@appland/scanner

AppMap Scanner

Code scanning, linting, assertions and alerts.

Provides consistent ways to filter (include and exclude) the AppMap events and property values.

Event filters

Two standard event filters are provided that can be used with every rule: include and exclude. These filters are applied to an event, and make a determination about whether or not that event should be checked by the rule.

An event filter can be applied in one of two ways:

• scope the entire scope - for example, http_server_request, command.
• event an individual event within a scope. When enumerateScope is true for a rule, the event filters are applied automatically by the scanner framework. When enumerateScope is false, the rule code must apply the filter itself.

The event filter consists of a property name and a test. The framework fetches the property value from the event, and then applies the test. The test can be one of three types:

• equal - value string matches the filter condition exactly.
• include - value string includes the filter condition.
• match - value string matches the filter condition regexp.

Here's an example of a rule configured with a custom include event filter. The event filter prevents the rule from being applied to SQL queries that include the fragment FROM "pg_class" INNER JOIN "pg_attribute" (because these queries are fetching ORM metadata, not application code).

- id: tooManyJoins
  exclude:
    - event:
        property: query
        test:
          include: FROM "pg_class" INNER JOIN "pg_attribute"

Pattern filters

A second type of filter is pattern filter. Pattern filters are provided by rules that need, or benefit from, specific configuration.

Like Event filters, a pattern filter uses equal, include, or match. The data to which the pattern filter is applied depends on the particulars of the rule. For example, this pattern filter finds slow function calls within a specific package:

- id: slowFunctionCall
  properties:
    functions:
      - match: ^app/models
    timeAllowed: 0.25

Schema validation

The configuration YAML is validated against the rule schema before the scan is run. Any errors in the configuration are reported, and must be fixed before the scan can continue. Consult the documentation for each rule to see it's pattern filters and other configurable properties.

Finding hash

To enable de-duplication of findings, a hash is calculated for each finding. The hash is the sha256 digest of a canonical content string for the finding. The canonical content string combines stable data from the finding, such as the rule id, normalized event, etc. See appmap-js/packages/models/src/event/hash.js for details.

Findings output file

summary

Summarizes key information about the scan, including: number of AppMaps scanned, number of checks performed, list of rules utilized, list of labels utilized, number of findings, and an enumeration of all the distinct values in AppMap metadata.

Example

"summary": {
  "numAppMaps": 507,
  "numChecks": 8112,
  "rules": [
    "authz-before-authn",
    ...
    "update-in-get-request"
  ],
  "ruleLabels": [
    "audit",
    ...
    "security.logout"
  ],
  "numFindings": 91,
  "appMapMetadata": {
    "labels": [],
    "apps": [
      "appland/appmap-server"
    ],
    "clients": [
      {
        "name": "appmap",
        "url": "https://github.com/applandinc/appmap-ruby",
        "version": "0.70.2"
      }
    ],
    "frameworks": [
      {
        "name": "rails",
        "version": "6.1.4.1"
      },
      {
        "name": "rspec",
        "version": "3.10.1"
      }
    ],
    "git": [
      {
        "repository": "[e-mail]:applandinc/appmap-server.git",
        "branch": "master",
        "commit": "3b028018ec1f84e2c351d01d1dac45aeeae887b6"
      },
      {
        "repository": "[e-mail]:applandinc/appmap-server.git",
        "branch": "master",
        "commit": "3b028018ec1f84e2c351d01d1dac45aeeae887b6",
        "status": [
          "D .npmrc",
          "M appmap.yml",
          "M package-lock.json",
          "M package.json"
        ]
      }
    ],
    "languages": [
      {
        "name": "ruby",
        "engine": "ruby",
        "version": "3.0.1"
      }
    ],
    "recorders": [
      {
        "name": "rspec"
      }
    ],
    "testStatuses": [],
    "exceptions": []
  }
}

configuration

Provides the configuration file, as JSON, that was used to configure the scanner.

Example

"configuration": {
  "checks": [
    {
      "rule": "authzBeforeAuthn"
    },
    {
      "rule": "circularDependency",
      "properties": {
        "ignoredPackages": [
          {
            "equal": "app/models/concerns"
          },
          {
            "equal": "app/controllers/concerns"
          }
        ]
      }
    },
    {
      "rule": "http500"
    }
  ]
}

appMapMetadata

Contains the metadata for each AppMap that was scanned. appMapMetadata is a JSON object, whose keys are AppMap file names, and values are AppMap metadata objects. Each metadata object contains all the metadata values, except for those values which are the same across all AppMaps. Those values can be found in summary.appMapMetadata. For example, using the summary example given above, the app, labels, languages, recorders, testStatuses and exceptions will all be omitted from appMapMetadata.

Example

"appMapMetadata": {
  "tmp/appmap/rspec/API_APIKeysController_create_a_new_api_key.appmap.json": {
    "client": {
      "name": "appmap",
      "url": "https://github.com/applandinc/appmap-ruby",
      "version": "0.70.1"
    },
    "git": {
      "repository": "[e-mail]:applandinc/appmap-server.git",
      "branch": "master",
      "commit": "3b028018ec1f84e2c351d01d1dac45aeeae887b6"
    },
    "name": "API::APIKeysController create a new api key",
    "source_location": "spec/requests/api_api_keys_spec.rb",
    "test_status": "succeeded",
    ...
  }
}

checks

Lists the configured checks that were performed on each AppMap. Each entry is a Check object that includes the properties of the check as configured by the configuration.

Example

"checks": [
  {
    "rule": {
      "id": "authz-before-authn",
      "title": "Authorization performed before authentication",
      "labels": [
        "security.authorization",
        "security.authentication"
      ],
      "scope": "http_server_request",
      "impactDomain": "Security",
      "enumerateScope": false,
      "references": {
        "CWE-863": "https://cwe.mitre.org/data/definitions/863.html"
      },
      "description": "Determines when authorization logic is applied to a user identity that has not been properly verified. Because the the user's identity has not been verified yet, the outcome of the authorization check cannot be trusted. A malicious user might be able to get themselves authorized as a different user than they really are - or they may not be logged in at all.",
      "url": "https://appland.com/docs/analysis/rules-reference.html#authz-before-authn"
    },
    "id": "authz-before-authn",
    "options": {},
    "scope": "http_server_request",
    "includeScope": [],
    "excludeScope": [],
    "includeEvent": [],
    "excludeEvent": []
  },
  {
    "rule": {
      "id": "circular-dependency",
      "title": "Circular package dependency",
      "scope": "command",
      "impactDomain": "Maintainability",
      "references": {
        "CWE-1047": "https://cwe.mitre.org/data/definitions/1047.html"
      },
      "enumerateScope": false,
      "description": "Finds cycles in the package dependency graph. Cyclic dependencies make code hard to maintain because all the code in the cycle is inter-dependent. While it might look like the code in the different packages has separate functions, in essence all the code in the cycle acts like one big package.",
      "url": "https://appland.com/docs/analysis/rules-reference.html#circular-dependency"
    }
  }
]

findings

Lists the findings that are reported by this scan. Findings are de-duplicated by comparing their hash values. Therefore, each unique finding hash is only reported once.

Note that the appMapFile of each finding will be available in the appMapMetadata section of the findings JSON document. Similarly, details of the checkId can be obtained from the checks section.

Example

"findings": [
    {
      "appMapFile": "./tmp/appmap/rspec/Extensions_Upload_processing_logged_in_appmap_with_org_name_with_org_membership_is_added_to_the_specified_org.appmap.json",
      "checkId": "illegal-package-dependency",
      "ruleId": "illegal-package-dependency",
      "ruleTitle": "Illegal use of code by a non-whitelisted package",
      "event": {
        "id": 244,
        "event": "call",
        "thread_id": 461760,
        "defined_class": "DAO::Scenario",
        "method_id": "validate",
        "path": "app/models/dao/scenario.rb",
        "lineno": 149,
        "static": false,
        "receiver": {
          "class": "DAO::Scenario",
          "object_id": 501420,
          "value": "#<DAO::Scenario:0x00007f7f50cd6a78>"
        }
      },
      "hash": "a3a2be87f722fe53e9fbbb57dd1acd82d8cf76d3c346556e8e495cd0a91eba2e",
      "stack": [
        "app/models/dao/scenario.rb:149",
        "app/controllers/concerns/mute_logging.rb:4",
        "app/models/scenario/save_scenario.rb:11",
        "app/models/scenario/build.rb:68",
        "app/controllers/scenario_uploads_controller.rb:60",
        "app/controllers/scenario_uploads_controller.rb:44",
        "app/controllers/concerns/with_authentication.rb:6",
        "app/controllers/concerns/in_transaction.rb:8"
      ],
      "scope": {
        "id": 11,
        "event": "call",
        "thread_id": 461760,
        "http_server_request": {
          "request_method": "GET",
          "path_info": "/scenario_uploads/1",
          "normalized_path_info": "/scenario_uploads/{id}",
          "headers": {
            "Host": "127.0.0.1:61019",
            "Connection": "keep-alive",
            "Upgrade-Insecure-Requests": "1",
            "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/97.0.4692.99 Safari/537.36",
            "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9",
            "Sec-Fetch-Site": "none",
            "Sec-Fetch-Mode": "navigate",
            "Sec-Fetch-User": "?1",
            "Sec-Fetch-Dest": "document",
            "Accept-Encoding": "gzip, deflate, br",
            "Accept-Language": "en-US",
            "Cookie": "appland_session=YKhMDBpgpV0hwKaBkxlaq%2BVzBRK2u6r%2BU%2BnFmJ61y5Q6TxptqxED597yhcmKqSTLfs%2FExRKU8WJ8iN7pV5Si7i0iJfPMa32ubjqMx0wVtcZ%2Fxo%2BwIcDF%2FI6Qaf7cU6oj6DaErr8GElQTTlA0TdRBrCgo43no%2BD4pSwkXvweqR175ZrCN%2FrjBZElvLaxyoY8kKsABEEtmI2aRcCcDJylP1hVrAI6%2BcWgVhb42ITJ8%2BuN0KiZDZSJWOsQFW6l656tyDDjC3UQvf65u5zvDAbqhIJkSEBXfn8p7c7I%2Bo8Cc9UWjLCNTCV%2BTL5iJ5qKDLHb7sHQftnOymCkyc%2FM57Bute59Lmyk6ZsNj4Y3Zbv6upszqyfJMhPyvcESz6BZCrzEGJudCueDtwNAnBPu3zE%2B1xQcKMpmF1R8Jw7ds41i90fFE0tkUCaiDzHdZUveVQKm7N%2F9pgTKE7a%2FyrevoPBKjpsqOrG%2BLe1Xhc%2FyWZBzXKbaTkHIRhoLijV9vGRH%2F%2Fk%2B9uZW0uhyfnoLDJB7af2vArKwNhEwuCBsXybPmyDDq2oLq8fMyWeVOpY7H44pGHho1D1qQdVfBzrLVoUG%2FqAbBSh0roHl%2FFjfRKmSil6iTQWQSNkemb73NNAsg3U2lI2AcjoNCzZHJS8S7iIpbZonabSR7AKyssx%2BSRYjdTsy5FplO--DN1nLB2Gux0u9W7x--RCmfYC53sopFkHidZ1uSNA%3D%3D",
            "Version": "HTTP/1.1"
          }
        }
      },
      "message": "Code object app/models/dao/DAO::Scenario#validate was invoked from app/controllers/concerns, not from ^app/models/?"
    }
]

Development

We use yarn for package management. Run yarn to install dependencies and yarn build to emit JavaScript. To run without first emitting JavaScript to the filesystem, use yarn start.

Installation

Install like any other Node.js package, using yarn or npm:

yarn add --dev @appland/scanner

Then, you may find it convenient to add some scripts to your package.json:

  "scripts": {
    "scan": "npx @appland/scanner scan --appmap-dir tmp/appmap",
    "scan-ci": "npx @appland/scanner ci --appmap-dir tmp/appmap",
  },

Note tmp/appmap is the standard AppMap location for some AppMap agents, but not all. Consult your agent documentation and settings to configure the --appmap-dir.

Scan locally

yarn run scan

Findings will be printed to the console, and saved to appland-findings.json.

CI integration

When using Appmap Scanner in CI you can post findings summary as a commit status and/or a PR comment (currently only GitHub is supported). In order to allow access to your repo you need to create a personal token with following privileges and add it as a GH_TOKEN env variable to your CI:

• repo for posting PR comments
• repo:status for posting commit statuses

yarn run scan-ci

When uploading findings to app.land, branch and commit information will be resolved from the environment if possible. If we do not yet support your CI provider or you have a non-standard configuration, you may provide your own overrides using the -b (branch) and -c (commit) options to the upload and ci commands. Note that this is only necessary when Git is in a detached HEAD state.

Development

Using a local branch of @appland/models

Use yarn link to create a symlink to a local version of @appland/models. Make sure the models package is built according to the instructions in its own README.

$ yarn link ../appmap-js/packages/models