Allow for configuration policies

Summary:
Implements a rough interface for validating configuration against
arbitrary policy rules. Policies are provided as YAML and passed via the
command line as file paths or remote URIs.

The format of policies is:

    enforcements:
      - path: <path>
        rule: <rule>

Where `<path>` is a YAML-ish path to a config field and `<rule>` is any
expression our config validator understands (expressions built in by the
validator library and custom tags defined in `config.validation.go`).

Example policy:

    enforcements:
      - path: variants.production.base
        rule: oneof=debian:jessie debian:stretch
      - path: variants.production.runs.as
        rule: ne=foo
      - path: variants.production.node.dependencies
        rule: isfalse

Command flag parsing was implemented in `main.go` to support the new
`--policy=uri` flag and improve existing handling of `--version` and the
usage statement.

Test Plan: Run `go test ./...`.

Reviewers: thcipriani, demon, hashar, mmodell, #release-engineering-team

Reviewed By: thcipriani, #release-engineering-team

Tags: #release-engineering-team

Differential Revision: https://phabricator.wikimedia.org/D999

1 files changed, 56 insertions, 0 deletions

diff --git a/vendor/github.com/pborman/getopt/duration.go b/vendor/github.com/pborman/getopt/duration.go
new file mode 100644
index 0000000..9061113
--- /dev/null
+++ b/vendor/github.com/pborman/getopt/duration.go
@@ -0,0 +1,56 @@
+// Copyright 2015 Google Inc.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package getopt
+
+import "time"
+
+type durationValue time.Duration
+
+func (d *durationValue) Set(value string, opt Option) error {
+	v, err := time.ParseDuration(value)
+	if err != nil {
+		return err
+	}
+	*d = durationValue(v)
+	return nil
+}
+
+func (d *durationValue) String() string {
+	return time.Duration(*d).String()
+}
+
+// Duration creates an option that parses its value as a time.Duration.
+func Duration(name rune, value time.Duration, helpvalue ...string) *time.Duration {
+	return CommandLine.Duration(name, value, helpvalue...)
+}
+
+func (s *Set) Duration(name rune, value time.Duration, helpvalue ...string) *time.Duration {
+	return s.DurationLong("", name, value, helpvalue...)
+}
+
+func DurationLong(name string, short rune, value time.Duration, helpvalue ...string) *time.Duration {
+	return CommandLine.DurationLong(name, short, value, helpvalue...)
+}
+
+func (s *Set) DurationLong(name string, short rune, value time.Duration, helpvalue ...string) *time.Duration {
+	s.DurationVarLong(&value, name, short, helpvalue...)
+	return &value
+}
+
+func DurationVar(p *time.Duration, name rune, helpvalue ...string) Option {
+	return CommandLine.DurationVar(p, name, helpvalue...)
+}
+
+func (s *Set) DurationVar(p *time.Duration, name rune, helpvalue ...string) Option {
+	return s.DurationVarLong(p, "", name, helpvalue...)
+}
+
+func DurationVarLong(p *time.Duration, name string, short rune, helpvalue ...string) Option {
+	return CommandLine.DurationVarLong(p, name, short, helpvalue...)
+}
+
+func (s *Set) DurationVarLong(p *time.Duration, name string, short rune, helpvalue ...string) Option {
+	return s.VarLong((*durationValue)(p), name, short, helpvalue...)
+}