Callisto
Callisto is an open-source Kubernetes-native implementation of Selenium Grid.
Architecture
Callisto architecture
Components
- Nginx proxies requests for creating/deleting sessions to Callisto. All other requests are proxied to browser pods directly.
- Callisto creates/deletes browser pods, watches the status of pods, and creates sessions via the webdriver.
- Browser pods contain a webdriver and a browser.
Nginx and Callisto must be running inside a Kubernetes cluster in order to access browser pods directly.
Features
- No Selenium Grid components used
- Selenoid images can be used
- Selenoid UI can be used
Requirements
- Running Kubernetes cluster
- kubectl and helm installed and pointing to the cluster
Installation
See helm chart to get started.
Configuration
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
| WEB_API_HOST | str | No | 127.0.0.1 | a host to run web api |
| WEB_API_PORT | int | No | 8080 | a port to run web api |
| LOG_LEVEL | str | No | INFO | log level |
| GRAYLOG_HOST | str | No | Graylog host address. Logging to Graylog is disabled if left empty | |
| GRAYLOG_PORT | int | No | 12201 | Graylog port |
| K8S_NAMESPACE | str | No | default | k8s namespace to spawn pods |
| POD_WEBDRIVER_PATH | str | No | webdriver path location. On selenoid images /wd/hub for firefox, empty for others |
|
| POD_WEBDRIVER_PORT | int | No | 4444 | webdriver port |
| POD_MANIFEST | str | No | /etc/callisto/pod_manifest.yaml | Path to pod manifest file |
| SENTRY_DSN | str | No | Sentry DSN. Sentry disabled if left empty |
Resources requests/limits, browser image, screen resolution and other parameters can be configured via pod_manifest.yaml.
Troubleshooting
Each request is marked with a unique trace id (tid). This information is available in the logs. Also, for debugging, it is recommended to set the LOG_LEVEL to DEBUG.