Enable traffic through a proxy server via HTTP_PROXY environment variable
Fluent Bit supports configuring an HTTP proxy for all egress HTTP/HTTPS traffic via the HTTP_PROXY or http_proxy environment variable.
The format for the HTTP proxy environment variable is http://USER:PASS@HOST:PORT, where:
USER is the username when using basic authentication.
PASS is the password when using basic authentication.
HOST is the HTTP proxy hostname or IP address.
PORT is the port the HTTP proxy is listening on.
To use an HTTP proxy with basic authentication, provide the username and password:
When no authentication is required, omit the username and password:
The HTTP_PROXY environment variable is a standard way for setting a HTTP proxy in a containerized environment, and it is also natively supported by any application written in Go. Therefore, we follow and implement the same convention for Fluent Bit. For convenience and compatibility, the http_proxy environment variable is also supported. When both the HTTP_PROXY and http_proxy environment variables are provided, HTTP_PROXY will be preferred.
Note: The HTTP output plugin also supports configuring an HTTP proxy. This configuration continues to work, however it should not be used together with the HTTP_PROXY or http_proxy environment variable. This is because under the hood, the environment variable based proxy configuration is implemented by setting up a TCP connection tunnel via HTTP CONNECT. Unlike the plugin's implementation, this supports both HTTP and HTTPS egress traffic.
Not all traffic should flow through the HTTP proxy. In this case, the NO_PROXY or no_proxy environment variable should be used.
The format for the no proxy environment variable is a comma-separated list of hostnames or IP addresses whose traffic should not flow through the HTTP proxy.
A domain name matches itself and all its subdomains (i.e. foo.com matches foo.com and bar.foo.com):
A domain with a leading . only matches its subdomains (i.e. .foo.com matches bar.foo.com but not foo.com):
One typical use case for NO_PROXY is when running Fluent Bit in a Kubernetes environment, where we want:
All real egress traffic to flow through an HTTP proxy.
All local Kubernetes traffic to not flow through the HTTP proxy.
In this case, we can set:
For convenience and compatibility, the no_proxy environment variable is also supported. When both the NO_PROXY and no_proxy environment variables are provided, NO_PROXY will be preferred.