{"id":2215,"date":"2019-08-27T08:03:21","date_gmt":"2019-08-27T05:03:21","guid":{"rendered":"https:\/\/upcloud.com\/global\/us\/resources\/tutorials\/automate-terraform-deployments\/"},"modified":"2019-08-27T08:03:21","modified_gmt":"2019-08-27T05:03:21","slug":"automate-terraform-deployments","status":"publish","type":"tutorial","link":"https:\/\/upcloud.com\/global\/resources\/tutorials\/automate-terraform-deployments\/","title":{"rendered":"How to automate Terraform deployments"},"content":{"rendered":"\n

Maintaining cloud infrastructure<\/a> of any substantial size can often require you to perform the same actions or processes over and over. While some might enjoy the routine, there is however another way. Automating repetitive and reactionary tasks is the perfect solution to saving time and guaranteeing results, and what better way to manage this than using Terraform<\/a>!<\/p>\n\n\n

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In this guide, we\u2019ll look into what you need to consider when automating infrastructure deployments using Terraform. If you haven\u2019t yet set up Terraform with the UpCloud module on your computer, head over to our starters guide<\/a> first to get going.<\/p>\n\n\n\n\n\n

Creating a new configuration<\/h2>\n\n\n\n

Automating tasks like Terraform deployments is a great way, for example, to create reactive scalability for a load-balanced website. If you expect to be deploying similar setups on multiple occasions, it\u2019ll be worth templating the configuration from the start.<\/p>\n\n\n\n

First, make a new directory for the template configuration.<\/p>\n\n\n\n

mkdir -p ~\/terraform\/template && cd ~\/terraform\/template<\/pre>\n\n\n\n
Next, let\u2019s create the template itself. Open a new file in your text editor, for example, using nano as below.<\/p>\n\n\n\n
nano template.tf<\/pre>\n\n\n\n
Then add a following basic config as a starting point. The example here already uses variables for most fields, we\u2019ll fill these in later.<\/p>\n\n\n\n
provider \"upcloud\" {\n  # export UPCLOUD_USERNAME=\"Username for Upcloud API user\"\n  # export UPCLOUD_PASSWORD=\"Password for Upcloud API user\"\n}\n\nresource \"upcloud_server\" \"template\" {\n  hostname = var.hostname\n  zone     = var.zones[var.zone]\n  plan     = var.plans[var.plan]\n\n  network_interface {\n    type = \"public\"\n  }\n  template {\n    size    = lookup(var.storages, var.plans[var.plan])\n    storage = var.templates[var.template]\n  }\n  \n  login {\n    user = \"root\"\n    keys = [\n      var.public_key,\n    ]\n  }\n  connection {\n    host        = self.network_interface[0].ip_address\n    type        = \"ssh\"\n    user        = \"root\"\n    private_key = file(var.private_key_path)\n  }\n}<\/pre>\n\n\n\n
Make sure to include your SSH keys<\/a>, the public key in the login section, and the private key file path in the connection. These are needed for automation in order to avoid password authentication.<\/p>\n\n\n\n
With a simple Terraform template created, you should initialize the working directory so that we can make a test deployment further down the line.<\/p>\n\n\n\n
Initializing a new Terraform directory generally does not need input but it accepts the following parameter for non-attended use.<\/p>\n\n\n\n
terraform init -input=false<\/pre>\n\n\n\n
Initializing provider plugins...\n\nTerraform has been successfully initialized!<\/pre>\n\n\n\n
Now that Terraform has been initialized with the required plugin continue below on how to use variables to automate Terraform deployments.<\/p>\n\n\n\n
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Try Terraform for free!<\/a><\/div>\n<\/div>\n\n\n\n
Customising deployment with variables<\/h2>\n\n\n\n
Terraform variables are very useful for reusing the same configuration file with different outcomes. With Terraform, you can include variables straight from the command line or add them in the configuration files. If you\u2019re not entirely up to speed on Terraform variables and how to use them, learn more in the guide to Terraform variables<\/a>.<\/p>\n\n\n\n
Below is an example of setting a variable on the command line during planning.<\/p>\n\n\n\n
terraform plan -var=\"variable=value\"<\/pre>\n\n\n\n
The above is handy for setting a couple of variables but not in large numbers. To set multiple variables at a time, it is more convenient to specify their values in a variable definitions file. Terraform automatically loads any filename ending in either .tfvars<\/tt> or .tfvars.json<\/tt> within the same working directory but the variable file can also be included at the command line with -var-file<\/tt> parameter.<\/p>\n\n\n\n
terraform plan -var-file=\"variables.tfvars\"<\/pre>\n\n\n\n
Now, to give Terraform some variables to work with, let\u2019s create the two files as shown below.<\/p>\n\n\n\n
touch config-options.tf default.tfvars<\/pre>\n\n\n\n
Then add the following variables to the config-options.tf<\/tt> file.<\/p>\n\n\n\n
variable \"private_key_path\" {\n  type = string\n  default = \"\/home\/user\/.ssh\/terraform_rsa<\/span>\"\n}\n\nvariable \"public_key\" {\n  type = string\n  default = \"ssh-rsa terraform_public_key<\/span>\"\n}\n\nvariable plans {\n  type = map\n  default = {\n    \"5USD\"  = \"1xCPU-1GB\"\n    \"10USD\" = \"1xCPU-2GB\"\n    \"20USD\" = \"2xCPU-4GB\"\n  }\n}\n\nvariable storages {\n  type = map\n  default = {\n    \"1xCPU-1GB\" = \"25\"\n    \"1xCPU-2GB\" = \"50\"\n    \"2xCPU-4GB\" = \"80\"\n  }\n}\n\nvariable zones {\n  type = map\n  default = {\n    \"amsterdam\" = \"nl-ams1\"\n    \"london\"    = \"uk-lon1\"\n    \"frankfurt\" = \"de-fra1\"\n    \"helsinki1\" = \"fi-hel1\"\n    \"helsinki2\" = \"fi-hel2\"\n    \"chicago\"   = \"us-chi1\"\n    \"singapore\" = \"sg-sin1\"\n  }\n}\n\nvariable templates {\n  type = map\n  default = {\n    \"ubuntu\" = \"01000000-0000-4000-8000-000030080200\"\n    \"centos\" = \"01000000-0000-4000-8000-000050010300\"\n    \"debian\" = \"01000000-0000-4000-8000-000020040100\"\n  }\n}\n\nvariable hostname { default = \"template\" }\nvariable plan { default = \"5USD\" }\nvariable zone { default = \"amsterdam\" }\nvariable template { default = \"debian\" }<\/pre>\n\n\n\n
Afterwards, add the example values in the example.tfvars<\/tt> file.<\/p>\n\n\n\n
\"hostname\" = \"example\"\n\"plan\"     = \"5USD\"\n\"zone\"     = \"frankfurt\"\n\"template\" = \"ubuntu\"<\/pre>\n\n\n\n
Once you\u2019ve set up the variable files, test the template by running the plan command as below.<\/p>\n\n\n\n
terraform plan -var-file=example.tfvars<\/pre>\n\n\n\n
Setting up variables this way allows you to configure your Terraform deployment quickly and easily without needing to edit the files.<\/p>\n\n\n\n
The above examples for setting variables can be used together in any combination. If the same variable is assigned multiple values, Terraform uses the last input, overriding any previous values.<\/p>\n\n\n\n
Terraform loads variables in a predefined order. Later sources take precedence over earlier ones.<\/p>\n\n\n\n