ct_snmp

Common Test user interface module for the OTP snmp application

The purpose of this module is to make snmp configuration easier for the test case writer. Many test cases can use default values for common operations and then no snmp configuration files need to be supplied. When it is necessary to change particular configuration parameters, a subset of the relevant snmp configuration files may be passed to ct_snmp by means of Common Test configuration files. For more specialized configuration parameters, it is possible to place a "simple snmp configuration file" in the test suite data directory. To simplify the test suite, Common Test keeps track of some of the snmp manager information. This way the test suite doesn't have to handle as many input parameters as it would if it had to interface the OTP snmp manager directly.

The following snmp manager and agent parameters are configurable:

   {snmp,
          %%% Manager config
          [{start_manager, boolean()}    % Optional - default is true
          {users, [{user_name(), [call_back_module(), user_data()]}]}, %% Optional
          {usm_users, [{usm_user_name(), [usm_config()]}]},%% Optional - snmp v3 only
          % managed_agents is optional
          {managed_agents,[{agent_name(), [user_name(), agent_ip(), agent_port(), [agent_config()]]}]},
          {max_msg_size, integer()},     % Optional - default is 484
          {mgr_port, integer()},         % Optional - default is 5000
          {engine _id, string()},        % Optional - default is "mgrEngine"
  
          %%% Agent config
          {start_agent, boolean()},      % Optional - default is false
          {agent_sysname, string()},     % Optional - default is "ct_test"
          {agent_manager_ip, manager_ip()}, % Optional - default is localhost
          {agent_vsns, list()},          % Optional - default is [v2]
          {agent_trap_udp, integer()},   % Optional - default is 5000
          {agent_udp, integer()},        % Optional - default is 4000
          {agent_notify_type, atom()},   % Optional - default is trap
          {agent_sec_type, sec_type()},  % Optional - default is none
          {agent_passwd, string()},      % Optional - default is ""
          {agent_engine_id, string()},   % Optional - default is "agentEngine"
          {agent_max_msg_size, string()},% Optional - default is 484
  
          %% The following parameters represents the snmp configuration files
          %% context.conf, standard.conf, community.conf, vacm.conf,
          %% usm.conf, notify.conf, target_addr.conf and target_params.conf.
          %% Note all values in agent.conf can be altered by the parametes
          %% above. All these configuration files have default values set
          %% up by the snmp application. These values can be overridden by
          %% suppling a list of valid configuration values or a file located
          %% in the test suites data dir that can produce a list
          %% of valid configuration values if you apply file:consult/1 to the
          %% file.
          {agent_contexts, [term()] | {data_dir_file, rel_path()}}, % Optional
          {agent_community, [term()] | {data_dir_file, rel_path()}},% Optional
          {agent_sysinfo,  [term()] | {data_dir_file, rel_path()}}, % Optional
          {agent_vacm, [term()] | {data_dir_file, rel_path()}},     % Optional
          {agent_usm, [term()] | {data_dir_file, rel_path()}},      % Optional
          {agent_notify_def, [term()] | {data_dir_file, rel_path()}},% Optional
          {agent_target_address_def, [term()] | {data_dir_file, rel_path()}},% Optional
          {agent_target_param_def, [term()] | {data_dir_file, rel_path()}},% Optional
         ]}.
   

The MgrAgentConfName parameter in the functions should be a name you allocate in your test suite using a require statement. Example (where MgrAgentConfName = snmp_mgr_agent):

 suite() -> [{require, snmp_mgr_agent, snmp}].

or

  ct:require(snmp_mgr_agent, snmp).

Note that Usm users are needed for snmp v3 configuration and are not to be confused with users.

Snmp traps, inform and report messages are handled by the user callback module. For more information about this see the snmp application.

Note: It is recommended to use the .hrl-files created by the Erlang/OTP mib-compiler to define the oids. Example for the getting the erlang node name from the erlNodeTable in the OTP-MIB:

Oid = ?erlNodeEntry ++ [?erlNodeName, 1] 

It is also possible to set values for snmp application configuration parameters, such as config, server, net_if, etc (see the "Configuring the application" chapter in the OTP snmp User's Guide for a list of valid parameters and types). This is done by defining a configuration data variable on the following form:

   {snmp_app, [{manager, [snmp_app_manager_params()]},
               {agent, [snmp_app_agent_params()]}]}.

A name for the data needs to be allocated in the suite using require (see example above), and this name passed as the SnmpAppConfName argument to start/3. ct_snmp specifies default values for some snmp application configuration parameters (such as {verbosity,trace} for the config parameter). This set of defaults will be merged with the parameters specified by the user, and user values override ct_snmp defaults.