---
stage: Configure
group: Configure
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
---

# Serverless (DEPRECATED) **(FREE)**

> - Introduced in GitLab 11.5.
> - [Deprecated](https://gitlab.com/groups/gitlab-org/configure/-/epics/6) in GitLab 14.3.

WARNING:
Serverless is currently in [alpha](https://about.gitlab.com/handbook/product/gitlab-the-product/#alpha).

## Overview

Serverless architectures offer Operators and Developers the ability write highly scalable applications without provisioning a single server.

GitLab supports several ways deploy Serverless applications in both Kubernetes Environments and also major cloud Function as a Service (FaaS) environments.

Currently we support:

- [Knative](#knative): Build Knative applications with Knative and `gitlabktl` on GKE and EKS.
- [AWS Lambda](aws.md): Create serverless applications via the Serverless Framework and GitLab CI/CD.

## Knative

Run serverless workloads on Kubernetes using [Knative](https://cloud.google.com/knative/).

Knative extends Kubernetes to provide a set of middleware components that are useful to build
modern, source-centric, container-based applications. Knative brings some significant benefits out
of the box through its main components:

- [Serving](https://github.com/knative/serving): Request-driven compute that can scale to zero.
- [Eventing](https://github.com/knative/eventing): Management and delivery of events.

For more information on Knative, visit the [Knative docs repository](https://github.com/knative/docs).

With GitLab Serverless, you can deploy both FaaS and serverless applications.

## Prerequisites

To run Knative on GitLab, you need:

1. **Existing GitLab project:** You need a GitLab project to associate all resources. The simplest way to get started:
   - If you are planning on [deploying functions](#deploying-functions),
     clone the [functions example project](https://gitlab.com/knative-examples/functions) to get
     started.
   - If you are planning on [deploying a serverless application](#deploying-serverless-applications),
     clone the sample [Knative Ruby App](https://gitlab.com/knative-examples/knative-ruby-app) to get
     started.
1. **Kubernetes Cluster:** An RBAC-enabled Kubernetes cluster is required to deploy Knative.
   The simplest way to get started is to add a cluster using the GitLab [GKE integration](../add_remove_clusters.md).
   The set of minimum recommended cluster specifications to run Knative is 3 nodes, 6 vCPUs, and 22.50 GB memory.
1. **GitLab Runner:** A runner is required to run the CI jobs that deploy serverless
   applications or functions onto your cluster. You can install GitLab Runner
   onto the [existing Kubernetes cluster](https://docs.gitlab.com/runner/install/kubernetes.html).
1. **Domain Name:** Knative provides its own load balancer using Istio, and an
   external IP address or hostname for all the applications served by Knative. Enter a
   wildcard domain to serve your applications. Configure your DNS server to use the
   external IP address or hostname for that domain.
1. **`.gitlab-ci.yml`:** GitLab uses [Kaniko](https://github.com/GoogleContainerTools/kaniko)
   to build the application. We also use [GitLab Knative tool](https://gitlab.com/gitlab-org/gitlabktl)
   CLI to simplify the deployment of services and functions to Knative.
1. **`serverless.yml`** (for [functions only](#deploying-functions)): When using serverless to deploy functions, the `serverless.yml` file
   contains the information for all the functions being hosted in the repository as well as a reference
   to the runtime being used.
1. **`Dockerfile`** (for [applications only](#deploying-serverless-applications)): Knative requires a
   `Dockerfile` in order to build your applications. It should be included at the root of your
   project's repository and expose port `8080`. `Dockerfile` is not require if you plan to build serverless functions
   using our [runtimes](https://gitlab.com/gitlab-org/serverless/runtimes).
1. **Prometheus** (optional): The [Prometheus cluster integration](../../../clusters/integrations.md#prometheus-cluster-integration)
   allows you to monitor the scale and traffic of your serverless function/application.
1. **Logging** (optional): Configuring logging allows you to view and search request logs for your serverless function/application.
   See [Configuring logging](#configuring-logging) for more information.

## Configuring Knative

> [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/58941) in GitLab 12.0.

1. Follow the steps to
   [add a Kubernetes
   cluster](../add_remove_clusters.md).

1. Ensure GitLab can manage Knative:
   - For a non-GitLab managed cluster, ensure that the service account for the token
     provided can manage resources in the `serving.knative.dev` API group.
   - For a GitLab managed cluster, if you added the cluster in [GitLab 12.1 or later](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/30235),
     then GitLab already has the required access and you can proceed to the next step.

     Otherwise, you need to manually grant the GitLab service account the ability to manage
     resources in the `serving.knative.dev` API group. Since every GitLab service account
     has the `edit` cluster role, the simplest way to do this is with an
     [aggregated ClusterRole](https://kubernetes.io/docs/reference/access-authn-authz/rbac/#aggregated-clusterroles)
     adding rules to the default `edit` cluster role: First, save the following YAML as
     `knative-serving-only-role.yaml`:

     ```yaml
     apiVersion: rbac.authorization.k8s.io/v1
     kind: ClusterRole
     metadata:
       name: knative-serving-only-role
       labels:
         rbac.authorization.k8s.io/aggregate-to-edit: "true"
     rules:
       - apiGroups:
           - serving.knative.dev
         resources:
           - configurations
           - configurationgenerations
           - routes
           - revisions
           - revisionuids
           - autoscalers
           - services
         verbs:
           - get
           - list
           - create
           - update
           - delete
           - patch
           - watch
     ```

     Then run the following command:

     ```shell
     kubectl apply -f knative-serving-only-role.yaml
     ```

     Alternatively, permissions can be granted on a per-service account basis
     using `Role`s and `RoleBinding`s (see the [Kubernetes RBAC
     documentation](https://kubernetes.io/docs/reference/access-authn-authz/rbac/)
     for more information).

1. Follow the steps to deploy [functions](#deploying-functions)
   or [serverless applications](#deploying-serverless-applications) onto your
   cluster.

1. **Optional:** For invocation metrics to show in GitLab, additional Istio metrics need to be configured in your cluster. For example, with Knative v0.9.0, you can use [this manifest](https://gitlab.com/gitlab-org/charts/knative/-/raw/v0.10.0/vendor/istio-metrics.yml).

## Supported runtimes

Serverless functions for GitLab can be run using:

- [GitLab-managed](#gitlab-managed-runtimes) runtimes.
- [OpenFaaS](#openfaas-runtimes) runtimes.

If a runtime is not available for the required programming language, consider deploying a
[serverless application](#deploying-serverless-applications).

### GitLab-managed runtimes

The following GitLab-managed [runtimes](https://gitlab.com/gitlab-org/serverless/runtimes)
are available:

- `go` (proof of concept)
- `nodejs`
- `ruby`

You must provide a `Dockerfile` to run serverless functions if no runtime is specified.

### OpenFaaS runtimes

> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/29253) in GitLab 12.5.

[OpenFaaS classic runtimes](https://github.com/openfaas/templates#templates-in-store) can be used with GitLab serverless.

OpenFaas runtimes are available for the following languages:

- C#
- Go
- NodeJS
- PHP
- Python
- Ruby

Runtimes are specified using the pattern: `openfaas/classic/<template_name>`. The following
example shows how to define a function in `serverless.yml` using an OpenFaaS runtime:

```yaml
hello:
  source: ./hello
  runtime: openfaas/classic/ruby
  description: "Ruby function using OpenFaaS classic runtime"
```

`handler` is not needed for OpenFaaS functions. The location of the handler is defined
by the conventions of the runtime.

See the [`ruby-openfaas-function`](https://gitlab.com/knative-examples/ruby-openfaas-function)
project for an example of a function using an OpenFaaS runtime.

## Deploying functions

> Introduced in GitLab 11.6.

You can find and import all the files referenced in this doc in the
**[functions example project](https://gitlab.com/knative-examples/functions)**.

Follow these steps to deploy a function using the Node.js runtime to your
Knative instance (you can skip these steps if you've cloned the example
project):

1. Create a directory to house the function. In this example we will
   create a directory called `echo` at the root of the project.

1. Create the file to contain the function code. In this example, our file is called `echo.js` and is located inside the `echo` directory. If your project is:
   - Public, continue to the next step.
   - Private, you must [create a GitLab deploy token](../../deploy_tokens/index.md#creating-a-deploy-token) with `gitlab-deploy-token` as the name and the `read_registry` scope.

1. `.gitlab-ci.yml`: this defines a pipeline used to deploy your functions.
   It must be included at the root of your repository:

   ```yaml
   include:
     - template: Serverless.gitlab-ci.yml

   functions:build:
     extends: .serverless:build:functions
     environment: production

   functions:deploy:
     extends: .serverless:deploy:functions
     environment: production
   ```

   This `.gitlab-ci.yml` creates jobs that invoke some predefined commands to
   build and deploy your functions to your cluster.

   `Serverless.gitlab-ci.yml` is a template that allows customization.
   You can either import it with `include` parameter and use `extends` to
   customize your jobs, or you can inline the entire template by choosing it
   from **Apply a template** dropdown when editing the `.gitlab-ci.yml` file through
   the user interface.

1. `serverless.yml`: this file contains the metadata for your functions,
   such as name, runtime, and environment.

   It must be included at the root of your repository.
   The following is a sample `echo` function which shows the required structure
   for the file.

   You can find the relevant files for this project in the [functions example project](https://gitlab.com/knative-examples/functions).

   ```yaml
   service: functions
   description: "GitLab Serverless functions using Knative"

   provider:
     name: triggermesh
     envs:
       FOO: value
     secrets:
       - my-secrets

   functions:
     echo-js:
       handler: echo-js
       source: ./echo-js
       runtime: gitlab/runtimes/nodejs
       description: "node.js runtime function"
       envs:
         MY_FUNCTION: echo-js
       secrets:
         - my-secrets
   ```

Explanation of the fields used above:

### `service`

| Parameter | Description |
|-----------|-------------|
| `service` | Name for the Knative service which serves the function. |
| `description` | A short description of the `service`. |

### `provider`

| Parameter | Description |
|-----------|-------------|
| `name` | Indicates which provider is used to execute the `serverless.yml` file. In this case, the TriggerMesh middleware. |
| `envs` | Includes the environment variables to be passed as part of function execution for **all** functions in the file, where `FOO` is the variable name and `BAR` are the variable contents. You may replace this with your own variables. |
| `secrets` | Includes the contents of the Kubernetes secret as environment variables accessible to be passed as part of function execution for **all** functions in the file. The secrets are expected in `INI` format. |

### `functions`

In the `serverless.yml` example above, the function name is `echo` and the
subsequent lines contain the function attributes.

| Parameter | Description |
|-----------|-------------|
| `handler` | The function's name. |
| `source` | Directory with sources of a functions. |
| `runtime` (optional)| The runtime to be used to execute the function. This can be a runtime alias (see [Runtime aliases](#runtime-aliases)), or it can be a full URL to a custom runtime repository. When the runtime is not specified, we assume that `Dockerfile` is present in the function directory specified by `source`. |
| `description` | A short description of the function. |
| `envs` | Sets an environment variable for the specific function only. |
| `secrets` | Includes the contents of the Kubernetes secret as environment variables accessible to be passed as part of function execution for the specific function only. The secrets are expected in `INI` format. |

### Deployment

#### Runtime aliases

The optional `runtime` parameter can refer to one of the following runtime aliases (also see [Supported runtimes](#supported-runtimes)):

| Runtime alias | Maintained by |
|-------------|---------------|
| `gitlab/runtimes/go` | GitLab |
| `gitlab/runtimes/nodejs` | GitLab |
| `gitlab/runtimes/ruby` | GitLab |
| `openfaas/classic/csharp` | OpenFaaS |
| `openfaas/classic/go` | OpenFaaS |
| `openfaas/classic/node` | OpenFaaS |
| `openfaas/classic/php7` | OpenFaaS |
| `openfaas/classic/python` | OpenFaaS |
| `openfaas/classic/python3` | OpenFaaS |
| `openfaas/classic/ruby` | OpenFaaS |

After the `.gitlab-ci.yml` template has been added and the `serverless.yml` file
has been created, pushing a commit to your project results in a CI pipeline
being executed which deploys each function as a Knative service. After the
deploy stage has finished, additional details for the function display
under **Infrastructure > Serverless platform**.

![serverless page](img/serverless-page_v14_0.png)

This page contains all functions available for the project, the description for
accessing the function, and, if available, the function's runtime information.
The details are derived from the Knative installation inside each of the project's
Kubernetes cluster. Click on each function to obtain detailed scale and invocation data.

The function details can be retrieved directly from Knative on the cluster:

```shell
kubectl -n "$KUBE_NAMESPACE" get services.serving.knative.dev
```

The sample function can now be triggered from any HTTP client using a simple `POST` call:

  1. Using curl (replace the URL on the last line with the URL of your application):

     ```shell
     curl \
     --header "Content-Type: application/json" \
     --request POST \
     --data '{"GitLab":"FaaS"}' \
     "http://functions-echo.functions-1.functions.example.com/"
     ```

  1. Using a web-based tool (such as Postman or Restlet)

     ![function execution](img/function-execution.png)

### Secrets

To access your Kubernetes secrets from within your function, the secrets should be created under the namespace of your serverless deployment and specified in your `serverless.yml` file as above.
You can create secrets in several ways. The following sections show some examples.

#### CLI example

```shell
kubectl create secret generic my-secrets -n "$KUBE_NAMESPACE" --from-literal MY_SECRET=imverysecure
```

#### Part of deployment job

You can extend your `.gitlab-ci.yml` to create the secrets during deployment using the [CI/CD variables](../../../../ci/variables/index.md)
stored securely under your GitLab project.

```yaml
deploy:function:
  stage: deploy
  environment: production
  extends: .serverless:deploy:functions
  before_script:
    - kubectl create secret generic my-secret
        --from-literal MY_SECRET="$GITLAB_SECRET_VARIABLE"
        --namespace "$KUBE_NAMESPACE"
        --dry-run -o yaml | kubectl apply -f -
```

### Running functions locally

Running a function locally is a good way to quickly verify behavior during development.

Running functions locally requires:

- Go 1.12 or newer installed.
- Docker Engine installed and running.
- `gitlabktl` installed using the Go package manager:

  ```shell
  GO111MODULE=on go get gitlab.com/gitlab-org/gitlabktl
  ```

To run a function locally:

1. Navigate to the root of your GitLab serverless project.
1. Build your function into a Docker image:

   ```shell
   gitlabktl serverless build
   ```

1. Run your function in Docker:

   ```shell
   docker run -itp 8080:8080 <your_function_name>
   ```

1. Invoke your function:

   ```shell
   curl "http://localhost:8080"
   ```

## Deploying Serverless applications

> Introduced in GitLab 11.5.

Serverless applications are an alternative to [serverless functions](#deploying-functions).
They're useful in scenarios where an existing runtime does not meet the needs of
an application, such as one written in a language that has no runtime available.
Note though that serverless applications should be stateless.

You can reference and import the sample [Knative Ruby App](https://gitlab.com/knative-examples/knative-ruby-app)
to get started. Add the following `.gitlab-ci.yml` to the root of your repository
(you may skip this step if you've previously cloned the previously mentioned,
sample [Knative Ruby App](https://gitlab.com/knative-examples/knative-ruby-app)):

```yaml
include:
  - template: Serverless.gitlab-ci.yml

build:
  extends: .serverless:build:image

deploy:
  extends: .serverless:deploy:image
```

`Serverless.gitlab-ci.yml` is a template that allows customization.
You can either import it with `include` parameter and use `extends` to
customize your jobs, or you can inline the entire template by choosing it
from **Apply a template** dropdown when editing the `.gitlab-ci.yml` file through
the user interface.

A `serverless.yml` file is not required when deploying serverless applications.

### Deploy the application with Knative

With all the pieces in place, the next time a CI pipeline runs the Knative application deploys. Navigate to
**CI/CD > Pipelines** and click the most recent pipeline.

### Function details

Go to the **Infrastructure > Serverless platform** page to see the final URL of your functions.

![function_details](img/function-list_v12_7.png)

### Invocation metrics

On the same page as above, click on one of the function
rows to bring up the function details page.

![function_details](img/function-details-loaded_v14_0.png)

The pod count gives you the number of pods running the serverless function instances on a given cluster.

For the Knative function invocations to appear, the
[Prometheus cluster integration must be enabled](../../../clusters/integrations.md#prometheus-cluster-integration).

Once Prometheus is enabled, a message may appear indicating that the metrics data _is
loading or is not available at this time._  It appears upon the first access of the
page, but should go away after a few seconds. If the message does not disappear, then it
is possible that GitLab is unable to connect to the Prometheus instance running on the
cluster.

## Configuring logging

> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/33330) in GitLab 12.5.

### Prerequisites

- A GitLab-managed cluster.
- `kubectl` installed and working.

Running `kubectl` commands on your cluster requires setting up access to the
cluster first. For clusters created on:

- GKE, see [GKE Cluster Access](https://cloud.google.com/kubernetes-engine/docs/how-to/cluster-access-for-kubectl)
- Other platforms, see [Install and Set Up kubectl](https://kubernetes.io/docs/tasks/tools/).

### Enable request log template

Run the following command to enable request logs:

```shell
kubectl edit cm -n knative-serving config-observability
```

Copy the `logging.request-log-template` from the `data._example` field to the data field one level up in the hierarchy.

### Enable request logs

Run the following commands to install Elasticsearch, Kibana, and Filebeat into a `kube-logging` namespace and configure all nodes to forward logs using Filebeat:

```shell
kubectl apply -f https://gitlab.com/gitlab-org/serverless/configurations/knative/raw/v0.7.0/kube-logging-filebeat.yaml
kubectl label nodes --all beta.kubernetes.io/filebeat-ready="true"
```

### Viewing request logs

To view request logs:

1. Run `kubectl proxy`.
1. Navigate to [Kibana UI](http://localhost:8001/api/v1/namespaces/kube-logging/services/kibana/proxy/app/kibana).

Or:

1. Open the [Kibana UI](http://localhost:8001/api/v1/namespaces/kube-logging/services/kibana/proxy/app/kibana).
1. Click on **Discover**, then select `filebeat-*` from the dropdown on the left.
1. Enter `kubernetes.container.name:"queue-proxy" AND message:/httpRequest/` into the search box.

## Enabling TLS for Knative services

By default, a GitLab serverless deployment is served over `http`. To serve
over `https`, you must manually obtain and install TLS certificates.

The simplest way to accomplish this is to use Certbot to
[manually obtain Let's Encrypt certificates](https://knative.dev/docs/serving/using-a-tls-cert/#using-certbot-to-manually-obtain-let-s-encrypt-certificates).
Certbot is a free, open source software tool for automatically using Let's Encrypt
certificates on manually-administered websites to enable HTTPS.

The following instructions relate to installing and running Certbot on a Linux
server that has Python 3 installed, and may not work on other operating systems
or with other versions of Python.

1. Install Certbot by running the
   [`certbot-auto` wrapper script](https://certbot.eff.org/docs/install.html#certbot-auto).
   On the command line of your server, run the following commands:

   ```shell
   wget https://dl.eff.org/certbot-auto
   sudo mv certbot-auto /usr/local/bin/certbot-auto
   sudo chown root /usr/local/bin/certbot-auto
   sudo chmod 0755 /usr/local/bin/certbot-auto
   /usr/local/bin/certbot-auto --help
   ```

   To check the integrity of the `certbot-auto` script, run:

   ```shell
   wget -N https://dl.eff.org/certbot-auto.asc
   gpg2 --keyserver ipv4.pool.sks-keyservers.net --recv-key A2CFB51FA275A7286234E7B24D17C995CD9775F2
   gpg2 --trusted-key 4D17C995CD9775F2 --verify certbot-auto.asc /usr/local/bin/certbot-auto
   ```

   The output of the last command should look something like:

   ```shell
   gpg: Signature made Mon 10 Jun 2019 06:24:40 PM EDT
   gpg:                using RSA key A2CFB51FA275A7286234E7B24D17C995CD9775F2
   gpg: key 4D17C995CD9775F2 marked as ultimately trusted
   gpg: checking the trustdb
   gpg: marginals needed: 3  completes needed: 1  trust model: pgp
   gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
   gpg: next trustdb check due at 2027-11-22
   gpg: Good signature from "Let's Encrypt Client Team <letsencrypt-client@eff.org>" [ultimate]
   ```

1. Run the following command to use Certbot to request a certificate
   using DNS challenge during authorization:

   ```shell
   /usr/local/bin/certbot-auto certonly --manual --preferred-challenges dns -d '*.<namespace>.example.com'
   ```

   Where `<namespace>` is the namespace created by GitLab for your serverless project (composed of `<project_name>-<project_id>-<environment>`) and
   `example.com` is the domain being used for your project. If you are unsure what the namespace of your project is, navigate
   to the **Infrastructure > Serverless platform** page of your project and inspect
   the endpoint provided for your function/app.

   ![function_endpoint](img/function-endpoint.png)

   In the above image, the namespace for the project is `node-function-11909507` and the domain is `knative.info`, thus
   certificate request line would look like this:

   ```shell
   ./certbot-auto certonly --manual --preferred-challenges dns -d '*.node-function-11909507.knative.info'
   ```

   The Certbot tool walks you through the steps of validating that you own each domain that you specify by creating TXT records in those domains.
   After this process is complete, the output should look something like this:

   ```shell
   IMPORTANT NOTES:
   - Congratulations! Your certificate and chain have been saved at:
     /etc/letsencrypt/live/namespace.example.com/fullchain.pem
     Your key file has been saved at:
     /etc/letsencrypt/live/namespace.example/privkey.pem
     Your cert will expire on 2019-09-19. To obtain a new or tweaked
     version of this certificate in the future, simply run certbot-auto
     again. To non-interactively renew *all* of your certificates, run
     "certbot-auto renew"
   -----BEGIN PRIVATE KEY-----
   - Your account credentials have been saved in your Certbot
     configuration directory at /etc/letsencrypt. You should make a
     secure backup of this folder now. This configuration directory will
     also contain certificates and private keys obtained by Certbot so
     making regular backups of this folder is ideal.
   ```

1. Create certificate and private key files. Using the contents of the files
   returned by Certbot, create two files in order to create the
   Kubernetes secret:

   Run the following command to see the contents of `fullchain.pem`:

   ```shell
   sudo cat /etc/letsencrypt/live/node-function-11909507.knative.info/fullchain.pem
   ```

   Output should look like this:

   ```shell
   -----BEGIN CERTIFICATE-----
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b4ag==
   -----END CERTIFICATE-----
   -----BEGIN CERTIFICATE-----
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   K2fcb195768c39e9a94cec2c2e30Qg==
   -----END CERTIFICATE-----
   ```

   Create a file with the name `cert.pem` with the contents of the entire output.

   Once `cert.pem` is created, run the following command to see the contents of `privkey.pem`:

   ```shell
   sudo cat /etc/letsencrypt/live/namespace.example/privkey.pem
   ```

   Output should look like this:

   ```shell
   -----BEGIN PRIVATE KEY-----
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
   -----BEGIN CERTIFICATE-----
   fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
   4f294d1eaca42b8692017b4262==
   -----END PRIVATE KEY-----
   ```

   Create a new file with the name `cert.pk` with the contents of the entire output.

1. Create a Kubernetes secret to hold your TLS certificate, `cert.pem`, and
   the private key `cert.pk`:

   NOTE:
   Running `kubectl` commands on your cluster requires setting up access to the cluster first.
   For clusters created on GKE, see
   [GKE Cluster Access](https://cloud.google.com/kubernetes-engine/docs/how-to/cluster-access-for-kubectl).
   For other platforms, [install `kubectl`](https://kubernetes.io/docs/tasks/tools/).

   ```shell
   kubectl create --namespace istio-system secret tls istio-ingressgateway-certs \
   --key cert.pk \
   --cert cert.pem
   ```

   Where `cert.pem` and `cert.pk` are your certificate and private key files. Note that the `istio-ingressgateway-certs` secret name is required.

1. Configure Knative to use the new secret that you created for HTTPS
   connections. Run the
   following command to open the Knative shared `gateway` in edit mode:

   ```shell
   kubectl edit gateway knative-ingress-gateway --namespace knative-serving
   ```

   Update the gateway to include the following `tls:` section and configuration:

   ```shell
   tls:
     mode: SIMPLE
     privateKey: /etc/istio/ingressgateway-certs/tls.key
     serverCertificate: /etc/istio/ingressgateway-certs/tls.crt
   ```

   Example:

   ```shell
   apiVersion: networking.istio.io/v1alpha3
   kind: Gateway
   metadata:
     # ... skipped ...
   spec:
     selector:
       istio: ingressgateway
     servers:
       - hosts:
           - "*"
         port:
           name: http
           number: 80
           protocol: HTTP
       - hosts:
           - "*"
         port:
           name: https
           number: 443
           protocol: HTTPS
         tls:
           mode: SIMPLE
           privateKey: /etc/istio/ingressgateway-certs/tls.key
           serverCertificate: /etc/istio/ingressgateway-certs/tls.crt
   ```

   After your changes are running on your Knative cluster, you can begin using the HTTPS protocol for secure access your deployed Knative services.
   In the event a mistake is made during this process and you need to update the cert, you must edit the gateway `knative-ingress-gateway`
   to switch back to `PASSTHROUGH` mode. Once corrections are made, edit the file again so the gateway uses the new certificates.

## Using an older version of `gitlabktl`

There may be situations where you want to run an older version of `gitlabktl`. This
requires setting an older version of the `gitlabktl` image in the `.gitlab-ci.yml` file.

To set an older version, add `image:` to the `functions:deploy` block. For example:

```yaml
functions:deploy:
  extends: .serverless:deploy:functions
  environment: production
  image: registry.gitlab.com/gitlab-org/gitlabktl:0.5.0
```

Different versions are available by changing the version tag at the end of the registry URL in the
format `registry.gitlab.com/gitlab-org/gitlabktl:<version>`.

For a full inventory of available `gitlabktl` versions, see the `gitlabktl` project's
[container registry](https://gitlab.com/gitlab-org/gitlabktl/container_registry).
