Add loading configuration from file.

config/Makefile

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+# Copyright 2013 Prometheus Team
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+all: generated/config.pb.go
+
+generated/config.pb.go: config.proto
+	protoc --go_out=generated/ config.proto

config/config.go

@@ -0,0 +1,69 @@
+// Copyright 2013 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"fmt"
+	"time"
+
+	"code.google.com/p/goprotobuf/proto"
+
+	pb "github.com/prometheus/alert_manager/config/generated"
+
+	"github.com/prometheus/alert_manager/manager"
+)
+
+// Config encapsulates the configuration of an Alert Manager instance. It wraps
+// the raw configuration protocol buffer to be able to add custom methods to
+// it.
+type Config struct {
+	// The protobuf containing the actual configuration values.
+	pb.AlertManagerConfig
+}
+
+// String returns an ASCII serialization of the loaded configuration protobuf.
+func (c Config) String() string {
+	return proto.MarshalTextString(&c.AlertManagerConfig)
+}
+
+// Validate checks an entire parsed Config for the validity of its fields.
+func (c Config) Validate() error {
+	for _, a := range c.AggregationRule {
+		for _, f := range a.Filter {
+			if f.NameRe == nil {
+				return fmt.Errorf("Missing name pattern (name_re) in filter definition: %s", proto.MarshalTextString(f))
+			}
+			if f.ValueRe == nil {
+				return fmt.Errorf("Missing value pattern (value_re) in filter definition: %s", proto.MarshalTextString(f))
+			}
+		}
+	}
+	return nil
+}
+
+// Rules returns all the AggregationRules in a Config object.
+func (c Config) AggregationRules() manager.AggregationRules {
+	rules := make(manager.AggregationRules, 0, len(c.AggregationRule))
+	for _, r := range c.AggregationRule {
+		filters := make(manager.Filters, 0, len(r.Filter))
+		for _, filter := range r.Filter {
+			filters = append(filters, manager.NewFilter(filter.GetNameRe(), filter.GetValueRe()))
+		}
+		rules = append(rules, &manager.AggregationRule{
+			Filters:    filters,
+			RepeatRate: time.Duration(r.GetRepeatRateSeconds()) * time.Second,
+		})
+	}
+	return rules
+}

config/config.proto

@@ -0,0 +1,31 @@
+// Copyright 2013 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package io.prometheus.alert_manager;
+
+// A regex-based label filter used in aggregations.
+message Filter {
+  // The regex matching the label name.
+  optional string name_re = 1;
+  // The regex matching the label value.
+  optional string value_re = 2;
+}
+
+message AggregationRule {
+  repeated Filter filter = 1;
+  optional int32 repeat_rate_seconds = 2 [default = 7200];
+}
+
+message AlertManagerConfig {
+  repeated AggregationRule aggregation_rule = 1;
+}

config/config_test.go

@@ -0,0 +1,64 @@
+// Copyright 2013 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"path"
+	"strings"
+	"testing"
+)
+
+var fixturesPath = "fixtures"
+
+type configTest struct {
+	inputFile   string
+	shouldFail  bool
+	errContains string
+}
+
+func (ct *configTest) test(i int, t *testing.T) {
+	_, err := LoadFromFile(path.Join(fixturesPath, ct.inputFile))
+
+	if err != nil {
+		if !ct.shouldFail {
+			t.Fatalf("%d. Error parsing config %v: %v", i, ct.inputFile, err)
+		} else {
+			if !strings.Contains(err.Error(), ct.errContains) {
+				t.Fatalf("%d. Expected error containing '%v', got: %v", i, ct.errContains, err)
+			}
+		}
+	}
+}
+
+func TestConfigs(t *testing.T) {
+	var configTests = []configTest{
+		{
+			inputFile: "empty.conf.input",
+		}, {
+			inputFile: "sample.conf.input",
+		}, {
+			inputFile:   "missing_name_re.conf.input",
+			shouldFail:  true,
+			errContains: "Missing name pattern",
+		}, {
+			inputFile:   "invalid_proto_format.conf.input",
+			shouldFail:  true,
+			errContains: "unknown field name",
+		},
+	}
+
+	for i, ct := range configTests {
+		ct.test(i, t)
+	}
+}

config/fixtures/invalid_proto_format.conf.input

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+aggregation_rule {
+  filter {
+    label_re: "service" // Unknown protobuf field name.
+    value_re: "discovery"
+  }
+  filter {
+    name_re: "zone"
+    value_re: "aa"
+  }
+  repeat_rate: 3600
+}
+
+aggregation_rule {
+  filter {
+    name_re: "service"
+    value_re: "test"
+  }
+}

config/fixtures/sample.conf.input

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+aggregation_rule {
+  filter {
+    name_re: "service"
+    value_re: "discovery"
+  }
+  filter {
+    name_re: "zone"
+    value_re: "aa"
+  }
+  repeat_rate_seconds: 3600
+}
+
+aggregation_rule {
+  filter {
+    name_re: "service"
+    value_re: "test"
+  }
+}

config/load.go

@@ -0,0 +1,43 @@
+// Copyright 2013 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"io/ioutil"
+
+	"code.google.com/p/goprotobuf/proto"
+
+	pb "github.com/prometheus/alert_manager/config/generated"
+)
+
+func LoadFromString(configStr string) (Config, error) {
+	configProto := pb.AlertManagerConfig{}
+	if err := proto.UnmarshalText(configStr, &configProto); err != nil {
+		return Config{}, err
+	}
+
+	config := Config{AlertManagerConfig: configProto}
+	err := config.Validate()
+
+	return config, err
+}
+
+func LoadFromFile(fileName string) (Config, error) {
+	configStr, err := ioutil.ReadFile(fileName)
+	if err != nil {
+		return Config{}, err
+	}
+
+	return LoadFromString(string(configStr))
+}

config/load_test.go

@@ -0,0 +1,25 @@
+// Copyright 2013 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"testing"
+)
+
+func TestLoadFromFile(t *testing.T) {
+	_, err := LoadFromFile("file-does-not-exist.conf")
+	if err == nil {
+		t.Error(err)
+	}
+}