster-wide
annotation in the SealedSecret
metadata:
annotations:
sealedsecrets.bitnami.com/cluster-wide: "true"
If you want to validate an existing sealed secret, kubeseal
has the flag --validate
to help you.
Giving a file named sealed-secrets.yaml
containing the following sealed secret:
apiVersion: bitnami.com/v1alpha1
kind: SealedSecret
metadata:
name: mysecret
namespace: mynamespace
spec:
encryptedData:
foo: AgBy3i4OJSWK+PiTySYZZA9rO43cGDEq.....
You can validate if the sealed secret was properly created or not:
$ cat sealed-secrets.yaml | kubeseal --validate
In case of an invalid sealed secret, kubeseal
will show:
$ cat sealed-secrets.yaml | kubeseal --validate
error: unable to decrypt sealed secret
You should always rotate your secrets. But since your secrets are encrypted with another secret, you need to understand how these two layers relate to take the right decisions.
TL;DR:
If a sealing private key is compromised, you need to follow the instructions below in "Early key renewal" section before rotating any of your actual secret values.
SealedSecret key renewal and re-encryption features are not a substitute for periodical rotation of your actual secret values.
Sealing keys are automatically renewed every 30 days. Which means a new sealing key is created and appended to the set of active sealing keys the controller can use to unseal SealedSecret
resources.
The most recently created sealing key is the one used to seal new secrets when you use kubeseal
and it's the one whose certificate is downloaded when you use kubeseal --fetch-cert
.
The renewal time of 30 days is a reasonable default, but it can be tweaked as needed
with the --key-renew-period=<value>
flag for the command in the pod template of the SealedSecret
controller. The value
field can be given as golang
duration flag (eg: 720h30m
). Assuming that you've installed Sealed Secrets into the kube-system
namespace, use the following command to edit the Deployment controller, and add the --key-renew-period
parameter. Once you close your text editor, and the Deployment controller has been modified, a new Pod will be automatically created to replace the old Pod.
kubectl edit deployment/sealed-secrets-controller --namespace=kube-system
A value of 0
will deactivate automatic key renewal. Of course, you may have a valid use case for deactivating automatic sealing key renewal but experience has shown that new users often tend to jump to conclusions that they want control over key renewal, before fully understanding how sealed secrets work. Read more about this in the common misconceptions section below.
Unfortunately, you cannot use e.g. "d" as a unit for days because that's not supported by the Go stdlib. Instead of hitting your face with a palm, take this as an opportunity to meditate on the falsehoods programmers believe about time.
A common misunderstanding is that key renewal is often thought of as a form of key rotation, where the old key is not only obsolete but actually bad and that you thus want to get rid of it. It doesn't help that this feature has been historically called "key rotation", which can add to the confusion.
Sealed secrets are not automatically rotated and old keys are not deleted
when new keys are generated. Old SealedSecret
resources can be still decrypted (that's because old sealing keys are not deleted).
The sealing key renewal and SealedSecret rotation are not a substitute for rotating your actual secrets.
A core value proposition of this tool is:
Encrypt your Secret into a SealedSecret, which is safe to store - even inside a public repository.
If you store anything in a version control storage, and in a public one in particular, you must assume you cannot ever delete that information.
If a sealing key somehow leaks out of the cluster you must consider all your SealedSecret
resources
encrypted with that key as compromised. No amount of sealing key rotation in the cluster or even re-encryption of existing SealedSecrets files can change that.
The best practice is to periodically rotate all your actual secrets (e.g. change the password) and craft new
SealedSecret
resources with those new secrets.
But if the SealedSecret
controller was not renewing the sealing key that rotation would be moot,
since the attacker could just decrypt the new secrets as well. Thus, you need to do both: periodically renew the sealing key and rotate your actual secrets!
If you know or suspect a sealing key has been compromised you should renew the key ASAP before you start sealing your new rotated secrets, otherwise you'll be giving attackers access to your new secrets as well.
A key can be generated early by passing the current timestamp to the controller into a flag called --key-cutoff-time
or an env var called SEALED_SECRETS_KEY_CUTOFF_TIME
. The expected format is RFC1123, you can generate it with the date -R
unix command.
Sealed secrets sealing keys are not access control keys (e.g. a password). They are more like the GPG key you might use to read encrypted mail sent to you. Let's continue with the email analogy for a bit:
Imagine you have reasons to believe your private GPG key might have been compromised. You'd have more to lose than to gain if the first thing you do is just delete your private key. All the previous emails sent with that key are no longer accessible to you (unless you have a decrypted copy of those emails), nor are new emails sent by your friends whom you have not yet managed to tell to use the new key.
Sure, the content of those encrypted emails is not secure, as an attacker might now be able to decrypt them, but what's done is done. Your sudden loss of the ability to read those emails surely doesn't undo the damage. If anything, it's worse because you no longer know for sure what secret the attacker got to know. What you really want to do is to make sure that your friend stops using your old key and that from now on all further communication is encrypted with a new key pair (i.e. your friend must know about that new key).
The same logic applies to SealedSecrets. The ultimate goal is to secure your actual "user" secrets. The "sealing" secrets are just a mechanism, an "envelope". If a secret is leaked there is no going back, what's done is done.
You first need to ensure that new secrets don't get encrypted with that old compromised key (in the email analogy above that's: create a new key pair and give all your friends your new public key).
The second logical step is to neutralize the damage, which depends on the nature of the secret. A simple example is a database password: if you accidentally leak your database password, the thing you're supposed to do is simply to change your database password (on the database; and revoke the old one!) and update the SealedSecret
resource with the new password (i.e. running kubeseal
again).
Both steps are described in the previous sections, albeit in a less verbose way. There is no shame in reading them again, now that you have a more in-depth grasp of the underlying rationale.
The SealedSecret
controller and the associated workflow are designed to keep old sealing keys around and periodically add new ones. You should not delete old keys unless you know what you're doing.
That said, if you want you can manually manage (create, move, delete) sealing keys. They are just normal k8s secrets living in the same namespace where the SealedSecret
controller lives (usually kube-system
, but it's configurable).
There are advanced use cases that you can address by creative management of the sealing keys. For example, you can share the same sealing key among a few clusters so that you can apply exactly the same sealed secret in multiple clusters. Since sealing keys are just normal k8s secrets you can even use sealed secrets themselves and use a GitOps workflow to manage your sealing keys (useful when you want to share the same key among different clusters)!
Labeling a sealing key secret with anything other than active
effectively deletes
the key from the SealedSecret
controller, but it is still available in k8s for
manual encryption/decryption if need be.
NOTE SealedSecret
controller currently does not automatically pick up manually created, deleted or relabeled sealing keys. An admin must restart the controller before the effect will apply.
Before you can get rid of some old sealing keys you need to re-encrypt your SealedSecrets with the latest private key.
kubeseal --re-encrypt <my_sealed_secret.json >tmp.json \
&& mv tmp.json my_sealed_secret.json
The invocation above will produce a new sealed secret file freshly encrypted with
the latest key, without making the secrets leave the cluster to the client. You can then save that file
in your version control system (kubeseal --re-encrypt
doesn't update the in-cluster object).
Currently, old keys are not garbage collected automatically.
It's a good idea to periodically re-encrypt your SealedSecrets. But as mentioned above, don't lull yourself in a false sense of security: you must assume the old version of the SealedSecret
resource (the one encrypted with a key you think of as dead) is still potentially around and accessible to attackers. I.e. re-encryption is not a substitute for periodically rotating your actual secrets.
This controller adds a new SealedSecret
custom resource. The
interesting part of a SealedSecret
is a base64-encoded
asymmetrically encrypted Secret
.
The controller maintains a set of private/public key pairs as kubernetes
secrets. Keys are labeled with sealedsecrets.bitnami.com/sealed-secrets-key
and identified in the label as either active
or compromised
. On startup,
The sealed secrets controller will...
- Search for these keys and add them to its local store if they are labeled as active.
- Create a new key
- Start the key rotation cycle
More details about crypto can be found here.
Developing guidelines can be found in the Developer Guide.
Yes, you can! Drop as many secrets as you like in one file. Make sure to separate them via ---
for YAML and as extra, single objects in JSON.
No, the private keys are only stored in the Secret managed by the controller (unless you have some other backup of your k8s objects). There are no backdoors - without that private key used to encrypt a given SealedSecrets, you can't decrypt it. If you can't get to the Secrets with the encryption keys, and you also can't get to the decrypted versions of your Secrets live in the cluster, then you will need to regenerate new passwords for everything, seal them again with a new sealing key, etc.
If you do want to make a backup of the encryption private keys, it's easy to do from an account with suitable access:
kubectl get secret -n kube-system -l sealedsecrets.bitnami.com/sealed-secrets-key -o yaml >main.key
echo "---" >> main.key
kubectl get secret -n kube-system sealed-secrets-key -o yaml >>main.key
NOTE: You need the second statement only if you ever installed sealed-secrets older than version 0.9.x on your cluster.
NOTE: This file will contain the controller's public + private keys and should be kept omg-safe!
NOTE: After sealing key renewal you should recreate your backup. Otherwise, your backup won't be able to decrypt new sealed secrets.
To restore from a backup after some disaster, just put that secrets back before starting the controller - or if the controller was already started, replace the newly-created secrets and restart the controller:
-
For Helm deployment:
kubectl apply -f main.key kubectl delete pod -n kube-system -l app.kubernetes.io/name=sealed-secrets
-
For deployment via
controller.yaml
manifestkubectl apply -f main.key kubectl delete pod -n kube-system -l name=sealed-secrets-controller
While treating sealed-secrets as long term storage system for secrets is not the recommended use case, some people
do have a legitimate requirement for being able to recover secrets when the k8s cluster is down and restoring a backup into a new SealedSecret
controller deployment is not practical.
If you have backed up one or more of your private keys (see previous question), you can use the kubeseal --recovery-unseal --recovery-private-key file1.key,file2.key,...
command to decrypt a sealed secrets file.
You can check the flags available using kubeseal --help
.
A kubernetes Secret
resource contains multiple items, basically a flat map of key/value pairs.
SealedSecrets operate at that level, and does not care what you put in the values. In other words
it cannot make sense of any structured configuration file you might have put in a secret and thus
cannot help you update individual fields in it.
Since this is a common problem, especially when dealing with legacy applications, we do offer an example of a possible workaround.
Yes, you can provide the controller with your own certificates, and it will consume them. Please check here for a workaround.
If you installed the controller in a different namespace than the default kube-system
, you need to provide this namespace
to the kubeseal
commandline tool. There are two options:
- You can specify the namespace via the command line option
--controller-namespace <namespace>
:
kubeseal --controller-namespace sealed-secrets <mysecret.json >mysealedsecret.json
- Via the environment variable
SEALED_SECRETS_CONTROLLER_NAMESPACE
:
export SEALED_SECRETS_CONTROLLER_NAMESPACE=sealed-secrets
kubeseal <mysecret.json >mysealedsecret.json
Our images are being signed using cosign. The signatures have been saved in our GitHub Container Registry.
Images up to and including v0.20.2 were signed using Cosign v1. Newer images are signed with Cosign v2.
It is pretty simple to verify the images:
# export the COSIGN_VARIABLE setting up the GitHub container registry signs path
export COSIGN_REPOSITORY=ghcr.io/bitnami-labs/sealed-secrets-controller/signs
# verify the image uploaded in GHCR
cosign verify --key .github/workflows/cosign.pub ghcr.io/bitnami-labs/sealed-secrets-controller:latest
# verify the image uploaded in Dockerhub
cosign verify --key .github/workflows/cosign.pub docker.io/bitnami/sealed-secrets-controller:latest
If you want to use one controller for more than one namespace, but not all namespaces, you can provide additional namespaces using the command line flag --additional-namespaces=<namespace1>,<namespace2>,<...>
. Make sure you provide appropriate roles and rolebindings in the target namespaces, so the controller can manage the secrets in there.
Click here to sign up to the Kubernetes Slack org.
kubeseal-convert
: https://github.com/EladLeev/kubeseal-convert- Visual Studio Code extension: https://marketplace.visualstudio.com/items?itemName=codecontemplator.kubeseal
- WebSeal: generates secrets in the browser: https://socialgouv.github.io/webseal
- HybridEncrypt TypeScript implementation: https://github.com/SocialGouv/aes-gcm-rsa-oaep
- [DEPRACATED] Sealed Secrets Operator: https://github.com/disposab1e/sealed-secrets-operator-helm