github.com/ticketmaster/terraform@v0.10.0-beta2.0.20170711045249-a12daf5aba4f/website/intro/getting-started/build.html.md (about) 1 --- 2 layout: "intro" 3 page_title: "Build Infrastructure" 4 sidebar_current: "gettingstarted-build" 5 description: |- 6 With Terraform installed, let's dive right into it and start creating some infrastructure. 7 --- 8 9 # Build Infrastructure 10 11 With Terraform installed, let's dive right into it and start creating 12 some infrastructure. 13 14 We'll build infrastructure on 15 [AWS](https://aws.amazon.com) for the getting started guide 16 since it is popular and generally understood, but Terraform 17 can [manage many providers](/docs/providers/index.html), 18 including multiple providers in a single configuration. 19 Some examples of this are in the 20 [use cases section](/intro/use-cases.html). 21 22 If you don't have an AWS account, 23 [create one now](https://aws.amazon.com/free/). 24 For the getting started guide, we'll only be using resources 25 which qualify under the AWS 26 [free-tier](https://aws.amazon.com/free/), 27 meaning it will be free. 28 If you already have an AWS account, you may be charged some 29 amount of money, but it shouldn't be more than a few dollars 30 at most. 31 32 ~> **Warning!** If you're not using an account that qualifies under the AWS 33 [free-tier](https://aws.amazon.com/free/), you may be charged to run these 34 examples. The most you should be charged should only be a few dollars, but 35 we're not responsible for any charges that may incur. 36 37 ## Configuration 38 39 The set of files used to describe infrastructure in Terraform is simply 40 known as a Terraform _configuration_. We're going to write our first 41 configuration now to launch a single AWS EC2 instance. 42 43 The format of the configuration files is 44 [documented here](/docs/configuration/index.html). 45 Configuration files can 46 [also be JSON](/docs/configuration/syntax.html), but we recommend only using JSON when the 47 configuration is generated by a machine. 48 49 The entire configuration is shown below. We'll go over each part 50 after. Save the contents to a file named `example.tf`. Verify that 51 there are no other `*.tf` files in your directory, since Terraform 52 loads all of them. 53 54 ```hcl 55 provider "aws" { 56 access_key = "ACCESS_KEY_HERE" 57 secret_key = "SECRET_KEY_HERE" 58 region = "us-east-1" 59 } 60 61 resource "aws_instance" "example" { 62 ami = "ami-2757f631" 63 instance_type = "t2.micro" 64 } 65 ``` 66 67 ~> **Note**: The above configuration is designed to work on most EC2 accounts, 68 with access to a default VPC. For EC2 Classic users, please use `t1.micro` for 69 `instance_type`, and `ami-408c7f28` for the `ami`. If you use a region other than 70 `us-east-1` then you will need to choose an AMI in that region 71 as AMI IDs are region specific. 72 73 Replace the `ACCESS_KEY_HERE` and `SECRET_KEY_HERE` with your 74 AWS access key and secret key, available from 75 [this page](https://console.aws.amazon.com/iam/home?#security_credential). 76 We're hardcoding them for now, but will extract these into 77 variables later in the getting started guide. 78 79 ~> **Note**: If you simply leave out AWS credentials, Terraform will 80 automatically search for saved API credentials (for example, 81 in `~/.aws/credentials`) or IAM instance profile credentials. 82 This option is much cleaner for situations where tf files are checked into 83 source control or where there is more than one admin user. 84 See details [here](https://aws.amazon.com/blogs/apn/terraform-beyond-the-basics-with-aws/). 85 Leaving IAM credentials out of the Terraform configs allows you to leave those 86 credentials out of source control, and also use different IAM credentials 87 for each user without having to modify the configuration files. 88 89 This is a complete configuration that Terraform is ready to apply. 90 The general structure should be intuitive and straightforward. 91 92 The `provider` block is used to configure the named provider, in 93 our case "aws." A provider is responsible for creating and 94 managing resources. Multiple provider blocks can exist if a 95 Terraform configuration is composed of multiple providers, 96 which is a common situation. 97 98 The `resource` block defines a resource that exists within 99 the infrastructure. A resource might be a physical component such 100 as an EC2 instance, or it can be a logical resource such as 101 a Heroku application. 102 103 The resource block has two strings before opening the block: 104 the resource type and the resource name. In our example, the 105 resource type is "aws\_instance" and the name is "example." 106 The prefix of the type maps to the provider. In our case 107 "aws\_instance" automatically tells Terraform that it is 108 managed by the "aws" provider. 109 110 Within the resource block itself is configuration for that 111 resource. This is dependent on each resource provider and 112 is fully documented within our 113 [providers reference](/docs/providers/index.html). For our EC2 instance, we specify 114 an AMI for Ubuntu, and request a "t2.micro" instance so we 115 qualify under the free tier. 116 117 ## Initialization 118 119 The first command to run for a new configuration -- or after checking out 120 an existing configuration from version control -- is `terraform init`, which 121 initializes various local settings and data that will be used by subsequent 122 commands. 123 124 In particular, this command will install the plugins for the providers in 125 use within the configuration, which in this case is just the `aws` provider: 126 127 ``` 128 $ terraform init 129 Initializing the backend... 130 Initializing provider plugins... 131 - downloading plugin for provider "aws"... 132 133 The following providers do not have any version constraints in configuration, 134 so the latest version was installed. 135 136 To prevent automatic upgrades to new major versions that may contain breaking 137 changes, it is recommended to add version = "..." constraints to the 138 corresponding provider blocks in configuration, with the constraint strings 139 suggested below. 140 141 * provider.aws: version = "~> 1.0" 142 143 Terraform has been successfully initialized! 144 145 You may now begin working with Terraform. Try running "terraform plan" to see 146 any changes that are required for your infrastructure. All Terraform commands 147 should now work. 148 149 If you ever set or change modules or backend configuration for Terraform, 150 rerun this command to reinitialize your environment. If you forget, other 151 commands will detect it and remind you to do so if necessary. 152 ``` 153 154 The `aws` provider plugin is downloaded and installed in a subdirectory of 155 the current working directory, along with various other book-keeping files. 156 157 The output specifies which version of the plugin was installed, and suggests 158 specifying that version in configuration to ensure that running 159 `terraform init` in future will install a compatible version. This step 160 is not necessary for following the getting started guide, since this 161 configuration will be discarded at the end. 162 163 ## Execution Plan 164 165 Next, let's see what Terraform would do if we asked it to 166 apply this configuration. In the same directory as the 167 `example.tf` file you created, run `terraform plan`. You 168 should see output similar to what is copied below. We've 169 truncated some of the output to save space. 170 171 ``` 172 $ terraform plan 173 # ... 174 175 + aws_instance.example 176 ami: "ami-2757f631" 177 availability_zone: "<computed>" 178 ebs_block_device.#: "<computed>" 179 ephemeral_block_device.#: "<computed>" 180 instance_state: "<computed>" 181 instance_type: "t2.micro" 182 key_name: "<computed>" 183 placement_group: "<computed>" 184 private_dns: "<computed>" 185 private_ip: "<computed>" 186 public_dns: "<computed>" 187 public_ip: "<computed>" 188 root_block_device.#: "<computed>" 189 security_groups.#: "<computed>" 190 source_dest_check: "true" 191 subnet_id: "<computed>" 192 tenancy: "<computed>" 193 vpc_security_group_ids.#: "<computed>" 194 ``` 195 196 `terraform plan` shows what changes Terraform will apply to 197 your infrastructure given the current state of your infrastructure 198 as well as the current contents of your configuration. 199 200 If `terraform plan` failed with an error, read the error message 201 and fix the error that occurred. At this stage, it is probably a 202 syntax error in the configuration. 203 204 The output format is similar to the diff format generated by tools 205 such as Git. The output has a "+" next to "aws\_instance.example", 206 meaning that Terraform will create this resource. Beneath that, 207 it shows the attributes that will be set. When the value displayed 208 is `<computed>`, it means that the value won't be known 209 until the resource is created. 210 211 ## Apply 212 213 The plan looks good, our configuration appears valid, so it's time to 214 create real resources. Run `terraform apply` in the same directory 215 as your `example.tf`, and watch it go! It will take a few minutes 216 since Terraform waits for the EC2 instance to become available. 217 218 ``` 219 $ terraform apply 220 aws_instance.example: Creating... 221 ami: "" => "ami-2757f631" 222 instance_type: "" => "t2.micro" 223 [...] 224 225 aws_instance.example: Still creating... (10s elapsed) 226 aws_instance.example: Creation complete 227 228 Apply complete! Resources: 1 added, 0 changed, 0 destroyed. 229 230 # ... 231 ``` 232 233 Done! You can go to the AWS console to prove to yourself that the 234 EC2 instance has been created. 235 236 Terraform also puts some state into the `terraform.tfstate` file 237 by default. This state file is extremely important; it maps various 238 resource metadata to actual resource IDs so that Terraform knows 239 what it is managing. This file must be saved and distributed 240 to anyone who might run Terraform. It is generally recommended to 241 [setup remote state](https://www.terraform.io/docs/state/remote.html) 242 when working with Terraform. This will mean that any potential secrets 243 stored in the state file, will not be checked into version control 244 245 246 You can inspect the state using `terraform show`: 247 248 ``` 249 $ terraform show 250 aws_instance.example: 251 id = i-32cf65a8 252 ami = ami-2757f631 253 availability_zone = us-east-1a 254 instance_state = running 255 instance_type = t2.micro 256 private_ip = 172.31.30.244 257 public_dns = ec2-52-90-212-55.compute-1.amazonaws.com 258 public_ip = 52.90.212.55 259 subnet_id = subnet-1497024d 260 vpc_security_group_ids.# = 1 261 vpc_security_group_ids.3348721628 = sg-67652003 262 ``` 263 264 You can see that by creating our resource, we've also gathered 265 a lot more metadata about it. This metadata can actually be referenced 266 for other resources or outputs, which will be covered later in 267 the getting started guide. 268 269 ## Provisioning 270 271 The EC2 instance we launched at this point is based on the AMI 272 given, but has no additional software installed. If you're running 273 an image-based infrastructure (perhaps creating images with 274 [Packer](https://www.packer.io)), then this is all you need. 275 276 However, many infrastructures still require some sort of initialization 277 or software provisioning step. Terraform supports 278 provisioners, 279 which we'll cover a little bit later in the getting started guide, 280 in order to do this. 281 282 ## Next 283 284 Congratulations! You've built your first infrastructure with Terraform. 285 You've seen the configuration syntax, an example of a basic execution 286 plan, and understand the state file. 287 288 Next, we're going to move on to [changing and destroying infrastructure](/intro/getting-started/change.html).