# HAProxy

## Logging

2.x versions of HAProxy can log to stdout which is picked up by journalctl.

```
global
# enable to only log special events
#    log /dev/log local0 info
# enable to see connection logs using journalctl -f
    log stdout format short daemon
```

1.x versions are limited to syslog communication. This is relevant for El 8.

## Logging the virtual host

For http `option httplog` works well. Translates to:
```
    # strict equivalent of "option httplog"
    log-format "%ci:%cp [%tr] %ft %b/%s %TR/%Tw/%Tc/%Tr/%Ta %ST %B %CC \
                %CS %tsc %ac/%fc/%bc/%sc/%rc %sq/%bq %hr %hs %{+Q}r"
```

For tcp/https passthrough there is less data available. To have a kind of equivalent output:
```
    # This is a TCP proxy
    mode tcp
    log-format "%ci:%cp [%t] %ft %b/%s %Tw/%Tc/%Tt %B %ts %ac/%fc/%bc/%sc/%rc %sq/%bq {%[capture.req.hdr(0)]}"

    acl clienthello req_ssl_hello_type 1

    tcp-request inspect-delay 5s
    # Used in custom log format. Needs to be before accept!
    tcp-request content capture req.ssl_sni len 100
    tcp-request content accept if clienthello
```

`option tcplog` will not capture SNI as TCP can also be any non TLS connection.