Skip to content

M
mongoose
Switch branch/tag
History Find file
  • Deomid Ryabkov's avatar
    Change from using #ifdef to #if for features tests · bafc30be
    Deomid Ryabkov authored 
    "#if FOO" still works with simple -DFOO, but gives more flexibility.
Specifically, if user expressed no preference (FOO is not defined),
we can apply reasonable defaults (this is the legitimate use of ifdef).

In short, from now on, please use

 #if MG_ENABLE_FOO

instead of

 #ifdef MG_ENABLE_FOO

Since we are all used to #ifdef, this change also adds a precommit check
to police this. Specifically, in *.h and *.c files that are Copyright Cesanta,
"ifdef" and "if defined()" are not allowed to be used with macros that contain
ENABLE or DISABLE, unless the like also contains "ifdef-ok".

Hence, if you are sure you want to use ifdef, use this:

 #ifdef MG_ENABLE_FOO /* ifdef-ok */

PUBLISHED_FROM=9be829448f53cff575d6cae8b9945fb12531c15a
    bafc30be
Name
Last commit
 Last update
..
Dockerfile Rename Mongoose constants: NS_ -> MG_, NSF_ -> MG_F_
Makefile Rename Mongoose constants: NS_ -> MG_, NSF_ -> MG_F_
README.md Merge dev branch code named Fossa as next stable Mongoose
load_balancer.c Change from using #ifdef to #if for features tests
unit_test.sh Merge dev branch code named Fossa as next stable Mongoose
README.md

Mongoose-based HTTP load balancer

Configuration

Load balancer is configured with command-line flags.

Global flags

  • -p port – TCP port to listen on. Default: 8000.
  • -l log_file – path to the log file. Default: none.
  • -s ssl_cert – path to SSL certificate. Default: none.

Backend configuration

Main flag is -b uri_prefix host_port – it adds a new backend for a given URI prefix. Example: -b /stuff/ 127.0.0.1:8080 will route all requests that start with '/stuff/' to a backend at port 8080 on localhost. There is a special syntax for uri_prefix that allows you to change the URIs that get passed to backends:

  • -b /stuff/=/ 127.0.0.1:8080 – for '/stuff/thing' backend will see '/thing'.
  • -b /stuff/=/other/ 127.0.0.1:8080 – '/stuff/thing' => '/other/thing'.

Also there are few per-backend flags that can be placed before -b and apply only to the next backend:

  • -r – instead of proxying requests load balancer will reply with 302 redirect.
  • -v vhost – match not only URI prefix but 'Host:' header as well.

Example

load_balancer -s path/to/cert.pem \
  -v example.com -b /site/=/ 127.0.0.1:8080 \
  -b /static/ 127.0.0.1:8081 \
  -b /static/ 127.0.0.1:8082

In this example requests to 'example.com/site/' will be forwarded to the backend on port 8080 with '/site' prefix stripped off and requests to '/static/' on any virtual host will be balanced in round-robin fashion between backends on ports 8081 and 8082.