Documentation
¶
Overview ¶
Package repl implements a Read-Eval-Print-Loop (REPL) for interacting with the policy engine.
The REPL is typically used from the command line, however, it can also be used as a library. nolint: goconst // String reuse here doesn't make sense to deduplicate.
Index ¶
- Constants
- type Error
- type REPL
- func (r *REPL) DisableMultiLineBuffering(yes bool) *REPL
- func (r *REPL) DisableUndefinedOutput(yes bool) *REPL
- func (r *REPL) Loop(ctx context.Context) error
- func (r *REPL) OneShot(ctx context.Context, line string) error
- func (r *REPL) SetOPAVersionReport(report [][2]string)
- func (r *REPL) WithCapabilities(capabilities *ast.Capabilities) *REPL
- func (r *REPL) WithConsoleInput(in io.Reader) *REPL
- func (r *REPL) WithInitBundles(b map[string]*bundle.Bundle) *REPL
- func (r *REPL) WithRegoVersion(v ast.RegoVersion) *REPL
- func (r *REPL) WithRuntime(term *ast.Term) *REPL
- func (r *REPL) WithStderrWriter(w io.Writer) *REPL
- func (r *REPL) WithV1Compatible(v1Compatible bool) *REPLdeprecated
Examples ¶
Constants ¶
const ( // BadArgsErr indicates bad arguments were provided to a built-in REPL // command. BadArgsErr string = "bad arguments" )
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type REPL ¶
type REPL struct {
// contains filtered or unexported fields
}
REPL represents an instance of the interactive shell.
func New ¶
func New(store storage.Store, historyPath string, output io.Writer, outputFormat string, errLimit int, banner string) *REPL
New returns a new instance of the REPL.
func (*REPL) DisableMultiLineBuffering ¶
DisableMultiLineBuffering causes the REPL to not buffer lines when a parse error occurs. Instead, the error will be returned to the caller.
func (*REPL) DisableUndefinedOutput ¶
DisableUndefinedOutput causes the REPL to not print any output when the query is undefined.
func (*REPL) Loop ¶
Loop reads, evaluates, and prints query results until the input is exhausted (EOF), the user exits, or an unexpected error occurs.
An interactive terminal gets the full readline editor (history, completion, bracketed paste); any non-terminal input (a pipe, a file, /dev/null) gets a plain line reader that stops cleanly at EOF. The readline editor must not be driven against a non-TTY: on macOS it busy-loops at 100% CPU without ever seeing EOF.
func (*REPL) OneShot ¶
OneShot evaluates the line and prints the result. If an error occurs it is returned for the caller to display.
Example ¶
nolint // example code
package main
import (
"bytes"
"context"
"fmt"
"github.com/open-policy-agent/opa/v1/ast"
"github.com/open-policy-agent/opa/v1/repl"
"github.com/open-policy-agent/opa/v1/storage/inmem"
)
func main() {
// Initialize context for the example. Normally the caller would obtain the
// context from an input parameter or instantiate their own.
ctx := context.Background()
// Instantiate the policy engine's storage layer.
store := inmem.New()
// Create a buffer that will receive REPL output.
var buf bytes.Buffer
// Create a new REPL.
r := repl.New(store, "", &buf, "json", 0, "").
WithRegoVersion(ast.RegoV1)
// Define a rule inside the REPL.
r.OneShot(ctx, "p if { a = [1, 2, 3, 4]; a[_] > 3 }")
// Query the rule defined above.
r.OneShot(ctx, "p")
// Inspect the output. Defining rules does not produce output so we only expect
// output from the second line of input.
fmt.Println(buf.String())
}
Output: { "result": [ { "expressions": [ { "value": true, "text": "p", "location": { "row": 1, "col": 1 } } ] } ] }
func (*REPL) SetOPAVersionReport ¶
SetOPAVersionReport sets the information about the latest OPA release.
func (*REPL) WithCapabilities ¶
func (r *REPL) WithCapabilities(capabilities *ast.Capabilities) *REPL
func (*REPL) WithConsoleInput ¶ added in v1.19.0
WithConsoleInput sets the reader the REPL reads query input from. It defaults to os.Stdin; a nil reader is ignored. Non-terminal input (a pipe, a file, /dev/null) uses a plain line reader instead of the terminal editor.
func (*REPL) WithRegoVersion ¶
func (r *REPL) WithRegoVersion(v ast.RegoVersion) *REPL
WithRegoVersion sets the Rego version to v.
func (*REPL) WithRuntime ¶
WithRuntime sets the runtime data to provide to the evaluation engine.
Source Files