# Yet another dynamic variable problem **URL:** \ **Category:** Ansible Project\ **Created:** [July 23, 2019, 10:19pm UTC](https://forum.ansible.com/t/yet-another-dynamic-variable-problem/30851 "2019-07-23T22:19:36Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![mark.tovey](https://avatars.discourse-cdn.com/v4/letter/m/ce73a5/32.png) [@mark.tovey](https://forum.ansible.com/u/mark.tovey)\ **Post date:** [July 23, 2019, 10:19pm UTC](https://forum.ansible.com/t/yet-another-dynamic-variable-problem/30851/1 "2019-07-23T22:19:36Z")
I am trying to generate a variable name dynamically, but so far I have been stymied. I have lists whose names are based upon the OS name: > myos7: > > - os7package1 > - os7package2 > - os7package3 > myos8: > > - os8package1 > - os8package2 > - os8package3 I want to access these lists dynamically in a shell command: > - shell: > for pkg in “{{‘myos’ + ansible\_facts.distribution\_major\_release}}”; \ > > do > echo “pkg=$pkg”; > done All I get in the output from the echo command is ‘myos7’ or ‘myos8’, but not the contents of those variables. If I output the variable in a debug task, I get the expected results, the list of packages: > - debug: > var: “{{item}}” > with\_items: > - “{{‘myos’ + ansible\_facts.distribution\_major\_release}}” So what is the difference? Why does it work as expected in the debug task but not in the shell task? ---
**Author:** ![cassell](https://avatars.discourse-cdn.com/v4/letter/c/ecae2f/32.png) [@cassell](https://forum.ansible.com/u/cassell)\ **Post date:** [July 24, 2019, 1:03am UTC](https://forum.ansible.com/t/yet-another-dynamic-variable-problem/30851/2 "2019-07-24T01:03:09Z")
> I am trying to generate a variable name dynamically, but so far I have > been stymied. > > I have lists whose names are based upon the OS name: > > \> myos7: > \> - os7package1 > \> - os7package2 > \> - os7package3 > > \> myos8: > \> - os8package1 > \> - os8package2 > \> - os8package3 > > I want to access these lists dynamically in a shell command: > > \> - shell: > \> for pkg in "{{'myos' + ansible\_facts.distribution\_major\_release}}"; \ > \> do \ > \> echo "pkg=$pkg"; \ > \> done You want lookup('vars', 'myos' ~ ansible\_facts.distribution\_major\_release) > All I get in the output from the echo command is 'myos7' or 'myos8', > but not the contents of those variables. If I output the variable in a > debug task, I get the expected results, the list of packages: > > \> - debug: > \> var: "{{item}}" > \> with\_items: > \> - "{{'myos' + ansible\_facts.distribution\_major\_release}}" > > So what is the difference? Why does it work as expected in the debug > task but not in the shell task? You're doing a double lookup here. Once in with\_items and again by using `var` instead of `msg` V/r, James Cassell ---
**Author:** ![mark.tovey](https://avatars.discourse-cdn.com/v4/letter/m/ce73a5/32.png) [@mark.tovey](https://forum.ansible.com/u/mark.tovey)\ **Post date:** [July 24, 2019, 2:50am UTC](https://forum.ansible.com/t/yet-another-dynamic-variable-problem/30851/3 "2019-07-24T02:50:56Z")
I tried that. I swear I tried that. And it kept telling me that it could not locate my variable. I thought maybe I had mistyped the variable name, but it looked good. It still would not work. But now, of course it does: TASK [debug] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* ok: [ldappoc4] =\> (item=myos7) =\>   ansible\_loop\_var: item   item: myos7   myos7:   - os7package1   - os7package2   - os7package3 TASK [shell] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* changed: [ldappoc4] =\> changed=true   cmd: for pkg in "[u'os7package1', u'os7package2', u'os7package3']"; do echo "pkg=$pkg"; done   delta: '0:00:00.031796'   end: '2019-07-24 04:40:34.798245'   rc: 0   start: '2019-07-24 04:40:34.766449'   stderr: ''   stderr\_lines: \   stdout: pkg=[u'os7package1', u'os7package2', u'os7package3']   stdout\_lines: \     That is what I expected to see. So at least now I have proof that it will work. I need to go back to my original code and see where I went wrong.     It has been a long day, sometimes just walking away for a bit makes all the difference in the world.     Thanks,     -Mark ---
**Author:** ![mark.tovey](https://avatars.discourse-cdn.com/v4/letter/m/ce73a5/32.png) [@mark.tovey](https://forum.ansible.com/u/mark.tovey)\ **Post date:** [July 24, 2019, 3:34am UTC](https://forum.ansible.com/t/yet-another-dynamic-variable-problem/30851/4 "2019-07-24T03:34:59Z")
Okay, I did not describe the problem properly. The code looks more like the following: vars:     packages:       myos7:           - os7package1           - os7package2           - os7package3       myos8:           - os8package1           - os8package2           - os8package3   - debug:         var: "{{item}}"     with\_items:         - "{{'packages.myos' + ansible\_distribution\_major\_version}}"   - shell:         for pkg in "{{lookup('vars', 'packages.myos' ~ ansible\_distribution\_major\_version)}}"; \         do \             echo "pkg=$pkg"; \         done And the output looks like this: TASK [debug] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* ok: [ldappoc4] =\> (item=packages.myos7) =\>   ansible\_loop\_var: item   item: packages.myos7   packages.myos7:   - os7package1   - os7package2   - os7package3 TASK [shell] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* fatal: [ldappoc4]: FAILED! =\>   msg: |-     The task includes an option with an undefined variable. The error was: No variable found with this name: packages.myos7 My data is actually stored in a dictionary. The debug task is able to interpret that but the lookup plugin is not. So now what? ---
**Author:** ![Kai\_Stian\_Olstad](https://avatars.discourse-cdn.com/v4/letter/k/e19adc/32.png) [@Kai\_Stian\_Olstad](https://forum.ansible.com/u/Kai_Stian_Olstad)\ **Post date:** [July 27, 2019, 3:05pm UTC](https://forum.ansible.com/t/yet-another-dynamic-variable-problem/30851/5 "2019-07-27T15:05:36Z")
The debug doesn't work eihter, at least not the way you think. The debug var: takes a variable name and print out the content of that variable. As you can see from the above output your item is "item: packages.myos7" So you    - debug:        var: "{{item}}" actually becomes    - debug:        var: "packages.myos7" and the content of packages.myos7 is the list    - os7package1    - os7package2    - os7package3 What you need is {{ packages['myos' ~ ansible\_distribution\_major\_version] }} ---
**Author:** ![mark.tovey](https://avatars.discourse-cdn.com/v4/letter/m/ce73a5/32.png) [@mark.tovey](https://forum.ansible.com/u/mark.tovey)\ **Post date:** [July 30, 2019, 4:01pm UTC](https://forum.ansible.com/t/yet-another-dynamic-variable-problem/30851/6 "2019-07-30T16:01:43Z")
Okay, that makes sense and looks a lot simpler. I will try that.     Thanks,     -Mark ---
**Author:** ![mark.tovey](https://avatars.discourse-cdn.com/v4/letter/m/ce73a5/32.png) [@mark.tovey](https://forum.ansible.com/u/mark.tovey)\ **Post date:** [July 30, 2019, 4:28pm UTC](https://forum.ansible.com/t/yet-another-dynamic-variable-problem/30851/7 "2019-07-30T16:28:27Z")
And that works. The actual 'for' line looks like the following to get one package name per iteration:         for pkg in $(echo "{{packages['myos' ~ ansible\_distribution\_major\_version]|to\_json|regex\_replace('[,\[\]]', '')}}");     But that got me what I am trying to achieve.     -Mark