Hello Joseph, I'm CCing Bhaskar since he was the one proposing the first solution, he may have some useful insights. Other points below.
On Thu, Jan 15, 2015 at 01:23:59PM -0800, Joseph Lynch wrote: > Hello, > > I am trying to set up a health check service similar to the inetd solutions > suggested in the documentation. Unfortunately, my backends run on different > ports because they are being created dynamically and as far as I can tell I > cannot include the server port in my healthcheck either as part of the > server declaration, a header, or as part of the healthcheck uri itself. > > I have been trying to come up with potential solutions that are not overly > invasive, and I think that the simplest solution is to include the server > host and port in the existing send-state header. I have included a patch > that I believe does this at the end of this email. Before I go off > maintaining a local fork, I wanted to ask if the haproxy devs would be > sympathetic to me trying to upstream this patch? I'm personally fine with it. As you say, it's really not invasive, so we could merge it and even backport it into 1.5-stable. I'd slightly change something however, I'd use "address" instead of "host" in the field, since that's what you're copying there. "Host" could be used later to copy the equivalent of a host name, so let's not misuse the field name. > As for prior art, I found a few posts on this mailing list about the > ability to add headers to http checks. I believe that something like > http://marc.info/?l=haproxy&m=139181606417120&w=2 would be more then what > we need to solve this problem, but that thread seems to have died. I do > believe that a general ability to add headers to healthchecks would be > superior to my patch, but the general solution is significantly harder to > pull off. I'd like to re-heat that thread. I didn't even remember about it, indeed we were busy finalizing 1.5. Bhaskar, I still think your work makes sense for 1.6, so if you still have your patch, it's probably time to resend it :-) > If you guys agree that this patch is ok, please let me know what > I need to do next. I don't see any tests for the send-state option but I > presume that I would need to update the documentation. Please check what your patch does with servers not having any IP nor port (ie: the ones reached over a unix socket). I suspect you'll have the socket path in the host part, and "0" as the port, but I'm not sure, so I'd like to be certain. Also, please verify that it's really the server's address and port, and not the ones from the check, that are passed in the header. So if you specify "addr" and "port" on the server line, these ones are only used for the check, and we want to be sure that the real ones are properly used. Once everything's OK, please update the doc about "send-state". Thanks, Willy > === Patch === > > diff --git a/src/checks.c b/src/checks.c > index 15a3c40..d620b5b 100644 > --- a/src/checks.c > +++ b/src/checks.c > @@ -477,6 +477,8 @@ static int httpchk_build_status_header(struct server > *s, char *buffer, int size) > int sv_state; > int ratio; > int hlen = 0; > + char host[46]; > + char port[6]; > const char *srv_hlt_st[7] = { "DOWN", "DOWN %d/%d", > "UP %d/%d", "UP", > "NOLB %d/%d", "NOLB", > @@ -507,8 +509,11 @@ static int httpchk_build_status_header(struct server > *s, char *buffer, int size) > (s->state != SRV_ST_STOPPED) ? (s->check.health - > s->check.rise + 1) : (s->check.health), > (s->state != SRV_ST_STOPPED) ? (s->check.fall) : > (s->check.rise)); > > - hlen += snprintf(buffer + hlen, size - hlen, "; name=%s/%s; node=%s; > weight=%d/%d; scur=%d/%d; qcur=%d", > - s->proxy->id, s->id, > + addr_to_str(&s->addr, host, sizeof(host)); > + port_to_str(&s->addr, port, sizeof(port)); > + > + hlen += snprintf(buffer + hlen, size - hlen, "; host=%s; port=%s; > name=%s/%s; node=%s; weight=%d/%d; scur=%d/%d; qcur=%d", > + host, port, s->proxy->id, s->id, > global.node, > (s->eweight * s->proxy->lbprm.wmult + s->proxy->lbprm.wdiv > - 1) / s->proxy->lbprm.wdiv, > (s->proxy->lbprm.tot_weight * s->proxy->lbprm.wmult + > s->proxy->lbprm.wdiv - 1) / s->proxy->lbprm.wdiv,
