Add reminder service with empty sendReminders logic

Signed-off-by: Vyom-Yadav <jackhammervyom@gmail.com>

.mk/build.mk

@@ -35,3 +35,8 @@ build-minder-cli: ## build minder cli
 build-minder-server: ## build minder-server
 	@echo "Building $(projectname)-server..."
 	@CGO_ENABLED=0 go build -trimpath -tags '$(BUILDTAGS)' -o ./bin/$(projectname)-server ./cmd/server
+
+.PHONY: build-reminder-cli
+build-reminder-cli: ## build reminder cli
+	@echo "Building reminder..."
+	@CGO_ENABLED=0 go build -trimpath -tags '$(BUILDTAGS)' -o ./bin/reminder ./cmd/reminder

cmd/reminder/app/root.go

@@ -0,0 +1,129 @@
+//
+// Copyright 2024 Stacklok, Inc.
+//
+// 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 app provides the cli subcommands for managing the reminder service
+package app
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+
+	"github.com/stacklok/minder/internal/config"
+	reminderconfig "github.com/stacklok/minder/internal/config/reminder"
+	"github.com/stacklok/minder/internal/util/cli"
+)
+
+var (
+	// RootCmd represents the base command when called without any subcommands
+	RootCmd = &cobra.Command{
+		Use:   "reminder",
+		Short: "reminder controls the reminder service",
+		Long:  `reminder sends entity reconciliation requests to the minder server`,
+	}
+)
+
+const configFileName = "reminder-config.yaml"
+
+// Execute adds all child commands to the root command and sets flags appropriately.
+func Execute() {
+	RootCmd.SetOut(os.Stdout)
+	RootCmd.SetErr(os.Stderr)
+	err := RootCmd.ExecuteContext(context.Background())
+	cli.ExitNicelyOnError(err, "Error executing root command")
+}
+
+func init() {
+	cobra.OnInitialize(initConfig)
+	reminderconfig.SetViperDefaults(viper.GetViper())
+
+	if err := reminderconfig.RegisterReminderFlags(viper.GetViper(), RootCmd.PersistentFlags()); err != nil {
+		RootCmd.PrintErrln("Error registering reminder flags")
+		os.Exit(1)
+	}
+
+	RootCmd.PersistentFlags().String("config", "", fmt.Sprintf("config file (default is $PWD/%s)", configFileName))
+	if err := viper.BindPFlag("config", RootCmd.PersistentFlags().Lookup("config")); err != nil {
+		RootCmd.Printf("error: %s", err)
+		os.Exit(1)
+	}
+}
+
+func initConfig() {
+	cfgFile := viper.GetString("config")
+	cfgFileData, err := config.GetConfigFileData(cfgFile, filepath.Join(".", configFileName))
+	if err != nil {
+		RootCmd.PrintErrln(err)
+		os.Exit(1)
+	}
+
+	keysWithNullValue := config.GetKeysWithNullValueFromYAML(cfgFileData, "")
+	if len(keysWithNullValue) > 0 {
+		RootCmd.PrintErrln("Error: The following configuration keys are missing values:")
+		for _, key := range keysWithNullValue {
+			RootCmd.PrintErrln("Null Value at: " + key)
+		}
+		os.Exit(1)
+	}
+
+	err = reminderconfig.ValidateConfig(cfgFileData)
+	if err != nil {
+		processValidationError(err)
+	}
+
+	if cfgFile != "" {
+		viper.SetConfigFile(cfgFile)
+	} else {
+		// use defaults
+		viper.SetConfigName(strings.TrimSuffix(configFileName, filepath.Ext(configFileName)))
+		viper.AddConfigPath(".")
+	}
+	viper.SetConfigType("yaml")
+	viper.AutomaticEnv()
+
+	if err = viper.ReadInConfig(); err != nil {
+		fmt.Println("Error reading config file:", err)
+	}
+}
+
+func processValidationError(err error) {
+	var batchSizeErr *reminderconfig.InvalidBatchSizeError
+	if errors.As(err, &batchSizeErr) {
+		batchSizeFlag := RootCmd.PersistentFlags().Lookup("batch-size")
+		var batchSizeVal int
+		if batchSizeFlag.Changed {
+			batchSizeVal, _ = strconv.Atoi(batchSizeFlag.Value.String())
+		} else {
+			batchSizeVal, _ = strconv.Atoi(os.Getenv("REMINDER_RECURRENCE_BATCH_SIZE"))
+		}
+
+		minAllowedBatchSize := batchSizeErr.MaxPerProject * batchSizeErr.MinProjectFetchLimit
+		if batchSizeVal < minAllowedBatchSize {
+			RootCmd.Println("⚠ WARNING: " + batchSizeErr.Error())
+			RootCmd.Printf("Setting batch size to minimum allowed value: %d\n", minAllowedBatchSize)
+			viper.Set("recurrence.batch_size", minAllowedBatchSize)
+		}
+	} else {
+		RootCmd.PrintErrln(err)
+		os.Exit(1)
+	}
+}

cmd/reminder/app/start.go

@@ -0,0 +1,85 @@
+//
+// Copyright 2024 Stacklok, Inc.
+//
+// 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 app
+
+import (
+	"database/sql"
+	"fmt"
+	"os"
+	"os/signal"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+	"golang.org/x/sync/errgroup"
+
+	"github.com/stacklok/minder/internal/config"
+	reminderconfig "github.com/stacklok/minder/internal/config/reminder"
+	"github.com/stacklok/minder/internal/db"
+	"github.com/stacklok/minder/internal/reminder"
+	"github.com/stacklok/minder/internal/util"
+)
+
+var startCmd = &cobra.Command{
+	Use:   "start",
+	Short: "Start the reminder process",
+	Long:  `Start the reminder process to send reminders to the minder server to process entities in background.`,
+	RunE:  start,
+}
+
+func start(cmd *cobra.Command, _ []string) error {
+	ctx, cancel := signal.NotifyContext(cmd.Context(), os.Interrupt)
+	defer cancel()
+
+	cfg, err := config.ReadConfigFromViper[reminderconfig.Config](viper.GetViper())
+	if err != nil {
+		return fmt.Errorf("unable to read config: %w", err)
+	}
+
+	level := util.ViperLogLevelToZerologLevel(cfg.LoggingLevel)
+	ctx = zerolog.New(os.Stdout).Level(level).With().Timestamp().Logger().WithContext(ctx)
+
+	dbConn, _, err := cfg.Database.GetDBConnection(ctx)
+	if err != nil {
+		return fmt.Errorf("unable to connect to database: %w", err)
+	}
+	defer func(dbConn *sql.DB) {
+		err := dbConn.Close()
+		if err != nil {
+			log.Printf("error closing database connection: %v", err)
+		}
+	}(dbConn)
+
+	store := db.NewStore(dbConn)
+	reminderService, err := reminder.NewReminder(ctx, store, cfg)
+	if err != nil {
+		return fmt.Errorf("unable to create reminder service: %w", err)
+	}
+	defer reminderService.Stop()
+
+	errg, ctx := errgroup.WithContext(ctx)
+
+	errg.Go(func() error {
+		return reminderService.Start(ctx)
+	})
+
+	return errg.Wait()
+}
+
+func init() {
+	RootCmd.AddCommand(startCmd)
+}

cmd/reminder/main.go

@@ -0,0 +1,22 @@
+// Copyright 2024 Stacklok, Inc.
+//
+// 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 main provides the entrypoint for the reminder service
+package main
+
+import "github.com/stacklok/minder/cmd/reminder/app"
+
+func main() {
+	app.Execute()
+}

config/reminder-config.yaml.example

@@ -0,0 +1,42 @@
+#
+# Copyright 2024 Stacklok, Inc.
+#
+# 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.
+
+recurrence:
+  interval: "1h"
+  batch_size: 100
+  max_per_project: 10
+  min_project_fetch_limit: 10
+  min_elapsed: "1h"
+
+database:
+  dbhost: "postgres"
+  dbport: 5432
+  dbuser: postgres
+  dbpass: postgres
+  dbname: minder
+  sslmode: disable
+
+cursor_file: "/tmp/reminder-cursor"
+
+logging_level: "debug"
+
+events:
+  sql_connection:
+    dbhost: "reminder-event-postgres"
+    dbport: 5432
+    dbuser: postgres
+    dbpass: postgres
+    dbname: reminder
+    sslmode: disable

docker/reminder/Dockerfile

@@ -0,0 +1,52 @@
+#
+# Copyright 2024 Stacklok, Inc.
+#
+# 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.
+
+FROM golang:1.22.1@sha256:34ce21a9696a017249614876638ea37ceca13cdd88f582caad06f87a8aa45bf3 AS builder
+ENV APP_ROOT=/opt/app-root
+ENV GOPATH=$APP_ROOT
+
+WORKDIR $APP_ROOT/src/
+ADD go.mod go.sum $APP_ROOT/src/
+RUN go mod download
+
+# Add source code
+ADD ./ $APP_ROOT/src/
+
+RUN CGO_ENABLED=0 go build -trimpath -o reminder ./cmd/reminder
+
+# Create a "nobody" non-root user for the next image by crafting an /etc/passwd
+# file that the next image can copy in. This is necessary since the next image
+# is based on scratch, which doesn't have adduser, cat, echo, or even sh.
+RUN echo "nobody:x:65534:65534:Nobody:/:" > /etc_passwd
+
+RUN mkdir -p /app
+
+FROM scratch
+
+COPY --chown=65534:65534 --from=builder /app /app
+
+WORKDIR /app
+
+COPY --from=builder /opt/app-root/src/reminder /usr/bin/reminder
+
+# Copy the /etc_passwd file we created in the builder stage into /etc/passwd in
+# the target stage. This creates a new non-root user as a security best
+# practice.
+COPY --from=builder /etc_passwd /etc/passwd
+
+USER nobody
+
+# Set the binary as the entrypoint of the container
+ENTRYPOINT ["/usr/bin/reminder"]