Consider this configuration fragment:

[code]
log_format test_log 'TEST: [$origin_ip] [$upstream_http_content_type]';

location / {
access_log /tmp/test.log test_log;
set $origin_ip $upstream_http_content_type;

proxy_pass http://127.0.0.1:6060;
}
[/code]


Why am I seeing this in the log file "test.log"?

TEST: [] [text/html]

Why is set not being loaded with $upstream_http_content_type? Shouldn't I see:

TEST: [text/html] [text/html]

Any ideas?