github.com/hugorut/terraform@v1.1.3/website/docs/internals/json-format.mdx (about)

     1  ---
     2  page_title: 'Internals: JSON Output Format'
     3  description: >-
     4    Terraform provides a machine-readable JSON representation of state,
     5    configuration and plan.
     6  ---
     7  
     8  # JSON Output Format
     9  
    10  -> **Note:** This format is available in Terraform 0.12 and later.
    11  
    12  When Terraform plans to make changes, it prints a human-readable summary to the terminal. It can also, when run with `-out=<PATH>`, write a much more detailed binary plan file, which can later be used to apply those changes.
    13  
    14  Since the format of plan files isn't suited for use with external tools (and likely never will be), Terraform can output a machine-readable JSON representation of a plan file's changes. It can also convert state files to the same format, to simplify data loading and provide better long-term compatibility.
    15  
    16  Use `terraform show -json <FILE>` to generate a JSON representation of a plan or state file. See [the `terraform show` documentation](/cli/commands/show) for more details.
    17  
    18  The output includes a `format_version` key, which as of Terraform 1.1.0 has
    19  value `"1.0"`. The semantics of this version are:
    20  
    21  - We will increment the minor version, e.g. `"1.1"`, for backward-compatible
    22    changes or additions. Ignore any object properties with unrecognized names to
    23    remain forward-compatible with future minor versions.
    24  - We will increment the major version, e.g. `"2.0"`, for changes that are not
    25    backward-compatible. Reject any input which reports an unsupported major
    26    version.
    27  
    28  We will introduce new major versions only within the bounds of
    29  [the Terraform 1.0 Compatibility Promises](/language/v1-compatibility-promises).
    30  
    31  ## Format Summary
    32  
    33  The following sections describe the JSON output format by example, using a pseudo-JSON notation.
    34  
    35  Important elements are described with comments, which are prefixed with `//`.
    36  
    37  To avoid excessive repetition, we've split the complete format into several discrete sub-objects, described under separate headers. References wrapped in angle brackets (like `<values-representation>`) are placeholders which, in the real output, would be replaced by an instance of the specified sub-object.
    38  
    39  The JSON output format consists of the following objects and sub-objects:
    40  
    41  - [State Representation](#state-representation) — The complete top-level object returned by `terraform show -json <STATE FILE>`.
    42  - [Plan Representation](#plan-representation) — The complete top-level object returned by `terraform show -json <PLAN FILE>`.
    43  - [Values Representation](#values-representation) — A sub-object of both plan and state output that describes current state or planned state.
    44  - [Configuration Representation](#configuration-representation) — A sub-object of plan output that describes a parsed Terraform configuration.
    45    - [Expression Representation](#expression-representation) — A sub-object of a configuration representation that describes an unevaluated expression.
    46    - [Block Expressions Representation](#block-expressions-representation) — A sub-object of a configuration representation that describes the expressions nested inside a block.
    47  - [Change Representation](#change-representation) — A sub-object of plan output that describes planned changes to an object.
    48  
    49  ## State Representation
    50  
    51  Because state does not currently have any significant metadata not covered by the common values representation ([described below](#values-representation)), the `<state-representation>` is straightforward:
    52  
    53  ```javascript
    54  {
    55    // "values" is a values representation object derived from the values in the
    56    // state. Because the state is always fully known, this is always complete.
    57    "values": <values-representation>
    58  
    59    "terraform_version": "version.string"
    60  }
    61  ```
    62  
    63  The extra wrapping object here will allow for any extension we may need to add in future versions of this format.
    64  
    65  ## Plan Representation
    66  
    67  A plan consists of a prior state, the configuration that is being applied to that state, and the set of changes Terraform plans to make to achieve that.
    68  
    69  For ease of consumption by callers, the plan representation includes a partial representation of the values in the final state (using a [value representation](#values-representation)), allowing callers to easily analyze the planned outcome using similar code as for analyzing the prior state.
    70  
    71  ```javascript
    72  {
    73    "format_version": "1.0",
    74  
    75    // "prior_state" is a representation of the state that the configuration is
    76    // being applied to, using the state representation described above.
    77    "prior_state":  <state-representation>,
    78  
    79    // "configuration" is a representation of the configuration being applied to the
    80    // prior state, using the configuration representation described above.
    81    "configuration": <configuration-representation>,
    82  
    83    // "planned_values" is a description of what is known so far of the outcome in
    84    // the standard value representation, with any as-yet-unknown values omitted.
    85    "planned_values": <values-representation>,
    86  
    87    // "proposed_unknown" is a representation of the attributes, including any
    88    // potentially-unknown attributes. Each value is replaced with "true" or
    89    // "false" depending on whether it is known in the proposed plan.
    90    "proposed_unknown": <values-representation>,
    91  
    92    // "variables" is a representation of all the variables provided for the given
    93    // plan. This is structured as a map similar to the output map so we can add
    94    // additional fields in later.
    95    "variables": {
    96      "varname": {
    97        "value": "varvalue"
    98      },
    99    },
   100  
   101    // "changes" is a description of the individual change actions that Terraform
   102    // plans to use to move from the prior state to a new state matching the
   103    // configuration.
   104    "resource_changes": [
   105      // Each element of this array describes the action to take
   106      // for one instance object. All resources in the
   107      // configuration are included in this list.
   108      {
   109        // "address" is the full absolute address of the resource instance this
   110        // change applies to, in the same format as addresses in a value
   111        // representation.
   112        "address": "module.child.aws_instance.foo[0]",
   113  
   114        // "previous_address" is the full absolute address of this resource
   115        // instance as it was known after the previous Terraform run.
   116        // Included only if the address has changed, e.g. by handling
   117        // a "moved" block in the configuration.
   118        "previous_address": "module.instances.aws_instance.foo[0]",
   119  
   120        // "module_address", if set, is the module portion of the above address.
   121        // Omitted if the instance is in the root module.
   122        "module_address": "module.child",
   123  
   124        // "mode", "type", "name", and "index" have the same meaning as in a
   125        // value representation.
   126        "mode": "managed",
   127        "type": "aws_instance",
   128        "name": "foo",
   129        "index": 0,
   130  
   131        // "deposed", if set, indicates that this action applies to a "deposed"
   132        // object of the given instance rather than to its "current" object.
   133        // Omitted for changes to the current object. "address" and "deposed"
   134        // together form a unique key across all change objects in a particular
   135        // plan. The value is an opaque key representing the specific deposed
   136        // object.
   137        "deposed": "deadbeef",
   138  
   139        // "change" describes the change that will be made to the indicated
   140        // object. The <change-representation> is detailed in a section below.
   141        "change": <change-representation>,
   142  
   143        // "action_reason" is some optional extra context about why the
   144        // actions given inside "change" were selected. This is the JSON
   145        // equivalent of annotations shown in the normal plan output like
   146        // "is tainted, so must be replaced" as opposed to just "must be
   147        // replaced".
   148        //
   149        // These reason codes are display hints only and the set of possible
   150        // hints may change over time. Users of this must be prepared to
   151        // encounter unrecognized reasons and treat them as unspecified reasons.
   152        //
   153        // The current set of possible values is:
   154        // - "replace_because_tainted": the object in question is marked as
   155        //   "tainted" in the prior state, so Terraform planned to replace it.
   156        // - "replace_because_cannot_update": the provider indicated that one
   157        //   of the requested changes isn't possible without replacing the
   158        //   existing object with a new object.
   159        // - "replace_by_request": the user explicitly called for this object
   160        //   to be replaced as an option when creating the plan, which therefore
   161        //   overrode what would have been a "no-op" or "update" action otherwise.
   162        // - "delete_because_no_resource_config": Terraform found no resource
   163        //   configuration corresponding to this instance.
   164        // - "delete_because_no_module": The resource instance belongs to a
   165        //   module instance that's no longer declared, perhaps due to changing
   166        //   the "count" or "for_each" argument on one of the containing modules.
   167        // - "delete_because_wrong_repetition": The instance key portion of the
   168        //   resource address isn't of a suitable type for the corresponding
   169        //   resource's configured repetition mode (count, for_each, or neither).
   170        // - "delete_because_count_index": The corresponding resource uses count,
   171        //   but the instance key is out of range for the currently-configured
   172        //   count value.
   173        // - "delete_because_each_key": The corresponding resource uses for_each,
   174        //   but the instance key doesn't match any of the keys in the
   175        //   currently-configured for_each value.
   176        //
   177        // If there is no special reason to note, Terraform will omit this
   178        // property altogether.
   179        action_reason: "replace_because_tainted"
   180      }
   181    ],
   182  
   183    // "output_changes" describes the planned changes to the output values of the
   184    // root module.
   185    "output_changes": {
   186      // Keys are the defined output value names.
   187      "foo": {
   188  
   189        // "change" describes the change that will be made to the indicated output
   190        // value, using the same representation as for resource changes except
   191        // that the only valid actions values are:
   192        //   ["create"]
   193        //   ["update"]
   194        //   ["delete"]
   195        // In the Terraform CLI 0.12.0 release, Terraform is not yet fully able to
   196        // track changes to output values, so the actions indicated may not be
   197        // fully accurate, but the "after" value will always be correct.
   198        "change": <change-representation>,
   199      }
   200    }
   201  }
   202  ```
   203  
   204  This overall plan structure, fully expanded, is what will be printed by the `terraform show -json <planfile>` command.
   205  
   206  ## Values Representation
   207  
   208  A values representation is used in both state and plan output to describe current state (which is always complete) and planned state (which omits values not known until apply).
   209  
   210  The following example illustrates the structure of a `<values-representation>`:
   211  
   212  ```javascript
   213  {
   214    // "outputs" describes the outputs from the root module. Outputs from
   215    // descendent modules are not available because they are not retained in all
   216    // of the underlying structures we will build this values representation from.
   217    "outputs": {
   218      "private_ip": {
   219        "value": "192.168.3.2",
   220        "sensitive": false
   221      }
   222    },
   223  
   224    // "root_module" describes the resources and child modules in the root module.
   225    "root_module": {
   226      "resources": [
   227        {
   228          // "address" is the absolute resource address, which callers must consider
   229          // opaque but may do full string comparisons with other address strings or
   230          // pass this verbatim to other Terraform commands that are documented to
   231          // accept absolute resource addresses. The module-local portions of this
   232          // address are extracted in other properties below.
   233          "address": "aws_instance.example[1]",
   234  
   235          // "mode" can be "managed", for resources, or "data", for data resources
   236          "mode": "managed",
   237          "type": "aws_instance",
   238          "name": "example",
   239  
   240          // If the count or for_each meta-arguments are set for this resource, the
   241          // additional key "index" is present to give the instance index key. This
   242          // is omitted for the single instance of a resource that isn't using count
   243          // or for_each.
   244          "index": 1,
   245  
   246          // "provider_name" is the name of the provider that is responsible for
   247          // this resource. This is only the provider name, not a provider
   248          // configuration address, and so no module path nor alias will be
   249          // indicated here. This is included to allow the property "type" to be
   250          // interpreted unambiguously in the unusual situation where a provider
   251          // offers a resource type whose name does not start with its own name,
   252          // such as the "googlebeta" provider offering "google_compute_instance".
   253          "provider_name": "aws",
   254  
   255          // "schema_version" indicates which version of the resource type schema
   256          // the "values" property conforms to.
   257          "schema_version": 2,
   258  
   259          // "values" is the JSON representation of the attribute values of the
   260          // resource, whose structure depends on the resource type schema. Any
   261          // unknown values are omitted or set to null, making them
   262          // indistinguishable from absent values; callers which need to distinguish
   263          // unknown from unset must use the plan-specific or configuration-specific
   264          // structures described in later sections.
   265          "values": {
   266            "id": "i-abc123",
   267            "instance_type": "t2.micro",
   268            // etc, etc
   269          },
   270  
   271          // "sensitive_values" is the JSON representation of the sensitivity of
   272          // the resource's attribute values. Only attributes which are sensitive
   273          // are included in this structure.
   274          "sensitive_values": {
   275            "id": true,
   276          }
   277        }
   278      ]
   279  
   280      "child_modules": [
   281        // Each entry in "child_modules" has the same structure as the root_module
   282        // object, with the additional "address" property shown below.
   283        {
   284          // "address" is the absolute module address, which callers must treat as
   285          // opaque but may do full string comparisons with other module address
   286          // strings and may pass verbatim to other Terraform commands that are
   287          // documented as accepting absolute module addresses.
   288          "address": "module.child",
   289  
   290          // "resources" is the same as in "root_module" above
   291          "resources": [
   292              {
   293                "address": "module.child.aws_instance.foo",
   294                // etc, etc
   295              }
   296          ],
   297  
   298          // Each module object can optionally have its own
   299          // nested "child_modules", recursively describing the
   300          // full module tree.
   301          "child_modules": [ ... ],
   302        }
   303      ]
   304    }
   305  }
   306  ```
   307  
   308  The translation of attribute and output values is the same intuitive mapping from HCL types to JSON types used by Terraform's [`jsonencode`](/language/functions/jsonencode) function. This mapping does lose some information: lists, sets, and tuples all lower to JSON arrays while maps and objects both lower to JSON objects. Unknown values and null values are both treated as absent or null.
   309  
   310  Only the "current" object for each resource instance is described. "Deposed" objects are not reflected in this structure at all; in plan representations, you can refer to the change representations for further details.
   311  
   312  The intent of this structure is to give a caller access to a similar level of detail as is available to expressions within the configuration itself. This common representation is not suitable for all use-cases because it loses information compared to the data structures it is built from. For more complex needs, use the more elaborate changes and configuration representations.
   313  
   314  ## Configuration Representation
   315  
   316  Configuration is the most complicated structure in Terraform, since it includes unevaluated expression nodes and other complexities.
   317  
   318  Because the configuration models are produced at a stage prior to expression evaluation, it is not possible to produce a values representation for configuration. Instead, we describe the physical structure of the configuration, giving access to constant values where possible and allowing callers to analyze any references to other objects that are present:
   319  
   320  ```javascript
   321  {
   322    // "provider_configs" describes all of the provider configurations throughout
   323    // the configuration tree, flattened into a single map for convenience since
   324    // provider configurations are the one concept in Terraform that can span
   325    // across module boundaries.
   326    "provider_configs": {
   327  
   328      // Keys in the provider_configs map are to be considered opaque by callers,
   329      // and used just for lookups using the "provider_config_key" property in each
   330      // resource object.
   331      "opaque_provider_ref_aws": {
   332  
   333        // "name" is the name of the provider without any alias
   334        "name": "aws",
   335  
   336        // "alias" is the alias set for a non-default configuration, or unset for
   337        // a default configuration.
   338        "alias": "foo",
   339  
   340        // "module_address" is included only for provider configurations that are
   341        // declared in a descendent module, and gives the opaque address for the
   342        // module that contains the provider configuration.
   343        "module_address": "module.child",
   344  
   345        // "expressions" describes the provider-specific content of the
   346        // configuration block, as a block expressions representation (see section
   347        // below).
   348        "expressions": <block-expressions-representation>
   349      }
   350    },
   351  
   352    // "root_module" describes the root module in the configuration, and serves
   353    // as the root of a tree of similar objects describing descendent modules.
   354    "root_module": {
   355  
   356      // "outputs" describes the output value configurations in the module.
   357      "outputs": {
   358  
   359        // Property names here are the output value names
   360        "example": {
   361          "expression": <expression-representation>,
   362          "sensitive": false
   363        }
   364      },
   365  
   366      // "resources" describes the "resource" and "data" blocks in the module
   367      // configuration.
   368      "resources": [
   369        {
   370          // "address" is the opaque absolute address for the resource itself.
   371          "address": "aws_instance.example",
   372  
   373          // "mode", "type", and "name" have the same meaning as for the resource
   374          // portion of a value representation.
   375          "mode": "managed",
   376          "type": "aws_instance",
   377          "name": "example",
   378  
   379          // "provider_config_key" is the key into "provider_configs" (shown
   380          // above) for the provider configuration that this resource is
   381          // associated with.
   382          "provider_config_key": "opaque_provider_ref_aws",
   383  
   384          // "provisioners" is an optional field which describes any provisioners.
   385          // Connection info will not be included here.
   386          "provisioners": [
   387            {
   388              "type": "local-exec",
   389  
   390              // "expressions" describes the provisioner configuration
   391              "expressions": <block-expressions-representation>
   392            },
   393          ],
   394  
   395          // "expressions" describes the resource-type-specific content of the
   396          // configuration block.
   397          "expressions": <block-expressions-representation>,
   398  
   399          // "schema_version" is the schema version number indicated by the
   400          // provider for the type-specific arguments described in "expressions".
   401          "schema_version": 2,
   402  
   403          // "count_expression" and "for_each_expression" describe the expressions
   404          // given for the corresponding meta-arguments in the resource
   405          // configuration block. These are omitted if the corresponding argument
   406          // isn't set.
   407          "count_expression": <expression-representation>,
   408          "for_each_expression": <expression-representation>
   409        },
   410      ],
   411  
   412      // "module_calls" describes the "module" blocks in the module. During
   413      // evaluation, a module call with count or for_each may expand to multiple
   414      // module instances, but in configuration only the block itself is
   415      // represented.
   416      "module_calls": {
   417  
   418        // Key is the module call name chosen in the configuration.
   419        "child": {
   420  
   421          // "resolved_source" is the resolved source address of the module, after
   422          // any normalization and expansion. This could be either a
   423          // go-getter-style source address or a local path starting with "./" or
   424          // "../". If the user gave a registry source address then this is the
   425          // final location of the module as returned by the registry, after
   426          // following any redirect indirection.
   427          "resolved_source": "./child"
   428  
   429          // "expressions" describes the expressions for the arguments within the
   430          // block that correspond to input variables in the child module.
   431          "expressions": <block-expressions-representation>,
   432  
   433          // "count_expression" and "for_each_expression" describe the expressions
   434          // given for the corresponding meta-arguments in the module
   435          // configuration block. These are omitted if the corresponding argument
   436          // isn't set.
   437          "count_expression": <expression-representation>,
   438          "for_each_expression": <expression-representation>,
   439  
   440          // "module" is a representation of the configuration of the child module
   441          // itself, using the same structure as the "root_module" object,
   442          // recursively describing the full module tree.
   443          "module": <module-configuration-representation>,
   444        }
   445      }
   446    }
   447  }
   448  ```
   449  
   450  ### Expression Representation
   451  
   452  Each unevaluated expression in the configuration is represented with an `<expression-representation>` object with the following structure:
   453  
   454  ```javascript
   455  {
   456    // "constant_value" is set only if the expression contains no references to
   457    // other objects, in which case it gives the resulting constant value. This is
   458    // mapped as for the individual values in a value representation.
   459    "constant_value": "hello",
   460  
   461    // Alternatively, "references" will be set to a list of references in the
   462    // expression. Multi-step references will be unwrapped and duplicated for each
   463    // significant traversal step, allowing callers to more easily recognize the
   464    // objects they care about without attempting to parse the expressions.
   465    // Callers should only use string equality checks here, since the syntax may
   466    // be extended in future releases.
   467    "references": [
   468      "data.template_file.foo[1].vars[\"baz\"]",
   469      "data.template_file.foo[1].vars", // implied by previous
   470      "data.template_file.foo[1]", // implied by previous
   471      "data.template_file.foo", // implied by previous
   472      "module.foo.bar",
   473      "module.foo", // implied by the previous
   474      "var.example[0]",
   475      "var.example", // implied by the previous
   476  
   477      // Partial references like "data" and "module" are not included, because
   478      // Terraform considers "module.foo" to be an atomic reference, not an
   479      // attribute access.
   480    ]
   481  }
   482  ```
   483  
   484  -> **Note:** Expressions in `dynamic` blocks are not included in the configuration representation.
   485  
   486  ### Block Expressions Representation
   487  
   488  In some cases, it is the entire content of a block (possibly after certain special arguments have already been handled and removed) that must be represented. For that, we have an `<block-expressions-representation>` structure:
   489  
   490  ```javascript
   491  {
   492    // Attribute arguments are mapped directly with the attribute name as key and
   493    // an <expression-representation> as value.
   494    "ami": <expression-representation>,
   495    "instance_type": <expression-representation>,
   496  
   497    // Nested block arguments are mapped as either a single nested
   498    // <block-expressions-representation> or an array object of these, depending on the
   499    // block nesting mode chosen in the schema.
   500    //  - "single" nesting is a direct <block-expressions-representation>
   501    //  - "list" and "set" produce arrays
   502    //  - "map" produces an object
   503    "root_block_device": <expression-representation>,
   504    "ebs_block_device": [
   505      <expression-representation>
   506    ]
   507  }
   508  ```
   509  
   510  For now we expect callers to just hard-code assumptions about the schemas of particular resource types in order to process these expression representations. In a later release we will add new inspection commands to return machine-readable descriptions of the schemas themselves, allowing for more generic handling in programs such as visualization tools.
   511  
   512  ## Change Representation
   513  
   514  A `<change-representation>` describes the change that will be made to the indicated object.
   515  
   516  ```javascript
   517  {
   518    // "actions" are the actions that will be taken on the object selected by the
   519    // properties below.
   520    // Valid actions values are:
   521    //    ["no-op"]
   522    //    ["create"]
   523    //    ["read"]
   524    //    ["update"]
   525    //    ["delete", "create"]
   526    //    ["create", "delete"]
   527    //    ["delete"]
   528    // The two "replace" actions are represented in this way to allow callers to
   529    // e.g. just scan the list for "delete" to recognize all three situations
   530    // where the object will be deleted, allowing for any new deletion
   531    // combinations that might be added in future.
   532    "actions": ["update"],
   533  
   534    // "before" and "after" are representations of the object value both before
   535    // and after the action. For ["create"] and ["delete"] actions, either
   536    // "before" or "after" is unset (respectively). For ["no-op"], the before and
   537    // after values are identical. The "after" value will be incomplete if there
   538    // are values within it that won't be known until after apply.
   539    "before": <value-representation>,
   540    "after": <value-representation>,
   541  
   542    // "after_unknown" is an object value with similar structure to "after", but
   543    // with all unknown leaf values replaced with "true", and all known leaf
   544    // values omitted. This can be combined with "after" to reconstruct a full
   545    // value after the action, including values which will only be known after
   546    // apply.
   547    "after_unknown": {
   548      "id": true
   549    },
   550  
   551    // "before_sensitive" and "after_sensitive" are object values with similar
   552    // structure to "before" and "after", but with all sensitive leaf values
   553    // replaced with true, and all non-sensitive leaf values omitted. These
   554    // objects should be combined with "before" and "after" to prevent accidental
   555    // display of sensitive values in user interfaces.
   556    "before_sensitive": {},
   557    "after_sensitive": {
   558      "triggers": {
   559        "boop": true
   560      }
   561    },
   562  
   563    // "replace_paths" is an array of arrays representing a set of paths into the
   564    // object value which resulted in the action being "replace". This will be
   565    // omitted if the action is not replace, or if no paths caused the
   566    // replacement (for example, if the resource was tainted). Each path
   567    // consists of one or more steps, each of which will be a number or a
   568    // string.
   569    "replace_paths": [["triggers"]]
   570  }
   571  ```