Avoid using ansible_failed_task in rescue blocks

ansible_failed_task can contain unexpanded Jinja2 templates with variable references that were valid when the task failed, but not valid anymore when using the variable in the rescue block. In this case the problem is with task names (.name) that contain references to storage_provider. Unfortunately this completely prevents using ansible_failed_task even if not using the problematic attribute. Other attribute could have been used if this were not the case, like .tags, but until ansible/ansible#49942 is fixed, it is better to avoid using ansible_failed_task and use the only other special variable describing the failed task: ansible_failed_result. Eliminate the previous workaround to set storage_provider on the tasks that expand ansible_failed_task and use ansible_failed_result with a special value of msg instead. This has a disadvantage of having to use a special msg with the fail module, while usually it is just a free-form message. The fail module does not set another attribute of the result that could be used though, and it is cleaner than the previous workaround.
linux-system-roles · May 7, 2020 · 787f00c · 787f00c
1 parent 10a78d7
commit 787f00c
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Showing 2 changed files with 42 additions and 84 deletions.
diff --git a/tests/tests_disk_errors.yml b/tests/tests_disk_errors.yml
@@ -26,19 +26,16 @@
                 disks: ['/dev/surelyidonotexist']
                 mount_point: "{{ mount_location }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
         # the following does not work properly,
         # blivet_output.failed is false.
@@ -114,19 +111,16 @@
                 fs_type: 'ext3'
                 disks: "{{ unused_disks }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     - name: Verify the output
       assert:
@@ -158,19 +152,16 @@
                 fs_type: 'ext3'
                 disks: "{{ unused_disks }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     - name: Verify the output
       assert:
@@ -212,19 +203,16 @@
                 disks: "{{ unused_disks }}"
                 type: partition
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
         - name: Verify the output
           assert:
@@ -244,19 +232,16 @@
                 disks: "{{ unused_disks }}"
                 type: lvm
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
         - name: Verify the output
           assert:

diff --git a/tests/tests_lvm_errors.yml b/tests/tests_lvm_errors.yml
@@ -37,19 +37,16 @@
                     size: "{{ volume1_size }}"
                     mount_point: "{{ mount_location1 }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     # the following does not work properly
     # - debug:
@@ -78,19 +75,16 @@
                     size: "{{ invalid_size }}"
                     mount_point: "{{ mount_location1 }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     # the following does not work properly
     # - name: Verify the output
@@ -114,19 +108,16 @@
                     size: "{{ too_large_size }}"
                     mount_point: "{{ mount_location1 }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     # the following does not work properly
     # - name: Verify the output
@@ -150,19 +141,16 @@
                     size: "{{ too_large_size }}"
                     mount_point: "{{ mount_location1 }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     # the following does not work properly
     # - name: Verify the output
@@ -186,19 +174,16 @@
                     size: "{{ too_large_size }}"
                     mount_point: "{{ mount_location1 }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     # the following does not work properly
     # - name: Verify the output
@@ -221,19 +206,16 @@
                 size: "{{ volume1_size }}"
                 mount_point: "{{ mount_location1 }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     # the following does not work properly
     # - name: Verify the output
@@ -347,19 +329,16 @@
                     fs_type: 'ext3'
                     size: '1g'
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
         - name: Verify the output
           assert:
@@ -401,19 +380,16 @@
                 disks: "{{ unused_disks }}"
                 type: lvm
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
         - name: Verify the output
           assert:
@@ -435,19 +411,16 @@
                 disks:
                   - "{{ unused_disks[0] }}"
 
-        - name: UNREACH
+        - name: unreachable task
           fail:
-            msg: "this should be unreachable"
+            msg: UNREACH
 
       rescue:
         - name: Check that we failed in the role
           assert:
             that:
-              - ansible_failed_task.name != 'UNREACH'
+              - ansible_failed_result.msg != 'UNREACH'
             msg: "Role has not failed when it should have"
-          vars:
-            # Ugh! needed to expand ansible_failed_task
-            storage_provider: blivet
 
     - name: Verify the output
       assert: