Common Configuration

config.yml

This YAML file, sometimes known as the Dropwizard configuration file (as it conforms to a structure defined by Dropwizard) is the primary means of configuring Stroom/Stroom-Proxy. As a minimum this file should be used to configure anything that needs to be set before stroom can start up, e.g. web server, logging, database connection details, etc. It is also used to configure anything that is specific to a node in a stroom cluster.

If you are using some form of scripted deployment, e.g. ansible then it can be used to set all stroom properties for the environment that stroom runs in. If you are not using scripted deployments then you can maintain stroom’s node agnostic configuration properties via the user interface.

Config File Structure

This file contains both the Dropwizard configuration settings (settings for ports, paths and application logging) and the Stroom/Stroom-Proxy application specific properties configuration. The file is in YAML format and the application properties are located under the appConfig key. For details of the Dropwizard configuration structure, see here .

The file is split into sections using these keys:

• server - Configuration of the web server, e.g. ports, paths, request logging.
• logging - Configuration of application logging
• jerseyClients - Configuration of the various Jersey HTTP clients in use. See Jersey HTTP Client Configuration.
• Application specific configuration:
  • appConfig - The Stroom configuration properties. These properties can be viewed/modified in the user interface.
  • proxyConfig - The Stroom-Proxy configuration properties. These properties can be viewed/modified in the user interface.

The following is an example of the YAML configuration file for Stroom:

# Dropwizard configuration section
server:
  # e.g. ports and paths
logging:
  # e.g. logging levels/appenders

jerseyClients:
  DEFAULT:
    # Configuration of the named client

# Stroom properties configuration section
appConfig:
  commonDbDetails:
    connection:
      jdbcDriverClassName: ${STROOM_JDBC_DRIVER_CLASS_NAME:-com.mysql.cj.jdbc.Driver}
      jdbcDriverUrl: ${STROOM_JDBC_DRIVER_URL:-jdbc:mysql://localhost:3307/stroom?useUnicode=yes&characterEncoding=UTF-8}
      jdbcDriverUsername: ${STROOM_JDBC_DRIVER_USERNAME:-stroomuser}
      jdbcDriverPassword: ${STROOM_JDBC_DRIVER_PASSWORD:-stroompassword1}
  contentPackImport:
    enabled: true
  ...

The following is an example of the YAML configuration file for Stroom-Proxy:

# Dropwizard configuration section
server:
  # e.g. ports and paths
logging:
  # e.g. logging levels/appenders

jerseyClients:
  DEFAULT:
    # Configuration of the named client

# Stroom properties configuration section
proxyConfig:
  path:
    home: /some/path
  ...

appConfig Section

The appConfig section is special as it maps to the Properties seen in the Stroom user interface so values can be managed in the file or via the Properties screen in the Stroom UI. The other sections of the file can only be managed via the YAML file. In the Stroom user interface, properties are named with a dot notation key, e.g. stroom.contentPackImport.enabled. Each part of the dot notation property name represents a key in the YAML file, e.g. for this example, the location in the YAML would be:

appConfig:
  contentPackImport:
    enabled: true   # stroom.contentPackImport.enabled

The stroom part of the dot notation name is replaced with appConfig.

For more details on the link between this YAML file and Stroom Properties, see Properties

Variable Substitution

The YAML configuration file supports Bash style variable substitution in the form of:

${ENV_VAR_NAME:-value_if_not_set}

This allows values to be set either directly in the file or via an environment variable, e.g.

      jdbcDriverClassName: ${STROOM_JDBC_DRIVER_CLASS_NAME:-com.mysql.cj.jdbc.Driver}

In the above example, if the STROOM_JDBC_DRIVER_CLASS_NAME environment variable is not set then the value com.mysql.cj.jdbc.Driver will be used instead.

Typed Values

YAML supports typed values rather than just strings, see https://yaml.org/refcard.html. YAML understands booleans, strings, integers, floating point numbers, as well as sequences/lists and maps. Some properties will be represented differently in the user interface to the YAML file. This is due to how values are stored in the database and how the current user interface works. This will likely be improved in future versions. For details of how different types are represented in the YAML and the UI, see Data Types.

Server configuration

The server section controls the configuration of the Jetty web server.

For full details of how to configure the server section see:

• Server
• Connectors

The following is an example of the configuration for an application listening on HTTP.

server:
  # The base path for the main application
  applicationContextPath: "/"
  # The base path for the admin pages/API
  adminContextPath: "/stroomAdmin"

  # The scheme/port for the main application
  applicationConnectors:
    - type: http
      port: 8080
      # Uses X-Forwarded-*** headers in request log instead of proxy server details.
      useForwardedHeaders: true
  # The scheme/port for the admin pages/API
  adminConnectors:
    - type: http
      port: 8081
      useForwardedHeaders: true

Jersey HTTP Client Configuration

Stroom and Stroom Proxy use the Jersey client for making HTTP connections with other nodes or other systems (e.g. Open ID Connect identity providers). In the YAML file, the jerseyClients key controls the configuration of the various clients in use.

To allow complete control of the client configuration, Stroom uses the concept of named client configurations. Each named client will be unique to a destination (where a destination is typically a server or a cluster of functionally identical servers). Thus the configuration of the connections to each of those destinations can be configured independently.

The client names are as follows:

• AWS_PUBLIC_KEYS - Connections to fetch AWS public keys used in Open ID Connect authentication.
• CONTENT_SYNC - Connections to downstream proxy/stroom instances to sync content. (Stroom Proxy only).
• DEFAULT - The default client configuration used if a named configuration is not present.
• FEED_STATUS - Connections to downstream proxy/stroom instances to check feed status. (Stroom Proxy only).
• OPEN_ID - Connections to an Open ID Connect identity provider, e.g. Cognito, Azure AD, KeyCloak, etc.
• STROOM - Inter-node communications within the Stroom cluster (Stroom only).

The following is an example of how the clients are configured in the YAML file:

jerseyClients:
  DEFAULT:
    # Default client configuration, e.g.
    timeout: 500ms
  STROOM:
    # Configuration items for stroom inter-node communications
    timeout: 30s
  # etc.

The configuration keys (along with their default values and descriptions) for each client can be found here:

• Jersey Client
• Base HTTP Client
• Proxy server settings
• TLS settings

The following is another example including most keys:

jerseyClients:
  DEFAULT:
    minThreads: 1
    maxThreads: 128
    workQueueSize: 8
    gzipEnabled: true
    gzipEnabledForRequests: true
    chunkedEncodingEnabled: true
    timeout: 500ms
    connectionTimeout: 500ms
    timeToLive: 1h
    cookiesEnabled: false
    maxConnections: 1024
    maxConnectionsPerRoute: 1024
    keepAlive: 0ms
    retries: 0
    userAgent: <application name> (<client name>)
    proxy:
      host: 192.168.52.11
      port: 8080
      scheme : http
      auth:
        username: secret
        password: stuff
        authScheme: NTLM
        realm: realm
        hostname: host
        domain: WINDOWSDOMAIN
        credentialType: NT
      nonProxyHosts:
        - localhost
        - '192.168.52.*'
        - '*.example.com'
    tls:
      protocol: TLSv1.2
      provider: SunJSSE
      verifyHostname: true
      keyStorePath: /path/to/file
      keyStorePassword: changeit
      keyStoreType: JKS
      trustStorePath: /path/to/file
      trustStorePassword: changeit
      trustStoreType: JKS
      trustSelfSignedCertificates: false
      supportedProtocols: TLSv1.1,TLSv1.2
      supportedCipherSuites: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
      certAlias: alias-of-specific-cert

Logging Configuration

The Dropwizard configuration file controls all the logging by the application. In addition to the main application log, there are additional logs such as stroom user events (for audit), Stroom-Proxy send and receive logs and database migration logs.

For full details of the logging configuration, see Dropwizard Logging Configuration

Request Log

The request log is slightly different to the other logs. It logs all requests to the web server. It is configured in the server section.

The property archivedLogFilenamePattern controls rolling of the active log file. The date pattern in the filename controls the frequency that the log files are rolled. In this example, files will be rolled every 1 minute.

server:
  requestLog:
    appenders:
    - type: file
      currentLogFilename: logs/access/access.log
      discardingThreshold: 0
      # Rolled and gzipped every minute
      archivedLogFilenamePattern: logs/access/access-%d{yyyy-MM-dd'T'HH:mm}.log.gz
      archivedFileCount: 10080
      logFormat: '%h %l "%u" [%t] "%r" %s %b "%i{Referer}" "%i{User-Agent}" %D'

Logback Logs

Dropwizard uses Logback for application level logging. All logs in Stroom and Stroom-Proxy apart from the request log are Logback based logs.

Logback uses the concept of Loggers and Appenders. A Logger is a named thing that that produces log messages. An _Appender is an output that a Logger can append its log messages to. Typical Appenders are:

• File - appends messages to a file that may or may not be rolled.
• Console - appends messages to stdout.
• Syslog - appends messages to syslog.

Loggers

A Logger can append to more than one Appender if required. For example, the default configuration file for Stroom has two appenders for the application logs. The rolled files from one appender are POSTed to Stroom to index its own logs, then deleted and the other is intended to remain on the server until archived off to allow viewing by an administrator.

A Logger can be configured with a severity, valid severities are (TRACE, DEBUG, WARN, ERROR). The severity set on a logger means that only messages with that severity or higher will be logged, with the rest not logged.

Logger names are typically the name of the Java class that is producing the log message. You don’t need to understand too much about Java classes as you are only likely to change logger severities when requested by one of the developers. Some loggers, such as event-logger do not have a Java class name.

As an example this is a portion of a Stroom config.yml file to illustrate the different loggers/appenders:

logging:
  # This is root logging severity level for all loggers. Only messages >= to WARN will be logged unless overridden
  # for a specific logger
  level: WARN

  # All the named loggers
  loggers:
    # Logs useful information about stroom. Only set DEBUG on specific 'stroom' classes or packages
    # due to the large volume of logs that would be produced for all of 'stroom' in DEBUG.
    stroom: INFO
    # Logs useful information about dropwizard when booting stroom
    io.dropwizard: INFO
    # Logs useful information about the jetty server when booting stroom
    org.eclipse.jetty: INFO
    # Logs REST request/responses with headers/payloads. Set this to OFF to turn disable that logging.
    org.glassfish.jersey.logging.LoggingFeature: INFO
    # Logs summary information about FlyWay database migrations
    org.flywaydb: INFO
    # Logger and custom appender for audit logs
    event-logger:
      level: INFO
      # Prevents messages from this logger from being sent to other appenders
      additive: false
      appenders:
        - type: file
          currentLogFilename: logs/user/user.log
          discardingThreshold: 0
          # Rolled every minute
          archivedLogFilenamePattern: logs/user/user-%d{yyyy-MM-dd'T'HH:mm}.log
          # Minute rolled logs older than a week will be deleted. Note rolled logs are deleted
          # based on the age of the window they contain, not the number of them. This value should be greater
          # than the maximum time stroom is not producing events for.
          archivedFileCount: 10080
          logFormat: "%msg%n"
    # Logger and custom appender for the flyway DB migration SQL output
    org.flywaydb.core.internal.sqlscript:
      level: DEBUG
      additive: false
      appenders:
        - type: file
          currentLogFilename: logs/migration/migration.log
          discardingThreshold: 0
          # Rolled every day
          archivedLogFilenamePattern: logs/migration/migration-%d{yyyy-MM-dd}.log
          archivedFileCount: 10
          logFormat: "%-6level [%d{\"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'\",UTC}] [%t] %logger - %X{code} %msg %n"

Appenders

The following is an example of the default appenders that will be used for all loggers unless they have their own custom appender configured.

logging:
  # Appenders for all loggers except for where a logger has a custom appender configured
  appenders:

    # stdout
  - type: console
    # Multi-coloured log format for console output
    logFormat: "%highlight(%-6level) [%d{\"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'\",UTC}] [%green(%t)] %cyan(%logger) - %X{code} %msg %n"
    timeZone: UTC
#
    # Minute rolled files for stroom/datafeed, will be curl'd/deleted by stroom-log-sender
  - type: file
    currentLogFilename: logs/app/app.log
    discardingThreshold: 0
    # Rolled and gzipped every minute
    archivedLogFilenamePattern: logs/app/app-%d{yyyy-MM-dd'T'HH:mm}.log.gz
    # One week using minute files
    archivedFileCount: 10080
    logFormat: "%-6level [%d{\"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'\",UTC}] [%t] %logger - %X{code} %msg %n"

Log Rolling

Rolling of log files can be done based on size of file or time. The archivedLogFilenamePattern property controls the rolling behaviour. The rolling policy is determined from the filename pattern, e.g a pattern with a minute precision date format will be rolled every minute. The following is an example of an appender that rolls based on the size of the log file:

  - type: file
    currentLogFilename: logs/app.log
    # The name pattern, where i a sequential number indicating age, where 1 is the most recent
    archivedLogFilenamePattern: logs/app-%i.log
    # The maximum number of rolled files to keep
    archivedFileCount: 10
    # The maximum size of a log file
    maxFileSize: "100MB"
    logFormat: "%-6level [%d{\"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'\",UTC}] [%t] %logger - %X{code} %msg %n"

The following is an example of an appender that rolls every minute to gzipped files:

  - type: file
    currentLogFilename: logs/app/app.log
    # Rolled and gzipped every minute
    archivedLogFilenamePattern: logs/app/app-%d{yyyy-MM-dd'T'HH:mm}.log.gz
    # One week using minute files
    archivedFileCount: 10080
    logFormat: "%-6level [%d{\"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'\",UTC}] [%t] %logger - %X{code} %msg %n"