SSE

Abstract

The sse service is responsible for sending sse (Server-Sent Events) to a user. See What is Server-Sent Events for a simple introduction and examples of server sent events.

The Log Service Ecosystem
Subscribing
Keep SSE Connections Alive
Example Yaml Config

The Log Service Ecosystem

Log services like the userlog, clientlog and sse are responsible for composing notifications for a certain audience.

The userlog service translates and adjusts messages to be human readable.
The clientlog service composes machine readable messages, so clients can act without the need to query the server.
The sse service is only responsible for sending these messages. It does not care about their form or language.

Subscribing

Clients can subscribe to the /sse endpoint to be informed by the server when an event happens. The sse endpoint will respect language changes of the user without needing to reconnect. Note that SSE has a limitation of six open connections per browser which can be reached if one has opened various tabs of the Web UI pointing to the same Infinite Scale instance.

Keep SSE Connections Alive

Some intermediate proxies drop connections after an idle time with no activity. If this is the case, configure the SSE_KEEPALIVE_INTERVAL envvar. This will send periodic SSE comments to keep connections open.

Example Yaml Config

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# Autogenerated
# Filename: sse-config-example.yaml

log:
  level: ""
  pretty: false
  color: false
  file: ""
debug:
  addr: 127.0.0.1:9139
  token: ""
  pprof: false
  zpages: false
tracing:
  enabled: false
  type: ""
  endpoint: ""
  collector: ""
keepalive_interval: 0s
events:
  endpoint: 127.0.0.1:9233
  cluster: ocis-cluster
  tls_insecure: false
  tls_root_ca_certificate: ""
  enable_tls: false
  username: ""
  password: ""
http:
  addr: 127.0.0.1:9135
  root: /
  cors:
    allow_origins:
    - '*'
    allow_methods:
    - GET
    allow_headers:
    - Authorization
    - Origin
    - Content-Type
    - Accept
    - X-Requested-With
    - X-Request-Id
    - Ocs-Apirequest
    allow_credentials: true
  tls:
    enabled: false
    cert: ""
    key: ""
token_manager:
  jwt_secret: ""

Environment Variables

Name	Type	Default Value	Description
OCIS_LOG_LEVEL SSE_LOG_LEVEL	string		The log level. Valid values are: ‘panic’, ‘fatal’, ’error’, ‘warn’, ‘info’, ‘debug’, ’trace’.
OCIS_LOG_PRETTY SSE_LOG_PRETTY	bool	false	Activates pretty log output.
OCIS_LOG_COLOR SSE_LOG_COLOR	bool	false	Activates colorized log output.
OCIS_LOG_FILE SSE_LOG_FILE	string		The path to the log file. Activates logging to this file if set.
SSE_DEBUG_ADDR	string	127.0.0.1:9139	Bind address of the debug server, where metrics, health, config and debug endpoints will be exposed.
SSE_DEBUG_TOKEN	string		Token to secure the metrics endpoint.
SSE_DEBUG_PPROF	bool	false	Enables pprof, which can be used for profiling.
SSE_DEBUG_ZPAGES	bool	false	Enables zpages, which can be used for collecting and viewing in-memory traces.
OCIS_TRACING_ENABLED SSE_TRACING_ENABLED	bool	false	Activates tracing.
OCIS_TRACING_TYPE SSE_TRACING_TYPE	string		The type of tracing. Defaults to ‘’, which is the same as ‘jaeger’. Allowed tracing types are ‘jaeger’ and ’’ as of now.
OCIS_TRACING_ENDPOINT SSE_TRACING_ENDPOINT	string		The endpoint of the tracing agent.
OCIS_TRACING_COLLECTOR SSE_TRACING_COLLECTOR	string		The HTTP endpoint for sending spans directly to a collector, i.e. http://jaeger-collector:14268/api/traces. Only used if the tracing endpoint is unset.
SSE_KEEPALIVE_INTERVAL	Duration	0s	To prevent intermediate proxies from closing the SSE connection, send periodic SSE comments to keep it open.
OCIS_EVENTS_ENDPOINT SSE_EVENTS_ENDPOINT	string	127.0.0.1:9233	The address of the event system. The event system is the message queuing service. It is used as message broker for the microservice architecture.
OCIS_EVENTS_CLUSTER SSE_EVENTS_CLUSTER	string	ocis-cluster	The clusterID of the event system. The event system is the message queuing service. It is used as message broker for the microservice architecture. Mandatory when using NATS as event system.
OCIS_INSECURE SSE_EVENTS_TLS_INSECURE	bool	false	Whether to verify the server TLS certificates.
OCIS_EVENTS_TLS_ROOT_CA_CERTIFICATE SSE_EVENTS_TLS_ROOT_CA_CERTIFICATE	string		The root CA certificate used to validate the server’s TLS certificate. If provided SSE_EVENTS_TLS_INSECURE will be seen as false.
OCIS_EVENTS_ENABLE_TLS SSE_EVENTS_ENABLE_TLS	bool	false	Enable TLS for the connection to the events broker. The events broker is the ocis service which receives and delivers events between the services.
OCIS_EVENTS_AUTH_USERNAME SSE_EVENTS_AUTH_USERNAME	string		The username to authenticate with the events broker. The events broker is the ocis service which receives and delivers events between the services.
OCIS_EVENTS_AUTH_PASSWORD SSE_EVENTS_AUTH_PASSWORD	string		The password to authenticate with the events broker. The events broker is the ocis service which receives and delivers events between the services.
SSE_HTTP_ADDR	string	127.0.0.1:9135	The bind address of the HTTP service.
SSE_HTTP_ROOT	string	/	Subdirectory that serves as the root for this HTTP service.
OCIS_CORS_ALLOW_ORIGINS SSE_CORS_ALLOW_ORIGINS	[]string	[*]	A list of allowed CORS origins. See following chapter for more details: Access-Control-Allow-Origin at https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin. See the Environment Variable Types description for more details.
OCIS_CORS_ALLOW_METHODS SSE_CORS_ALLOW_METHODS	[]string	[GET]	A list of allowed CORS methods. See following chapter for more details: Access-Control-Request-Method at https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Request-Method. See the Environment Variable Types description for more details.
OCIS_CORS_ALLOW_HEADERS SSE_CORS_ALLOW_HEADERS	[]string	[Authorization Origin Content-Type Accept X-Requested-With X-Request-Id Ocs-Apirequest]	A list of allowed CORS headers. See following chapter for more details: Access-Control-Request-Headers at https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Request-Headers. See the Environment Variable Types description for more details.
OCIS_CORS_ALLOW_CREDENTIALS SSE_CORS_ALLOW_CREDENTIALS	bool	true	Allow credentials for CORS.See following chapter for more details: Access-Control-Allow-Credentials at https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Credentials.
OCIS_HTTP_TLS_ENABLED	bool	false	Activates TLS for the http based services using the server certifcate and key configured via OCIS_HTTP_TLS_CERTIFICATE and OCIS_HTTP_TLS_KEY. If OCIS_HTTP_TLS_CERTIFICATE is not set a temporary server certificate is generated - to be used with PROXY_INSECURE_BACKEND=true.
OCIS_HTTP_TLS_CERTIFICATE	string		Path/File name of the TLS server certificate (in PEM format) for the http services.
OCIS_HTTP_TLS_KEY	string		Path/File name for the TLS certificate key (in PEM format) for the server certificate to use for the http services.
OCIS_JWT_SECRET SSE_JWT_SECRET	string		The secret to mint and validate jwt tokens.

SSE