在mac本机设置ansible环境，执行如下指令
ansible-playbook --connection=ssh --timeout=30 --extra-vars=ansible_user\=\'root\' --limit="all" --inventory-file=deploy/profiles/ha/hosts --extra-vars=\{\"docker_cleanup_legacy_resources\":true,\"cloudmgr_image_version\":\"2.2.0-SNAPSHOT-20190624.142052\",\"cloudmgr_deploy_profile\":\"ha\"\} --become -v deploy/deploy-demo.yml
报错日志：
TASK [Gathering Facts] ********************************************************************************************************************
fatal: [192.168.108.27]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: root@192.168.108.27: Permission denied (publickey).", "unreachable": true}
fatal: [192.168.108.31]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: root@192.168.108.31: Permission denied (publickey).", "unreachable": true}
fatal: [192.168.108.30]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: root@192.168.108.30: Permission denied (publickey).", "unreachable": true}
fatal: [192.168.108.32]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: root@192.168.108.32: Permission denied (publickey).", "unreachable": true}
fatal: [192.168.108.33]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: root@192.168.108.33: Permission denied (publickey).", "unreachable": true}
原因：默认使用当前用户home目录.ssh/id_rsa，而非代码目录下的deploy/keys/id_rsa
解决历程：
1. ansible-playbook 打印执行日志，找到出错指令，加-vvv查看详细执行过程
ssh -vvv -C -o ControlMaster=auto -o ControlPersist=60s -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey -o PasswordAuthentication=no -o 'User="root"' -o ConnectTimeout=30 -o ControlPath=/Users/qiaoxiaolin/.ansible/cp/aa117ff50a 192.168.108.31 '/bin/sh -c '"'"'echo ~root && sleep 0'"'"''
2. 在本地环境和远程主机环境比对执行出错指令，远程主机执行无问题
3. 确认私钥问题，在本地复制一份可用私钥，执行指令仍报错
4. 单独使用私钥ssh root@192.168.108.31 -i ~/.ssh/id_rsa 可连接，确认私钥正确
5. 怀疑公钥问题。删除公钥~/.ssh/id_rsa.pub，测试指令可连接。
