> ## Documentation Index
> Fetch the complete documentation index at: https://cloudanix.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Consider External Secret Storage

### More Info:

Storing secrets in an external, dedicated secrets manager can improve protection over native Kubernetes Secrets. Evaluate such options.

### Risk Level

Informational

### Address

Security

### Compliance Standards

* CIS Kubernetes

### Triage and Remediation

<Tabs>
  <Tab title="Remediation">
    ### Remediation

    <AccordionGroup>
      <Accordion title="Manual Steps" defaultOpen="true">
        1. **Inventory how Kubernetes Secrets are currently used**
           * On any machine with kubectl access, list all Secret objects and their types:
             ```bash theme={null}
             kubectl get secrets -A -o custom-columns='NAMESPACE:.metadata.namespace,NAME:.metadata.name,TYPE:.type' | sort
             ```
           * Identify workloads that mount or reference these Secrets:
             ```bash theme={null}
             kubectl get pods -A -o yaml | grep -nE 'secretName:|valueFrom:' -n
             ```
           * Note any use of type `kubernetes.io/basic-auth`, `kubernetes.io/ssh-auth`, database creds, API keys, tokens, etc., which are strong candidates for external storage.

        2. **Assess in-cluster Secret protection and sensitivity**
           * Check if Encryption at Rest is enabled for Secrets (control plane–specific; if you do not manage it, retrieve documentation/config from your provider or IaC):
             * For self-managed clusters, on every control plane node:
               ```bash theme={null}
               sudo cat /etc/kubernetes/manifests/kube-apiserver.yaml | grep -n 'encryption-provider-config'
               ```
               ```bash theme={null}
               sudo cat /etc/kubernetes/encryption-config.yaml
               ```
           * Classify secrets by sensitivity (e.g., “high” for long-lived credentials to production systems, “medium” for non-production, “low” for ephemeral tokens) and record which namespaces and apps depend on them.

        3. **Review available external secrets managers and cluster integration options**
           * From your cloud console or IaC, identify supported secrets managers and their Kubernetes integrations, for example (depending on environment):
             * AWS: AWS Secrets Manager / SSM Parameter Store + External Secrets Operator or Secrets Store CSI Driver.
             * GCP: Secret Manager + Secret Manager CSI driver / external-secrets.
             * Azure: Key Vault + Secrets Store CSI Driver / external-secrets.
           * Confirm organizational standards or regulatory requirements that may mandate a particular secrets manager or key management scheme (e.g., use of HSM-backed keys, centralized audit, rotation policies).

        4. **Decide scope and pattern for migration to external secret storage**
           * Choose a preferred integration pattern (e.g., External Secrets Operator with CRDs like `ExternalSecret`, or CSI driver volume mounts) based on your platform.
           * Select a pilot scope: one or a few high-sensitivity applications and their Secrets (from step 1) to migrate first.
           * For those pilot apps, map each existing `Secret` to a candidate external secret path/name in the chosen manager.

        5. **Implement and test external secrets for a pilot workload**
           * Using cloud console or IaC, create corresponding secrets in the external manager for the pilot application, ensuring:
             * Access control (IAM/RBAC) only allows the Kubernetes cluster/namespace/service account to read them.
             * Rotation policy is defined where supported.
           * On any machine with kubectl access, deploy the chosen integration (operator or CSI driver) according to its vendor documentation, then define a test manifest that consumes the external secret (example pattern only, adjust to your tool):
             ```bash theme={null}
             kubectl apply -f external-secret-test.yaml
             ```
           * Verify the pod(s) receive correct secret data and the original Kubernetes `Secret` is no longer required for that workload.

        6. **Plan progressive rollout and deprecation of native Secrets where appropriate**
           * For remaining high- and medium-sensitivity Secrets, repeat the mapping and migration process, updating manifests in your IaC to source data from the external store instead of embedding values into Kubernetes Secrets.
           * Verify after each migration that no workloads still depend on the old Secrets:
             ```bash theme={null}
             kubectl get pods -A -o yaml | grep -n 'secretName:' | grep '<old-secret-name>' || echo "No remaining references"
             ```
           * Once confirmed, delete or minimize high-sensitivity native Secrets and document the new standard: which classes of secrets must be stored in the external manager, and which (if any) may remain as Kubernetes Secrets.
      </Accordion>

      <Accordion title="Using kubectl">
        ```bash theme={null}
        # 1) List all namespaces
        # Run on: any machine with kubectl access
        kubectl get ns

        # 2) List secrets per namespace (excluding service-account token secrets)
        # Replace <namespace> with each namespace from the previous command
        kubectl get secrets -n <namespace> \
          --field-selector='type!=kubernetes.io/service-account-token'

        # 3) Inspect individual secrets for sensitive data patterns
        # Replace <secret-name> and <namespace>
        kubectl get secret <secret-name> -n <namespace> -o yaml
        ```

        What to look for in the output (indicates a problem / candidate for external storage):

        * `type: Opaque` secrets containing:
          * Long-lived application credentials (database users/passwords, API keys, TLS private keys not associated with short-lived certs).
          * Cloud provider access keys, tokens, or passwords to external services.
        * Secrets with generic names but clearly sensitive values, for example:
          * `db-credentials`, `payment-gateway-key`, `smtp-password`, `aws-credentials`, `gcp-service-account`, `azure-sp-credentials`.
        * Secrets referenced broadly across many workloads (suggesting high blast radius).

        ```bash theme={null}
        # 4) See how secrets are consumed by workloads (env vars and volumes)
        # Replace <namespace>
        kubectl get deploy,sts,ds -n <namespace> -o yaml
        ```

        In the above output, potential issues:

        * `env:` or `envFrom:` entries that reference sensitive secrets via `valueFrom.secretKeyRef`.
        * `volumes:` with `secret:` sources that mount sensitive secrets to many pods.
        * Same secret name used across many different applications/namespaces (central, critical credential).

        ```bash theme={null}
        # 5) Identify secrets likely holding cloud or external service credentials
        # Common keyword search in secret names (namespace by namespace)
        kubectl get secrets -n <namespace> | grep -Ei 'aws|gcp|azure|db|mysql|postgres|mongo|redis|api|token|key|cert|tls'
        ```

        If this surfaces secrets whose values (from step 3) are:

        * Long-lived,
        * Grant access to external or critical systems,
        * Needed by many different workloads,

        then they are strong candidates to be moved to an external secrets manager, with Kubernetes only holding references or short-lived material.

        ```bash theme={null}
        # 6) Check for cluster-wide TLS / CA material stored as regular secrets
        kubectl get secrets -A | grep -Ei 'tls|ca|certificate'
        ```

        Potential concern:

        * TLS private keys or CA roots that are long-lived and reused across multiple services or ingresses; those are often better managed in a dedicated secrets/PKI system.

        Next step (manual decision):

        * Based on the above inspection, decide which secrets should remain as native Kubernetes Secrets (low-risk, internal-only, non-critical),
          and which should instead be sourced from an external secrets manager per your cloud provider or chosen third-party solution.
      </Accordion>

      <Accordion title="Automation">
        ```bash theme={null}
        #!/usr/bin/env bash
        # Run on: any machine with kubectl access and current context set to the target cluster
        # Purpose: Report how Kubernetes Secrets are used so you can decide
        # whether to move to an external secrets manager.

        set -euo pipefail

        echo "=== Cluster-wide secret inventory (by namespace and type) ==="
        kubectl get secrets --all-namespaces -o json \
          | jq -r '
            .items[]
            | {ns: .metadata.namespace, name: .metadata.name, type: .type}
            | [.ns, .name, .type]
            | @tsv' \
          | column -t

        echo
        echo "=== Count of secrets per namespace (excluding service-account tokens) ==="
        kubectl get secrets --all-namespaces -o json \
          | jq -r '
            .items[]
            | select(.type != "kubernetes.io/service-account-token")
            | .metadata.namespace' \
          | sort \
          | uniq -c \
          | sort -nr

        echo
        echo "=== Workloads that mount or reference native Kubernetes Secrets ==="
        echo "--- Pods (includes Deployments, StatefulSets, etc. via their Pods) ---"
        kubectl get pods --all-namespaces -o json \
          | jq -r '
            .items[]
            | {
                ns: .metadata.namespace,
                pod: .metadata.name,
                containers: ([.spec.containers[], (.spec.initContainers[]?)]),
                volumes: .spec.volumes
              }
            | {
                ns,
                pod,
                envSecrets: (
                  [ .containers[]
                    | .env[]? 
                    | select(.valueFrom.secretKeyRef?)
                    | .valueFrom.secretKeyRef.name
                  ] | unique
                ),
                envFromSecrets: (
                  [ .containers[]
                    | .envFrom[]?
                    | select(.secretRef?)
                    | .secretRef.name
                  ] | unique
                ),
                volumeSecrets: (
                  [ .volumes[]
                    | select(.secret?)
                    | .secret.secretName
                  ] | unique
                )
              }
            | select((.envSecrets + .envFromSecrets + .volumeSecrets) | length > 0)
            | [
                .ns,
                .pod,
                ( ( .envSecrets // [] ) | join(",") | if . == "" then "-" else . end ),
                ( ( .envFromSecrets // [] ) | join(",") | if . == "" then "-" else . end ),
                ( ( .volumeSecrets // [] ) | join(",") | if . == "" then "-" else . end )
              ]
            | @tsv' \
          | column -t \
          | sed '1iNAMESPACE  POD  ENV_SECRETREFS  ENVFROM_SECRETREFS  VOLUME_SECRETS'

        echo
        echo "=== ConfigMaps that embed data with names suggesting secrets/credentials ==="
        kubectl get configmaps --all-namespaces -o json \
          | jq -r '
            .items[]
            | {
                ns: .metadata.namespace,
                name: .metadata.name,
                keys: (.data | keys? // [])
              }
            | select(.keys | length > 0)
            | select(
                ([.keys[]]
                  | map( ascii_downcase
                         | test("password|passwd|pass|secret|token|apikey|api_key|key|cert|certificate")
                       )
                  | any
                )
              )
            | [.ns, .name, (.keys | join(","))]
            | @tsv' \
          | column -t \
          || echo "No suspicious ConfigMaps detected."

        echo
        echo "=== Namespaces with signs of external secret managers already in use ==="
        echo "--- Looking for common CRDs and controllers (external-secrets.io, secrets-store.csi.x-k8s.io, etc.) ---"

        echo "- CustomResourceDefinitions related to external secrets:"
        kubectl get crd 2>/dev/null | grep -E 'externalsecret|secrets-store|vault|onepassword' || \
          echo "  None of the common external-secret CRDs found."

        echo
        echo "- Pods in namespaces commonly used by external secret operators:"
        kubectl get pods -A \
          | grep -Ei 'external-secret|external.secrets|secrets-store|vault|hashicorp-vault|1password|onepassword' \
          || echo "  No obvious external secret controllers found."

        echo
        echo "=== SUMMARY: manual interpretation guidance ==="
        cat <<'EOF'
        Interpretation:

        1) High native secret usage
           - Many non-service-account Secrets (see "Count of secrets per namespace") and
             many workloads in the "Workloads that mount or reference native Kubernetes Secrets"
             section indicate heavy reliance on Kubernetes Secrets.
           - That is a SIGNAL to review whether these should instead come from an external
             secrets manager per CIS 5.4.2.

        2) Riskier patterns
           Treat the following as *higher concern* and candidates for externalization:
           - Namespaces with:
             - Large counts of Secrets holding long-lived app credentials (DB passwords,
               API keys, tokens, private keys).
           - Workloads where:
             - Secrets are mounted widely across many pods or namespaces.
             - The same sensitive Secret is reused across multiple apps.
           - ConfigMaps that appear to hold passwords/tokens (see the ConfigMap section);
             those should almost always be moved to a secrets manager.

        3) Signs external secret storage is already in use
           - If you see CRDs like "externalsecrets.external-secrets.io" or
             "secretproviderclasses.secrets-store.csi.x-k8s.io", or controllers such as
             external-secrets, secrets-store-csi-driver, or vault agents, your cluster
             may already be integrated with an external secrets system.
           - In that case, focus review on namespaces and workloads that still rely
             primarily on native Kubernetes Secrets.

        This script does NOT implement an automatic fix.
        Use the output to:
        - Identify high-value / high-risk secrets.
        - Decide which should move to an external secrets manager offered by your cloud
          provider or a third party, in line with CIS 5.4.2.
        EOF
        ```

        **What output indicates a problem (for review):**

        * Large counts of non-service-account Secrets in critical namespaces (e.g., `default`, app namespaces) suggest widespread storage of app credentials in native Secrets.
        * Many pods showing populated `ENV_SECRETREFS`, `ENVFROM_SECRETREFS`, or `VOLUME_SECRETS` columns mean extensive direct use of Kubernetes Secrets instead of an external manager.
        * ConfigMaps listed in the “ConfigMaps that embed data…” section likely contain secrets in plain text and are strong candidates for migration to an external secrets manager.
        * Absence of any external-secrets-related CRDs or controllers plus heavy native secret use suggests the cluster relies solely on native Secrets and should be evaluated for adoption of an external secrets manager.
      </Accordion>
    </AccordionGroup>
  </Tab>
</Tabs>