Last updated 2023-06-14
(The following information has been confirmed for RHEL/CentOS deployments using the default yum module installation.)
The default install location for the SigSci Apache module is
/etc/httpd/modules but some systems may have Apache loading it's config from a non-standard directory. When this happens the
yum installer will not install
/etc/httpd/modules but instead to the following path:
If Apache fails to restart after the module installation because it cannot locate
mod_signalsciences.so change the LoadModules line in
httpd.conf to reflect the correct location on the target system.
The agent can be configured to use a local proxy for egress traffic to the Signal Sciences cloud infrastructure by setting the
HTTPS_PROXY environment variable. Add the following line to
IP-OR-HOST-NAME with the IP address or hostname to proxy traffic to:
Restart the agent and verify the configuration.
When configuring rules with a block or allow action, you can use the Request logging menu to select whether a sample of matched requests are logged or not logged.
When a request is logged, the individual request data and time series data for that request will be available throughout the web interface (e.g., on the Requests page). When a request is not logged, only time series data for that request will be available in the web interface.
By default, the agent asks the OS for the hostname configuration. The agent can be configured to instead use a custom hostname in one of two ways:
-server-hostname="HOSTNAME" flag when starting the
sigsci-agent process via command line:
Add the following line to your agent configuration file (by default at
server-hostname = "HOSTNAME"
When the module and agent have been successfully installed you will be able to see them reporting within the Agents page of the console. In many cases, customers first realize there may be a problem with their configuration when they have started the agent and everything appears to be running normally but the agent or module are not listed correctly.
Although the agent appears to be running, it's possible for the agent to not be listed in the Agents page of the console. This is typically due to either the agent being misconfigured or a connection issue between the agent and our cloud-hosted backend. Run through the following troubleshooting steps:
Check if the agent is running:$ ps -aef | grep sigsci-agent
Try restarting the agent with:$ sudo restart sigsci-agent
If the agent is running, ensure communication between the agent and the cloud-hosted backend isn't blocked by your firewall. The Signal Sciences agent communicates with the following endpoints outbound via port 443/TCP:
Additional information about firewall restrictions can be found in Architecture.
Review any log files for error messages:$ ls -l /var/log/sigsci-agent$ tail -n 20 /var/log/sigsci-agent
If the agent is not starting and nothing is written to the log files, check what messages are displayed if you run the agent manually:$ stop sigsci-agent$ /usr/sbin/sigsci-agent
Run the debug tool and send the output, along with a detailed description of the issue and all log files, to our Support team.$ /usr/sbin/sigsci-agent-diag
Alternatively, although the console may show that the agent is reporting, the module may be listed as "undetected". There are a few possible causes to this scenario and the following steps are intended to help troubleshoot this condition:
It is necessary to send a request through the system in order for the module to report to the agent. Generating a manual 404 to the server in question by requesting a page that doesn't exist is the easiest way to start seeing traffic validated on the console. Allow up to 30 seconds from the time of the request for the module to report and the console to display the anomaly.
Confirm the steps for module installation specific to your web server, and any optional configuration changes, have been made correctly.
Restart the web server after module installation.
If the module is still not reporting and no data is showing in the console, check for issues related to domain socket permissions. By default, the agent and module are configured to use
/var/run/sigsci.sockas the local domain socket under Linux operating systems and will require sufficient privileges to run properly:
If using Red Hat/CentOS, check for SELinux:$ sestatus
If SELinux is enabled refer to the SELinux support guide.
If using Ubuntu check for AppArmor and adjust security profiles if necessary:$ sudo apparmor_status
If the module is still not reporting, reach out to our Support team with a detailed description of the issue and the following logs:
NGINX or Apache
error.log, IIS error logs (default
If NGINX is your web server, capture the output of:$ /opt/sigsci/bin/check-nginx
Collect the configuration files
/etc/sigsci/agent.confand if running NGINX
/etc/nginx/nginx.confor if running Apache your
httpd.confnormally located in
The Ambassador configuration may not have AuthService defined, which is required for the Signal Sciences agent to receive request data. AuthService is enabled by default; if the agent is not receiving requests, run
kubectl get authservice to check on the status of this service.
Why are my F5 load balancer health checks failing when going through the Signal Sciences reverse proxy?
F5 load balancer health checks use HTTP/0.9 by default. However, the SigSci reverse proxy does not support HTTP/0.9 because Go---which the Signal Sciences agent is written in---does not support it. This results in the F5 health checks failing with
400 Bad Request response codes.
To resolve this, force the F5 health checks to use HTTP/1.0 or HTTP/1.1 instead. Specify the HTTP version in the send string, which will force the monitor to send an HTTP/1.0 or 1.1 request instead.
Below is an example of an HTTP/0.9 GET request:
HTTP/1.0, it will instead become an HTTP/1.0 GET request:
GET /index.html HTTP/1.0
For additional information about altering the F5 health check requests, see F5's official documentation.
The following options were derived from running the command
sigsci-agent -help and can be used as command line flags, set in
/etc/sigsci/agent.conf or set as ENV vars.
Refer to our Configuration Options to view all flags.
Generated environment variables: