在 cloud-init 中使用有效的 YAML 运行将文本添加到文件的命令

Question

使用 cloud-init，如何运行将文本（字符串列表）添加到文件？另外，我需要转义冒号:字符吗？看来这个问题是 YAML 验证，但找不到任何示例来帮助我解决。

这是我尝试过的。所有 echo 命令似乎都无效。

#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，因此语句:中的echo被解释为key: value分隔符。您想要引用每一行的全部内容，最好的方法可能是使用 YAML 引用运算符之一（>、折叠引用运算符或|文字引用运算符）。您可以在此处找到有关此主题的一些文档。

像这样：

#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 转换器来验证此解析是否正确，该转换器将向您显示：

[
  "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语句替换为单个“here”-document）：

[
  "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"
]

这可能更容易阅读，也更容易维护。