gcs-helper is inspired by s3-helper and is used to provide access to private GCS buckets.
It was designed to be used with Kaltura's nginx-vod-module, but it can also work as a standalone proxy.
Specific to nginx-vod-module, gcs-helper provides support for the mapped mode
(when using the proper environment variables - GCS_HELPER_PROXY_PREFIX,
GCS_HELPER_MAP_PREFIX and GCS_HELPER_MAP_REGEX_FILTER).
The following environment variables control the behavior of gcs-helper:
| Variable | Default value | Required | Description |
|---|---|---|---|
| GCS_HELPER_LISTEN | :8080 | No | Address to bind the server |
| GCS_HELPER_BUCKET_NAME | Yes | Name of the bucket | |
| GCS_HELPER_LOG_LEVEL | debug | No | Logging level |
| GCS_HELPER_PROXY_PREFIX | No | Prefix to use for the proxy binding. Required if running in map and proxy modes (example value: /proxy/) |
|
| GCS_HELPER_PROXY_TIMEOUT | 10s | No | Defines the maximum time in serving the proxy requests, this is a hard timeout and includes retries |
| GCS_HELPER_MAP_PREFIX | No | Prefix to use for the map binding. Required if running in map and proxy modes (example value: /map/) |
|
| GCS_HELPER_MAP_REGEX_FILTER | No | A regular expression that is used to deliver only those files that match the specified naming convention (example value: \d{3,4}p(.mp4 |
The are also some configuration variables for network communication with Google Cloud Storage API:
| Variable | Default value | Required | Description |
|---|---|---|---|
| GCS_CLIENT_TIMEOUT | 2s | No | Hard timeout on requests that gcs-helper sends to the Google Storage API |
| GCS_CLIENT_IDLE_CONN_TIMEOUT | 120s | No | Maximum duration of idle connections between gcs-helper and the Google Storage API |
| GCS_CLIENT_MAX_IDLE_CONNS | 10 | No | Maximum number of idle connections to keep open. This doesn't control the maximum number of connections |
The timeout configuration is mainly controlled by two environment variables:
GCS_HELPER_PROXY_TIMEOUT and GCS_CLIENT_TIMEOUT. The
GCS_HELPER_PROXY_TIMEOUT controls how long requests to gcs-helper can take,
and GCS_CLIENT_TIMEOUT controls how long requests from gcs-helper to
Google's API can take. Since gcs-helper automatically retries on failures, the
number of retries is roughly the value of GCS_HELPER_PROXY_TIMEOUT divided
by the value of GCS_CLIENT_TIMEOUT.