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Warning

Filtering is a powerful tool, but it is also a double-edged sword. It is easy to make mistakes in the filter configuration. Also, since gcp-nuke is in continuous development, there is always a possibility to introduce new bugs, no matter how careful we review new code.

Filtering

Filtering is used to exclude or include resources from being deleted. This is important for a number of reasons to include but limited to removing the user that runs the tool.

Note

Filters are OR'd together. This means that if a resource matches any filter, it will be excluded from deletion. Currently, there is no way to do AND'ing of filters.

Global

Filters are traditionally done against a specific resource. However, __global__ as been introduced as a unique resource type that can be used to apply filters to all defined resources. It's all or nothing, global cannot be used to against some resources and not others.

Global works by taking all filters defined under __global__ and prepends to any filters found for a resource type. If a resource does NOT have any filters defined, the __global__ ones will still be used.

Example

In this example, we are ignoring all resources that have the tag gcp-nuke set to ignore. Additionally filtering a specific instance by its id. When the ComputeInstance resource is processed, it will have both filters applied. These

__global__:
  - property: label:gcp-nuke
    value: "ignore"

ComputeInstance:
  - "test-instance-01b489457a60298dd"

This will ultimately render as the following filters for the ComputeInstance resource:

ComputeInstance:
  - "test-instance-01b489457a60298dd"
  - property: label:gcp-nuke
    value: "ignore"

Types

The following are comparisons that you can use to filter resources. These are used in the configuration file.

  • exact
  • contains
  • glob
  • regex
  • dateOlderThan

To use a non-default comparison type, it is required to specify an object with type and value instead of the plain string.

These types can be used to simplify the configuration. For example, it is possible to protect all access keys of a single user by using glob:

IAMServiceAccountKey:
- type: glob
  value: "admin -> *"

Exact

The identifier must exactly match the given string. This is the default.

Exact is just that, an exact match to a resource. The following examples are identical for the exact filter.

IAMRole:
- custom-role
- type: exact
  value: custom-role

Contains

The contains filter is a simple string contains match. The following examples are identical for the contains filter.

IAMRole:
  - type: contains
    value: Nuke

Glob

The identifier must match against the given glob pattern. This means the string might contain wildcards like * and ?. Note that globbing is designed for file paths, so the wildcards do not match the directory separator (/). Details about the glob pattern can be found in the library documentation

IAMUser:
  - type: glob
    value: "gcp-nuke*"

Regex

The identifier must match against the given regular expression. Details about the syntax can be found in the library documentation.

IAMUser:
  - type: regex
    value: "gcp-nuke.*"

DateOlderThan

This works by parsing the specified property into a timestamp and comparing it to the current time minus the specified duration. The duration is specified in the value field. The duration syntax is based on golang's duration syntax.

ParseDuration parses a duration string. A duration string is a possibly signed sequence of decimal numbers, each with optional fraction and a unit suffix, such as "300ms", "-1.5h" or "2h45m". Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".

Full details on duration syntax can be found in the time library documentation.

The value from the property is parsed as a timestamp and the following are the supported formats:

  • 2006-01-02
  • 2006/01/02
  • 2006-01-02T15:04:05Z
  • 2006-01-02T15:04:05.999999999Z07:00
  • 2006-01-02T15:04:05Z07:00

In the follow example we are filtering EC2 Images that have a CreationDate older than 1 hour.

ComputeDisk:
  - type: dateOlderThan
    property: CreationDate
    value: 1h

Properties

By default, when writing a filter if you do not specify a property, it will use the Name property. However, resources that do no support Properties, gcp-nuke will fall back to what is called the Legacy String, it's essentially a function that returns a string representation of the resource.

Some resources support filtering via properties. When a resource support these properties, they will be listed in the output like in this example:

global - IAMUserPolicyAttachment - 'admin -> AdministratorAccess' - [RoleName: "admin", PolicyArn: "arn:gcp:iam::gcp:policy/AdministratorAccess", PolicyName: "AdministratorAccess"] - would remove

To use properties, it is required to specify an object with properties and value instead of the plain string.

These types can be used to simplify the configuration. For example, it is possible to protect all access keys of a single user:

IAMUserAccessKey:
  - property: UserName
    value: "admin"

Inverting

Any filter result can be inverted by using invert: true, for example:

ComputeInstance:
  - property: Name
    value: "foo"
    invert: true

In this case any CloudFormationStack but the ones called "foo" will be filtered. Be aware that gcp-nuke internally takes every resource and applies every filter on it. If a filter matches, it marks the node as filtered.

Example

It is also possible to use Filter Properties and Filter Types together. For example to protect all Hosted Zone of a specific TLD:

ComputeInstance:
  - property: Name
    type: glob
    value: "*.testing"

Project Level

It is possible to filter this is important for not deleting the current user for example or for resources like S3 Buckets which have a globally shared namespace and might be hard to recreate. Currently, the filtering is based on the resource identifier. The identifier will be printed as the first step of gcp-nuke (eg i-01b489457a60298dd for an EC2 instance).

Warning

Even with filters you should not run gcp-nuke on any gcp account, where you cannot afford to lose all resources. It is easy to make mistakes in the filter configuration. Also, since gcp-nuke is in continuous development, there is always a possibility to introduce new bugs, no matter how careful we review new code.

The filters are part of the account-specific configuration and are grouped by resource types. This is an example of a config that deletes all resources but the admin user with its access permissions and two access keys:

---
regions:
  - global
  - us-central1

blocklist:
  - bootstrap-12345

accounts:
  playground-12345:
    filters:
      IAMUser:
        - "admin"
      IAMUserPolicyAttachment:
        - "admin -> AdministratorAccess"
      IAMUserAccessKey:
        - "admin -> AKSDAFRETERSDF"
        - "admin -> AFGDSGRTEWSFEY"

Any resource whose resource identifier exactly matches any of the filters in the list will be skipped. These will be marked as "filtered by config" on the gcp-nuke run.

Presets

It might be the case that some filters are the same across multiple accounts. This especially could happen, if provisioning tools like Terraform are used or if IAM resources follow the same pattern.

For this case gcp-nuke supports presets of filters, that can applied on multiple accounts. A configuration could look like this:

---
regions:
  - global
  - us-central1

account-blocklist:
  - bootstrap-12345

accounts:
  playground-12345:
    presets:
      - "common"
  dev-9484:
    presets:
      - "common"
      - "terraform"
  sandbox-134313:
    presets:
      - "common"
      - "terraform"
    filters:
      IAMRole:
        - "notebook"

presets:
  terraform:
    filters:
      StorageBucket:
        - type: glob
          value: "my-statebucket-*"
      DynamoDBTable:
        - "terraform-lock"
  common:
    filters:
      IAMRole:
        - custom-role

Included and Excluding

gcp-nuke deletes a lot of resources and there might be added more at any release. Eventually, every resource should get deleted. You might want to restrict which resources to delete. There are multiple ways to configure this.

One way are filters, which already got mentioned. This requires to know the identifier of each resource. It is also possible to prevent whole resource types (eg StorageBucket) from getting deleted with two methods.

It is also possible to configure the resource types in the config file like in these examples:

regions:
  - us-central1

blocklist:
  - playground-12345

resource-types:
  # Specifying this in the configuration will ensure that only these three
  # resources are targeted by gcp-nuke during it's run.
  includes:
    - StorageBucketObject
    - StorageBucket
    - IAMRole

accounts:
  playground-12345: {}

regions:
  - us-central1

blocklist:
  - production-12345

resource-types:
  # Specifying this in the configuration will ensure that these resources
  # will be specifically excluded from gcp-nuke during it's run.
  excludes:
  - IAMRole

accounts:
  playground-12345: {}

If includes are specified in multiple places (e.g. CLI and account specific), then a resource type must be specified in all places. In other words each configuration limits the previous ones.

If an exclude is used, then all its resource types will not be deleted.

Hint: You can see all available resource types with this command:

gcp-nuke resource-types

It is also possible to include and exclude resources using the command line arguments:

  • The --include flag limits nuking to the specified resource types.
  • The --exclude flag prevent nuking of the specified resource types.