inventory/linux.cf

Table of Contents

This policy is inventory related to linux hosts.

common bodies

inventory_linux

Prototype: inventory_linux

Description: Linux inventory

This common bundle is for Linux inventory work.

Provides: os_release_id, and os_release_version based on parsing of /etc/os-release systemd class based on linktarget of /proc/1/cmdline

Implementation:

bundle common inventory_linux
{
  vars:
    has_os_release::
      "os_release_info" string => readfile("/etc/os-release", "512"),
      comment => "Read /etc/os-release" ;

    os_release_has_id::
      "os_release_id" string => canonify("$(id_array[1])");

    os_release_has_version::
      "os_release_version" string => canonify("$(version_array[1])");

    has_proc_1_cmdline::
      "proc_1_cmdline_split" slist => string_split(readfile("/proc/1/cmdline", "512"), " ", "2"),
      comment => "Read /proc/1/cmdline and split off arguments";

      "proc_1_cmdline" string => nth("proc_1_cmdline_split", 0),
      comment => "Get argv[0] of /proc/1/cmdline";

      # this is the same as the original file for non-links
      "proc_1_process" string => filestat($(proc_1_cmdline), "linktarget");

    any::
      "proc_routes" data => data_readstringarrayidx("/proc/net/route",
                                                    "#[^\n]*","\s+",40,4k),
        if => fileexists("/proc/net/route");
      "routeidx" slist => getindices("proc_routes");
      "dgw_ipv4_iface" string => "$(proc_routes[$(routeidx)][0])",
        comment => "Name of the interface where default gateway is routed",
        if => strcmp("$(proc_routes[$(routeidx)][1])", "00000000");

    linux::
      "nfs_servers" -> { "CFE-3259" }
        comment => "NFS servers (to list hosts impacted by NFS outages)",
        slist => maplist( regex_replace( $(this) , ":.*", "", "g"),
                          # NFS server is before the colon (:), that's all we want
                          # e.g., nfs.example.com:/vol/homedir/user1 /home/user1 ...
                          #       ^^^^^^^^^^^^^^^
                          grep( ".* nfs .*",
                                readstringlist("/proc/mounts", "", "\n", inf, inf)
                              )
                        ),
        if => fileexists( "/proc/mounts" );


        "nfs_server[$(nfs_servers)]"
          string => "$(nfs_servers)",
          meta => { "inventory", "attribute_name=NFS Server" };


  classes:

    any::
      "has_os_release" expression => fileexists("/etc/os-release"),
      comment => "Check if we can get more info from /etc/os-release";

      "os_release_has_id" expression => regextract('^ID="?([^"\s]+)"?$',
                                                   $(os_release_info),
                                                   "id_array"),
      comment => "Extract ID= line from os-release to id_array";

      "os_release_has_version" expression => regextract('^VERSION_ID="?([^"]+)"?$',
                                                        $(os_release_info),
                                                        "version_array"),
      comment => "Extract VERSION_ID= line from os-release to version_array";

      "has_proc_1_cmdline" expression => fileexists("/proc/1/cmdline"),
      comment => "Check if we can read /proc/1/cmdline";

    os_release_has_id::
      "$(os_release_id)" expression => "any";

    os_release_has_version::
      "$(os_release_id)_$(os_release_version)" expression => "any";

    has_proc_1_cmdline::
      "systemd" expression => strcmp(lastnode($(proc_1_process), "/"), "systemd"),
      comment => "Check if (the link target of) /proc/1/cmdline is systemd";

  reports:
    (DEBUG|DEBUG_inventory_linux).has_os_release::
      "DEBUG $(this.bundle)";
      "$(const.t)OS release ID = $(os_release_id), OS release version = $(os_release_version)";
}

monitor bundles

measure_entropy_available

Prototype: measure_entropy_available

Description: Measure amount of entropy available

Implementation:

bundle monitor measure_entropy_available
{
  measurements:
    linux::
      # A lack of entropy can cause agents to hang
      "/proc/sys/kernel/random/entropy_avail" -> { "ENT-6495", "ENT-6494" }
        if => fileexists( "/proc/sys/kernel/random/entropy_avail" ),
        handle => "entropy_avail",
        stream_type => "file",
        data_type => "int",
        units => "bits",
        history_type => "weekly",
        match_value => single_value("\d+"),
        comment => "Amount of entropy available";
}