HAProxy community

Order of configuration changes after Dataplane API commit

Hi,
I’m using Dataplane API to update HAProxy configuration and everything works well except the new version of configuration has a different order of directives under backends and frontends. To give an example, let’s say I have this pseudo backend block;

backend be_static
  mode http
  http-request set-header Host example.net
  http-response add-header Set-Cookie my_cookie=%[var(txn.my_cookie)]
  server example example.net ssl verify none sni str(example.net)

After adding another backend with Dataplane API my be_static backend ends up in this order;

backend be_static
  mode http
  http-request set-header Host example.net
  server example example.net ssl verify none sni str(example.net)
  http-response add-header Set-Cookie my_cookie=%[var(txn.my_cookie)]

and it breaks the functionality. Not only backends but my frontend configurations suffer from this change of order too after an API commit. For example;

capture request header Referer len 200
capture request header User-Agent len 200
log-format %ci\ -\ %{+Q}r\ %ST\ %U\ %{+Q}[capture.req.hdr(0)]\ %{+Q}[capture.req.hdr(1)]\ %{+Q}b\ %{+Q}s
use_backend %[base,lower,map_beg(api.map)]-http if { path_beg /api }
use_backend %[base,lower,map_beg(http.map)]

becomes

log-format %ci\ -\ %{+Q}r\ %ST\ %U\ %{+Q}[capture.req.hdr(0)]\ %{+Q}[capture.req.hdr(1)]\ %{+Q}b\ %{+Q}s
use_backend %[base,lower,map_beg(api.map)]-http if { path_beg /api }
use_backend %[base,lower,map_beg(http.map)]
capture request header Referer len 200
capture request header User-Agent len 200

Any idea why this happens or a workaround to prevent it happening?

Thanks in advance

# haproxy -vv
HA-Proxy version 2.0.14-1ppa1~bionic 2020/04/16 - https://haproxy.org/
Build options :
  TARGET  = linux-glibc
  CPU     = generic
  CC      = gcc
  CFLAGS  = -O2 -g -O2 -fdebug-prefix-map=/build/haproxy-vOKb8p/haproxy-2.0.14=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fno-strict-aliasing -Wdeclaration-after-statement -fwrapv -Wno-unused-label -Wno-sign-compare -Wno-unused-parameter -Wno-old-style-declaration -Wno-ignored-qualifiers -Wno-clobbered -Wno-missing-field-initializers -Wno-implicit-fallthrough -Wno-stringop-overflow -Wtype-limits -Wshift-negative-value -Wshift-overflow=2 -Wduplicated-cond -Wnull-dereference
  OPTIONS = USE_PCRE2=1 USE_PCRE2_JIT=1 USE_REGPARM=1 USE_OPENSSL=1 USE_LUA=1 USE_ZLIB=1 USE_SYSTEMD=1

Feature list : +EPOLL -KQUEUE -MY_EPOLL -MY_SPLICE +NETFILTER -PCRE -PCRE_JIT +PCRE2 +PCRE2_JIT +POLL -PRIVATE_CACHE +THREAD -PTHREAD_PSHARED +REGPARM -STATIC_PCRE -STATIC_PCRE2 +TPROXY +LINUX_TPROXY +LINUX_SPLICE +LIBCRYPT +CRYPT_H -VSYSCALL +GETADDRINFO +OPENSSL +LUA +FUTEX +ACCEPT4 -MY_ACCEPT4 +ZLIB -SLZ +CPU_AFFINITY +TFO +NS +DL +RT -DEVICEATLAS -51DEGREES -WURFL +SYSTEMD -OBSOLETE_LINKER +PRCTL +THREAD_DUMP -EVPORTS

Default settings :
  bufsize = 16384, maxrewrite = 1024, maxpollevents = 200

Built with multi-threading support (MAX_THREADS=64, default=2).
Built with OpenSSL version : OpenSSL 1.1.1  11 Sep 2018
Running on OpenSSL version : OpenSSL 1.1.1  11 Sep 2018
OpenSSL library supports TLS extensions : yes
OpenSSL library supports SNI : yes
OpenSSL library supports : TLSv1.0 TLSv1.1 TLSv1.2 TLSv1.3
Built with Lua version : Lua 5.3.3
Built with network namespace support.
Built with transparent proxy support using: IP_TRANSPARENT IPV6_TRANSPARENT IP_FREEBIND
Built with zlib version : 1.2.11
Running on zlib version : 1.2.11
Compression algorithms supported : identity("identity"), deflate("deflate"), raw-deflate("deflate"), gzip("gzip")
Built with PCRE2 version : 10.31 2018-02-12
PCRE2 library supports JIT : yes
Encrypted password support via crypt(3): yes
Built with the Prometheus exporter as a service

Available polling systems :
      epoll : pref=300,  test result OK
       poll : pref=200,  test result OK
     select : pref=150,  test result OK
Total: 3 (3 usable), will use epoll.

Available multiplexer protocols :
(protocols marked as <default> cannot be specified using 'proto' keyword)
              h2 : mode=HTX        side=FE|BE     mux=H2
              h2 : mode=HTTP       side=FE        mux=H2
       <default> : mode=HTX        side=FE|BE     mux=H1
       <default> : mode=TCP|HTTP   side=FE|BE     mux=PASS

Available services :
	prometheus-exporter

Available filters :
	[SPOE] spoe
	[COMP] compression
	[CACHE] cache
	[TRACE] trace

Reported as bug: https://github.com/haproxytech/dataplaneapi/issues/107