github.com/cycloidio/terraform@v1.1.10-0.20220513142504-76d5c768dc63/website/docs/cli/commands/plan.mdx (about) 1 --- 2 page_title: 'Command: plan' 3 description: >- 4 The terraform plan command creates an execution plan with a preview of the 5 changes that Terraform will make to your infrastructure. 6 --- 7 8 # Command: plan 9 10 The `terraform plan` command creates an execution plan, which lets you preview 11 the changes that Terraform plans to make to your infrastructure. By default, 12 when Terraform creates a plan it: 13 14 * Reads the current state of any already-existing remote objects to make sure 15 that the Terraform state is up-to-date. 16 * Compares the current configuration to the prior state and noting any 17 differences. 18 * Proposes a set of change actions that should, if applied, make the remote 19 objects match the configuration. 20 21 > **Hands-on:** Try the [Terraform: Get Started](https://learn.hashicorp.com/collections/terraform/aws-get-started?utm_source=WEBSITE&utm_medium=WEB_IO&utm_offer=ARTICLE_PAGE&utm_content=DOCS) collection on HashiCorp Learn. 22 23 The plan command alone will not actually carry out the proposed changes, and 24 so you can use this command to check whether the proposed changes match what 25 you expected before you apply the changes or share your changes with your 26 team for broader review. 27 28 If Terraform detects that no changes are needed to resource instances or to 29 root module output values, `terraform plan` will report that no actions need 30 to be taken. 31 32 If you are using Terraform directly in an interactive terminal and you expect 33 to apply the changes Terraform proposes, you can alternatively run 34 [`terraform apply`](/cli/commands/apply) directly. By default, the "apply" command 35 automatically generates a new plan and prompts for you to approve it. 36 37 You can use the optional `-out=FILE` option to save the generated plan to a 38 file on disk, which you can later execute by passing the file to 39 [`terraform apply`](/cli/commands/apply) as an extra argument. This two-step workflow 40 is primarily intended for when 41 [running Terraform in automation](https://learn.hashicorp.com/tutorials/terraform/automate-terraform?in=terraform/automation&utm_source=WEBSITE&utm_medium=WEB_IO&utm_offer=ARTICLE_PAGE&utm_content=DOCS). 42 43 If you run `terraform plan` without the `-out=FILE` option then it will create 44 a _speculative plan_, which is a description of the effect of the plan but 45 without any intent to actually apply it. 46 47 In teams that use a version control and code review workflow for making changes 48 to real infrastructure, developers can use speculative plans to verify the 49 effect of their changes before submitting them for code review. However, it's 50 important to consider that other changes made to the target system in the 51 meantime might cause the final effect of a configuration change to be different 52 than what an earlier speculative plan indicated, so you should always re-check 53 the final non-speculative plan before applying to make sure that it still 54 matches your intent. 55 56 ## Usage 57 58 Usage: `terraform plan [options]` 59 60 The `plan` subcommand looks in the current working directory for the root module 61 configuration. 62 63 Because the plan command is one of the main commands of Terraform, it has 64 a variety of different options, described in the following sections. However, 65 most of the time you should not need to set any of these options, because 66 a Terraform configuration should typically be designed to work with no special 67 additional options for routine work. 68 69 The remaining sections on this page describe the various options: 70 71 * **[Planning Modes](#planning-modes)**: There are some special alternative 72 planning modes that you can use for some special situations where your goal 73 is not just to change the remote system to match your configuration. 74 * **[Planning Options](#planning-options)**: Alongside the special planning 75 modes, there are also some options you can set in order to customize the 76 planning process for unusual needs. 77 * **[Resource Targeting](#resource-targeting)** is one particular 78 special planning option that has some important caveats associated 79 with it. 80 * **[Other Options](#other-options)**: These change the behavior of the planning 81 command itself, rather than customizing the content of the generated plan. 82 83 ## Planning Modes 84 85 The previous section describes Terraform's default planning behavior, which 86 changes the remote system to match the changes you make to 87 your configuration. Terraform has two alternative planning modes, each of which creates a plan with a different intended outcome. These options are available for both `terraform plan` and [`terraform apply`](/cli/commands/apply). 88 89 * **Destroy mode:** creates a plan whose goal is to destroy all remote objects 90 that currently exist, leaving an empty Terraform state. This can be useful 91 for situations like transient development environments, where the managed 92 objects cease to be useful once the development task is complete. 93 94 Activate destroy mode using the `-destroy` command line option. 95 96 * **Refresh-only mode:** creates a plan whose goal is only to update the 97 Terraform state and any root module output values to match changes made to 98 remote objects outside of Terraform. This can be useful if you've 99 intentionally changed one or more remote objects outside of the usual 100 workflow (e.g. while responding to an incident) and you now need to reconcile 101 Terraform's records with those changes. 102 103 Activate refresh-only mode using the `-refresh-only` command line option. 104 105 In situations where we need to discuss the default planning mode that Terraform 106 uses when none of the alternative modes are selected, we refer to it as 107 "Normal mode". Because these alternative modes are for specialized situations 108 only, some other Terraform documentation only discusses the normal planning 109 mode. 110 111 The planning modes are all mutually-exclusive, so activating any non-default 112 planning mode disables the "normal" planning mode, and you can't use more than 113 one alternative mode at the same time. 114 115 -> **Note:** In Terraform v0.15 and earlier, the `-destroy` option is 116 supported only by the `terraform plan` command, and not by the 117 `terraform apply` command. To create and apply a plan in destroy mode in 118 earlier versions you must run [`terraform destroy`](/cli/commands/destroy). 119 120 -> **Note:** The `-refresh-only` option is available only in Terraform v0.15.4 121 and later. 122 123 > **Hands-on:** Try the [Use Refresh-Only Mode to Sync Terraform State](https://learn.hashicorp.com/tutorials/terraform/refresh) tutorial on HashiCorp Learn. 124 125 ## Planning Options 126 127 In addition to alternate [planning modes](#planning-modes), there are several options that can modify planning behavior. These options are available for both `terraform plan` and [`terraform apply`](/cli/commands/apply). 128 129 - `-refresh=false` - Disables the default behavior of synchronizing the 130 Terraform state with remote objects before checking for configuration changes. This can make the planning operation faster by reducing the number of remote API requests. However, setting `refresh=false` causes Terraform to ignore external changes, which could result in an incomplete or incorrect plan. You cannot use `refresh=false` in refresh-only planning mode because it would effectively disable the entirety of the planning operation. 131 132 - `-replace=ADDRESS` - Instructs Terraform to plan to replace the 133 resource instance with the given address. This is helpful when one or more remote objects have become degraded, and you can use replacement objects with the same configuratation to align with immutable infrastructure patterns. Terraform will use a "replace" action if the specified resource would normally cause an "update" action or no action at all. Include this option multiple times to replace several objects at once. You cannot use `-replace` with the `-destroy` option, and it is only available from Terraform v0.15.2 onwards. For earlier versions, use [`terraform taint`](/cli/commands/taint) to achieve a similar result. 134 135 - `-target=ADDRESS` - Instructs Terraform to focus its planning efforts only 136 on resource instances which match the given address and on any objects that 137 those instances depend on. 138 139 -> **Note:** Use `-target=ADDRESS` in exceptional circumstances only, such as recovering from mistakes or working around Terraform limitations. Refer to [Resource Targeting](#resource-targeting) for more details. 140 141 - `-var 'NAME=VALUE'` - Sets a value for a single 142 [input variable](/language/values/variables) declared in the 143 root module of the configuration. Use this option multiple times to set 144 more than one variable. Refer to 145 [Input Variables on the Command Line](#input-variables-on-the-command-line) for more information. 146 147 - `-var-file=FILENAME` - Sets values for potentially many 148 [input variables](/language/values/variables) declared in the 149 root module of the configuration, using definitions from a 150 ["tfvars" file](/language/values/variables#variable-definitions-tfvars-files). 151 Use this option multiple times to include values from more than one file. 152 153 There are several other ways to set values for input variables in the root 154 module, aside from the `-var` and `-var-file` options. Refer to 155 [Assigning Values to Root Module Variables](/language/values/variables#assigning-values-to-root-module-variables) for more information. 156 157 ### Input Variables on the Command Line 158 159 You can use the `-var` command line option to specify values for 160 [input variables](/language/values/variables) declared in your 161 root module. 162 163 However, to do so will require writing a command line that is parsable both 164 by your chosen command line shell _and_ Terraform, which can be complicated 165 for expressions involving lots of quotes and escape sequences. In most cases 166 we recommend using the `-var-file` option instead, and write your actual values 167 in a separate file so that Terraform can parse them directly, rather than 168 interpreting the result of your shell's parsing. 169 170 To use `-var` on a Unix-style shell on a system like Linux or macOS we 171 recommend writing the option argument in single quotes `'` to ensure the 172 shell will interpret the value literally: 173 174 ``` 175 terraform plan -var 'name=value' 176 ``` 177 178 If your intended value also includes a single quote then you'll still need to 179 escape that for correct interpretation by your shell, which also requires 180 temporarily ending the quoted sequence so that the backslash escape character 181 will be significant: 182 183 ``` 184 terraform plan -var 'name=va'\''lue' 185 ``` 186 187 When using Terraform on Windows, we recommend using the Windows Command Prompt 188 (`cmd.exe`). When you pass a variable value to Terraform from the Windows 189 Command Prompt, use double quotes `"` around the argument: 190 191 ``` 192 terraform plan -var "name=value" 193 ``` 194 195 If your intended value includes literal double quotes then you'll need to 196 escape those with a backslash: 197 198 ``` 199 terraform plan -var "name=va\"lue" 200 ``` 201 202 PowerShell on Windows cannot correctly pass literal quotes to external programs, 203 so we do not recommend using Terraform with PowerShell when you are on Windows. 204 Use Windows Command Prompt instead. 205 206 The appropriate syntax for writing the variable value is different depending 207 on the variable's [type constraint](/language/expressions/type-constraints). 208 The primitive types `string`, `number`, and `bool` all expect a direct string 209 value with no special punctuation except that required by your shell, as 210 shown in the above examples. For all other type constraints, including list, 211 map, and set types and the special `any` keyword, you must write a valid 212 Terraform language expression representing the value, and write any necessary 213 quoting or escape characters to ensure it will pass through your shell 214 literally to Terraform. For example, for a `list(string)` type constraint: 215 216 ``` 217 # Unix-style shell 218 terraform plan -var 'name=["a", "b", "c"]' 219 220 # Windows Command Prompt (do not use PowerShell on Windows) 221 terraform plan -var "name=[\"a\", \"b\", \"c\"]" 222 ``` 223 224 Similar constraints apply when setting input variables using environment 225 variables. For more information on the various methods for setting root module 226 input variables, see 227 [Assigning Values to Root Module Variables](/language/values/variables#assigning-values-to-root-module-variables). 228 229 ### Resource Targeting 230 231 > **Hands-on:** Try the [Target resources](https://learn.hashicorp.com/tutorials/terraform/resource-targeting?in=terraform/state&utm_source=WEBSITE&utm_medium=WEB_IO&utm_offer=ARTICLE_PAGE&utm_content=DOCS) tutorial on HashiCorp Learn. 232 233 You can use the `-target` option to focus Terraform's attention on only a 234 subset of resources. 235 You can use [resource address syntax](/cli/state/resource-addressing) 236 to specify the constraint. Terraform interprets the resource address as follows: 237 238 * If the given address identifies one specific resource instance, Terraform 239 will select that instance alone. For resources with either `count` or 240 `for_each` set, a resource instance address must include the instance index 241 part, like `aws_instance.example[0]`. 242 243 * If the given address identifies a resource as a whole, Terraform will select 244 all of the instances of that resource. For resources with either `count` 245 or `for_each` set, this means selecting _all_ instance indexes currently 246 associated with that resource. For single-instance resources (without 247 either `count` or `for_each`), the resource address and the resource instance 248 address are identical, so this possibility does not apply. 249 250 * If the given address identifies an entire module instance, Terraform will 251 select all instances of all resources that belong to that module instance 252 and all of its child module instances. 253 254 Once Terraform has selected one or more resource instances that you've directly 255 targeted, it will also then extend the selection to include all other objects 256 that those selections depend on either directly or indirectly. 257 258 This targeting capability is provided for exceptional circumstances, such 259 as recovering from mistakes or working around Terraform limitations. It 260 is _not recommended_ to use `-target` for routine operations, since this can 261 lead to undetected configuration drift and confusion about how the true state 262 of resources relates to configuration. 263 264 Instead of using `-target` as a means to operate on isolated portions of very 265 large configurations, prefer instead to break large configurations into 266 several smaller configurations that can each be independently applied. 267 [Data sources](/language/data-sources) can be used to access 268 information about resources created in other configurations, allowing 269 a complex system architecture to be broken down into more manageable parts 270 that can be updated independently. 271 272 ## Other Options 273 274 The `terraform plan` command also has some other options that are related to 275 the input and output of the planning command, rather than customizing what 276 sort of plan Terraform will create. These commands are not necessarily also 277 available on `terraform apply`, unless otherwise stated in the documentation 278 for that command. 279 280 The available options are: 281 282 * `-compact-warnings` - Shows any warning messages in a compact form which 283 includes only the summary messages, unless the warnings are accompanied by 284 at least one error and thus the warning text might be useful context for 285 the errors. 286 287 * `-detailed-exitcode` - Returns a detailed exit code when the command exits. 288 When provided, this argument changes the exit codes and their meanings to 289 provide more granular information about what the resulting plan contains: 290 * 0 = Succeeded with empty diff (no changes) 291 * 1 = Error 292 * 2 = Succeeded with non-empty diff (changes present) 293 294 * `-input=false` - Disables Terraform's default behavior of prompting for 295 input for root module input variables that have not otherwise been assigned 296 a value. This option is particularly useful when running Terraform in 297 non-interactive automation systems. 298 299 * `-json` - Enables the [machine readable JSON UI][machine-readable-ui] output. 300 This implies `-input=false`, so the configuration must have no unassigned 301 variable values to continue. 302 303 [machine-readable-ui]: /internals/machine-readable-ui 304 305 * `-lock=false` - Don't hold a state lock during the operation. This is 306 dangerous if others might concurrently run commands against the same 307 workspace. 308 309 * `-lock-timeout=DURATION` - Unless locking is disabled with `-lock=false`, 310 instructs Terraform to retry acquiring a lock for a period of time before 311 returning an error. The duration syntax is a number followed by a time 312 unit letter, such as "3s" for three seconds. 313 314 * `-no-color` - Disables terminal formatting sequences in the output. Use this 315 if you are running Terraform in a context where its output will be 316 rendered by a system that cannot interpret terminal formatting. 317 318 * `-out=FILENAME` - Writes the generated plan to the given filename in an 319 opaque file format that you can later pass to `terraform apply` to execute 320 the planned changes, and to some other Terraform commands that can work with 321 saved plan files. 322 323 Terraform will allow any filename for the plan file, but a typical 324 convention is to name it `tfplan`. **Do not** name the file with a suffix 325 that Terraform recognizes as another file format; if you use a `.tf` suffix 326 then Terraform will try to interpret the file as a configuration source 327 file, which will then cause syntax errors for subsequent commands. 328 329 The generated file is not in any standard format intended for consumption 330 by other software, but the file _does_ contain your full configuration, 331 all of the values associated with planned changes, and all of the plan 332 options including the input variables. If your plan includes any sort of 333 sensitive data, even if obscured in Terraform's terminal output, it will 334 be saved in cleartext in the plan file. You should therefore treat any 335 saved plan files as potentially-sensitive artifacts. 336 337 * `-parallelism=n` - Limit the number of concurrent operations as Terraform 338 [walks the graph](/internals/graph#walking-the-graph). Defaults 339 to 10. 340 341 For configurations using 342 [the `local` backend](/language/settings/backends/local) only, 343 `terraform plan` accepts the legacy command line option 344 [`-state`](/language/settings/backends/local#command-line-arguments). 345 346 ### Passing a Different Configuration Directory 347 348 Terraform v0.13 and earlier accepted an additional positional argument giving 349 a directory path, in which case Terraform would use that directory as the root 350 module instead of the current working directory. 351 352 That usage was deprecated in Terraform v0.14 and removed in Terraform v0.15. 353 If your workflow relies on overriding the root module directory, use 354 [the `-chdir` global option](/cli/commands/#switching-working-directory-with-chdir) 355 instead, which works across all commands and makes Terraform consistently look 356 in the given directory for all files it would normally read or write in the 357 current working directory. 358 359 If your previous use of this legacy pattern was also relying on Terraform 360 writing the `.terraform` subdirectory into the current working directory even 361 though the root module directory was overridden, use 362 [the `TF_DATA_DIR` environment variable](/cli/config/environment-variables#tf_data_dir) 363 to direct Terraform to write the `.terraform` directory to a location other 364 than the current working directory.