Configuration API

This section describes how Amanda reads amanda.conf and amanda-client.conf configuration files.

Data Structures

common/util.h

conftype_t

all possible types of config options.

tok_t

tokens

keytab_t

string to tok_t conversion.

command_option_t

data structure to keep -o command line argument.

val_t

Store the value of a configuration option. It has following fields:

• • v  : value
  • seen : If the value was seen on a config file
  • type : the type of the value

t_conf_var

structure for all configuration options with following fields:

• • token : the internal token use.
  • type : the type of the value
  • read_function : the function to read that value
  • parm : confparm_t, tapetype_ee, dumptype_ee, interface_ee or holdingdisk_ee
  • validate : a function to validate the value

server-src/conffile.h

confparm_t

global option

tapetype_ee, dumptype_ee, interface_ee,holdingdisk_ee

tapetype/dumptype/interface/holding options

tapetype_t, dumptype_t, interface_t, holdingdisk_t

Data structures with following fields:

• • seen:
  • name: name of the option
  • value: all value of that tapetype/dumptype/interface

There are lot of macros tapetype_*, dumptype_*, interface_*, holdingdisk_* to retrieve configuration values.

To retrieve global value, use one of these functions: getconf_int, getconf_long, getconf_size, getconf_time, getconf_am64, getconf_real, getconf_str.

server-src/conffile.c

server_keytab

Keytab for the server configuration

server_var

Array describing global server options

holding_var

Array describing holdingdisk options

dumptype_var

Array describing dumptype options

tapetype_var

Array describing tapetype options

interface_var

Array describing interface options

Accessing Configuration

Accessing configuration values from Amanda applications is straightforward. Global configuration options are accessed with getconf_xxx (depending on type):

conf_tapetype = getconf_str(CNF_TAPETYPE);
run_tapes = getconf_int(CNF_RUNTAPES);

Note that getconf_str() returns a pointer to a string in the configuration data structures -- do not free the result!

To access one of the named configuration sections (dumptypes, holding disks, etc.), first look up the object you want:

tape = lookup_tapetype(getconf_str(CNF_TAPETYPE));

then use one of the macros for that object to get the actual value:

tt_blocksize_kb = (size_t)tapetype_get_blocksize(tape);

See conffile.h for the full list of such macros.

Adding New Options

How to add a new global option

• Add a token in tok_t (CONF_*)
• Add a token in confparm_t (CNF_*)
• Add an entry in server_keytab
• Add an entry in server_var
• Change init_defaults(): Set default value for the option
• User should use the correct getconf_* function according to the data type given in server_var

How to add a dumptype option

• Add a token in tok_t (CONF_*)
• Add a token in dumptype_ee (DUMPTYPE_*)
• Add a macro to retrive the value (dumptype_get_*)
• Add an entry in server_keytab
• Add an entry in dumptype_var
• Change init_dumptype_defaults(): Set default value.
• The dumptype_get_* macro should return the correct field according to the type defined in dumptype_var

Adding a tapetype, holdingdisk or interface option is done similar to adding a dumptype option.

• For a dumptype, the value must also be copied to the disk_t structure.
  • Add a NEWVAR field in the disk_t struct with the type.
  • In diskfile.c(parse_diskline) you must add the following line:

   disk->NEWVAR = dumptype_get_NEWVAR(dtype);

You can then use disk->NEWVAR as you like.