support env vars for options in server config

config/policy-bot.example.yml

@@ -15,9 +15,11 @@ server:
 logging:
   # If true, logs are printed in human-readable form. We recommend using
   # "false" to output JSON-formatted logs in production
+  # Can also be set by the POLICYBOT_LOG_PRETTY environment variable.
   text: false
   # Set a minimum logging level threshold
   # Choose from: debug, info, warn, error
+  # Can also be set by the POLICYBOT_LOG_LEVEL environment variable.
   level: debug
 
 # Options for the GitHub response cache. When the cache reaches max_size, the
@@ -78,17 +80,21 @@ sessions:
 # Options for application behavior. The defaults are shown below.
 #
 # options:
-#   # The path to the policy file in a repository.
+#   # The path to the policy file in a repository. Can also be set by the
+#   # POLICYBOT_POLICY_PATH environment variable.
 #   policy_path: .policy.yml
 #
 #   # The name of an organization repository to look in for a shared policy if
-#   # a repository does not define a policy file.
+#   # a repository does not define a policy file. Can also be set by the
+#   # POLICYBOT_SHARED_REPOSITORY environment variable.
 #   shared_repository: .github
 #
 #   # The path to the policy file in the shared organization repository.
+#   # Can also be set by the POLICYBOT_SHARED_POLICY_PATH environment variable.
 #   shared_policy_path: policy.yml
 #
-#   # The context prefix for status checks created by the bot.
+#   # The context prefix for status checks created by the bot. Can also be set by the
+#   # POLICYBOT_STATUS_CHECK_CONTEXT environment variable.
 #   status_check_context: policy-bot
 
 # Options for locating the frontend files. By default, the server uses appropriate

server/config.go

@@ -65,7 +65,7 @@ func ParseConfig(bytes []byte) (*Config, error) {
 		return nil, errors.Wrapf(err, "failed unmarshalling yaml")
 	}
 
-	c.Options.FillDefaults()
+	c.Options.SetValuesFromEnv("POLICYBOT_OPTIONS_")
 	c.Server.SetValuesFromEnv("POLICYBOT_")
 	c.Github.SetValuesFromEnv("")
 

server/handler/base.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"fmt"
 	"math/rand"
+	"os"
 	"strings"
 	"time"
 
@@ -75,7 +76,7 @@ type PullEvaluationOptions struct {
 	Deprecated_AppName string `yaml:"app_name"`
 }
 
-func (p *PullEvaluationOptions) FillDefaults() {
+func (p *PullEvaluationOptions) fillDefaults() {
 	if p.PolicyPath == "" {
 		p.PolicyPath = DefaultPolicyPath
 	}
@@ -91,6 +92,14 @@ func (p *PullEvaluationOptions) FillDefaults() {
 	}
 }
 
+func (p *PullEvaluationOptions) SetValuesFromEnv(prefix string) {
+	setStringFromEnv("POLICY_PATH", prefix, &p.PolicyPath)
+	setStringFromEnv("SHARED_REPOSITORY", prefix, &p.SharedRepository)
+	setStringFromEnv("SHARED_POLICY_PATH", prefix, &p.SharedPolicyPath)
+	setStringFromEnv("STATUS_CHECK_CONTEXT", prefix, &p.StatusCheckContext)
+	p.fillDefaults()
+}
+
 func (b *Base) PostStatus(ctx context.Context, prctx pull.Context, client *github.Client, state, message string) {
 	logger := zerolog.Ctx(ctx)
 
@@ -381,3 +390,11 @@ func selectionToReviewersRequest(s reviewer.Selection) github.ReviewersRequest {
 
 	return req
 }
+
+func setStringFromEnv(key, prefix string, value *string) bool {
+	if v, ok := os.LookupEnv(prefix + key); ok {
+		*value = v
+		return true
+	}
+	return false
+}