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In-file Instrumentation

Terrascan can be instrumented using special commands inside your IaC files (Terraform, K8s and dockerfile)

Today, Terrascan supports these instrumentations:

  • Rule Skipping
  • Resource Prioritization

Rule Skipping

Rule skipping allows you to specify a rule that should not be applied to a particular resource.

Note: In-file instrumentation will skip the rule only for the resource it is defined in. The skip_rules parameter in the config file will skip the rule for the entire scan.

In Terraform

Use the syntax #ts:skip=RuleID optional_comment inside a resource to skip the rule for that resource.

Example

resource "aws_db_instance" "PtShGgAdi4" {
  #ts:skip=AWS.RDS.DataSecurity.High.0414 Reason to skip this rule
  allocated_storage       = 20
  storage_type            = "gp2"
  engine                  = "mysql"
  engine_version          = "5.7"
  instance_class          = "db.t2.micro"
 .
 .
 .
}

In Kubernetes

Use the annotation runterrascan.io/skip:[{\"rule\": \RuleID\", \"comment\": \"reason to skip the rule\"}] inside a resource to skip the rule for that resource.

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingress-demo-disallowed
  annotations:
    runterrascan.io/skip: "[{\"rule\": \"AC-K8-NS-IN-H-0020\", \"comment\": \"reason to skip the rule\"}]"
spec:
  rules:
    - host: example-host.example.com
      http:
        paths:
          - backend:
              serviceName: nginx
              servicePort: 80

In Dockerfile

Use the syntax #ts:skip=RuleID optional_comment inside the dockerfile to skip the rule for that resource.

Example

FROM runatlantis/atlantis:v0.16.1
#ts:skip=AC_DOCKER_0001 skip this rule.
ENV DEFAULT_TERRASCAN_VERSION=1.5.1
RUN terrascan init
ENTRYPOINT ["/bin/bash", "entrypoint.sh"]
CMD ["server"]

Resource Prioritization

Resource prioritization allows you set maximum and minimum severities for violations in a given resource. Are you configuring a very sensitive resource? Set the minimum severity to High, so low and medium violations will be escalated. Need to suppress all violations from a particular resource? Set the maximum severity to None.

For maximum severity, meaningful options are Medium, Low, and None.

For minimum severity, meaningful options are High and Medium.

In Terraform

Use the syntax #ts:maxseverity=SEVERITY, or #ts:minseverity=SEVERITY inside a resource to skip the rule for that resource.

Example

resource "aws_db_instance" "PtShGgAdi4" {
  #ts:maxseverity=Low
  allocated_storage       = 20
  storage_type            = "gp2"
  engine                  = "mysql"
  engine_version          = "5.7"
  instance_class          = "db.t2.micro"
  .
  .
  .
}

In Kubernetes

Use the annotation runterrascan.io/minseverity: SEVERITY, or runterrascan.io/maxseverity: SEVERITY inside a resource to skip the rule for that resource.

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingress-demo-disallowed
  annotations:
    runterrascan.io/minseverity: Low
spec:
  rules:
    - host: example-host.example.com
      http:
        paths:
          - backend:
              serviceName: nginx
              servicePort: 80

In Dockerfile

Use the syntax #ts:maxseverity=SEVERITY, or #ts:minseverity=SEVERITY inside a dockerfile to skip the rule for that resource.

Example

#ts:maxseverity=None
FROM runatlantis/atlantis:v0.16.1
ENV DEFAULT_TERRASCAN_VERSION=1.5.1
RUN terrascan init
ENTRYPOINT ["/bin/bash", "entrypoint.sh"]
CMD ["server"]