HTTP Proxy

Enable traffic through a proxy server via HTTP_PROXY environment variable

HTTP Proxy

Fluent Bit supports setting up a HTTP proxy for all egress HTTP/HTTPS traffic by setting HTTP_PROXY environment variable:

• You can set up basic authentication with HTTP_PROXY=http://<username>:<password>@<proxy host>:<port> to provide your username and password when connecting to the proxy.

• You can also set up HTTP_PROXY=http://<proxy host>:<port> to omit username and password if there is none.

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.

Note: HTTP proxy is also supported using the HTTP output plugin. This configuration continues to work, however it should not be used together with the HTTP_PROXY environment variable. This is because under the hood, the HTTP_PROXY environment variable based proxy support 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.

NO_PROXY

In some environments, we wish HTTP traffic for some domains don't go through the HTTP_PROXY, and this is where we need to use NO_PROXY environment variable.

NO_PROXY is a comma-separated list of host names that shouldn't go through any proxy is set in (only an asterisk, * matches all hosts), e.g. foo.com,bar.com. This is as a curl convention.

One typical use case for NO_PROXY is when running fluent-bit in a Kubernetes environment, where we want:

• All real egress traffic goes through a HTTP proxy.

• All "Kubernetes local" traffic does not go through the HTTP proxy.

• We can set NO_PROXY=127.0.0.1,localhost,kubernetes.default.svc in this case.