ct_snmp(3)

MODULE
ct_snmp - Common Test user interface module for the OTP snmp application.

DESCRIPTION

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.

DATA TYPES

    agent_config() = {Item, Value}

    agent_ip() = ip()

    agent_name() = atom()

    agent_port() = integer()

    call_back_module() = atom()

    error_index() = integer()

    error_status() = noError | atom()

    ip() = string() | {integer(), integer(), integer(), integer()}

    manager_ip() = ip()

    oid() = [byte()]

    oids() = [oid()]

    rel_path() = string()

    sec_type() = none | minimum | semi

    snmp_app_agent_params() = term()

    snmp_app_manager_params() = term()

    snmpreply() = {error_status(), error_index(), varbinds()}

    user_data() = term()

    user_name() = atom()

    usm_config() = string()

    usm_user_name() = string()

    value_type() = o('OBJECT IDENTIFIER') | i('INTEGER') | u('Unsigned32') | g('Unsigned32') | s('OCTET STRING')

    var_and_val() = {oid(), value_type(), value()}

    varbind() = term()

    varbinds() = [varbind()]

    varsandvals() = [var_and_val()]

EXPORTS

get_next_values(Agent, Oids, MgrAgentConfName) -> SnmpReply

    Types
        Agent = agent_name()
        Oids = oids()
        MgrAgentConfName = atom()
        SnmpReply = snmpreply()

    Issues a synchronous snmp get next request.

get_values(Agent, Oids, MgrAgentConfName) -> SnmpReply

    Types
        Agent = agent_name()
        Oids = oids()
        MgrAgentConfName = atom()
        SnmpReply = snmpreply()

    Issues a synchronous snmp get request.

load_mibs(Mibs) -> ok | {error, Reason}

    Types
        Mibs = [MibName]
        MibName = string()
        Reason = term()

    Load the mibs into the agent 'snmp_master_agent'.

register_agents(MgrAgentConfName, ManagedAgents) -> ok | {error, Reason}

    Types
        MgrAgentConfName = atom()
        ManagedAgents = [agent()]
        Reason = term()

    Explicitly instruct the manager to handle this agent. Corresponds to making an entry in agents.conf

register_users(MgrAgentConfName, Users) -> ok | {error, Reason}

    Types
        MgrAgentConfName = atom()
        Users = [user()]
        Reason = term()

    Register the manager entity (=user) responsible for specific agent(s). Corresponds to making an entry in users.conf

register_usm_users(MgrAgentConfName, UsmUsers) -> ok | {error, Reason}

    Types
        MgrAgentConfName = atom()
        UsmUsers = [usm_user()]
        Reason = term()

    Explicitly instruct the manager to handle this USM user. Corresponds to making an entry in usm.conf

set_info(Config) -> [{Agent, OldVarsAndVals, NewVarsAndVals}]

    Types
        Config = [{Key, Value}]
        Agent = agent_name()
        OldVarsAndVals = varsandvals()
        NewVarsAndVals = varsandvals()

    Returns a list of all successful set requests performed in the test case in reverse order. The list contains the involved user and agent, the value prior to the set and the new value. This is intended to facilitate the clean up in the end_per_testcase function i.e. the undoing of the set requests and its possible side-effects.

set_values(Agent, VarsAndVals, MgrAgentConfName, Config) -> SnmpReply

    Types
        Agent = agent_name()
        Oids = oids()
        MgrAgentConfName = atom()
        Config = [{Key, Value}]
        SnmpReply = snmpreply()

    Issues a synchronous snmp set request.

start(Config, MgrAgentConfName) -> ok

    Equivalent to start(Config, MgrAgentConfName, undefined).

start(Config, MgrAgentConfName, SnmpAppConfName) -> ok

    Types
        Config = [{Key, Value}]
        Key = atom()
        Value = term()
        MgrAgentConfName = atom()
        SnmpConfName = atom()

    Starts an snmp manager and/or agent. In the manager case, registrations of users and agents as specified by the configuration MgrAgentConfName will be performed. When using snmp v3 also so called usm users will be registered. Note that users, usm_users and managed agents may also be registered at a later time using ct_snmp:register_users/2, ct_snmp:register_agents/2, and ct_snmp:register_usm_users/2. The agent started will be called snmp_master_agent. Use ct_snmp:load_mibs/1 to load mibs into the agent. With SnmpAppConfName it's possible to configure the snmp application with parameters such as config, mibs, net_if, etc. The values will be merged with (and possibly override) default values set by ct_snmp.

stop(Config) -> ok

    Types
        Config = [{Key, Value}]
        Key = atom()
        Value = term()

    Stops the snmp manager and/or agent removes all files created.

unregister_agents(MgrAgentConfName) -> ok | {error, Reason}

    Types
        MgrAgentConfName = atom()
        Reason = term()

    Removes information added when calling register_agents/2.

unregister_users(MgrAgentConfName) -> ok | {error, Reason}

    Types
        MgrAgentConfName = atom()
        Reason = term()

    Removes information added when calling register_users/2.

update_usm_users(MgrAgentConfName, UsmUsers) -> ok | {error, Reason}

    Types
        MgrAgentConfName = atom()
        UsmUsers = usm_users()
        Reason = term()

    Alters information added when calling register_usm_users/2.