GitLab Kubernetes Agent (PREMIUM ONLY)
- Introduced in GitLab Premium 13.4.
- It's disabled on GitLab.com. Rolling this feature out to GitLab.com is planned.
CAUTION: Warning: This feature might not be available to you. Check the version history note above for details.
The GitLab Kubernetes Agent is an active in-cluster component for solving GitLab and Kubernetes integration tasks in a secure and cloud-native way. It enables:
- Integrating GitLab with a Kubernetes cluster behind a firewall or NAT (network address translation).
- Pull-based GitOps deployments by leveraging the GitOps Engine.
- Real-time access to API endpoints within a cluster.
Many more features are planned. Please review our roadmap.
GitLab Agent GitOps workflow
The GitLab Agent uses multiple GitLab projects to provide a flexible workflow that can suit various needs. This diagram shows these repositories and the main actors involved in a deployment:
sequenceDiagram
participant D as Developer
participant A as Application code repository
participant M as Manifest repository
participant K as Kubernetes agent
participant C as Agent configuration repository
K->C: Grab the configuration
D->>+A: Pushing code changes
A->>M: Updating manifest
loop Regularly
K-->>M: Watching changes
M-->>K: Pulling and applying changes
end
There are several components that work in concert for the Agent to accomplish GitOps deployments:
- A properly-configured Kubernetes cluster.
- A configuration repository that contains a
config.yamlfile, which tells the Agent which repositories to synchronize with. - A manifest repository that contains a
manifest.yaml, which is tracked by the Agent and can be auto-generated. Any changes tomanifest.yamlare applied to the cluster.
These repositories might be the same GitLab project or separate projects.
For more details, please refer to our full architecture documentation in the Agent project.
Get started with GitOps and the GitLab Agent
The setup process involves a few steps to enable GitOps deployments:
- Install the Agent server.
- Define a configuration repository.
- Create an Agent record in GitLab.
- Generate and copy a Secret token used to connect to the Agent.
- Install the Agent into the cluster.
-
Create a
manifest.yaml.
Upgrades and version compatibility
As the GitLab Kubernetes Agent is a new product, we are constantly adding new features
to it. As a result, while shipped features are production ready, its internal API is
neither stable nor versioned yet. For this reason, GitLab only guarantees compatibility
between corresponding major.minor (X.Y) versions of GitLab and its cluster side
component, agentk.
Upgrade your agent installations together with GitLab upgrades. To decide which version of agentkto install follow:
- Open the GITLAB_KAS_VERSION file from the GitLab Repository, which contains the latest
agentkversion associated with themasterbranch. - Change the
masterbranch and select the Git tag associated with your version. For instance, you could change it to GitLab v13.5.3-ee release
The available agentk versions can be found in
its container registry.
Install the Kubernetes Agent Server
The GitLab Kubernetes Agent Server (KAS) can be deployed using Omnibus GitLab or the GitLab chart. If you don't already have GitLab installed, please refer to our installation documentation.
NOTE: Note: GitLab plans to include the KAS on GitLab.com.
Install with Omnibus
When using the Omnibus GitLab package:
-
Edit
/etc/gitlab/gitlab.rb:gitlab_kas['enable'] = true
To configure any additional options related to GitLab Kubernetes Agent Server,
refer to the Enable GitLab KAS section of the
gitlab.rb.template.
Install with the Helm chart
When installing or upgrading the GitLab Helm chart, consider the following Helm v3 example. If you're using Helm v2, you must modify this example. See our notes regarding deploy with Helm.
You must set global.kas.enabled=true for the KAS to be properly installed and configured:
helm repo add gitlab https://charts.gitlab.io/
helm repo update
helm upgrade --install gitlab gitlab/gitlab \
--timeout 600s \
--set global.hosts.domain=<YOUR_DOMAIN> \
--set global.hosts.externalIP=<YOUR_IP> \
--set certmanager-issuer.email=<YOUR_EMAIL> \
--set global.kas.enabled=true
To specify other options related to the KAS sub-chart, create a gitlab.kas sub-section
of your values.yaml file:
gitlab:
kas:
# put your KAS custom options here
For details, read Using the GitLab-KAS chart.
Define a configuration repository
Next, you need a GitLab repository to contain your Agent configuration. The minimal repository layout looks like this:
.gitlab/agents/<agent-name>/config.yaml
Your config.yaml file can specify multiple manifest projects in the
section manifest_projects:
gitops:
manifest_projects:
- id: "path-to/your-manifest-project-number1"
...
GitLab versions 13.7 and later also
supports manifest projects containing multiple directories (or subdirectories)
of YAML files. To use multiple YAML files, specify a paths attribute:
gitops:
manifest_projects:
- id: "path-to/your-manifest-project-number1"
paths:
# Read all .yaml files from team1/app1 directory.
# See https://github.com/bmatcuk/doublestar#about and
# https://pkg.go.dev/github.com/bmatcuk/doublestar/v2#Match for globbing rules.
- glob: '/team1/app1/*.yaml'
# Read all .yaml files from team2/apps and all subdirectories
- glob: '/team2/apps/**/*.yaml'
# If 'paths' is not specified or is an empty list, the configuration below is used
- glob: '/**/*.{yaml,yml,json}'
Create an Agent record in GitLab
Next, create an GitLab Rails Agent record so the Agent can associate itself with the configuration repository project. Creating this record also creates a Secret needed to configure the Agent in subsequent steps. You can create an Agent record either:
-
Through the Rails console:
project = ::Project.find_by_full_path("path-to/your-configuration-project") # agent-name should be the same as specified above in the config.yaml agent = ::Clusters::Agent.create(name: "<agent-name>", project: project) token = ::Clusters::AgentToken.create(agent: agent) token.token # this will print out the token you need to use on the next stepFor full details, read Starting a Rails console session.
-
Through GraphQL: (PREMIUM ONLY)
mutation createAgent { # agent-name should be the same as specified above in the config.yaml createClusterAgent(input: { projectPath: "path-to/your-configuration-project", name: "<agent-name>" }) { clusterAgent { id name } errors } } mutation createToken { clusterAgentTokenCreate(input: { clusterAgentId: <cluster-agent-id-taken-from-the-previous-mutation> }) { secret # This is the value you need to use on the next step token { createdAt id } errors } }NOTE: Note: GraphQL only displays the token one time after creating it.
If you are new to using the GitLab GraphQL API, refer to the Getting started with the GraphQL API page, or the GraphQL Explorer.
Create the Kubernetes secret
After generating the token, you must apply it to the Kubernetes cluster.
-
If you haven't previously defined or created a namespace, run the following command:
kubectl create namespace <YOUR-DESIRED-NAMESPACE> -
Run the following command to create your Secret:
kubectl create secret generic -n <YOUR-DESIRED-NAMESPACE> gitlab-agent-token --from-literal=token='YOUR_AGENT_TOKEN'
Install the Agent into the cluster
Next, install the in-cluster component of the Agent. This example file contains the
Kubernetes resources required for the Agent to be installed. You can modify this
example resources.yml file in the following ways:
- Replace
namespace: gitlab-agentwithnamespace: <YOUR-DESIRED-NAMESPACE>. - You can configure
kas-address(Kubernetes Agent Server) in several ways. The agent can use the WebSockets or gRPC protocols to connect to the Agent Server. Select the option appropriate for your cluster configuration and GitLab architecture:- The
wssscheme (an encrypted WebSockets connection) is specified by default after you installgitlab-kassub-chart or enablekasfor Omnibus GitLab. In this case, you must setwss://GitLab.host.tld:443/-/kubernetes-agentaskas-address, whereGitLab.host.tldis your GitLab hostname. - Specify the
wsscheme (such asws://GitLab.host.tld:80/-/kubernetes-agent) to use an unencrypted WebSockets connection. - Specify the
grpcscheme if both Agent and Server are installed in one cluster. In this case, you may specifykas-addressvalue asgrpc://gitlab-kas.<your-namespace>:5005) to use gRPC directly, wheregitlab-kasis the name of the service created bygitlab-kaschart, andyour-namespaceis the namespace where the chart was installed. Encrypted gRPC is not supported yet. Follow the Support TLS for gRPC communication issue for progress updates.
- The
- If you defined your own secret name, replace
gitlab-agent-tokenwith your secret name in thesecretName:section.
To apply this file, run the following command:
kubectl apply -n <YOUR-DESIRED-NAMESPACE> -f ./resources.yml
To review your configuration, run the following command:
$ kubectl get pods -n <YOUR-DESIRED-NAMESPACE>
NAMESPACE NAME READY STATUS RESTARTS AGE
gitlab-agent gitlab-agent-77689f7dcb-5skqk 1/1 Running 0 51s
Example resources.yml file
apiVersion: v1
kind: ServiceAccount
metadata:
name: gitlab-agent
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: gitlab-agent
spec:
replicas: 1
selector:
matchLabels:
app: gitlab-agent
template:
metadata:
labels:
app: gitlab-agent
spec:
serviceAccountName: gitlab-agent
containers:
- name: agent
image: "registry.gitlab.com/gitlab-org/cluster-integration/gitlab-agent/agentk:latest"
args:
- --token-file=/config/token
- --kas-address
- wss://gitlab.host.tld:443/-/kubernetes-agent
volumeMounts:
- name: token-volume
mountPath: /config
volumes:
- name: token-volume
secret:
secretName: gitlab-agent-token
strategy:
type: RollingUpdate
rollingUpdate:
maxSurge: 0
maxUnavailable: 1
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: gitlab-agent-write
rules:
- resources:
- '*'
apiGroups:
- '*'
verbs:
- create
- update
- delete
- patch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: gitlab-agent-write-binding
roleRef:
name: gitlab-agent-write
kind: ClusterRole
apiGroup: rbac.authorization.k8s.io
subjects:
- name: gitlab-agent
kind: ServiceAccount
namespace: gitlab-agent
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: gitlab-agent-read
rules:
- resources:
- '*'
apiGroups:
- '*'
verbs:
- get
- list
- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: gitlab-agent-read-binding
roleRef:
name: gitlab-agent-read
kind: ClusterRole
apiGroup: rbac.authorization.k8s.io
subjects:
- name: gitlab-agent
kind: ServiceAccount
namespace: gitlab-agent
Create a manifest.yaml
In a previous step, you configured a config.yaml to point to the GitLab projects
the Agent should synchronize. In each of those projects, you must create a manifest.yaml
file for the Agent to monitor. You can auto-generate this manifest.yaml with a
templating engine or other means. Only public projects are supported as
manifest projects. Support for private projects is planned in the issue
Agent authorization for private manifest projects.
Each time you commit and push a change to this file, the Agent logs the change:
2020-09-15_14:09:04.87946 gitlab-k8s-agent : time="2020-09-15T10:09:04-04:00" level=info msg="Config: new commit" agent_id=1 commit_id=e6a3651f1faa2e928fe6120e254c122451be4eea
Example manifest.yaml file
This file creates an NGINX deployment.
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
namespace: gitlab-agent # Can be any namespace managed by you that the agent has access to.
spec:
selector:
matchLabels:
app: nginx
replicas: 2
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
Example projects
The following example projects can help you get started with the Kubernetes Agent.
Simple NGINX deployment
This basic GitOps example deploys NGINX:
Deploying GitLab Runner with the Agent
These instructions assume that the Agent is already set up as described in the Get started with GitOps:
-
Check the possible Runner chart YAML values on the Runner chart documentation, and create a
runner-chart-values.yamlfile with the configuration that fits your needs, such as:## The GitLab Server URL (with protocol) that want to register the runner against ## ref: https://docs.gitlab.com/runner/commands/README.html#gitlab-runner-register ## gitlabUrl: https://gitlab.my.domain.com/ ## The Registration Token for adding new Runners to the GitLab Server. This must ## be retrieved from your GitLab Instance. ## ref: https://docs.gitlab.com/ce/ci/runners/README.html ## runnerRegistrationToken: "XXXXXXYYYYYYZZZZZZ" ## For RBAC support: rbac: create: true ## Run all containers with the privileged flag enabled ## This will allow the docker:dind image to run if you need to run Docker ## commands. Please read the docs before turning this on: ## ref: https://docs.gitlab.com/runner/executors/kubernetes.html#using-dockerdind runners: privileged: true -
Create a single manifest file to install the Runner chart with your cluster agent:
helm template --namespace gitlab gitlab-runner -f runner-chart-values.yaml gitlab/gitlab-runner > manifest.yaml -
Push your
manifest.yamlto your manifest repository.
Troubleshooting
If you face any issues while using GitLab Kubernetes Agent, you can read the service logs with the following commands:
- KAS pod logs - Tail these logs with the
kubectl logs -f -l=app=kas -n <YOUR-GITLAB-NAMESPACE>command. In Omnibus GitLab, the logs reside in/var/log/gitlab/gitlab-kas/. - Agent pod logs - Tail these logs with the
kubectl logs -f -l=app=gitlab-agent -n <YOUR-DESIRED-NAMESPACE>command.
KAS logs - GitOps: failed to get project info
{"level":"warn","time":"2020-10-30T08:37:26.123Z","msg":"GitOps: failed to get project info","agent_id":4,"project_id":"root/kas-manifest001","error":"error kind: 0; status: 404"}
This error is shown if the specified manifest project root/kas-manifest001
doesn't exist, or if a project is private. To fix it, make sure the project exists
and its visibility is set to public.
KAS logs - Configuration file not found
time="2020-10-29T04:44:14Z" level=warning msg="Config: failed to fetch" agent_id=2 error="configuration file not found: \".gitlab/agents/test-agent/config.yaml\
This error is shown if the path to the configuration project was specified incorrectly,
or if the path to config.yaml inside the project is not valid.
Agent logs - Transport: Error while dialing failed to WebSocket dial
{"level":"warn","time":"2020-11-04T10:14:39.368Z","msg":"GetConfiguration failed","error":"rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing failed to WebSocket dial: failed to send handshake request: Get \\\"https://gitlab-kas:443/-/kubernetes-agent\\\": dial tcp: lookup gitlab-kas on 10.60.0.10:53: no such host\""}
This error is shown if there are some connectivity issues between the address
specified as kas-address, and your Agent pod. To fix it, make sure that you
specified the kas-address correctly.
Agent logs - ValidationError(Deployment.metadata
{"level":"info","time":"2020-10-30T08:56:54.329Z","msg":"Synced","project_id":"root/kas-manifest001","resource_key":"apps/Deployment/kas-test001/nginx-deployment","sync_result":"error validating data: [ValidationError(Deployment.metadata): unknown field \"replicas\" in io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta, ValidationError(Deployment.metadata): unknown field \"selector\" in io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta, ValidationError(Deployment.metadata): unknown field \"template\" in io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta]"}
This error is shown if your manifest.yaml file is malformed, and Kubernetes can't
create specified objects. Make sure that your manifest.yaml file is valid. You
may try using it to create objects in Kubernetes directly for more troubleshooting.
Agent logs - Error while dialing failed to WebSocket dial: failed to send handshake request
{"level":"warn","time":"2020-10-30T09:50:51.173Z","msg":"GetConfiguration failed","error":"rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing failed to WebSocket dial: failed to send handshake request: Get \\\"https://GitLabhost.tld:443/-/kubernetes-agent\\\": net/http: HTTP/1.x transport connection broken: malformed HTTP response \\\"\\\\x00\\\\x00\\\\x06\\\\x04\\\\x00\\\\x00\\\\x00\\\\x00\\\\x00\\\\x00\\\\x05\\\\x00\\\\x00@\\\\x00\\\"\""}
This error is shown if you configured wss as kas-address on the agent side,
but KAS on the server side is not available via wss. To fix it, make sure the
same schemes are configured on both sides.
It's not possible to set the grpc scheme due to the issue
It is not possible to configure KAS to work with grpc without directly editing GitLab KAS deployment. To use grpc while the
issue is in progress, directly edit the deployment with the
kubectl edit deployment gitlab-kas command, and change --listen-websocket=true to --listen-websocket=false. After running that command, you should be able to use
grpc://gitlab-kas.<YOUR-NAMESPACE>:5005.
Agent logs - Decompressor is not installed for grpc-encoding
{"level":"warn","time":"2020-11-05T05:25:46.916Z","msg":"GetConfiguration.Recv failed","error":"rpc error: code = Unimplemented desc = grpc: Decompressor is not installed for grpc-encoding \"gzip\""}
This error is shown if the version of the agent is newer that the version of KAS.
To fix it, make sure that both agentk and KAS use the same versions.