Ansible - read inventory hosts and variables to group vars all file

Question

I have a dummy doubt that keeps me stuck for a long time  I have a very banal inventory file with hosts and variables    lb  10 112 84 122   tomcat  10 112 84 124   jboss5  10 112 84 122        tests children  lb tomcat jboss5   default children  tests   tests vars  data base user NETWIN-4 3 data base password NETWIN data base encrypted password  data base host 10 112 69 48 data base port 1521 data base service ssdenwdb data base url jdbc oracle thin  10 112 69 48 1521 ssdenwdb   The problem is that I need to access all these hosts and variables  in the inventory file  from the group vars all file   I ve tried the following manners to access the host IP      lb        hostvars lb          hostvars  lb          hostvars lb       To access a host variable I tried       hostvars tests    data base host         All of them are wrong    Can anyone help me find out the best practice to access hosts and variables  not from a playbook but from a variables file   EDIT   Ok  Let s clarify   Problem  Use a host declared in the inventory file in a variable file  let s say  group vars all   Example  I have a DB host with IP 10 112 83 37   Inventory file    db  10 112 83 37   In the group vars all file I want to use that IP to build a variable   group vars all file   data base url jdbc oracle thin     db    1521 ssdenwdb   In a template I use the variable built in the group vars all file   Template file   oracle url      data base url      The problem is that the    db    variable in the group vars all file is not replaced by the DB host IP  The user can only edit the inventory file

User · Answer

Just in case if the problem is still there, You can refer to ansible inventory through ‘hostvars’, ‘group_names’, and ‘groups’ ansible variables.

Example:

To be able to get ip addresses of all servers within group "mygroup", use the below construction:

- debug: msg="{{ hostvars[item]['ansible_eth0']['ipv4']['address'] }}" 
  with_items:
     - "{{ groups['mygroup'] }}"

User · Answer

- name  host    debug  msg     item         with items      -     groups  tests         This piece of code will give the message    10 112 84 122   10 112 84 124    as groups  tests   basically return a list of unique ip addresses   10 112 84 122   10 112 84 124   whereas groups  tomcat   0  returns 10 112 84 124

User · Answer

If you want to refer one host define under  etc ansible host in a task or role  the bellow link might help  https   www middlewareinventory com blog ansible-get-ip-address

User · Answer

If you want to have your vars in files under group vars  just move them here  Vars can be in the inventory   group vars  section  but also  and foremost  in files under group vars or hosts vars   For instance  with your example above  you can move your vars for group tests in the file group vars tests    Inventory file     lb  10 112 84 122   tomcat  10 112 84 124   jboss5  10 112 84 122        tests children  lb tomcat jboss5   default children  tests   group vars tests file    data base user NETWIN-4 3 data base password NETWIN data base encrypted password  data base host 10 112 69 48 data base port 1521 data base service ssdenwdb data base url jdbc oracle thin  10 112 69 48 1521 ssdenwdb

User · Answer

Considering your previous example   inventory file    db  10 112 83 37   group vars all  data base url jdbc oracle thin     db    1521 ssdenwdb   template file   oracle url      data base url      You might want to replace your group vars all with   data base url  jdbc oracle thin     groups  db   0     1521 ssdenwdb

User · Answer

If you want to programmatically access the inventory entries to include them in a task for example  You can refer to it like this      hostvars tomcat      This returns you a structure with all variables related with that host  If you want just an IP address  or hostname   you can refer to it like this      hostvars jboss5 ansible ssh host      Here is a list of variables which you can refer to  click  Moreover  you can declare a variable and set it with for example result of some step in a playbook   - name  Change owner and group of some file   file  path  tmp my-file owner new-owner group new-group   register  chown result   Then if you play this step on tomcat  you can access it from jboss5 like this   - name  Print out the result of chown   debug  msg     hostvars tomcat chown result

User · Answer

Yes the example by nixlike works very well    Inventory    docker-host  myhost1 user barbara myhost2 user heather   playbook   ---  - hosts  localhost   connection  local                tasks              - name  loop debug inventory hostnames           debug               msg   the docker host is    item               with inventory hostnames  docker-host         - name  loop debug items           debug               msg   the docker host is    hostvars item   user                 with items      groups  docker-host         output      ansible-playbook ansible tests vars-test-local yml       PLAY  localhost             TASK  setup                                                                        ok   localhost       TASK  loop debug inventory hostnames                                               ok   localhost      item myhost2              item    myhost2           msg    the docker host is myhost2    ok   localhost      item myhost1              item    myhost1           msg    the docker host is myhost1         TASK  loop debug items                                                             ok   localhost      item myhost1              item    myhost1           msg    the docker host is barbara    ok   localhost      item myhost2              item    myhost2           msg    the docker host is heather         PLAY RECAP                                                                         localhost                    ok 3    changed 0    unreachable 0   failed 0   thanks

[ansible] Ansible - read inventory hosts and variables to group_vars/all file

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