make user and group configurable thru envvar

Author: tifayuki

README.md

@@ -198,7 +198,7 @@ Settings in this part is immutable, you have to redeploy HAProxy service to make
 
 |Environment Variable|Default|Description|
 |:-----:|:-----:|:----------|
-|ADDITIONAL_BACKENDS| |list of additional backends to balance. The format is `backend name, FORCE_SSL(True|False), server name, host:port, options`|
+|ADDITIONAL_BACKEND_\<NAME\>| |add an additional backend with the name set in <NAME>. Possible values include:`balance source, server 127.0.0.1:8080`|
 |ADDITIONAL_SERVICES| |list of additional services to balance (es: `prj1:web,prj2:sql`). Discovery will be based on `com.docker.compose.[project|service]` container labels. This environment variable only works on compose v2, and the referenced services must be on a network resolvable and accessible to this containers.|
 |BALANCE|roundrobin|load balancing algorithm to use. Possible values include: `roundrobin`, `static-rr`, `source`, `leastconn`. See:[HAProxy:balance](https://cbonte.github.io/haproxy-dconv/configuration-1.5.html#4-balance)|
 |CA_CERT_FILE| |the path of a ca-cert file. This allows you to mount your ca-cert file directly from a volume instead of from envvar. If set, `CA_CERT` envvar will be ignored. Possible value: `/cacerts/cert0.pem`|
@@ -228,6 +228,8 @@ Settings in this part is immutable, you have to redeploy HAProxy service to make
 |STATS_PORT|1936|port for the HAProxy stats section. If this port is published, stats can be accessed at `http://<host-ip>:<STATS_PORT>/`
 |TIMEOUT|connect 5000, client 50000, server 50000|comma-separated list of HAProxy `timeout` entries to the `default` section.|
 |NBPROC|1|sets the `nbproc` entry to the `global` section. By default, only one process is created, which is the recommended mode of operation.|
+|HAPROXY_USER|haproxy|sets the user of the UNIX sockets to the designated system user name|
+|HAPROXY_GROUP|haproxy|sets the group of the UNIX sockets to the designated system group name|
 
 ### Settings in linked application services###
 

haproxy/config.py

@@ -85,6 +85,8 @@ def parse_additional_backend_settings(envvars):
 TIMEOUT = os.getenv("TIMEOUT", "connect 5000, client 50000, server 50000")
 NBPROC = int(os.getenv("NBPROC", 1))
 SWARM_MODE_POLLING_INTERVAL = int(os.getenv("SWARM_MODE_POLLING_INTERVAL", 5))
+HAPROXY_USER=os.getenv("HAPROXY_USER", "haproxy")
+HAPROXY_GROUP=os.getenv("HAPROXY_GROUP", "haproxy")
 
 # global
 RUNNING_MODE = None

haproxy/haproxycfg.py

@@ -242,8 +242,8 @@ def _config_global_section():
                       "log-send-hostname",
                       "maxconn %s" % MAXCONN,
                       "pidfile /var/run/haproxy.pid",
-                      "user haproxy",
-                      "group haproxy",
+                      "user %s" % HAPROXY_USER,
+                      "group %s" % HAPROXY_GROUP,
                       "daemon",
                       "stats socket /var/run/haproxy.stats level admin"]