/canary

Primary LanguageHCLApache License 2.0Apache-2.0

viget.aws-canary-heartbeat

Terraform module to set up an AWS synthetic canary to conduct heartbeat monitoring of a given endpoint.

Usage

IMPORTANT: We do not pin modules to versions in our examples because of the difficulty of keeping the versions in the documentation in sync with the latest released versions. We highly recommend that in your code you pin the version to the exact version you are using so that your infrastructure remains stable, and update versions in a systematic way so that they do not catch you by surprise.

This module does not set up a notification topic

Simple Monitoring Using Defaults

module "canary" {
  source = "github.com/vigetlabs/terraform-aws-canary-heartbeat.git"

  namespace = "vgt"
  stage     = "example"
  component = "canary"

  attributes = ["monitoring-example"]

  heartbeat_endpoint = "https://www.viget.com"
}

Advanced Monitoring Changing Defaults

module "canary" {
  source = "github.com/vigetlabs/terraform-aws-canary-heartbeat.git"

  namespace = "vgt"
  stage     = "example"
  component = "canary"

  attributes = ["monitoring-example"]

  heartbeat_endpoint        = "https://www.viget.com"
  take_screenshot           = false
  schedule_expression       = "rate(5 minutes)"
  timeout_in_seconds        = 20
  artifacts_expiration_days = 90
}

Cleanup

See DeleteCanary for additional information

Due to AWS and Terraform not always cleaning up all canary resources it may be necessary to locate and manually remove some resources. This module manages the artifacts S3 bucket and IAM roles so terraform destroy will locate and remove them as well as throw the relevant errors for you.

The resources you may need to manually remove will be:

  • The CloudWatch alarms created for this canary. These alarms have a name of Synthetics-SharpDrop-Alarm-CanaryName
  • CloudWatch Logs log groups created for the canary. These logs groups have the name /aws/lambda/cwsyn-CanaryName

Before running terraform destroy be sure to take note of the canary_name output.

Requirements

Name Version
terraform >= 1.0
aws >= 4.44.0

Providers

Name Version
archive n/a
aws >= 4.44.0

Resources

Name Type
aws_iam_policy.logs_policy resource
aws_iam_policy.metrics_policy resource
aws_iam_policy.s3_policy resource
aws_iam_policy.xray_policy resource
aws_iam_role.this resource
aws_iam_role_policy_attachment.role_logs resource
aws_iam_role_policy_attachment.role_metrics resource
aws_iam_role_policy_attachment.role_s3 resource
aws_iam_role_policy_attachment.role_xray resource
aws_s3_bucket.artifacts_bucket resource
aws_s3_bucket_lifecycle_configuration.artifacts_bucket resource
aws_synthetics_canary.this resource
archive_file.heartbeat_zip data source
aws_caller_identity.current data source
aws_iam_policy_document.assume_role_policy data source
aws_iam_policy_document.logs_policy data source
aws_iam_policy_document.metrics_policy data source
aws_iam_policy_document.s3_policy data source
aws_iam_policy_document.xray_policy data source
aws_region.current data source

Inputs

Name Description Type Default Required
additional_tag_map Additional key-value pairs to add to each map in tags_as_list_of_maps. Not added to tags or id.
This is for some rare cases where resources want additional configuration of tags
and therefore take a list of maps with tag key, value, and additional configuration.
map(string) {} no
artifacts_expiration_days The number of days to keep artifacts for the canary. number 30 no
attributes ID element. Additional attributes (e.g. workers or cluster) to add to id,
in the order they appear in the list. New attributes are appended to the
end of the list. The elements of the list are joined by the delimiter
and treated as a single ID element.
list(string) [] no
component ID element. Usually the component or solution name, e.g. 'eks', 'rds', 'app'. string null no
context Single object for setting entire context at once.
See description of individual variables for details.
Leave string and numeric variables as null to use default value.
Individual variable settings (non-null) override settings in context object,
except for attributes, tags, and additional_tag_map, which are merged.
any
{
"additional_tag_map": {},
"attributes": [],
"component": null,
"delimiter": null,
"descriptor_formats": {},
"enabled": true,
"id_length_limit": null,
"label_key_case": null,
"label_order": [],
"label_value_case": null,
"labels_as_tags": [
"unset"
],
"namespace": null,
"regex_replace_chars": null,
"tags": {},
"tenant": null
}
no
delimiter Delimiter to be used between ID elements.
Defaults to - (hyphen). Set to "" to use no delimiter at all.
string null no
descriptor_formats Describe additional descriptors to be output in the descriptors output map.
Map of maps. Keys are names of descriptors. Values are maps of the form
{<br> format = string<br> labels = list(string)<br>}
(Type is any so the map values can later be enhanced to provide additional options.)
format is a Terraform format string to be passed to the format() function.
labels is a list of labels, in order, to pass to format() function.
Label values will be normalized before being passed to format() so they will be
identical to how they appear in id.
Default is {} (descriptors output will be empty).
any {} no
enabled Set to false to prevent the module from creating any resources bool null no
heartbeat_endpoint The URL for the canary to check if the site is healthy. string n/a yes
id_length_limit Limit id to this many characters (minimum 6).
Set to 0 for unlimited length.
Set to null for keep the existing setting, which defaults to 0.
Does not affect id_full.
number null no
label_key_case Controls the letter case of the tags keys (label names) for tags generated by this module.
Does not affect keys of tags passed in via the tags input.
Possible values: lower, title, upper.
Default value: title.
string null no
label_order The order in which the labels (ID elements) appear in the id.
Defaults to ["namespace", "stage", "component", "attributes"].
You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present.
list(string) null no
label_value_case Controls the letter case of ID elements (labels) as included in id,
set as tag values, and output by this module individually.
Does not affect values of tags passed in via the tags input.
Possible values: lower, title, upper and none (no transformation).
Set this to title and set delimiter to "" to yield Pascal Case IDs.
Default value: lower.
string null no
labels_as_tags Set of labels (ID elements) to include as tags in the tags output.
Default is to include all labels.
Tags with empty values will not be included in the tags output.
Set to [] to suppress all generated tags.
Notes:
The value of the name tag, if included, will be the id.
Unlike other context inputs, the initial setting of labels_as_tags cannot be
changed in later chained modules. Attempts to change it will be silently ignored.
set(string)
[
"default"
]
no
namespace ID element. Usually an abbreviation of the organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique string null no
regex_replace_chars Terraform regular expression (regex) string.
Characters matching the regex will be removed from the ID elements.
If not set, "/[^a-zA-Z0-9-]/" is used to remove all characters other than hyphens, letters and digits.
string null no
schedule_expression The schedule expression for the canary to run see https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/synthetics_canary#expression. string "rate(15 minutes)" no
stage ID element. Used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release' string null no
tags Additional tags (e.g. {'BusinessUnit': 'XYZ'}).
Neither the tag keys nor the tag values will be modified by this module.
map(string) {} no
take_screenshot Take a screenshot of the response when the canary runs. bool true no
tenant ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for string null no
timeout_in_seconds The timeout in seconds for the canary to run before it must stop. number 60 no

Outputs

Name Description
canary_name The name of the canary.