• ansible facts


    facts

    Facts通过访问远程系统获取相应的信息。

    一个例子就是远程主机的IP地址或者操作系统是什么. 使用以下命令可以查看哪些信息是可用的:

    ansible hostname -m setup

    这会返回巨量的变量数据,比如对于Ubutu 12.04系统,Ansible 1.4获取的信息显示如下:

    "ansible_all_ipv4_addresses": [
        "REDACTED IP ADDRESS"
    ],
    "ansible_all_ipv6_addresses": [
        "REDACTED IPV6 ADDRESS"
    ],
    "ansible_architecture": "x86_64",
    "ansible_bios_date": "09/20/2012",
    "ansible_bios_version": "6.00",
    "ansible_cmdline": {
        "BOOT_IMAGE": "/boot/vmlinuz-3.5.0-23-generic",
        "quiet": true,
        "ro": true,
        "root": "UUID=4195bff4-e157-4e41-8701-e93f0aec9e22",
        "splash": true
    },
    "ansible_date_time": {
        "date": "2013-10-02",
        "day": "02",
        "epoch": "1380756810",
        "hour": "19",
        "iso8601": "2013-10-02T23:33:30Z",
        "iso8601_micro": "2013-10-02T23:33:30.036070Z",
        "minute": "33",
        "month": "10",
        "second": "30",
        "time": "19:33:30",
        "tz": "EDT",
        "year": "2013"
    },
    "ansible_default_ipv4": {
        "address": "REDACTED",
        "alias": "eth0",
        "gateway": "REDACTED",
        "interface": "eth0",
        "macaddress": "REDACTED",
        "mtu": 1500,
        "netmask": "255.255.255.0",
        "network": "REDACTED",
        "type": "ether"
    },
    "ansible_default_ipv6": {},
    "ansible_devices": {
        "fd0": {
            "holders": [],
            "host": "",
            "model": null,
            "partitions": {},
            "removable": "1",
            "rotational": "1",
            "scheduler_mode": "deadline",
            "sectors": "0",
            "sectorsize": "512",
            "size": "0.00 Bytes",
            "support_discard": "0",
            "vendor": null
        },
        "sda": {
            "holders": [],
            "host": "SCSI storage controller: LSI Logic / Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI (rev 01)",
            "model": "VMware Virtual S",
            "partitions": {
                "sda1": {
                    "sectors": "39843840",
                    "sectorsize": 512,
                    "size": "19.00 GB",
                    "start": "2048"
                },
                "sda2": {
                    "sectors": "2",
                    "sectorsize": 512,
                    "size": "1.00 KB",
                    "start": "39847934"
                },
                "sda5": {
                    "sectors": "2093056",
                    "sectorsize": 512,
                    "size": "1022.00 MB",
                    "start": "39847936"
                }
            },
            "removable": "0",
            "rotational": "1",
            "scheduler_mode": "deadline",
            "sectors": "41943040",
            "sectorsize": "512",
            "size": "20.00 GB",
            "support_discard": "0",
            "vendor": "VMware,"
        },
        "sr0": {
            "holders": [],
            "host": "IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)",
            "model": "VMware IDE CDR10",
            "partitions": {},
            "removable": "1",
            "rotational": "1",
            "scheduler_mode": "deadline",
            "sectors": "2097151",
            "sectorsize": "512",
            "size": "1024.00 MB",
            "support_discard": "0",
            "vendor": "NECVMWar"
        }
    },
    "ansible_distribution": "Ubuntu",
    "ansible_distribution_release": "precise",
    "ansible_distribution_version": "12.04",
    "ansible_domain": "",
    "ansible_env": {
        "COLORTERM": "gnome-terminal",
        "DISPLAY": ":0",
        "HOME": "/home/mdehaan",
        "LANG": "C",
        "LESSCLOSE": "/usr/bin/lesspipe %s %s",
        "LESSOPEN": "| /usr/bin/lesspipe %s",
        "LOGNAME": "root",
        "LS_COLORS": "rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arj=01;31:*.taz=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lz=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.axa=00;36:*.oga=00;36:*.spx=00;36:*.xspf=00;36:",
        "MAIL": "/var/mail/root",
        "OLDPWD": "/root/ansible/docsite",
        "PATH": "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
        "PWD": "/root/ansible",
        "SHELL": "/bin/bash",
        "SHLVL": "1",
        "SUDO_COMMAND": "/bin/bash",
        "SUDO_GID": "1000",
        "SUDO_UID": "1000",
        "SUDO_USER": "mdehaan",
        "TERM": "xterm",
        "USER": "root",
        "USERNAME": "root",
        "XAUTHORITY": "/home/mdehaan/.Xauthority",
        "_": "/usr/local/bin/ansible"
    },
    "ansible_eth0": {
        "active": true,
        "device": "eth0",
        "ipv4": {
            "address": "REDACTED",
            "netmask": "255.255.255.0",
            "network": "REDACTED"
        },
        "ipv6": [
            {
                "address": "REDACTED",
                "prefix": "64",
                "scope": "link"
            }
        ],
        "macaddress": "REDACTED",
        "module": "e1000",
        "mtu": 1500,
        "type": "ether"
    },
    "ansible_form_factor": "Other",
    "ansible_fqdn": "ubuntu2.example.com",
    "ansible_hostname": "ubuntu2",
    "ansible_interfaces": [
        "lo",
        "eth0"
    ],
    "ansible_kernel": "3.5.0-23-generic",
    "ansible_lo": {
        "active": true,
        "device": "lo",
        "ipv4": {
            "address": "127.0.0.1",
            "netmask": "255.0.0.0",
            "network": "127.0.0.0"
        },
        "ipv6": [
            {
                "address": "::1",
                "prefix": "128",
                "scope": "host"
            }
        ],
        "mtu": 16436,
        "type": "loopback"
    },
    "ansible_lsb": {
        "codename": "precise",
        "description": "Ubuntu 12.04.2 LTS",
        "id": "Ubuntu",
        "major_release": "12",
        "release": "12.04"
    },
    "ansible_machine": "x86_64",
    "ansible_memfree_mb": 74,
    "ansible_memtotal_mb": 991,
    "ansible_mounts": [
        {
            "device": "/dev/sda1",
            "fstype": "ext4",
            "mount": "/",
            "options": "rw,errors=remount-ro",
            "size_available": 15032406016,
            "size_total": 20079898624
        }
    ],
    "ansible_nodename": "ubuntu2.example.com",
    "ansible_os_family": "Debian",
    "ansible_pkg_mgr": "apt",
    "ansible_processor": [
        "Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz"
    ],
    "ansible_processor_cores": 1,
    "ansible_processor_count": 1,
    "ansible_processor_threads_per_core": 1,
    "ansible_processor_vcpus": 1,
    "ansible_product_name": "VMware Virtual Platform",
    "ansible_product_serial": "REDACTED",
    "ansible_product_uuid": "REDACTED",
    "ansible_product_version": "None",
    "ansible_python_version": "2.7.3",
    "ansible_selinux": false,
    "ansible_ssh_host_key_dsa_public": "REDACTED KEY VALUE"
    "ansible_ssh_host_key_ecdsa_public": "REDACTED KEY VALUE"
    "ansible_ssh_host_key_rsa_public": "REDACTED KEY VALUE"
    "ansible_swapfree_mb": 665,
    "ansible_swaptotal_mb": 1021,
    "ansible_system": "Linux",
    "ansible_system_vendor": "VMware, Inc.",
    "ansible_user_id": "root",
    "ansible_userspace_architecture": "x86_64",
    "ansible_userspace_bits": "64",
    "ansible_virtualization_role": "guest",
    "ansible_virtualization_type": "VMware"

    引用返回的fact变量:

    {{ ansible_devices.sda.model }}  #第一个硬盘的model
    {{ ansible_hostname } #ansible 远程主机名

    在模板和条件判断中会经常使用facts。

    关闭facts

    如果你不需要使用你主机的任何fact数据,你已经知道了你系统的一切,那么你可以关闭fact数据的获取。

    - hosts: whatever
      gather_facts: false

    本地facts

    ansible facts主要是用于获取远程系统的数据,从而可以在playbook中作为变量使用。

    通常facts中的数据是由Ansible中的 ‘setup’模块自动发现的.用户也可以自定义facts模块。

    如果远程受管理的机器有一个 “/etc/ansible/facts.d” 目录,那么在该目录中任何以 ”.fact”结尾的文件都可以在Ansible中提供局部facts.

    这些文件可以是JSON,INI或者任何可以返回JSON的可执行文件.

    例如建设有一个 /etc/ansible/facts.d/perferences.fact文件:

    [general]
    asdf=1
    bar=2

    这将产生一个名为 “general” 的哈希表fact,里面成员有 ‘asdf’ 和 ‘bar’. 可以这样验证:

    ansible <hostname> -m setup -a "filter=ansible_local"

    然后你会看到有以下fact被添加:

    "ansible_local": {
            "preferences": {
                "general": {
                    "asdf" : "1",
                    "bar"  : "2"
                }
            }
     }

    而且也可以在template或palybook中访问该数据:

    {{ ansible_local.preferences.general.asdf }}

    本地命名空间放置其它用户提供的fact或者playbook中定义的变量覆盖系统facts值。

    如果你有个一个playook,它复制了一个自定义的fact,然后运行它,请显式调用来重新运行setup模块,

    这样可以让我们在该playbook中使用这些fact.否则,在下一个play中才能获取这些自定义的fact信息.这里有一个示例:

    - hosts: webservers
      tasks:
        - name: create directory for ansible custom facts
          file: state=directory recurse=yes path=/etc/ansible/facts.d
        - name: install custom impi fact
          copy: src=ipmi.fact dest=/etc/ansible/facts.d
        - name: re-read facts after adding custom fact
          setup: filter=ansible_local

    然而在该模式中你也可以编写一个fact模块,这只不过是多了一个选项。

    fact缓存

    从一个服务器引用另一个服务器的变量是可行的,比如:

    {{ hostvars['asdf.example.com']['ansible_os_family'] }}

    如果禁用 “Fact Caching”,为了实现以上功能,Ansible在当前play之前已经与 ‘asdf.example.com’ 通讯过,或者在playbook有其它优先的play.这是ansible的默认配置.

    为了避免这些,Ansible 1.8以后版本允许在playbook运行期间保存facts.但该功能需要手动开启.这有什么用处那?

    想象一下,如果我们有一个非常大的基础设施,里面有数千个主机.Fact缓存可以配置在夜间运行,

    但小型服务器集群可以配置fact随时运行,或者在白天定期运行.即使开启了fact缓存,也不需要访问所有服务器来引用它们的变量和信息.

    使用fact缓存可以跨群组访问变量,即使群组间在当前/user/bin/ansible-playbook执行中并没有通讯过.

    为了启用fact缓存,在大多数plays中你可以修改 ‘gathering’ 设置为 ‘smart’ 或者 ‘explicit’,也可以设置 ‘gather_facts’ 为False.

    当前,Ansible可以使用两种持久的缓存插件: redis和jsonfile.

    可以在ansible.cfg中配置fact缓存使用redis:

    [defaults]
    gathering = smart
    fact_caching = redis
    fact_caching_timeout = 86400
    # seconds

    请执行适当的系统命令来启动和运行redis:

    yum install redis
    service redis start
    pip install redis

    请注意可以使用pip来安装Python redis库,在EPEL中的包版本对Ansible来说太旧了.

    在当前Ansible版本中,该功能还处于试用状态,Redis插件还不支持端口或密码配置,以后会改善这点.

    在ansible.cfg中使用以下代码来配置fact缓存使用jsonfile:

    [defaults]
    gathering = smart
    fact_caching = jsonfile
    fact_caching_connection = /path/to/cachedir
    fact_caching_timeout = 86400
    # seconds

    fact_caching_connection 是一个放置在可读目录(如果目录不存在,ansible会试图创建它)中的本地文件路径。

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  • 原文地址:https://www.cnblogs.com/nineep/p/8984251.html
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