sysctl

# sysctl
修改内核属性

## 允许tcp转发
```yaml
- name: 配置IP转发
  sysctl:
    name: net.ipv4.ip_forward
    value: '1'
    state: present
```

## 开启bbr
需要更新内核版本到最小4.9

```yaml
- name: 配置BBR拥塞算法
  sysctl:
    name: "{{ item.name }}"
    value: "{{ item.value }}"
    state: present
  with_items:
  - { "name":"net.core.default_qdisc", "value":"fq" }
  - { "name":"net.ipv4.tcp_congestion_control", "value":"bbr" }
```

## 帮助文档
`ansible-doc sysctl`

```yaml
EXAMPLES:

# Set vm.swappiness to 5 in /etc/sysctl.conf
- sysctl:
    name: vm.swappiness
    value: '5'
    state: present

# Remove kernel.panic entry from /etc/sysctl.conf
- sysctl:
    name: kernel.panic
    state: absent
    sysctl_file: /etc/sysctl.conf

# Set kernel.panic to 3 in /tmp/test_sysctl.conf
- sysctl:
    name: kernel.panic
    value: '3'
    sysctl_file: /tmp/test_sysctl.conf
    reload: no

# Set ip forwarding on in /proc and verify token value with the sysctl command
- sysctl:
    name: net.ipv4.ip_forward
    value: '1'
    sysctl_set: yes

# Set ip forwarding on in /proc and in the sysctl file and reload if necessary
- sysctl:
    name: net.ipv4.ip_forward
    value: '1'
    sysctl_set: yes
    state: present
    reload: yes
```