Hi, Everyone.
I’m trying to run an Ansible playbook on two servers, and occasionally either one or both of them fail a task with the error “/usr/bin/python: can’t open file ‘command’: [Errno 13] Permission denied”. I started looking into why this was happening (and why it was only happening some of the time). I traced the error to the temporary directory where Ansible copies its command file sometimes being empty instead of the normal random directory created in /tmp (runner/init.py:Runner._make_tmp_path()). Looking into it further, it looks like sometimes the mkdir && echo command used to create the temporary directory is assumed to be successful, but the output, which should be the created directory, is empty (runner/connection_plugins/ssh.py:Connection._communicate()).
The mkdir && echo commands looks identical to me:
EXEC ssh -C -tt -vvv -o ControlMaster=auto -o ControlPersist=60s -o ControlPath=“/home/user/.ansible/cp/ansible-ssh-%h-%p-%r” -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey -o PasswordAuthentication=no -o ConnectTimeout=30 server1 /bin/sh -c 'mkdir -p /tmp/ansible-tmp-1415576481.52-184054006705534 && chmod a+rx /tmp/ansible-tmp-1415576481.52-184054006705534 && echo /tmp/ansible-tmp-1415576481.52-18405400670
EXEC ssh -C -tt -vvv -o ControlMaster=auto -o ControlPersist=60s -o ControlPath=“/home/user/.ansible/cp/ansible-ssh-%h-%p-%r” -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey -o PasswordAuthentication=no -o ConnectTimeout=30 server2 /bin/sh -c ‘mkdir -p /tmp/ansible-tmp-1415576481.52-82470479460561 && chmod a+rx /tmp/ansible-tmp-1415576481.52-82470479460561 && echo /tmp/ansible-tmp-1415576481.52-82470479460561’
But when I print out the stderr output from the commands, they are very different:
Server 1 (failed):
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: auto-mux: Trying existing master
debug1: Control socket “/home/user/.ansible/cp/ansible-ssh-server1-22-user” does not exist
debug2: ssh_connect: needpriv 0
debug1: Connecting to server1 [[server1 IP]] port 22.
debug2: fd 3 setting O_NONBLOCK
debug1: fd 3 clearing O_NONBLOCK
debug1: Connection established.
debug3: timeout: 30000 ms remain after connect
debug1: identity file /home/user/.ssh/identity type -1
debug1: identity file /home/user/.ssh/identity-cert type -1
debug3: Not a RSA1 key file /home/user/.ssh/id_rsa.
debug2: key_type_from_name: unknown key type ‘-----BEGIN’
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type ‘-----END’
debug3: key_read: missing keytype
debug1: identity file /home/user/.ssh/id_rsa type 1
debug1: identity file /home/user/.ssh/id_rsa-cert type -1
debug1: identity file /home/user/.ssh/id_dsa type -1
debug1: identity file /home/user/.ssh/id_dsa-cert type -1
debug1: identity file /home/user/.ssh/id_ecdsa type -1
debug1: identity file /home/user/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.3
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug3: Wrote 960 bytes for a total of 981
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa-cert-v01@openssh.com,ssh-dss-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-dss-cert-v00@openssh.com,ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: zlib@openssh.com,zlib,none
debug2: kex_parse_kexinit: zlib@openssh.com,zlib,none
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib@openssh.com
debug2: kex_parse_kexinit: none,zlib@openssh.com
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_setup: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 zlib@openssh.com
debug2: mac_setup: found hmac-md5
debug1: kex: client->server aes128-ctr hmac-md5 zlib@openssh.com
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug3: Wrote 24 bytes for a total of 1005
debug2: dh_gen_key: priv key bits set: 146/256
debug2: bits set: 521/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: Wrote 144 bytes for a total of 1149
debug3: check_host_in_hostfile: host server1 filename /home/user/.ssh/known_hosts
debug3: check_host_in_hostfile: host server1 filename /home/user/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 9
debug3: check_host_in_hostfile: host [server1 IP] filename /home/user/.ssh/known_hosts
debug3: check_host_in_hostfile: host [server1 IP] filename /home/user/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 10
debug1: Host ‘server1’ is known and matches the RSA host key.
debug1: Found key in /home/user/.ssh/known_hosts:9
debug2: bits set: 501/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: Wrote 16 bytes for a total of 1165
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug3: Wrote 48 bytes for a total of 1213
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/user/.ssh/identity ((nil))
debug2: key: /home/user/.ssh/id_rsa (0x7f4dc338f2d0)
debug2: key: /home/user/.ssh/id_dsa ((nil))
debug2: key: /home/user/.ssh/id_ecdsa ((nil))
debug3: Wrote 64 bytes for a total of 1277
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic,password
debug3: preferred gssapi-with-mic,gssapi-keyex,hostbased,publickey
debug3: authmethod_lookup gssapi-with-mic
debug3: remaining preferred: gssapi-keyex,hostbased,publickey
debug3: authmethod_is_enabled gssapi-with-mic
debug1: Next authentication method: gssapi-with-mic
debug3: Trying to reverse map address [server1 IP].
debug1: Unspecified GSS failure. Minor code may provide more information
Credentials cache file ‘/tmp/krb5cc_12444’ not found
debug1: Unspecified GSS failure. Minor code may provide more information
Credentials cache file ‘/tmp/krb5cc_12444’ not found
debug1: Unspecified GSS failure. Minor code may provide more information
debug1: Unspecified GSS failure. Minor code may provide more information
Credentials cache file ‘/tmp/krb5cc_12444’ not found
debug2: we did not send a packet, disable method
debug3: authmethod_lookup gssapi-keyex
debug3: remaining preferred: hostbased,publickey
debug3: authmethod_is_enabled gssapi-keyex
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug2: we did not send a packet, disable method
debug3: authmethod_lookup publickey
debug3: remaining preferred: ,publickey
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/user/.ssh/identity
debug3: no such identity: /home/user/.ssh/identity
debug1: Offering public key: /home/user/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug3: Wrote 368 bytes for a total of 1645
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug2: input_userauth_pk_ok: SHA1 fp d3:31:a6:e5:17:09:6c:cb:aa:f1:02:85:5f:fc:e9:94:56:e5:3e:d1
debug3: sign_and_send_pubkey: RSA d3:31:a6:e5:17:09:6c:cb:aa:f1:02:85:5f:fc:e9:94:56:e5:3e:d1
debug1: read PEM private key done: type RSA
debug3: Wrote 640 bytes for a total of 2285
debug1: Enabling compression at level 6.
debug1: Authentication succeeded (publickey).
debug1: setting up multiplex master socket
debug3: muxserver_listen: temporary control path /home/user/.ansible/cp/ansible-ssh-server1-22-user.FZ7QTgXgs6oGvNas
debug2: fd 4 setting O_NONBLOCK
debug3: fd 4 is O_NONBLOCK
debug3: fd 4 is O_NONBLOCK
debug1: channel 0: new [/home/user/.ansible/cp/ansible-ssh-server1-22-user.FZ7QTgXgs6oGvNas]
debug3: muxserver_listen: mux listener channel 0 fd 4
debug1: Entering interactive session.
debug2: set_control_persist_exit_time: schedule exit in 60 seconds
Server 2 (ok):
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: auto-mux: Trying existing master
debug2: fd 3 setting O_NONBLOCK
debug2: mux_client_hello_exchange: master version 4
debug3: mux_client_request_forwards: requesting forwardings: 0 local, 0 remote
debug3: mux_client_request_session: entering
debug3: mux_client_request_alive: entering
debug3: mux_client_request_alive: done pid = 18226
debug3: mux_client_request_session: session request sent
debug1: mux_client_request_session: master session id: 2
debug1: mux_client_request_session: master session id: 2
debug3: mux_client_read_packet: read header failed: Broken pipe
debug2: Received exit status from master 0
Shared connection to server2 closed.
I’m not familiar with SSH, so I don’t understand much what’s going on in the failing case. It looks to me like it’s trying out different authentication methods, and eventually is successful. (For authentication, I have keys set up in authorized_keys in both servers.)
Version info:
control:
CentOS release 6.6 (Final)
Python 2.7.3
openssh.x86_64 5.3p1-104.el6
server1:
CentOS release 6.2 (Final)
Python 2.6.6
openssh.x86_64 5.3p1-70.el6
server2:
CentOS release 6.2 (Final)
Python 2.6.6
openssh.x86_64 5.3p1-70.el6
I hope someone could shed some light on this, or at least be able to propose a workaround, so I could get it to work.
Paavo