From 1e2387474a449452b78520b9ad96a8b4b5e99722 Mon Sep 17 00:00:00 2001 From: Harald Pfeiffer Date: Wed, 17 Apr 2019 19:07:19 +0200 Subject: initial commit of source fetch --- .../contrib/README.my-extensions | 139 +++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100755 nagios-plugins-contrib-24.20190301~bpo9+1/check_mysql_health/check_mysql_health-2.2.2/contrib/README.my-extensions (limited to 'nagios-plugins-contrib-24.20190301~bpo9+1/check_mysql_health/check_mysql_health-2.2.2/contrib/README.my-extensions') diff --git a/nagios-plugins-contrib-24.20190301~bpo9+1/check_mysql_health/check_mysql_health-2.2.2/contrib/README.my-extensions b/nagios-plugins-contrib-24.20190301~bpo9+1/check_mysql_health/check_mysql_health-2.2.2/contrib/README.my-extensions new file mode 100755 index 0000000..92aec08 --- /dev/null +++ b/nagios-plugins-contrib-24.20190301~bpo9+1/check_mysql_health/check_mysql_health-2.2.2/contrib/README.my-extensions @@ -0,0 +1,139 @@ +# you will find instructions how to write extensions here + +Self-written code is addressed by using a mode which starts with my- +--mode=my-thing-does ? + +check_mysql_health will then look for a package named MyThing. + +So you first have to write a Module which describes MyThing. Such a thing iinherits from DBD::MySQL::Server and needs two methods: init and nagios. + +Start with a file called CheckMySQLHealthExt1.pm and skeleton code: + +################################################### +package MyThing; + +our @ISA = qw(DBD::MySQL::Server); + +sub init { + my $self = shift; + my %params = @_; +} + +sub nagios { + my $self = shift; + my %params = @_; +} +################################################### + +When you call check_mysql_health with --mode=my-thing-does, it will +- create a DBD::MySQL::Server object + $obj = DBD::MySQL::Server->new() +- connect to the database + $obj->connect() +- re-bless the object + bless $obj, "MyThing" +- call $obj->init() +- if that was ok, call $obj->nagios() + + +So you need to write code which +- initializes the parameters you want to check +- calculates the nagios result from these parameters + +For your convenience there are some predefined methods and variables: + +Variable $self + $self is a hash-based object of type My::Thing + You can pass metrics from the init() method to the nagios() method by + adding attributes to the hash. + One important predefined attribute is $self->{handle} which points to + a database Connection object. You surely will use this. + +Variable %params + $params{mode} contains the string you passed to the + --mode command line parameter, only with the "-" replaced by "::". + In the above example it will be "my::thing::does". + Because you can have only one init() method for your MyThing object but + more than one related modes (my-thing-does, my-thing-length, my-thing-rate) + you use $params{mode} for branching in your code. (see the example file) + +Method add_nagios + $self->add_nagios(1, "i warn you"); + This method can be called several times. The messages will be concatenated. + The first parameter is one of 0..3 and sets the nagios level. The worst level + among several calls to add_nagios will determine the plugin's exit code. + +Method add_nagios_[ok|warning|critical|unknown] + $self->add_nagios_critical("i warned you!!! now it's too late"); + $self->add_nagios_ok("everything is ok. i am the exit message"); + These methods are wrappers for add_nagios which make your code more readable. + +Method add_perfdata + $self->add_perfdata("metric1=0 metric2=100"); + $self->add_perfdata("metric3=0); + $self->add_perfdata(sprintf "metric_xy=%d", $self->{xy}); + You can call add_perfdata as often as you like. + The strings will be concatenated. + +Method valdiff + $self->valdiff(\%params, qw(metric1 metric2)); + Use this if you want to know how a metric has changed since the last run + of check_mysql_health. + Provided you have attributes metric1 and metric2 this method will create + new attributes for your $self object. + $self->{delta_metric1} which is the difference between the value of + $self->{metric1} during the current run and $self->{metric1} during the + last run. + $self->{delta_timestamp} which is the number of seconds which passed + since the last run of check_mysql_health. + If you have ever-growing values, you can simply calculate the rate: + $self->{metric1_per_second} = $self->{delta_metric1} / $self->{delta_timestamp} + The valdiff method will automatically save the current value to a state file + and read the past value from this file. + If you used the --name parameter which appears as $params{name} in your code + then you probably need to separate the saved values from each other. Otherwise + name1 would read the same saved value as name2. They would overwrite the + saved values. Use $params{differentiator} to use different state files. + $params{differenciator} = lc $self->{name}; + $self->valdiff(\%params, qw(gets misses)); + +Method fetchrow_array + my($column1, $column2) = $self->{handle}->fetchrow_array(q{ + SELECT col1, col2 FROM table1 where col1 = 'val1' + }); + $self->{connected_users} = $self->{handle}->fetchrow_array(q{ + SELECT COUNT(*) FROM v$session WHERE type = 'USER' + }); + This method is used like the Perl DBI method fetchrow_array. + + +Method fetchall_array + my @results = $self->{handle}->fetchall_array(q{ + SELECT col1, col2, col3 FROM table1 + }); + foreach (@results) { + my($column1, $column2, $column3) = @{$_}; + ... + } + This method is used like the Perl DBI method fetchall_array. + + + + +Now you have written your first extension to check_mysql_health. Maybe you +just modified the example file contrib/CheckMySQLHealthExt1.pm +There are two methods how to import your own code into check_mysql_health: + +- the static method +with ./configure --with-mymodules-dir= parameter you build a plugin which +contains both my code and your code in a single file. When you call "make" +every file in which matches CheckMySQLHealthExt*.pm is appended +to the final plugin check_mysql_health. + +- the dynamic method +with ./configure --with-mymodules-dyn-dir= you build a plugin which will +search at runtime the for files matching CheckMySQLHealthExt*.pm and +import them. This way you can have different extensions on different hosts. +You also can modify your extension without having to rebuild the plugin. +On the other hand you have to distribute your extensions along with the plugin. + -- cgit v1.2.3