rego_unsafe_var_error: expression is unsafe

Has anyone been diagnosed with PTSD and been able to get a first class medical? The canonical form does away with . In the example the untyped literal constant 500 is multiplied by time.Millisecond, itself a constant of type time.Duration. --entrypoint. However, there may be slight differences in the commands you need to run. That is, they can be queried under OPAs Data API provided the appropriate package is given. goroutines, and invoked repeatedly with different inputs. It started happening when we moved over to using PrepareForEval. will see the unmodified value. I would have something like this: where label is used to build the error message. Here are some examples that are all safe: Safety errors can also occur with variables that appear in the head of the rule: Safety is important as it ensures that OPA can enumerate all of the values that could be assigned to the variable. If admission control Similarly, if you edit the queries or rules in the examples below the output execute the prepared query. Examples: # Unsafe: x in head does not appear in body. To ensure backwards-compatibility, the keywords discussed below introduced slowly. This means that rule bodies and queries express FOR ANY and not FOR Note that the second allow rule doesnt have a METADATA comment block attached to it, and hence will not be type checked with any schemas. Read more, A list of organizations related to the annotation target. The Basics For example, with: The rule r above asserts that there exists (at least) one document within sites where the name attribute equals "prod". In such strings, certain characters must be escaped to appear in the string, such as double quotes themselves, backslashes, etc. Generating sets: Head declares only keys whose value is defined and returned from the body. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. rev2023.5.1.43405. You can query for the value generated by rules just like any other value: All values generated by rules can be queried via the global data variable. Thanks for contributing an answer to Stack Overflow! , So no patch yet, but I'm closing in on the problem. The type checker is able to identify such keywords and derive a more robust Rego type through more complex schemas. When the allow document is queried, the return value will be either true or false. Annotations are grouped within a metadata block, and must be specified as YAML within a comment block that must start with # METADATA. rego_unsafe_var_error: expression is unsafe networks are public. In particular the following features are not yet supported: A note of caution: overriding is a powerful capability that must be used carefully. Asking for help, clarification, or responding to other answers. We can write test cases for all the scenarios and check if the system behaves the way we expect it to. Safety is a property of Rego that ensures that all variables can be assigned a finite number of values. The organizations annotation is a list of string values representing the organizations associated with the annotation target. Load policy or data files into OPA. Specifically, allOf keyword implies that all conditions under allOf within a schema must be met by the given data. They are optional, and you will find examples below of defining rules without them. organized into many sub-packages, it is useful to declare schemas recursively for those bindings. Evaluating every does not introduce new bindings into the rule evaluation. operations like string manipulation, regular expression matching, arithmetic, Rego has a gradual type system meaning that types can be partially known statically. The related_resources annotation is a list of related-resource entries, where each links to some related external resource; such as RFCs and other reading material. You can start OPA as a server with -s or --server: By default OPA listens for HTTP connections on 0.0.0.0:8181. Composite keys may not be used in refs Which clusters a workload must be deployed to. This section introduces the main aspects of Rego. By clicking Sign up for GitHub, you agree to our terms of service and You We can use with to iterate over the resources in input and written output as a list. arguments, parentheses are required to use the form with two left-hand side Notice that when a directory is passed the input document does not have a schema associated with it globally. The policy decision is contained in the results returned by the Eval() call. Modules consist of: Modules are typically represented in Unicode text and encoded in UTF-8. Unification lets you ask for values for variables that make an expression true. In simple cases, composite values can be treated as constants like Scalar Values: Composite values can also be defined in terms of Variables or References. statement is undefined. We can query for the content of the pi document generated by the rule above: Rules can also be defined in terms of Composite Values: You can compare two scalar or composite values, and when you do so you are checking if the two values are the same JSON value. In the future, we will take this feature into account when deriving Rego types. function declarations below are equivalent: The outputs of user functions have some additional limitations, namely that they must resolve to a single value. Which times of day the system can be accessed at. OPA and supplies structured data (e.g., JSON) as input. These queries can be used to You can query for the entire The head of the rule is assigned values that are an aggregation of all the rules that evaluate to true. (none of which are public): Partial rules are if-then statements that generate a set of values and Consider the following Rego code, which assumes as input a Kubernetes admission review. I can even add the above test into the playground and it works as expected too. Most REPLs let you define variables that you can reference later on. If the variable is unsafe it means there could be an infinite number of variable assignments. When Rego values are converted to JSON non-string object keys are marshalled to your account. Read this page to learn about the core concepts in OPAs policy language For example, the following rule defines a document containing apps deployed on the same site as "mysql": Comprehensions provide a concise way of building Composite Values from sub-queries. Then you don't need the import. implicitly when you inject variables into expressions. Therefore, this additional clean up is going to incur some amount of latency and service should be okay with that. the Policy Reference page. In that case, the equivalent opa eval invocation would be (essentially): You signed in with another tab or window. . # There are infinitely many . Just like intermediate variables, OPA returns the values of the variables. evaluated: The rego.Rego supports several options that let you customize evaluation. Parameters in Rego rules [Open Policy Agent] - Stack Overflow package. and will bind its variables (key, value position) to the collection items. If evaluation produces multiple values for the same document, an error defined in terms of scalars, variables, references, and other composite values. When we query for the value of t2 we see the obvious result: Rego References help you refer to nested documents. If the body is omitted, it defaults to true. Schemas in annotations are proper Rego references. Note that we use the relative path inside the mySchemasDir directory to identify a schema, omit the .json suffix, and use the global variable schema to stand for the top-level of the directory. As a result, if either operand is a variable, the variable Which subnets egress traffic is allowed to. at some point in time, but have been introduced gradually. The key idea is that Rego, as a query language, is heavily based towards disjunctions (or statements). The rule above defines an object that maps hostnames to app names. In most cases, policies do not have to implement any kind of error handling When you execute queries without providing a path, you do not have to wrap the It started happening when we moved over to using PrepareForEval. update their policies, so that the new keyword will not cause clashes with existing Rego will assign variables to values that make the comparison true. When reordering this rule body for safety. I made sure the error is the exact same after trimming it down and anonymizing it, but I'm not sure if that could have changed something unintentionally--there are several rules in actual usage that aren't in the policies above. When a variable is used in multiple locations, OPA will only produce documents for the rule with the variable bound to the same value in all expressions. annotation multiple times: This is obviously redundant and error-prone. a time. Using the (future) keyword if is optional here. The data that your service and its users publish can be inspected and transformed using OPAs native query language Rego. To learn more, see our tips on writing great answers. and referencing a schema from http://localhost/ will fail. References are used to access nested documents. logic statements. Because rules are namespaced they can be safely shared across projects. In your example, the statement valid_route_request generates a set of values (labels?). Steps Several of the steps below require root or sudo access. Schema files can be referenced by path, where each path starts with the schema namespace, and trailing components specify documents. absolute path. Making statements based on opinion; back them up with references or personal experience. constraint, as they are already provided by OPAs schema checker without requiring I think the "missing imports" are a red herring. Have a question about this project? Optionally, the last word may represent an email, if enclosed with <>. Can I use the spell Immovable Object to create a castle which floats above the clouds? When The body of a comprehension can be understood in exactly the same way as the body of a rule, that is, one or more expressions that must all be true in order for the overall body to be true. Read more, A list of URLs pointing to related resources/documentation. For reproduction steps, policies, and example go code that reproduces the problem, see below. See the Replicating Data for more info. logic. Comprehensions are similar to the same constructs found in other languages like Python. When using data.iam.bar(role, resource, ["foo"], "bar") in policy.rego, we get this rule body. We often make batch calls in a single request. If a call matches multiple functions, they must produce the same output, or else a conflict error will occur: On the other hand, if a call matches no functions, then the result is undefined. rego package - github.com/andy-styra/opa/rego - Go Packages And its failing with the ingest error rego_unsafe_var_error: expression is unsafe. more. The order of expressions does not matter. Array Comprehensions have the form: For example, the following rule defines an object where the keys are application names and the values are hostnames of servers where the application is deployed. I get error from OPA: var label is unsafe Generally speaking, it is still not clear to me how to pass parameters in Rego. E.g., input["foo~bar"]. please use some x in xs; not p(x) instead. Already on GitHub? 2. GitHub open-policy-agent / gatekeeper Public Notifications Fork 663 Star 3.1k Code Issues 158 Pull requests 15 Actions Projects 1 Security Insights New issue containing your results. define policies that enumerate instances of data that violate the expected state I tried this rego policy on the playground and it worked just fine. code: rego_unsafe_var_error, Code causing the error: sum(a,b) = x { a + b} Cause: this happens because x is not assigned. Magento 2.3.5-p1 CSP font-src self unsafe-inline is_Action_Allowed becomes not is_Action_Allowed) as shown. The with keyword only affects the attached expression. It is not safe because the comprehension on line 4 comes after the object.get call of line 1. Verify the macOS binary checksum: The simplest way to interact with OPA is via the command-line using the opa eval sub-command. it: Quit out of the REPL by pressing Control-D or typing exit: You can load policy and data files into the REPL by passing them on the command opa eval supports a large number of options for controlling evaluation. And denies Pod creation if namespace does not have resoucequota defined. rather than how queries should be executed. Inside of another terminal use curl (or a similar tool) to access OPAs HTTP walks through each part of the language in more detail. collections of unique values. This article should help you get started writing Rego. if x := {"a":"b"} is selected and OPA: Evaluate Selection is run, I get, If t := x is selected and OPA: Evaluate Selection is run, I get And then you use negation to check There may be multiple sets of bindings that make the rule rego_unsafe_var_error: expression is unsafejack paar cause of death. There are just two important points: Using a different key on the same array or object provides the equivalent of self-join in SQL. This can create conflicts in decision making, especially when both the permit and deny get executed. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, Open policy agent satisfy condition for all array items, Open policy agent define dynamic global variable, UTF-8 character support in Rego policies/rules, Is it possible to use the output of an external program in an Open policy agent policy, Open Policy Agent (OPA) Rego - Accessing Input Object Nested Fields At Runtime, Open Policy Agent - Improve performance of a grouping comprehension, How to compact and optimize open policy agent, in a single rego policy, Kubernetes Open Policy Agent (OPA) If Else, A boy can regenerate, so demons eat him for years. If so, you need to import the rule under test into the test module: It's also possible to split the same package over multiple modules/files by declaring the same package in them, which might be what you actually want to do. The scope values that are currently For example, an object could have certain fields whose types are known and others that are unknown statically. An incrementally defined rule can be intuitively understood as OR OR OR . its can be any of the following: When the replacement value is a function, its arity needs to match the replaced For example: By defining composite values in terms of variables and references, rules can define abstractions over raw data and other rules. When you enter statements in the REPL, OPA evaluates them and prints the result. Like other applications which support declarative query languages, OPA is able to optimize queries to improve performance. Paths must start with input or data (i.e., they must be fully-qualified.). We only know that it refers to a collections of values. As you discovered you can select individual expressions as well as rule names. This is useful to verify if an input exists in the array list. the path of the schema file (sans file-ending) relative to the root directory specified by the --schema flag on applicable commands. If the The idea is that I want to look for annotations in the metadata which have the key of value either "apparmor" or "seccomp", Anything else you would like to add: Open Policy Agent | How Do I Write Policies? Here's my constraint template. repository), add Call the rego.New function to create an object that can be prepared or The Rego compiler supports strict mode, where additional constraints and safety checks are enforced during compilation. The Basics What is Wario dropping at the end of Super Mario Land 2 and why? In these cases, negation must be used. Transforming variables with Jinja2 filters . Thanks for contributing an answer to Stack Overflow! rules were defined inside packages like kubernetes.admission.workloads.pods, annotations, grouped by the path and location of their targeted package or -rule. document itself) or data document, or references to functions (built-in or not). Whether you use negation, comprehensions, or every to express FOR ALL is up to you. One for the case where the path input.request.object.metadata.labels["route-selector'] is undefined and the other for an invalid value. You can query the value of any rule loaded into OPA by referring to it with an following syntax: The s must be references to values in the input document (or the input As a result, if either operand is a variable, the variable must appear in another expression in the same rule that would cause the variable to be bound, i.e., an equality expression or the target position of a built-in function. For example, these are all valid package names: For more details see the language Grammar. (CNCF) landscape. checking on the second (or other rules in the same file) we could specify the import future.keywords.every introduces the every keyword described here. Is this a bug? Your boss has asked you to determine if OPA would be a good fit for implementing If the --schema flag is not present, referenced schemas are ignored during type checking. general-purpose policy engine that unifies policy enforcement across the stack. To be considered "safe", a variable must appear as the output of at-least-one non-negated expression. Reference for a formal definition. 1 comment prageetika commented on Mar 31, 2021 Here's my constraint template. @jguenther-va With the branch of that PR your main.go runs through without errors. We also do clean up like remove whitespaces, spellchecks, basic validations, concatenations etc. This actually becomes a bit clearer if you include 'some' in the deny rule: Technically there would be an infinite number of assignments to label that satisfy this rule (e.g., the string "12345" would NOT be contained in valid_route_request and so would "123456" and so would ). If we had a video livestream of a clock being sent to Mars, what would we see? Read more, A list of authors for the annotation target. (Importing every means also importing in without an extra import statement.). Since the rule body is true, the rule head is always true/defined. For this policy, you can also define a rule that finds if there exists a bitcoin-mining Rego extends Datalog to support By default, JSON and YAML files are rooted under data. Open Policy Agent | Policy Language commonly used for constants: Documents produced by rules with complete definitions can only have one value at Composite values define collections. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Parameters in Rego rules [Open Policy Agent], When AI meets IP: Can artists sue AI imitators? network access. If you refer to a value that does not exist, OPA returns undefined. Details. For For example, the following policy will not compile: A simple form of destructuring can be used to unpack values from arrays and assign them to variables: Comparison checks if two values are equal within a rule. Constants defined like this can be queried just like any other values: If OPA cannot find variable assignments that satisfy the rule body, we say that For more examples, please see https://github.com/aavarghese/opa-schema-examples. Why the obscure but specific description of Jane Doe II in the original complaint for Westenbroek v. Kappa Kappa Gamma Fraternity? worked with the previous version of OPA stop working. For example, the following function will return the result of trimming the spaces from a string and then splitting it by periods. rego_unsafe_var_error: expression is unsafe . Unification lets you ask for values for variables that make an expression true. implemented: The policy needs to be enforced when servers, networks, and ports are If there are no variable assignments that make all of with the input document for the rule whocan. The Open Policy Agent (OPA, pronounced oh-pa) is an open source, If you omit the = part of the rule head the value defaults to true. // Construct a Rego object that can be prepared or evaluated. The scope of the schema annotation can be controlled through the scope annotation. Built-ins can include . characters in the name. Rego is declarative so policy authors can focus on what queries should return rather than how queries should be executed. PRE31-C. Avoid side effects in arguments to unsafe macros to true. If you select both lines in the rule body, the query should evaluate. The scope annotation in under the input Document or the Undefined OPA will reject rules containing negated expressions that do not meet the safety criteria described above. Rego is existentially quantified. In some cases, when policies are In the example below, you can see how to access an annotation from within a policy. Sanitizing HTML As you read through this section, try changing the input, queries, While plain iteration serves as a powerful building block, Rego also features ways these tasks. When a schema is fully specified, we derive a type with its dynamic part set to nil, meaning that we take a strict interpretation in order to get the most out of static type checking. Open Policy Agent | Documentation recursion. To implement this policy we could define rules called violation Please let me know if it would help to see the actual policies we're using (can share privately). What it says is that we know the type of data.acl statically, but not that of other paths. keyword, because the rule is true whenever there is SOME app that is not a Please tell us how we can improve. All rules have the following form (where key, value, and body are all optional): For a more formal definition of the rule syntax, see the Policy Reference document. rego_unsafe_var_error: expression is unsafe The with keyword allows queries to programmatically specify values nested The modules have already been parsed, so the import doesn't need to be there Anyways, commenting out the first eval, to avoid potential crossed wires, running only. As such, they Used with a key argument, the index, or property name (for objects), comes into the There is no constraint on the name of the file, it could be anything. Testing is an important part of the software development process. We would expect that PrepareForEval() completes without error using WithPartialEval(), i.e. a built-in function. details on each built-in function. update their policies, so that the new keyword will not cause clashes with existing not the same as false.) Unless stated otherwise, all built-ins accept values or variables as objects is that sets are unkeyed while arrays and objects are keyed, i.e., you Commonly used flags include: OPA includes an interactive shell or REPL (Read-Eval-Print-Loop) accessible via them to avoid naming conflicts, e.g., org.example.special_func. For example, we could write the above comprehension in Python as follows: Comprehensions are often used to group elements by some key. In the first stage, users can opt-in to using the new keywords via a special import: Because the properties kind, version, and accessNum are all under the allOf keyword, the resulting schema that the given data must be validated against will contain the types contained in these properties children (string and integer). Be First! document that is defined by the rule. In the example above, the second rule does not include an annotation so type they would be able to pick up that one schema declaration. To solve for both the issues, we use negations by using the not operator as follows: Glob is useful for matching the pattern separated by delimiters as defined. Function arguments may be any kind of term. your own machine. Getting Started With Rego R ego is the language used by OPA (Open Policy Agent) to write declarative, easily extensible policy decisions. @srenatus on the sr/issue-4766 branch (commit 3c400b8) I'm now seeing a different error: not sure what the difference is here that you're not seeing that error, just double checked and the only change after the original PR description was the 2 policy files mentioned in this comment, edit: if I try the branch in that second PR this is the error I get (may just be because it doesn't have the fix from the first PR though? If we query for the tuples we get two results: Since we have declared i, j, and server to be local, we can introduce The keyword is used to explicitly assert that its body is true for any element in the domain. variables or references. The package and individual rules in a module can be annotated with a rich set of metadata. following form: Built-ins usually take one or more input values and produce one output time, but have been introduced gradually. To allow more precise type checking in such cases, we support overriding existing schemas. operator. Modules use the same syntax to declare dependencies on Base and Virtual Documents. Annotations can be listed through the inspect command by using the -a flag: The ast.AnnotationSet is a collection of all ast.Annotations declared in a set of modules. To forbid all network access in schema checking, set allow_net to []. Deprecated built-in functions: String keys containing characters other than. these scopes are applied over all files with applicable package- and rule paths. OPA and Rego are domain-agnostic so you can describe almost From the devdocs, it says: Regardless of restrict or report-only mode, CSP violations may be reported to an endpoint for collection. rego_unsafe_var_error: expression is unsafe. On the other hand, if we evaluate q with an input value for name we can determine whether name exists in the document defined by q: Variables appearing in the head of a rule must also appear in a non-negated equality expression within the same rule. be safe, i.e., it must be assigned elsewhere in the query. assign that set to a variable. ', referring to the nuclear power plant in Ignalina, mean? In this case, we evaluate q with a variable x (which is not bound to a value). By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. ClientError: GraphQL.ExecutionError: Error trying to resolve rendered. Rego allows authors to omit the body of rules. Hopefully, it will benefit a lot of people. Notice that the order of schema annotations matter for overriding to work correctly. The idea is that I want to defines a maximum total CPU and memory for a given namespace. errors treated as exceptions that halt policy evaluation enable strict built-in More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata", https://github.com/aavarghese/opa-schema-examples/, https://github.com/aavarghese/opa-schema-examples/blob/main/kubernetes/schemas/input.json, https://github.com/aavarghese/opa-schema-examples/tree/main/acl, https://github.com/aavarghese/opa-schema-examples, http://json-schema.org/understanding-json-schema/reference/index.html, A human-readable name for the annotation target.

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