Terraform：在Docker容器内将JSON文件作为环境变量值与systemd单位文件一起传递

编程问答 2022-08-15

问题描述

我正在尝试在terraform的systemd单位文件的环境变量中传递json。我正在使用名为CT的外部提供程序来从YAML配置生成点火。

CT配置：

data "ct_config" "ignition" {
  # Reference: https://github.com/poseidon/terraform-provider-ct/
  content      = data.template_file.bastion_user_data.rendered
  strict       = true
  pretty_print = false
}

错误：

Error: error converting to Ignition: error at line 61,column 17
invalid unit content: unexpected newline encountered while parsing option name

  on ../../modules/example/launch-template.tf line 91,in data "ct_config" "ignition":
  91: data "ct_config" "ignition" {

单位文件内容：

- name: cw-agent.service
  enabled: true
  contents: |
    [Unit]
    Description=Cloudwatch Agent Service
    Documentation=https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Agent-Configuration-File-Details.html
    Requires=docker.socket
    After=docker.socket
    [Service]
    TimeoutStartSec=0
    Restart=always
    RestartSec=10s
    Environment=CONfig=${cw-agent-config}
    ExecStartPre=-/usr/bin/docker kill cloudwatch-agent
    ExecStartPre=-/usr/bin/docker rm cloudwatch-agent
    ExecStartPre=/usr/bin/docker pull amazon/cloudwatch-agent
    ExecStart=/usr/bin/docker run --name cloudwatch-agent \
                              --net host \
                              --env CW_CONfig_CONTENT=$CONfig \
                              amazon/cloudwatch-agent
    ExecStop=/usr/bin/docker stop cloudwatch-agent
    [Install]
    WantedBy=multi-user.target

渲染：

data "template_file" "cw_agent_config" {
  template = file("${path.module}/../cw-agent-config.json")
}

cw-agent-config = indent(10,data.template_file.cw_agent_config.rendered)

文件内容：

{
    "agent": {
        "metrics_collection_interval": 60,"run_as_user": "cwagent"
    },"metrics": {
        "append_dimensions": {
            "AutoScalingGroupName": "$${aws:AutoScalingGroupName}","ImageId": "$${aws:ImageId}","InstanceId": "$${aws:InstanceId}","InstanceType": "$${aws:InstanceType}"
        },"metrics_collected": {
            "disk": {
                "drop_device" : true,"measurement": [
                    "used_percent"
                ],"metrics_collection_interval": 120,"resources": [
                    "/"
                ]
            },"mem": {
                "measurement": [
                    "mem_used_percent"
                ],"metrics_collection_interval": 120
            }
        }
    }
}

我需要此json文件作为docker容器内名为CW_CONfig_CONTENT的环境变量的值来提供。

解决方法

此问题通过使用Terraform jsonencode函数解决。

    cw-agent-config = jsonencode(data.template_file.cw_agent_config.rendered)
coreosdockersystemdterraform