dexter
dexter is a OIDC (OpenId Connect) helper to create a hassle-free Kubernetes login experience powered by Google or Azure as Identity Provider.
All you need is a properly configured Google or Azure client ID & secret.
Supported identity providers
| Identity Provider | State |
|---|---|
| complete | |
| Microsoft Azure | complete |
Authentication Flow
dexter will open a new browser tag/window and redirect you to your configured Idp. The only interaction you have is the login at your provider and your k8s config is updated automatically.
See dexter in action
OIDCProvider Configuration
Each OpenID Connect provider requires some configuration. This basic description may not be all you have to do but it worked at the time of writing.
- Open console.developers.google.com
- Create new credentials
- OAuth Client ID
- Web Application
- Authorized redirect URIs: http://127.0.0.1:64464/callback
Microsoft Azure
- Open portal.azure.com
- Go to Appregistrations and create a new app
- Enter reply URI http://127.0.0.1:64464/callback
- Create secret key
- Collect application ID (client ID)
Auto pilot configuration
dexter also support auto pilot mode. If your existing kubectl context uses one of the supported Identity Providers, dexter will try to use extract the OIDC data from kubeconfig.
Installation
You can download a prebuilt version from the Github release section or build it yourself. The easiest way to get everything set up correctly (e.g. ldflags) is to use goreleaser.
# cd DEXTER_SOURCE
# goreleaser release --snapshot --rm-dist
• releasing...
• loading config file file=.goreleaser.yml
• loading environment variables
• getting and validating git state
• building... commit=377677a03da17461acf7775519518fb3336e6753 latest tag=v0.4.1
• pipe skipped error=disabled during snapshot mode
• parsing tag
• running before hooks
• running hook=go mod tidy
• setting defaults
• snapshotting
• building snapshot... version=0.4.2-next
• checking distribution directory
• --rm-dist is set, cleaning it up
• loading go mod information
• build prerequisites
• writing effective config file
• writing config=dist/config.yaml
• building binaries
• building binary=dist/dexter_darwin_arm64/dexter
• building binary=dist/dexter_darwin_amd64/dexter
• building binary=dist/dexter_linux_amd64/dexter
• universal binaries
• creating from 2 binaries binary=dist/dexter_darwin_all/dexter
• archives
• creating archive=dist/dexter_0.4.2-next_Linux_x86_64.tar.gz
• creating archive=dist/dexter_0.4.2-next_Darwin_all.tar.gz
• calculating checksums
• storing release metadata
• writing file=dist/artifacts.json
• writing file=dist/metadata.json
• release succeeded after 8.18s
Check ./dist for the build that matches your platform.
Embed credentials and template
You can also customize the build and embed client credentails and a default kubectl config into the binary. Again, using goreleaser for the build is the easiest approach.
Client credentials are embedded automatically when you set two environment variables.
CLIENT_ID=abc123.apps.googleusercontent.com
CLIENT_SECRET=mySecret
You can streamline your user experience even more by also specifying a default provider. dexter auth will then run the specified provider.
Valid choices are google and azure.
DEFAULT_PROVIDER=google
If you want to to change the default config template that is deployed when there is no config on the system you have to replace the contents of ./tmpl/kube-config.yaml with your valid kubectl configuration.
This can come in handy if you want to pre-populate clusters and certificates.
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: XXX
server: https://stage.cluster:6443
name: stage
- cluster:
certificate-authority-data: YYY
server: https://production.cluster:6443
name: production
contexts:
- context:
cluster: stage
user: {{ .User }}
name: stage
- context:
cluster: production
user: {{ .User }}
name: production
current-context: stage
kind: Config
preferences: {}
Please make sure that you have {{ .User }} in all contexts that need you want to enrich with the OIDC account you are about to configure.
Run dexter
Run dexter without a command to access the help screen/intro.
❯ ./dexter
.___ __
__| _/____ ___ ____/ |_ ___________
/ __ |/ __ \\ \/ /\ __\/ __ \_ __ \
/ /_/ \ ___/ > < | | \ ___/| | \/
\____ |\___ >__/\_ \ |__| \___ >__|
\/ \/ \/ \/
dexter is a authentication helper for Kubernetes that does the heavy
lifting for SSO (Single Sign On) for Kubernetes.
Usage:
dexter [command]
Available Commands:
auth Authenticate with OIDC provider
help Help about any command
version Print the version number of dexter
Flags:
-h, --help help for dexter
--timeout int Timeout for HTTP requests to OIDC providers (default 2)
-v, --verbose verbose output
Use "dexter [command] --help" for more information about a command.
Running dexter auth [Idp] will start the authentication process.
❯ ./dexter auth --help
Use a provider sub-command to authenticate against your identity provider of choice.
For details go to: https://gini.net/en/blog/frictionless-kubernetes-openid-connect-integration/
Usage:
dexter auth [flags]
dexter auth [command]
Available Commands:
azure Authenticate with the Microsoft Azure Identity Provider
google Authenticate with the Google Identity Provider
Flags:
-c, --callback string Callback URL. The listen address is dreived from that. (default "http://127.0.0.1:64464/callback")
-i, --client-id string Google clientID (default "REDACTED")
-s, --client-secret string Google clientSecret (default "REDACTED")
-d, --dry-run Toggle config overwrite
-h, --help help for auth
-k, --kube-config string Overwrite the default location of kube config (default "/Users/dkerwin/.kube/config")
-t, --kube-template Use the embedded template when there is no kubectl configuration (default true)
-u, --kube-username string Username identifier in the kube config
-f, --write-email string Write user email to the specified file for use with other tooling
Global Flags:
-v, --verbose verbose output
Use "dexter auth [command] --help" for more information about a command.
Contribution Guidelines
It's awesome that you consider contributing to dexter and it's really simple. Here's how it's done:
- fork repository on Github
- create a topic/feature branch
- push your changes
- update documentation if necessary
- open a pull request
Authors & Contributors
Initial code was written by Daniel Kerwin & David González Ruiz
Contributors (in alphabetical order):
- https://github.com/andrewsav-datacom
- https://github.com/cblims
- https://github.com/Lujeni
- https://github.com/pussinboots
- https://github.com/tillepille
Thank you so much!
Acknowledgements
dexter was inspired by this blog post series by Joel Speed, Micah Hausler's k8s-oidc-helper
& CoreOS dex.
License
MIT License. See License for full text.