在“provisioner”块上的 AWS EC2 实例上运行 Hashicorp Vault 服务器

Question

我正在创建一个 AWS 实例，并尝试在创建后运行一个 Vault 服务器。我的问题是创建过程永远不会完成，因为服务器没有在后台运行。这是我的配置：

resource "aws_instance" "web" {
  ami           = "ami-466768ac"
  instance_type = "t2.micro"
  key_name = "my_key"

  tags {
    Name = "Vault"
  }

  provisioner "remote-exec" {

    connection {
      type        = "ssh"
      agent       = false
      user        = "ec2-user"
      private_key = "${file("/path/to/my_key")}"
    }

    inline = [
      "curl -O https://releases.hashicorp.com/vault/0.10.4/vault_0.10.4_linux_amd64.zip",
      "unzip vault_0.10.4_linux_amd64.zip",
      "./vault server -dev -dev-listen-address=0.0.0.0:8200"
    ]
  }

}

基本上，我通过 curl 下载 Vault 并运行开发服务器。服务器实际运行（我在终端日志中看到），但实例创建（由 Terraform）从未完成：

aws_instance.web: Still creating... (40s elapsed)
aws_instance.web: Still creating... (50s elapsed)
aws_instance.web: Still creating... (1m0s elapsed)
aws_instance.web: Still creating... (1m10s elapsed)
aws_instance.web: Still creating... (1m20s elapsed)
aws_instance.web: Still creating... (1m30s elapsed)
...

我尝试在启动 Vault 服务器命令的末尾添加 &，以免阻塞 shell，但是当我这样做时，实例已创建但 Vault 服务器并未实际启动。

如何在创建实例时以后台模式启动服务器？

编辑

我也试过nohup:

nohup ./vault server -dev -dev-listen-address=0.0.0.0:8200

但是当 terraform 完成时服务器没有启动...

Answer 1

最后，正如@StephenKing 在评论中告诉我的那样，我创建了一个 systemd 服务。这是我的配置：

resource "aws_instance" "web" {
  ami           = "ami-466768ac"
  instance_type = "t2.micro"
  key_name = "my_key"

  tags {
    Name = "Vault"
  }

  //upload vault.service file (systemd unit)
  provisioner "file" {
    connection {
      type        = "ssh"
      agent       = false
      user        = "ec2-user"
      private_key = "${file("/path/to/my/key")}"
    }
    source = "./vault.service"
    destination = "/home/ec2-user/vault.service"
  }

  //download vault and start service
  provisioner "remote-exec" {
    connection {
      type        = "ssh"
      agent       = false
      user        = "ec2-user"
      private_key = "${file("/path/to/my/key")}"
    }
    inline = [
      "curl -O https://releases.hashicorp.com/vault/0.10.4/vault_0.10.4_linux_amd64.zip",
      "unzip vault_0.10.4_linux_amd64.zip",
      "sudo mv /home/ec2-user/vault.service /etc/systemd/system/",
      "sudo systemctl start vault.service"
    ]
  }

}

vault.service

[Unit]
Description=Vault dev server

[Service]
ExecStart=/home/ec2-user/vault server -dev -dev-listen-address=0.0.0.0:8200 

Answer 2

这真的不是 Terraform 特定的事情，如果您要通过 SSH 连接到一个实例并运行您的命令，您会看到它在进程处于前台时被阻塞，并且如果您通过将 & 添加到退出 SSH 会话后，您会看到命令结束。

这里的解决方案是使用nohup，这样Vault 服务器进程将忽略您的会话存在时触发的HUP（或挂断）信号。

所以你应该把你的命令改成：

...
    inline = [
      "curl -O https://releases.hashicorp.com/vault/0.10.4/vault_0.10.4_linux_amd64.zip",
      "unzip vault_0.10.4_linux_amd64.zip",
      "nohup ./vault server -dev -dev-listen-address=0.0.0.0:8200 &"
    ]
...