The patch is not obvious at the first glance. But it is just a reorg. Functions
have been grouped and ordered in a more logical way. Some structures and flags
are now private to the checks module (so moved from the .h to the .c file).
Thanks to previous change, it is now possible to removed all code handling pure
tcp checks. Now every connection based health-checks are handled by the
tcpcheck_main() function. __event_srv_chk_w() and __event_srv_chk_r() have been
removed. And all connection establishment is handled at one place.
Defaut health-checks, without any option, doing only a connection check, are now
based on tcp-checks. An implicit default tcp-check connect rule is used. A
shared tcp-check ruleset, name "*tcp-check" is created to support these checks.
When a tcp-check connect rule is evaluated, the mux protocol corresponding to
the health-check is chosen. So for TCP based health-checks, the mux-pt is
used. For HTTP based health-checks, the mux-h1 is used. The connection is marked
as private to be sure to not ruse regular HTTP connection for
health-checks. Connections reuse will be evaluated later.
The functions evaluating HTTP send rules and expect rules have been updated to
be HTX compliant. The main change for users is that HTTP health-checks are now
stricter on the HTTP message format. While before, the HTTP formatting and
parsing were minimalist, now messages should be well formatted.
This function is unused for now. But it will have be used to install a mux for
an outgoing connection openned in a health-check context. In this case, the
session's origin is the check itself, and it is used to know the mode, HTTP or
TCP, depending on the tcp-check type and not the proxy mode. The check is also
used to get the mux protocol if configured.
It is not set and not used for now, but it will be possible to force the mux
protocol thanks to this patch. A mux proto field is added to the checks and to
tcp-check connect rules.
Before, the server was used as origin during session creation. It was only used
to get the check associated to the server when a variable is get or set in the
check scope or when a check sample fetch was called. So it seems easier to use
the check as origin of a session. It is also more logical becaues the session is
created by the health-check itself and not its server.
A dedicated function is now used to received data. fundamentally, it should do
the same operations than before. But the way data are received has been reworked
to be closer to the si_cs_recv() function.
First tests before executing the loop on tcp-check rules in tcpcheck_main()
function have been slightly modified to be more explicit and easier to
understand.
HTTP health-checks are now internally based on tcp-checks. Of course all the
configuration parsing of the "http-check" keyword and the httpchk option has
been rewritten. But the main changes is that now, as for tcp-check ruleset, it
is possible to perform several send/expect sequences into the same
health-checks. Thus the connect rule is now also available from HTTP checks, jst
like set-var, unset-var and comment rules.
Because the request defined by the "option httpchk" line is used for the first
request only, it is now possible to set the method, the uri and the version on a
"http-check send" line.
the get_last_tcpcheck_rule() function iters on a rule list in the reverse order
and returns the first non comment and non action-kw rule. If no such rule is
found, NULL is returned.
Instead of having 2 independent integers, used as boolean values, to know if the
expect rule is invered and to know if the matching regexp has captures, we know
use a 32-bits bitfield.
All tcp-check rules are now stored in the globla shared list. The ones created
to parse a specific protocol, for instance redis, are already stored in this
list. Now pure tcp-check rules are also stored in it. The ruleset name is
created using the proxy name and its config file and line. tcp-check rules
declared in a defaults section are also stored this way using "defaults" as
proxy name.
For now, all tcp-check ruleset are stored in a list. But it could be a bit slow
to looks for a specific ruleset with a huge number of backends. So, it could be
a good idea to use a tree instead.
It is now possible to specified the healthcheck status to use on success of a
tcp-check rule, if it is the last evaluated rule. The option "ok-status"
supports "L4OK", "L6OK", "L7OK" and "L7OKC" status.
A shared tcp-check ruleset is now created to support agent checks. The following
sequence is used :
tcp-check send "%[var(check.agent_string)] log-format
tcp-check expect custom
The custom function to evaluate the expect rule does the same that it was done
to handle agent response when a custom check was used.
Parsing of following keywords have been moved in checks.c file : addr, check,
check-send-proxy, check-via-socks4, no-check, no-check-send-proxy, rise, fall,
inter, fastinter, downinter and port.
A share tcp-check ruleset is now created to support SPOP checks. This way no
extra memory is used if several backends use a SPOP check.
The following sequence is used :
tcp-check send-binary SPOP_REQ
tcp-check expect custom min-recv 4
The spop request is the result of the function
spoe_prepare_healthcheck_request() and the expect rule relies on a custom
function calling spoe_handle_healthcheck_response().
A shared tcp-check ruleset is now created to support LDAP check. This way no
extra memory is used if several backends use a LDAP check.
The following sequance is used :
tcp-check send-binary "300C020101600702010304008000"
tcp-check expect rbinary "^30" min-recv 14 \
on-error "Not LDAPv3 protocol"
tcp-check expect custom
The last expect rule relies on a custom function to check the LDAP server reply.
A share tcp-check ruleset is now created to support MySQL checks. This way no
extra memory is used if several backends use a MySQL check.
One for the following sequence is used :
## If no extra params are set
tcp-check connect default linger
tcp-check expect custom ## will test the initial handshake
## If the username is defined
tcp-check connect default linger
tcp-check send-binary MYSQL_REQ log-format
tcp-check expect custom ## will test the initial handshake
tcp-check expect custom ## will test the reply to the client message
The log-format hexa string MYSQL_REQ depends on 2 preset variables, the packet
header containing the packet length and the sequence ID (check.header) and the
username (check.username). If is also different if the "post-41" option is set
or not. Expect rules relies on custom functions to check MySQL server packets.
A shared tcp-check ruleset is now created to support postgres check. This way no
extra memory is used if several backends use a pgsql check.
The following sequence is used :
tcp-check connect default linger
tcp-check send-binary PGSQL_REQ log-format
tcp-check expect !rstring "^E" min-recv 5 \
error-status "L7RSP" on-error "%[check.payload(6,0)]"
tcp-check expect rbinary "^520000000800000000 min-recv "9" \
error-status "L7STS" \
on-success "PostgreSQL server is ok" \
on-error "PostgreSQL unknown error"
The log-format hexa string PGSQL_REQ depends on 2 preset variables, the packet
length (check.plen) and the username (check.username).
A share tcp-check ruleset is now created to support smtp checks. This way no
extra memory is used if several backends use a smtp check.
The following sequence is used :
tcp-check connect default linger
tcp-check expect rstring "^[0-9]{3}[ \r]" min-recv 4 \
error-status "L7RSP" on-error "%[check.payload(),cut_crlf]"
tcp-check expect rstring "^2[0-9]{2}[ \r]" min-recv 4 \
error-status "L7STS" \
on-error %[check.payload(4,0),ltrim(' '),cut_crlf] \
status-code "check.payload(0,3)"
tcp-echeck send "%[var(check.smtp_cmd)]\r\n" log-format
tcp-check expect rstring "^2[0-9]{2}[- \r]" min-recv 4 \
error-status "L7STS" \
on-error %[check.payload(4,0),ltrim(' '),cut_crlf] \
on-success "%[check.payload(4,0),ltrim(' '),cut_crlf]" \
status-code "check.payload(0,3)"
The variable check.smtp_cmd is by default the string "HELO localhost" by may be
customized setting <helo> and <domain> parameters on the option smtpchk
line. Note there is a difference with the old smtp check. The server gretting
message is checked before send the HELO/EHLO comand.
A shared tcp-check ruleset is now created to support ssl-hello check. This way
no extra memory is used if several backends use a ssl-hello check.
The following sequence is used :
tcp-check send-binary SSLV3_CLIENT_HELLO log-format
tcp-check expect rbinary "^1[56]" min-recv 5 \
error-status "L6RSP" tout-status "L6TOUT"
SSLV3_CLIENT_HELLO is a log-format hexa string representing a SSLv3 CLIENT HELLO
packet. It is the same than the one used by the old ssl-hello except the sample
expression "%[date(),htonl,hex]" is used to set the date field.
A share tcp-check ruleset is now created to support redis checks. This way no
extra memory is used if several backends use a redis check.
The following sequence is used :
tcp-check send "*1\r\n$4\r\nPING\r\n"
tcp-check expect string "+PONG\r\n" error-status "L7STS" \
on-error "%[check.payload(),cut_crlf]" on-success "Redis server is ok"
It is now possible to set a custom function to evaluate a tcp-check expect
rule. It is an internal and not documentd option because the right pointer of
function must be set and it is not possible to express it in the
configuration. It will be used to convert some protocol healthchecks to
tcp-checks.
Custom functions must have the following signature:
enum tcpcheck_eval_ret (*custom)(struct check *, struct tcpcheck_rule *, int);
A list of variables is now associated to each tcp-check ruleset. It is more a
less a list of set-var expressions. This list may be filled during the
configuration parsing. The listed variables will then be set during each
execution of the tcp-check healthcheck, at the begining, before execution of the
the first tcp-check rule.
This patch is mandatory to convert all protocol checks to tcp-checks. It is a
way to customize shared tcp-check rulesets.
This option defines a sample expression, evaluated as an integer, to set the
status code (check->code) if a tcp-check healthcheck ends on the corresponding
expect rule.
These options define log-format strings used to produce the info message if a
tcp-check expect rule fails (on-error option) or succeeds (on-success
option). For this last option, it must be the ending rule, otherwise the
parameter is ignored.
It is now possible to extract information from the check input buffer using the
check.payload sample fetch. As req.payload or res.payload, an offset and a
length must be specified.
A new section has been added in the configuration manual. Now check sample
fetches will have to be documented under the section 7.3.7 (Fetching
health-check samples).
When a tcp-check healthcheck fails on a specific rule with no dedicated comment,
we look in previous rules if a comment rule is specified. Now, instead of doing
it during tcp-checks execution, we assign the comment to the corresponding rules
during the configuration parsing. So after HAProxy startup, no more comment
rules remains in a tcp-check ruleset.
It is now possible to specified the healthcheck status to use on error or on
timeout for tcp-check expect rules. First, to define the error status, the
option "error-status" must be used followed by "L4CON", "L6RSP", "L7RSP" or
"L7STS". Then, to define the timeout status, the option "tout-status" must be
used followed by "L4TOUT", "L6TOUT" or "L7TOUT".
These options will be used to convert specific protocol healthchecks (redis,
pgsql...) to tcp-check ones.
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