Zero trust Kubernetes

Kubernetes access without a kubeconfig

Octelium is a free and open source, self-hosted zero trust access platform. Its Kubernetes mode holds the kubeconfig, client certificate or bearer token, authorizes every API request on its verb, resource and namespace, and records what was called and by whom.

  • Free and open source
  • Designed for self-hosting
  • Works with ordinary kubectl

Every request from a human, a browser, a CLI, a workload or an AI agent is authenticated against your identity providers, authorized per request at the application layer by the Octelium Service in front of the resource, exported to your SIEM and observability stack whether it is allowed or denied, and only then routed to the upstream HTTP API, database, SSH server, Kubernetes cluster, LLM or MCP server.

Signing in once, then reaching Services with and without a client

  • A browser opens grafana.acme.com and is redirected to the Cluster sign-in page at acme.com/login.
  • jane signs in with a passkey verified by a biometric on the device, and the browser returns to the Grafana dashboard at grafana.acme.com with no client installed.
  • In a terminal, octelium connect -d opens the browser at acme.com/callback/success/approval, where the same browser session approves the login with one click.
  • ~ ❯ octelium connect -d
  • Please authenticate yourself using Octelium web Portal
  • Waiting for you to approve the login in your browser. Press Ctrl-C to cancel.
  • You are now authenticated as jane
  • Octelium has started running in detached mode.
  • ~ ❯ curl -s my-api/v1/users/42 | jq
  • {
  • "id": 42,
  • "name": "Jane Doe",
  • "email": "jane@acme.com"
  • }
  • ~ ❯ psql -h pg-prod -d shop
  • psql (17.4)
  • Type "help" for help.
  • shop=> SELECT * FROM orders LIMIT 3;
  • id | status | total
  • -----+---------+--------
  • 981 | paid | 129.00
  • 982 | shipped | 48.50
  • 983 | paid | 310.25
  • (3 rows)
  • shop=> \q
  • ~ ❯ ssh bastion
  • Welcome to Ubuntu 24.04.1 LTS (GNU/Linux 6.8.0-1021-aws x86_64)

Requests authorized one by one against CEL rules in the HTTP, LLM and Kubernetes modes

  • HTTP: the HTTP Service billing is configured as follows.
  • kind: Service
  • metadata:
  • name: billing
  • spec:
  • mode: HTTP
  • config:
  • authorization:
  • inlinePolicies:
  • - spec:
  • rules:
  • - effect: ALLOW
  • condition:
  • all:
  • of:
  • - match: '"finance" in ctx.user.spec.groups'
  • - match: ctx.request.http.method == "GET"
  • - match: ctx.request.http.path.startsWith("/invoices")
  • jane, a member of the finance Group, runs curl -i billing/invoices/42 and gets HTTP/1.1 200 OK Content-Type: application/json {"id":42,"status":"paid","total":1290}. The access log records ALLOWED GET /invoices/42 with POLICY_MATCH.
  • jane, a member of the finance Group, runs curl -i -X DELETE billing/invoices/42 and gets HTTP/1.1 403 Forbidden X-Octelium-Unauthorized: true Content-Length: 0. The access log records DENIED DELETE /invoices/42 with NO_POLICY_MATCH.
  • LLM: the LLM Service openai is configured as follows.
  • kind: Service
  • metadata:
  • name: openai
  • spec:
  • mode: LLM
  • config:
  • authorization:
  • inlinePolicies:
  • - spec:
  • rules:
  • - effect: ALLOW
  • condition:
  • any:
  • of:
  • - match: '"ai-admins" in ctx.user.spec.groups'
  • - all:
  • of:
  • - match: '"ai-agents" in ctx.user.spec.groups'
  • - match: ctx.request.llm.operation == "GENERATE"
  • - match: ctx.request.llm.model == "gpt-5-mini"
  • support-bot, a member of the ai-agents Group, runs curl openai/v1/responses --json '{"model":"gpt-5-mini","input":"Hello"}' and gets { "id": "resp_68e8e1f0c4d0", "object": "response", "created_at": 1791628935, "status": "completed", "model": "gpt-5-mini-2025-08-07",. The access log records ALLOWED RESPONSES gpt-5-mini with POLICY_MATCH.
  • support-bot, a member of the ai-agents Group, runs curl openai/v1/responses --json '{"model":"gpt-5","input":"Hello"}' and gets {"error":{"message":"Octelium: unauthorized request","type":"permission_error","param":null,"code":"octelium_unauthorized"}}. The access log records DENIED RESPONSES gpt-5 with NO_POLICY_MATCH.
  • Kubernetes: the KUBERNETES Service k8s-prod is configured as follows.
  • kind: Service
  • metadata:
  • name: k8s-prod
  • spec:
  • mode: KUBERNETES
  • config:
  • authorization:
  • inlinePolicies:
  • - spec:
  • rules:
  • - effect: ALLOW
  • condition:
  • all:
  • of:
  • - match: '"sre-agents" in ctx.user.spec.groups'
  • - match: ctx.request.kubernetes.verb in ["get", "list"]
  • - match: ctx.request.kubernetes.namespace == "production"
  • - not: ctx.request.kubernetes.resource == "secrets"
  • ops-agent, a member of the sre-agents Group, runs kubectl get configmaps -n production and gets NAME DATA AGE app-config 4 12d feature-flags 2 3d kube-root-ca.crt 1 12d. The access log records ALLOWED list configmaps · production with POLICY_MATCH.
  • ops-agent, a member of the sre-agents Group, runs kubectl get secrets -n production and gets Error from server (Forbidden): Octelium: Unauthorized request. The access log records DENIED list secrets · production with NO_POLICY_MATCH.

Upstream credentials injected per request by identity in the HTTP, SSH and PostgreSQL modes

  • HTTP: the HTTP Service stripe proxies https://api.stripe.com and picks the upstream credential of every request with dynamic configuration rules.
  • elena, a member of the finance-eu Group, runs curl -s stripe/v1/account | jq '{id, country}' without holding any credential. The rule "finance-eu" in ctx.user.spec.groups selects the eu config, so Octelium injects the Secret stripe-eu and the upstream authenticates the request as acct_1Pq8EuGmbH2bXvK3. The terminal shows { "id": "acct_1Pq8EuGmbH2bXvK3", "country": "DE" }
  • pay-agent, a member of the finance-us Group, runs curl -s stripe/v1/account | jq '{id, country}' without holding any credential. The rule "finance-us" in ctx.user.spec.groups selects the us config, so Octelium injects the Secret stripe-us and the upstream authenticates the request as acct_1Nf2UsQ7cLm4RtW9. The terminal shows { "id": "acct_1Nf2UsQ7cLm4RtW9", "country": "US" }
  • SSH: the SSH Service web-01 proxies ssh://10.0.4.21 and picks the upstream credential of every request with dynamic configuration rules.
  • sam, a member of the sre Group, runs ssh web-01 without holding any credential. The rule "sre" in ctx.user.spec.groups selects the root config, so Octelium injects the Secret root-key and the upstream authenticates the request as root. The terminal shows Welcome to Ubuntu 24.04.3 LTS (GNU/Linux 6.14.0-1015-aws x86_64) root@web-01:~# id uid=0(root) gid=0(root) groups=0(root)
  • noah, a member of the developers Group, runs ssh web-01 without holding any credential. The rule "developers" in ctx.user.spec.groups selects the deploy config, so Octelium injects the Secret deploy-key and the upstream authenticates the request as deploy. The terminal shows Welcome to Ubuntu 24.04.3 LTS (GNU/Linux 6.14.0-1015-aws x86_64) deploy@web-01:~$ id uid=1001(deploy) gid=1001(deploy) groups=1001(deploy)
  • PostgreSQL: the POSTGRES Service orders-db proxies postgres://10.0.2.8:5432 and picks the upstream credential of every request with dynamic configuration rules.
  • priya, a member of the backend Group, runs psql -h orders-db orders without holding any credential. The rule "backend" in ctx.user.spec.groups selects the rw config, so Octelium injects the Secret pg-rw and the upstream authenticates the request as app_rw. The terminal shows psql (17.2) Type "help" for help. orders=> UPDATE orders SET status = 'shipped' WHERE id = 42; UPDATE 1
  • bi-agent, a member of the analytics Group, runs psql -h orders-db orders without holding any credential. The rule "analytics" in ctx.user.spec.groups selects the ro config, so Octelium injects the Secret pg-ro and the upstream authenticates the request as app_ro. The terminal shows psql (17.2) Type "help" for help. orders=> UPDATE orders SET status = 'shipped' WHERE id = 42; ERROR: permission denied for table orders

Signing in with a passkey and opening the Portal

  • The sign-in page of the Cluster at acme.com/login offers login with Okta, with GitHub, or with a passkey.
  • jane@acme.com chooses Login with a Passkey and verifies it with a biometric on the device through native WebAuthn.
  • The browser is redirected to the Portal at portal.acme.com/services, which lists the Services the User can access:
  • grafana.monitoring: Grafana dashboards, Web App, Namespace monitoring.
  • aws-postgres.production: Amazon RDS for PostgreSQL, PostgreSQL, Namespace production.
  • k8s-prod: Production EKS cluster, Kubernetes, Namespace default.
  • bastion.production: SSH bastion host, SSH, Namespace production.
  • github-mcp: GitHub MCP server, MCP, Namespace default.
  • openai: OpenAI API, AI / LLM, Namespace default.
Visibility and auditing

Every API call, with the identity that made it

Every request produces an AccessLog identifying the User, Session and Device alongside the Kubernetes detail of the request itself, emitted in real time to your OpenTelemetry OTLP receivers.

Read about visibility and auditing
AccessLogOTLP
ALLOWlinus@acme.compg-prod.dbPOSTGRESquery: select id, email from users limit 50
ALLOWci-runnerprod-k8sKUBERNETESverb=list resource=pods namespace=production
DENYagent-07tools-mcpMCPtools/call name=transfer policy=mcp-tools
ALLOWjane@acme.combastionSSHsession recorded, upstream user=deploy
ALLOWagent-07openaiLLMCHAT_COMPLETIONS model=gpt-5-mini tokens=1284
Deployment and scale

Self-hosted, Kubernetes-native and fully programmable

Run the Cluster on Kubernetes infrastructure you control, scale the data plane horizontally, manage resources declaratively, automate the platform through APIs and SDKs, and optionally deploy containerized Service upstreams with the Cluster itself.

Read the management guide

Cluster resources applied declaratively from YAML with octeliumctl and managed programmatically with the Go, TypeScript, Python and Rust SDKs

  • GitOps: cluster.yaml in the main branch of the ~/octelium repository describes the desired state of the Cluster. Its diff reads as follows, with + for added, ~ for changed and - for removed lines.
  • + kind: Group
  • + metadata:
  • + name: payments
  • + spec: {}
  • + ---
  • + kind: User
  • + metadata:
  • + name: alice
  • + spec:
  • + type: HUMAN
  • + email: alice@acme.com
  • + groups: ["payments"]
  • ---
  • kind: User
  • metadata:
  • name: bob
  • spec:
  • type: HUMAN
  • ~ groups: ["payments"]
  • ---
  • kind: Service
  • metadata:
  • name: billing
  • spec:
  • mode: HTTP
  • config:
  • upstream:
  • ~ url: http://10.0.3.24:8080
  • - ---
  • - kind: Service
  • - metadata:
  • - name: billing-legacy
  • - spec: ⋯
  • - ---
  • - kind: User
  • - metadata:
  • - name: john
  • - spec: ⋯
  • ~/octelium ❯ octeliumctl apply --prune .
  • Group: payments Created
  • User: alice Created
  • User: bob Updated
  • Service: billing.default Updated
  • Service: billing-legacy.default Deleted
  • User: john Deleted
  • Cluster Core resources successfully applied
  • 2 resources created
  • 2 resources updated
  • 2 resources deleted
  • Go: main.go uses the octelium-go SDK to list the Users of the Cluster and update the email and Policies of linus.
  • client, err := octelium.New(ctx)
  • if err != nil {⋯}
  • conn, err := client.Conn(ctx)
  • if err != nil {⋯}
  • api := corev1.NewMainServiceClient(conn)
  • users, err := api.ListUser(ctx, &corev1.ListUserOptions{})
  • if err != nil {⋯}
  • for _, u := range users.Items {
  • fmt.Println(u.Metadata.Name)
  • }
  • user, err := api.GetUser(ctx, &metav1.GetOptions{Name: "linus"})
  • if err != nil {⋯}
  • user.Spec.Email = "linus@acme.com"
  • user.Spec.Authorization = &corev1.User_Spec_Authorization{
  • Policies: []string{"db-readonly"},
  • }
  • if _, err := api.UpdateUser(ctx, user); err != nil {⋯}
  • fmt.Println("updated", user.Metadata.Name)
  • ~/app ❯ go run .
  • alice
  • bob
  • linus
  • updated linus
  • TypeScript: main.ts uses the @octelium/sdk SDK to list the Users of the Cluster and update the email and Policies of linus.
  • const client = await OcteliumClient.create({
  • domain: "acme.com",
  • auth: {⋯},
  • });
  • const users = await client.coreV1.listUser(ListUserOptions.create());
  • for (const u of users.response.items) {
  • console.log(u.metadata?.name);
  • }
  • const { response: user } = await client.coreV1.getUser(
  • GetOptions.create({ name: "linus" }),
  • );
  • user.spec!.email = "linus@acme.com";
  • user.spec!.authorization = User_Spec_Authorization.create({
  • policies: ["db-readonly"],
  • });
  • await client.coreV1.updateUser(user);
  • console.log("updated", user.metadata?.name);
  • await client.close();
  • ~/app ❯ npx tsx main.ts
  • alice
  • bob
  • linus
  • updated linus
  • Python: main.py uses the octelium-sdk SDK to list the Users of the Cluster and update the email and Policies of linus.
  • async with await OcteliumClient.create() as client:
  • users = await client.core_v1.list_user(ListUserOptions())
  • for u in users.items:
  • print(u.metadata.name)
  • user = await client.core_v1.get_user(GetOptions(name="linus"))
  • user.spec.email = "linus@acme.com"
  • user.spec.authorization.policies = ["db-readonly"]
  • await client.core_v1.update_user(user)
  • print("updated", user.metadata.name)
  • ~/app ❯ python main.py
  • alice
  • bob
  • linus
  • updated linus
  • Rust: main.rs uses the octelium SDK to list the Users of the Cluster and update the email and Policies of linus.
  • let client = Client::from_env().await?;
  • let mut api = client.core_v1();
  • let users = api.list_user(ListUserOptions::default()).await?;
  • for u in users.into_inner().items {
  • println!("{}", u.metadata.unwrap_or_default().name);
  • }
  • let options = GetOptions {
  • name: "linus".into(),
  • ..Default::default()
  • };
  • let mut user = api.get_user(options).await?.into_inner();
  • let spec = user.spec.get_or_insert_default();
  • spec.email = "linus@acme.com".into();
  • spec.authorization.get_or_insert_default().policies = vec!["db-readonly".into()];
  • let user = api.update_user(user).await?.into_inner();
  • println!("updated {}", user.metadata.unwrap_or_default().name);
  • ~/app ❯ cargo run -q
  • alice
  • bob
  • linus
  • updated linus
The request

What a Kubernetes API request carries, and what checks it

A kubectl call is not one decision. These are the parts of a request that matter for access control and auditing, next to the mechanism in an Octelium Cluster that handles each one.

  1. 01

    Who is making the call

    The request carries an Octelium identity rather than a kubeconfig. People authenticate through your OpenID Connect or SAML 2.0 identity provider, and workloads through OAuth2 client credentials, access tokens or federated OIDC assertions.

    Read more
  2. 02

    The verb

    get, list, watch, create, update, patch and delete are normalized into the request context, so read access and write access to the same resource are separate decisions rather than one role binding.

    Read more
  3. 03

    The resource and its API group

    The resource, API group and API version are each available, so a policy can allow pods and services while leaving custom resources or cluster-scoped objects untouched.

    Read more
  4. 04

    The namespace

    The namespace is a normalized field, so the same Service can allow one group everything in staging and only reads in production, without maintaining parallel RBAC in each cluster.

    Read more
  5. 05

    The object and subresource

    The object name and subresource are available too, which is what makes rules such as reading pod logs without reading pod specs, or reading a status without patching it, expressible.

    Read more
  6. 06

    The underlying HTTP request

    Kubernetes is an HTTP API, and the full HTTP request is exposed alongside the normalized fields, including headers and paths, for the cases the normalized view does not cover.

    Read more
  7. 07

    The credential used upstream

    A kubeconfig, a client certificate or a bearer token is held as a Secret and used to authenticate to the API server after authorization. Which one is used can itself be selected per request from identity and context.

    Read more
  8. 08

    What ends up in the audit trail

    Each request produces an identity-aware AccessLog with the verb, resource, namespace, API version and the User behind it, streamed in real time over OpenTelemetry to your own log management and SIEM providers.

    Read more

RBAC still decides what the credential the Cluster holds may do. What changes is that nobody carries that credential, and the decision about who may use it is made per request against an identity you already manage.

Questions

Frequently asked

Does this replace Kubernetes RBAC?
No. RBAC still governs what the credential held by the Cluster is allowed to do inside the cluster. What changes is who holds that credential and how each request is decided: the kubeconfig, client certificate or bearer token stays in the Cluster, and every API call is authorized per request against an identity you already manage, before it reaches the API server.
How do people use kubectl?
With their ordinary kubectl. The Service is reached at a stable private name over the client-based tunnel, and the identity-aware proxy authenticates to the API server on the User's behalf. Nobody is issued a kubeconfig, a client certificate or a service account token of their own.
Which upstream credentials are supported?
Three. A kubeconfig stored as a Secret, optionally pinned to a specific context when the file contains several; a client certificate with its private key and trusted CAs; or a bearer token with trusted CAs. All three are referenced by Secret name from the Service definition.
Can workloads reach the API without a client?
Yes. A KUBERNETES Service can be published clientlessly, so an application authenticates with the standard OAuth2 client credentials flow or a bearer access token and calls the API over ordinary HTTPS, without a kubeconfig, a client or a proprietary SDK.
Does it work across several clusters?
Yes. Each cluster is its own Service with its own upstream credential and its own Policies, and a cluster in a network the Octelium Cluster cannot reach directly can be served from the side of a connected host inside that network with no inbound port. People reach all of them through the same single route and the same identity.
Do I need Kubernetes experience to run Octelium itself?
No. An Octelium Cluster runs on top of Kubernetes, but you do not need Kubernetes experience to install, operate or use it. The quick installer provisions a complete single-node Cluster, including Kubernetes itself, on one fresh Linux VM with 2 vCPUs, 2 GB of RAM and a domain you own.
Get started

Run Octelium on your own infrastructure

Install a self-hosted Cluster and start applying identity-aware access control to your Services.