在云init中使用有效的YAML运行将文本添加到文件的命令。

Question

使用云init，如何将文本(字符串列表)添加到文件中？另外，我是否需要转义冒号:字符？似乎这个问题是YAML验证，但找不到任何例子来帮助我。

这是我试过的。似乎没有一个回显命令是有效的。

#cloud-config

runcmd:
  - aws s3 cp s3://my-bucket/elasticsearch/elasticsearch.tar.gz /opt/elastic/elasticsearch.tar.gz
  - tar -xf /opt/elastic/elasticsearch.tar.gz
  - ln -sv /opt/elastic/elasticsearch-7.7.6 /opt/elastic/elasticsearch
  - cp /opt/elastic/elasticsearch/config/elasticsearch.yml /opt/elastic/elasticsearch/config/elasticsearch.yml.bkp
  - echo 'cluster.name: DEMO' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - echo 'node.name: node1' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - echo 'path.data: /opt/elastic/data' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - echo 'path.logs: /opt/elastic/logs' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - echo 'network.host: host1.domain.internal' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - echo 'http.port: 9200' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - echo 'discovery.seed_hosts: ["host1.domain.internal", "host2.domain.internal", "host3.domain.internal"]' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - echo 'cluster.initial_master_nodes: ["node1", "node2", "node3"]' >> /opt/elastic/elasticsearch/config/elasticsearch.yml

Answer 1

您没有充分引用列表中的值，因此您的echo语句中的echo被解释为key: value分隔符。您希望引用每一行的全部内容，最好的方法可能是使用YAML引号操作符(>、折叠引号运算符或|文字引号运算符)。您可以找到一些关于这个主题的文档，这里。

如下所示：

#cloud-config

runcmd:
  - |
    aws s3 cp s3://my-bucket/elasticsearch/elasticsearch.tar.gz /opt/elastic/elasticsearch.tar.gz
  - |
    tar -xf /opt/elastic/elasticsearch.tar.gz
  - |
    ln -sv /opt/elastic/elasticsearch-7.7.6 /opt/elastic/elasticsearch
  - |
    cp /opt/elastic/elasticsearch/config/elasticsearch.yml /opt/elastic/elasticsearch/config/elasticsearch.yml.bkp
  - |
    echo 'cluster.name: DEMO' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - |
    echo 'node.name: node1' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - |
    echo 'path.data: /opt/elastic/data' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - |
    echo 'path.logs: /opt/elastic/logs' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - |
    echo 'network.host: host1.domain.internal' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - |
    echo 'http.port: 9200' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - |
    echo 'discovery.seed_hosts: ["host1.domain.internal", "host2.domain.internal", "host3.domain.internal"]' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
  - |
    echo 'cluster.initial_master_nodes: ["node1", "node2", "node3"]' >> /opt/elastic/elasticsearch/config/elasticsearch.yml

您可以通过YAML到JSON转换器来验证这些分析是否正确，这将显示：

[
  "aws s3 cp s3://my-bucket/elasticsearch/elasticsearch.tar.gz /opt/elastic/elasticsearch.tar.gz\n",
  "tar -xf /opt/elastic/elasticsearch.tar.gz\n",
  "ln -sv /opt/elastic/elasticsearch-7.7.6 /opt/elastic/elasticsearch\n",
  "cp /opt/elastic/elasticsearch/config/elasticsearch.yml /opt/elastic/elasticsearch/config/elasticsearch.yml.bkp\n",
  "echo 'cluster.name: DEMO' >> /opt/elastic/elasticsearch/config/elasticsearch.yml\n",
  "echo 'node.name: node1' >> /opt/elastic/elasticsearch/config/elasticsearch.yml\n",
  "echo 'path.data: /opt/elastic/data' >> /opt/elastic/elasticsearch/config/elasticsearch.yml\n",
  "echo 'path.logs: /opt/elastic/logs' >> /opt/elastic/elasticsearch/config/elasticsearch.yml\n",
  "echo 'network.host: host1.domain.internal' >> /opt/elastic/elasticsearch/config/elasticsearch.yml\n",
  "echo 'http.port: 9200' >> /opt/elastic/elasticsearch/config/elasticsearch.yml\n",
  "echo 'discovery.seed_hosts: [\"host1.domain.internal\", \"host2.domain.internal\", \"host3.domain.internal\"]' >> /opt/elastic/elasticsearch/config/elasticsearch.yml\n",
  "echo 'cluster.initial_master_nodes: [\"node1\", \"node2\", \"node3\"]' >> /opt/elastic/elasticsearch/config/elasticsearch.yml\n"
]

您应该能够将这些行组合成一个多行shell脚本，如下所示(我冒昧地将多个echo语句替换为一个单一的“这里”-document)：

#cloud-config

runcmd:
  - |
    aws s3 cp s3://my-bucket/elasticsearch/elasticsearch.tar.gz /opt/elastic/elasticsearch.tar.gz
    tar -xf /opt/elastic/elasticsearch.tar.gz
    ln -sv /opt/elastic/elasticsearch-7.7.6 /opt/elastic/elasticsearch
    cp /opt/elastic/elasticsearch/config/elasticsearch.yml /opt/elastic/elasticsearch/config/elasticsearch.yml.bkp

    cat >> /opt/elastic/elasticsearch/config/elasticsearch.yml <<EOF
    cluster.name: DEMO' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
    node.name: node1' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
    path.data: /opt/elastic/data' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
    path.logs: /opt/elastic/logs' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
    network.host: host1.domain.internal' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
    http.port: 9200' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
    discovery.seed_hosts: ["host1.domain.internal", "host2.domain.internal", "host3.domain.internal"]' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
    cluster.initial_master_nodes: ["node1", "node2", "node3"]' >> /opt/elastic/elasticsearch/config/elasticsearch.yml
    EOF

这可能既容易阅读，又易于维护。