Add Host header support to http health check.

Author: bugre

CHANGELOG.md

@@ -1,6 +1,10 @@
 # Changelog
 
 
+## 2020-03-26 (1.8-1.5)
+
+- Add HTTPCHK_HOST variable to allow health check to include "Host: xyz.com" HTTP Header. Defaults to "localhost"
+
 ## 2019-11-28 (1.8-1.5)
 
 - Add COOKIES_PARAMS variable to give the possibility to add expiration time to cookies

haproxy/Readme.md

@@ -147,6 +147,7 @@ either when running the container or in a `docker-compose.yml` file.
   * `TIMEOUT_CLIENT` timeouts apply when the client is expected to acknowledge or send data during the TCP process. Default `50000` ms
   * `TIMEOUT_SERVER` timeouts apply when the server is expected to acknowledge or send data during the TCP process. Default `50000` ms
   * `HTTPCHK` The HTTP method and uri used to check on the servers health - default `HEAD /`
+  * `HTTPCHK_HOST` Host Header override on http Health Check - default `localhost`
   * `INTER` parameter sets the interval between two consecutive health checks. If not specified, the default value is `2s`
   * `FAST_INTER` parameter sets the interval between two consecutive health checks when the server is any of the transition state (read above): UP - transitionally DOWN or DOWN - transitionally UP. If not set, then `INTER` is used.
   * `DOWN_INTER` parameter sets the interval between two consecutive health checks when the server is in the DOWN state. If not set, then `INTER` is used.

haproxy/docker-entrypoint.sh

@@ -45,6 +45,7 @@ if ! test -e /etc/haproxy/haproxy.cfg; then
     if [ ! -z "$FRONTEND_PORT" ]; then echo "export FRONTEND_PORT=\"$FRONTEND_PORT\""  >> /etc/environment; fi
     if [ ! -z "$FRONTEND_MODE" ]; then echo "export FRONTEND_MODE=\"$FRONTEND_MODE\""  >> /etc/environment; fi
     if [ ! -z "$HTTPCHK" ]; then echo "export HTTPCHK=\"$HTTPCHK\""  >> /etc/environment; fi
+    if [ ! -z "$HTTPCHK_HOST" ]; then echo "export HTTPCHK_HOST=\"$HTTPCHK_HOST\""  >> /etc/environment; fi
     if [ ! -z "$INTER" ]; then echo "export INTER=\"$INTER\""  >> /etc/environment; fi
     if [ ! -z "$LOGGING" ]; then echo "export LOGGING=\"$LOGGING\""  >> /etc/environment; fi
     if [ ! -z "$LOG_LEVEL" ]; then echo "export LOG_LEVEL=\"$LOG_LEVEL\""  >> /etc/environment; fi

haproxy/src/configure.py

@@ -28,6 +28,7 @@
 TIMEOUT_CLIENT = os.environ.get('TIMEOUT_CLIENT', '50000')
 TIMEOUT_SERVER = os.environ.get('TIMEOUT_SERVER', '50000')
 HTTPCHK = os.environ.get('HTTPCHK', 'HEAD /')
+HTTPCHK_HOST = os.environ.get('HTTPCHK_HOST', 'localhost')
 INTER = os.environ.get('INTER', '2s')
 FAST_INTER = os.environ.get('FAST_INTER', INTER)
 DOWN_INTER = os.environ.get('DOWN_INTER', INTER)
@@ -81,7 +82,7 @@
     option forwardfor
     http-request set-header X-Forwarded-Port %[dst_port]
     http-request add-header X-Forwarded-Proto https if { ssl_fc }
-    option httpchk $httpchk HTTP/1.1\\r\\nHost:localhost
+    option httpchk $httpchk HTTP/1.1\\r\\nHost:$httpchk_host
 """)
 
 backend_conf_plus = Template("""
@@ -107,7 +108,8 @@
 
 if BACKENDS_MODE == 'http':
     backend_conf += backend_type_http.substitute(
-        httpchk=HTTPCHK
+        httpchk=HTTPCHK,
+        httpchk_host=HTTPCHK_HOST
     )
 
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