How to test that a registered variable is not empty

Question

How can I test that stderr is non empty    - name  Check script   shell       venv name    bin activate  amp  amp  myscritp py   args      chdir      home       sudo user      user       register  test myscript  - debug  msg  myscritp is Ok    when  not test myscript stderr   So if there is no error I could read      TASK   deploy   debug msg  critp is Ok            ok   vagrant    gt           msg    myscritp is Ok        In case the stderr is not empty a FATAl error occurs

User · Answer

- name  set pkg copy dir name   set fact      PKG DIR   gt -          if ansible os family     quot RedHat quot    centos   rpm         - elif ansible distribution     quot Ubuntu quot    ubuntu   deb         - elif ansible distribution     quot Kylin Linux Advanced Server quot    kylin   deb         - else     - endif

User · Answer

You can check for empty string  when stderr is empty   - name  Check script   shell       venv name    bin activate  amp  amp  myscritp py   args      chdir      home       sudo user      user       register  test myscript  - debug  msg  myscritp is Ok    when  test myscript stderr         If you want to check for fail   - debug  msg  myscritp has error    test myscript stderr      when  test myscript stderr         Also look at this stackoverflow question

User · Answer

when  myvar   default     true    trim         I use   trim       to check if a variable has an empty value or not  I also  always add the   default      true  check to catch when myvar is undefined too

User · Answer

ansible 2 9 6 ansible-lint 4 2 0  See ansible-lint default rules  The condition below causes E602 Don   t compare to empty string     when  test myscript stderr     quot  quot   Correct syntax and also  quot Ansible Galaxy Warning-Free quot  option is     when  test myscript stderr   length  gt  0  Quoting from source code   quot Use when  var length  gt  0 rather than when  var     quot  quot   or    conversely when  var length    0 rather than when  var     quot  quot   quot    Notes  Test empty bare variable e g       - debug          msg   quot Empty string     var     evaluates to False quot        when  not var       vars          var          - debug          msg   quot Empty list    var    evaluates to False quot        when  not var       vars          var      give      quot msg quot    quot Empty string    evaluates to False quot       quot msg quot    quot Empty list    evaluates to False quot    But  testing non-empty bare variable string depends on CONDITIONAL BARE VARS  Setting ANSIBLE CONDITIONAL BARE VARS false the condition works fine but setting ANSIBLE CONDITIONAL BARE VARS true the condition will fail      - debug          msg   quot String     var     evaluates to True quot        when  var       vars          var   abc   gives fatal   localhost   FAILED    gt     msg   -     The conditional check  var  failed  The error was  error while      evaluating conditional  var    abc  is undefined  Explicit cast to Boolean prevents the error but evaluates to False i e  will be always skipped  unless var  True    When the filter bool is used the options ANSIBLE CONDITIONAL BARE VARS true and ANSIBLE CONDITIONAL BARE VARS false have no effect     - debug          msg   quot String     var     evaluates to True quot        when  var bool       vars          var   abc   gives skipping   localhost    Quoting from Porting guide 2 8 Bare variables in conditionals    - include tasks  teardown yml     when  teardown    - include tasks  provision yml     when  not teardown    quot  based on a variable you define as a string  with quotation marks around it   quot    In Ansible 2 7 and earlier  the two conditions above evaluated as True and False respectively if teardown   true   In Ansible 2 7 and earlier  both conditions evaluated as False if teardown   false   In Ansible 2 8 and later  you have the option of disabling conditional bare variables  so when  teardown always evaluates as True and when  not teardown always evaluates as False when teardown is a non-empty string  including  true  or  false      Quoting from CONDITIONAL BARE VARS    quot Expect that this setting eventually will be deprecated after 2 12 quot

[ansible] How to test that a registered variable is not empty?

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