Advanced Configuration in Ruby

Ruby agent configuration

You can configure the Sqreen Ruby agent with settings in a configuration file, or with environment variables. This page describes the configuration options available for the Ruby agent.

Configuration methods and precedence

The default method to configure the Sqreen Ruby agent is through the configuration file sqreen.yml in the config directory.

You can also configure most options with environment variables. Here are the order of precedence for configuration:

  1. Environment variables
  2. Configuration file sqreen.yml
  3. Default configuration options

Environment variables override the settings in the sqreen.yml configuration file. The configuration file settings override the agent default options.

Edit configuration file options

The Ruby agent configuration file sqreen.yml uses a standard yaml format. As in Ruby on Rails, you can use ERB inside sqreen.yml

The most important configuration option is the Sqreen token, used to identify the application on Sqreen. Options are listed below.

YAML indentation

When you edit the config file, be sure to indent only with two spaces. If you do not indent correctly, the Sqreen agent will throw an error at Startup ("Unable to parse configuration file")

Deploying Sqreen configuration

Configuration file should be deployed on the servers running Sqreen

Sqreen settings can be optionally adjusted according to your needs. This section lists the possible configuration options you have with Sqreen Ruby agent.

Setting up the path of the configuration file

You can use a specific path for the configuration file using SQREEN_CONFIG_FILE environment variable:

export SQREEN_CONFIG_FILE=/custom/path/sqreen.yml 

Configuration variables

The Sqreen agent can be configured using environment variables or a YAML file. Here are the settings that can be changed:

Variable name Role YAML key name Default value Allowed values
SQREEN_TOKEN The Sqreen token. This identifies the agent to Sqreen backend servers token Empty String
SQREEN_CONFIG_FILE Custom location for the YAML based config Empty String
SQREEN_LOG_LOCATION Specify a custom file to write Sqreen logs log_location log/sqreen.log String
SQREEN_REPORT_PERF Report overhead for each request in the log (WARN level) report_perf false (disabled) Boolean
SQREEN_REPORT_PERF_NR Report overhead for each request to NewRelic as custom transaction attributes report_perf_newrelic 0 (disabled) 0 (disabled), 1 (global overhead), 2 (report duration for each protection category)
SQREEN_IP_HEADER Specify the preferred request header for extracting the client IP address ip_header Empty a header name (case insensitive)
SQREEN_DISABLE Prevent the Sqreen agent from starting. Any value in this environment variable will disable Sqreen. disable false (Sqreen is enabled) Boolean
SQREEN_STRIP_SENSITIVE_DATA Remove sensitive data before sending them to Sqreen strip_sensitive_data true Boolean
SQREEN_STRIP_SENSITIVE_KEYS Comma separated list of keys to strip, refer to the dedicated section below for details strip_sensitive_keys Empty (use default values) (arbitrary)
SQREEN_STRIP_SENSITIVE_REGEX Regular expression used for value stripping, refer to the dedicated section below for details strip_sentitive_regex Empty (use default values) (arbitrary)
HTTP_PROXY, http_proxy HTTP proxy for the agent's reporting connection to Sqreen backend servers - - proxy URI (e.g. http://proxy:port )

Multiple Rails environments

The Sqreen token is the only required setting. The YAML configuration also supports using a different section per Rails environment:

token: mysecrettoken #general configuration

    token:  mysecretproductiontoken # override general configuration

PII scrubbing

Unless strip_sensitive_data is set to false, the Sqreen gem will redact certain data prior to sending to Sqreen's servers. It will redact the values of key-value pairs where the key is listed in strip_sensitive_keys (compared in a case insensitive manner), and it will also redact any values, including array elements — but not keys —, that fully match the strip_sensitive_regex configuration setting.

Default PII scrubbing values are listed in PII Scrubbing.

Changing strip_sensitive_keys or strip_sensitive_regex will override the defaults. Therefore, you will probably want to append your extra keys to the list of predefined keys and combine the default regular expression with your new one.