Dev: ssh-agent: add diagnose messages

crmsh/ssh_key.py

@@ -5,6 +5,7 @@
 import subprocess
 import tempfile
 import typing
+from io import StringIO
 
 from crmsh import sh
 
@@ -18,11 +19,29 @@ def __init__(self, msg: str):
 
 
 class AgentNotAvailableError(Error):
-    pass
+    def __init__(self, msg):
+        super().__init__(f'{msg}{self.diagnose()}')
+
+    @staticmethod
+    def diagnose() -> str:
+        with StringIO() as buf:
+            if 'SSH_AUTH_SOCK' not in os.environ:
+                buf.write(' Environmental variable SSH_AUTH_SOCK does not exists.')
+                if 'SUDO_USER' in os.environ:
+                    buf.write(' Please make sure environmental variables are preserved across sudo calls.')
+            return buf.getvalue()
 
 
 class NoKeysInAgentError(Error):
-    pass
+    def __init__(self, msg):
+        super().__init__(f'{msg}{self.diagnose()}')
+
+    @staticmethod
+    def diagnose() -> str:
+        ssh_auth_sock = os.environ["SSH_AUTH_SOCK"]
+        st = os.stat(ssh_auth_sock)
+        owner_name = pwd.getpwuid(st.st_uid).pw_name
+        return f' crmsh is using an ssh-agent listening at {ssh_auth_sock}, owned by {owner_name}. Please add at least one key pair with `ssh-add`'
 
 
 class Key:

test/features/ssh_agent.feature

@@ -4,9 +4,19 @@ Feature: ssh-agent support
   Test ssh-agent support for crmsh
   Need nodes: hanode1 hanode2 hanode3
 
+  Scenario: Errors are reported when ssh-agent is not avaible
+    When    Try "crm cluster init --use-ssh-agent -y" on "hanode1"
+    Then    Expected "Environmental variable SSH_AUTH_SOCK does not exists." in stderr
+    When    Try "SSH_AUTH_SOCK=/root/ssh-auth-sock crm cluster init --use-ssh-agent -y" on "hanode1"
+    Then    Expected "Environmental variable SSH_AUTH_SOCK does not exists." not in stderr
+
+  Scenario: Errors are reported when there are no keys in ssh-agent
+    Given   ssh-agent is started at "/root/ssh-auth-sock" on nodes ["hanode1", "hanode2", "hanode3"]
+    When    Try "SSH_AUTH_SOCK=/root/ssh-auth-sock crm cluster init --use-ssh-agent -y" on "hanode1"
+    Then    Expected "ssh-add" in stderr
+
   Scenario: Skip creating ssh key pairs with --use-ssh-agent
     Given   Run "mkdir /root/ssh_disabled && mv /root/.ssh/id_* /root/ssh_disabled" OK on "hanode1,hanode2,hanode3"
-    And     ssh-agent is started at "/root/ssh-auth-sock" on nodes ["hanode1", "hanode2", "hanode3"]
     When    Run "SSH_AUTH_SOCK=/root/ssh-auth-sock ssh-add /root/ssh_disabled/id_rsa" on "hanode1,hanode2,hanode3"
     And     Run "SSH_AUTH_SOCK=/root/ssh-auth-sock crm cluster init --use-ssh-agent -y" on "hanode1"
     And     Run "SSH_AUTH_SOCK=/root/ssh-auth-sock crm cluster join --use-ssh-agent -y -c hanode1" on "hanode2"

test/features/steps/step_implementation.py

@@ -100,7 +100,7 @@ def step_impl(context, addr, iface):
 
 @given('Run "{cmd}" OK on "{addr}"')
 def step_impl(context, cmd, addr):
-    _, out, _ = run_command_local_or_remote(context, cmd, addr)
+    _, out, _ = run_command_local_or_remote(context, cmd, addr, True)
 
 @when('Run "{cmd}" on "{addr}"')
 def step_impl(context, cmd, addr):
@@ -109,7 +109,7 @@ def step_impl(context, cmd, addr):
 
 @then('Run "{cmd}" OK on "{addr}"')
 def step_impl(context, cmd, addr):
-    _, out, _ = run_command_local_or_remote(context, cmd, addr)
+    _, out, _ = run_command_local_or_remote(context, cmd, addr, True)
 
 
 @then('Print stdout')