I have a simple Python 3 script (I’m running Python 3.6.1, compiled from source) that does the following 3 things:<\/p>\n
scp<\/code> to get files<\/li>\n- Processes the files.<\/li>\n
- Connects to another remote server and uploads the processed files.<\/li>\n<\/ol>\n
I moved this script from a soon-to-be-retired CentOS 6 host to a CentOS 7 host, and when I ran it there I received the following error message:<\/p>\n
AttributeError: module 'paramiko' has no attribute 'SSHClient'<\/code><\/pre>\nThe line number specified in the stack trace led me to:<\/p>\n
ssh = paramiko.SSHClient()<\/code><\/pre>\nFirst things first: Google the error. Someone else has seen this before. Sure enough, on StackOverflow I found Paramiko: Module object has no attribute error ‘SSHClient’<\/a><\/p>\nBut no, that’s not the problem I’m having.<\/p>\n
I tried to create the the simplest possible script that would reproduce the error:<\/p>\n
#!\/usr\/bin\/python3\r\n\r\nimport paramiko\r\n\r\ndef main():\r\n ssh = paramiko.SSHClient()\r\n\r\nif __name__ == \"__main__\":\r\n main()<\/code><\/pre>\nI ran it as a super-user and received no errors:<\/p>\n
$ sudo \/usr\/bin\/python3 test.py<\/code><\/pre>\nI ran it as myself, though, and it reproduced the error message. Maybe something with the user permissions?<\/p>\n
$ ls -l \/usr\/local\/lib\/python3.6\/site-packages\/\r\ntotal 1168\r\n...\r\ndrwxr-x---. 3 root root 4096 May 29 14:25 paramiko\r\n...<\/code><\/pre>\nOh! From that you can see that unless you are the root user, or a member of the root group, there’s no way you can even see<\/em> the files within the paramiko directory.<\/p>\nWhat’s the default umask on the system?<\/p>\n
$ umask\r\n0027<\/code><\/pre>\nThat explains it. Now, to fix it. I could probably just run:<\/p>\n
$ sudo chmod -R 0755 \/usr\/local\/lib\/python3.6\/site-packages\/*<\/code><\/pre>\nThat should have been the end of that, problem solved! But in my case, installation of the pip modules had been handled by Ansible. I needed to fix the Ansible tasks to account for restrictive umask settings on future deployments. See the umask<\/code> parameter in the documentation for the Ansible pip module<\/a>. I updated the task:<\/p>\n- name: Install specified python requirements\r\n pip:\r\n executable: \/usr\/local\/bin\/pip3\r\n requirements: \/tmp\/pip3-packages\r\n umask: 0022<\/code><\/pre>\nRunning the playbook with that task, I received an error:<\/p>\n
fatal: [trinculo.osric.net]: FAILED! => {\"changed\": false, \"details\": \"invalid literal for int() with base 8: '18'\", \"msg\": \"umask must be an octal integer\"}<\/code><\/pre>\nAnother helpful StackOverflow post suggested the value needed to be in quotes:<\/p>\n
- name: Install specified python requirements\r\n pip:\r\n executable: \/usr\/local\/bin\/pip3\r\n requirements: \/tmp\/pip3-packages\r\n umask: \"0022\"<\/code><\/pre>\nNow the playbook runs without error, but it doesn’t change the existing permissions. The task does nothing, since the Python pip modules are already installed. To really test the playbook, I need to clear out the existing modules first.<\/p>\n
Warning:<\/strong> this breaks things!:<\/p>\n$ sudo rm -rf \/usr\/local\/lib\/python3.6\/site-packages\/*<\/code><\/pre>\nI tried running the playbook again and received this error message:<\/p>\n
stderr: Traceback (most recent call last):\\n File \"\/usr\/local\/bin\/pip3\", line 7, in <module>\\n from pip import main\\nModuleNotFoundError: No module named 'pip'\\n<\/code><\/pre>\nI wasn’t able to run pip<\/code> at all:<\/p>\n$ pip3\r\nTraceback (most recent call last):\r\n File \"\/usr\/local\/bin\/pip3\", line 7, in <module>\r\n from pip import main\r\nModuleNotFoundError: No module named 'pip'<\/code><\/pre>\nClearly, I had deleted something important! I reinstalled Python from the gzipped source tarball for Python 3.6.1<\/a> (newer versions available from Python source releases<\/a>) and then everything worked as expected.<\/p>\n","protected":false},"excerpt":{"rendered":"I have a simple Python 3 script (I’m running Python 3.6.1, compiled from source) that does the following 3 things: Connects to remote server(s) and using scp to get files Processes the files. Connects to another remote server and uploads the processed files. I moved this script from a soon-to-be-retired CentOS 6 host to a … Continue reading AttributeError: module ‘paramiko’ has no attribute ‘SSHClient’<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[439,86],"tags":[423,504,506,358,505],"class_list":["post-2672","post","type-post","status-publish","format-standard","hentry","category-ansible","category-python","tag-ansible","tag-paramiko","tag-pip","tag-python","tag-umask"],"_links":{"self":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/2672","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/comments?post=2672"}],"version-history":[{"count":14,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/2672\/revisions"}],"predecessor-version":[{"id":2688,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/2672\/revisions\/2688"}],"wp:attachment":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/media?parent=2672"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/categories?post=2672"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/tags?post=2672"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}