Rewritten using replace to make one line.

linux/system/repo.sls

@@ -85,8 +85,7 @@ linux_repo_{{ name }}_pin:
 
 linux_repo_{{ name }}_key:
   cmd.wait:
-    - name: |
-        echo '{{ repo.key|indent(8, false) }}' | apt-key add -
+    - name: echo -e '{{ repo.key|replace('\n', '\\n') }}' | apt-key add -
     - watch:
       - file: default_repo_list
 
@@ -142,10 +141,8 @@ linux_repo_{{ name }}:
 
 linux_repo_{{ name }}_key:
   cmd.run:
-    - name: |
-        echo '{{ repo.key|indent(8, false) }}' | apt-key add -
-    - unless: |
-        apt-key finger --with-colons | grep -qF $(echo '{{ repo.key|indent(8, false) }}' | gpg --with-fingerprint --with-colons | grep -E '^fpr')
+    - name: echo -e '{{ repo.key|replace('\n', '\\n') }}' | apt-key add -
+    - unless: apt-key finger --with-colons | grep -qF $(echo -e '{{ repo.key|replace('\n', '\\n') }}' | gpg --with-fingerprint --with-colons | grep -E '^fpr')
     - require_in:
       - pkgrepo: linux_repo_{{ name }}