如何在远程主机上执行 ansible 序列化命令？

Question

如果目标主机上没有代理，Ansible 能够执行诸如添加用户（-m 用户）之类的任务。

为了理解这一点，我读了这个article，上面写着：

“Ansible 通过连接到您的节点并推出 小程序（称为“Ansible 模块”）来工作。这些程序被编写为系统所需状态的资源模型。”

为了理解这一点，我的解释是，user 模块是位于控制服务器中的 python 模块，并且在运行带有-m user 选项的ansible 命令后，该模块在线上序列化到目标主机。

---

ansible 是否通过 ssh 序列化这些程序（user 源代码）？在远程主机上执行...

此序列化是否涉及 ssh 代理转发技术？

Answer 1

当 ansible 在你的 playbook 中执行一个模块时，它会将需要运行的代码与遇到的参数一起序列化到一个名为 <local user home>/.ansible/tmp/ansible-local-<current-run-hash>/tmp<some-other-hash> 的本地 python 文件中。

该文件使用为该主机声明的连接（ssh、docker、本地...）上传到<remote_user home dir>/.ansible/tmp/ansible-tmp-<current-run-hashed-id>/AnsiballZ_<module_name>.py 中的远程主机。

python 文件通过该连接在远程主机上执行，结果被取回本地机器并清理文件。

您可以使用ansible-playbook 的-vvv 选项（或ansible，如果您正在发送临时命令）确切地看到所有这些是如何执行的。这是在我的本地机器上针对 docker 主机运行 stat 模块的示例。

任务：

- name: Check if SystemD service is installed
  stat:
    path: /etc/systemd/system/nexus.service
  register: nexus_systemd_service_file

使用-vvv 运行。文件复制到远程从第 7 行开始。

    TASK [nexus3-oss : Check if SystemD service is installed] **********************
    task path: /projects/ansible/nexus3-oss/tasks/main.yml:13
    <nexus3-oss-debian-stretch> ESTABLISH DOCKER CONNECTION FOR USER: root
    <nexus3-oss-debian-stretch> EXEC ['/usr/bin/docker', b'exec', b'-i', 'nexus3-oss-debian-stretch', '/bin/sh', '-c', "/bin/sh -c 'echo ~ && sleep 0'"]
    <nexus3-oss-debian-stretch> EXEC ['/usr/bin/docker', b'exec', b'-i', 'nexus3-oss-debian-stretch', '/bin/sh', '-c', '/bin/sh -c \'( umask 77 && mkdir -p "` echo /home/deployuser/.ansible/tmp/ansible-tmp-1555848182.1761565-31974482443721 `" && echo ansible-tmp-1555848182.1761565-31974482443721="` echo /deployuser/.ansible/tmp/ansible-tmp-1555848182.1761565-31974482443721 `" ) && sleep 0\'']
    Using module file /home/localuser/.local/lib/python3.6/site-packages/ansible/modules/files/stat.py
    <nexus3-oss-debian-stretch> PUT /home/localuser/.ansible/tmp/ansible-local-30458wt820190/tmpq2vjarrv TO /home/deployuser/.ansible/tmp/ansible-tmp-1555848182.1761565-31974482443721/AnsiballZ_stat.py
    <nexus3-oss-debian-stretch> EXEC ['/usr/bin/docker', b'exec', b'-i', 'nexus3-oss-debian-stretch', '/bin/sh', '-c', "/bin/sh -c 'chmod u+x /home/deployuser/.ansible/tmp/ansible-tmp-1555848182.1761565-31974482443721/ /home/deployuser/.ansible/tmp/ansible-tmp-1555848182.1761565-31974482443721/AnsiballZ_stat.py && sleep 0'"]
    <nexus3-oss-debian-stretch> EXEC ['/usr/bin/docker', b'exec', b'-i', 'nexus3-oss-debian-stretch', '/bin/sh', '-c', '/bin/sh -c \'http_proxy=\'"\'"\'\'"\'"\' https_proxy=\'"\'"\'\'"\'"\' no_proxy=\'"\'"\'\'"\'"\' /usr/bin/python /home/deployuser/.ansible/tmp/ansible-tmp-1555848182.1761565-31974482443721/AnsiballZ_stat.py && sleep 0\'']
    <nexus3-oss-debian-stretch> EXEC ['/usr/bin/docker', b'exec', b'-i', 'nexus3-oss-debian-stretch', '/bin/sh', '-c', "/bin/sh -c 'rm -f -r /home/deployuser/.ansible/tmp/ansible-tmp-1555848182.1761565-31974482443721/ > /dev/null 2>&1 && sleep 0'"]
    ok: [nexus3-oss-debian-stretch] => {
        "changed": false,
        "invocation": {
            "module_args": {
                "checksum_algorithm": "sha1",
                "follow": false,
                "get_attributes": true,
                "get_checksum": true,
                "get_md5": null,
                "get_mime": true,
                "path": "/etc/systemd/system/nexus.service"
            }
        },
        "stat": {
            "atime": 1555848116.0796735,
            "attr_flags": "",
            "attributes": [],
            "block_size": 4096,
            "blocks": 8,
            "charset": "us-ascii",
            "checksum": "f1de2c2bc91adc019e58f83a29c970d1d79d5cc9",
            "ctime": 1553622777.8884165,
            "dev": 77,
            "device_type": 0,
            "executable": false,
            "exists": true,
            "gid": 0,
            "gr_name": "root",
            "inode": 22997,
            "isblk": false,
            "ischr": false,
            "isdir": false,
            "isfifo": false,
            "isgid": false,
            "islnk": false,
            "isreg": true,
            "issock": false,
            "isuid": false,
            "mimetype": "text/plain",
            "mode": "0644",
            "mtime": 1553622777.3485653,
            "nlink": 1,
            "path": "/etc/systemd/system/nexus.service",
            "pw_name": "root",
            "readable": true,
            "rgrp": true,
            "roth": true,
            "rusr": true,
            "size": 248,
            "uid": 0,
            "version": "687353",
            "wgrp": false,
            "woth": false,
            "writeable": true,
            "wusr": true,
            "xgrp": false,
            "xoth": false,
            "xusr": false
        }
    }