cron, db, cache and migrations

.gitignore

@@ -0,0 +1 @@
+tmp/

.idea/dataSources.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DataSourceManagerImpl" format="xml" multifile-model="true">
+    <data-source source="LOCAL" name="serverctl@localhost" uuid="372f3f01-6672-42bd-a724-099a867af00b">
+      <driver-ref>postgresql</driver-ref>
+      <synchronize>true</synchronize>
+      <jdbc-driver>org.postgresql.Driver</jdbc-driver>
+      <jdbc-url>jdbc:postgresql://localhost:5432/serverctl</jdbc-url>
+      <working-dir>$ProjectFileDir$</working-dir>
+    </data-source>
+  </component>
+</project>

docker-compose.yml

@@ -0,0 +1,18 @@
+version: "3"
+
+services:
+  db:
+    image: postgres
+    restart: always
+    volumes:
+      - db_data:/var/lib/postgresql/data/pgdata
+    ports:
+      - 5432:5432
+    environment:
+      PGDATA: /var/lib/postgresql/data/pgdata
+      POSTGRES_USER: serverctl
+      POSTGRES_PASSWORD: serverctlsecret
+      POSTGRES_DB: serverctl 
+
+volumes:
+  db_data: {}

go.mod

@@ -1,3 +1,77 @@
 module serverctl
 
 go 1.17
+
+require (
+	github.com/Microsoft/go-winio v0.4.17 // indirect
+	github.com/XiaoMi/pegasus-go-client v0.0.0-20210427083443-f3b6b08bc4c2 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/bradfitz/gomemcache v0.0.0-20190913173617-a41fca850d0b // indirect
+	github.com/cenkalti/backoff/v4 v4.1.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.1 // indirect
+	github.com/containerd/containerd v1.5.9 // indirect
+	github.com/dgraph-io/ristretto v0.1.0 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+	github.com/docker/distribution v2.8.0+incompatible // indirect
+	github.com/docker/docker v20.10.12+incompatible // indirect
+	github.com/docker/go-connections v0.4.0 // indirect
+	github.com/docker/go-units v0.4.0 // indirect
+	github.com/dustin/go-humanize v1.0.0 // indirect
+	github.com/eko/gocache v1.2.0 // indirect
+	github.com/gin-contrib/sse v0.1.0 // indirect
+	github.com/gin-gonic/gin v1.7.7 // indirect
+	github.com/go-co-op/gocron v1.12.0 // indirect
+	github.com/go-playground/locales v0.13.0 // indirect
+	github.com/go-playground/universal-translator v0.17.0 // indirect
+	github.com/go-playground/validator/v10 v10.4.1 // indirect
+	github.com/go-redis/redis/v8 v8.8.2 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b // indirect
+	github.com/golang/protobuf v1.5.0 // indirect
+	github.com/jackc/chunkreader/v2 v2.0.1 // indirect
+	github.com/jackc/pgconn v1.11.0 // indirect
+	github.com/jackc/pgio v1.0.0 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgproto3/v2 v2.2.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20200714003250-2b9c44734f2b // indirect
+	github.com/jackc/pgtype v1.10.0 // indirect
+	github.com/jackc/pgx v3.6.2+incompatible // indirect
+	github.com/jackc/pgx/v4 v4.15.0 // indirect
+	github.com/jackc/puddle v1.2.1 // indirect
+	github.com/json-iterator/go v1.1.10 // indirect
+	github.com/leodido/go-urn v1.2.0 // indirect
+	github.com/mattn/go-isatty v0.0.12 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.1 // indirect
+	github.com/opencontainers/go-digest v1.0.0 // indirect
+	github.com/opencontainers/image-spec v1.0.2 // indirect
+	github.com/pegasus-kv/thrift v0.13.0 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/prometheus/client_golang v1.10.0 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.18.0 // indirect
+	github.com/prometheus/procfs v0.6.0 // indirect
+	github.com/robfig/cron/v3 v3.0.1 // indirect
+	github.com/sirupsen/logrus v1.8.1 // indirect
+	github.com/spf13/cast v1.3.1 // indirect
+	github.com/ugorji/go/codec v1.1.7 // indirect
+	go.opentelemetry.io/otel v0.19.0 // indirect
+	go.opentelemetry.io/otel/metric v0.19.0 // indirect
+	go.opentelemetry.io/otel/trace v0.19.0 // indirect
+	go.uber.org/atomic v1.7.0 // indirect
+	go.uber.org/multierr v1.6.0 // indirect
+	go.uber.org/zap v1.21.0 // indirect
+	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 // indirect
+	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 // indirect
+	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
+	golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 // indirect
+	golang.org/x/text v0.3.6 // indirect
+	google.golang.org/genproto v0.0.0-20201110150050-8816d57aaa9a // indirect
+	google.golang.org/grpc v1.44.0 // indirect
+	google.golang.org/protobuf v1.27.1 // indirect
+	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect
+	gopkg.in/tomb.v2 v2.0.0-20161208151619-d5d1b5820637 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+	k8s.io/apimachinery v0.20.6 // indirect
+)

main.go

@@ -1,5 +1,161 @@
 package main
 
-func main() {
-	println("hello world")
+import (
+	"context"
+	"errors"
+	"github.com/dgraph-io/ristretto"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/client"
+	"github.com/eko/gocache/cache"
+	"github.com/eko/gocache/store"
+	"github.com/gin-gonic/gin"
+	"github.com/go-co-op/gocron"
+	"github.com/jackc/pgx/v4/pgxpool"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"time"
+)
+
+func setupLogger() *zap.Logger {
+	highPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
+		return lvl >= zapcore.ErrorLevel
+	})
+	lowPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
+		return lvl < zapcore.ErrorLevel
+	})
+	fileDebugging := zapcore.AddSync(ioutil.Discard)
+	fileErrors := zapcore.AddSync(ioutil.Discard)
+
+	consoleDebugging := zapcore.Lock(os.Stdout)
+	consoleErrors := zapcore.Lock(os.Stderr)
+
+	fileEncoder := zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig())
+	consoleEncoder := zapcore.NewConsoleEncoder(zap.NewDevelopmentEncoderConfig())
+
+	core := zapcore.NewTee(
+		zapcore.NewCore(fileEncoder, fileErrors, highPriority),
+		zapcore.NewCore(consoleEncoder, consoleErrors, highPriority),
+		zapcore.NewCore(fileEncoder, fileDebugging, lowPriority),
+		zapcore.NewCore(consoleEncoder, consoleDebugging, lowPriority),
+	)
+
+	logger := zap.New(core)
+	defer logger.Sync()
+	return logger
+}
+func setupApi(l *zap.Logger, cc *cache.Cache) {
+	l.Info("Setting up serverctl setupApi (using gin)")
+
+	r := gin.Default()
+
+	r.GET("/containers", func(c *gin.Context) {
+		type container struct {
+			Name string `json:"name"`
+		}
+		var msg struct {
+			Containers []container `json:"containers"`
+		}
+
+		get, err := cc.Get("docker-containers")
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"message": "could not get containers from container runtime"})
+			return
+		}
+
+		msg.Containers = []container{}
+		for _, cont := range get.([]types.Container) {
+			msg.Containers = append(msg.Containers, container{
+				Name: cont.Names[0],
+			})
+		}
+
+		c.JSON(http.StatusOK, msg)
+	})
+
+	r.Run(":8080")
+
+}
+func setupDocker(l *zap.Logger) *client.Client {
+	l.Info("Setting up Docker")
+	cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
+	if err != nil {
+		panic(err)
+	}
+
+	return cli
+}
+func setupCache(l *zap.Logger) *cache.Cache {
+	l.Info("Setting up cache")
+	ristrettoCache, err := ristretto.NewCache(&ristretto.Config{
+		NumCounters: 1000,
+		MaxCost:     100,
+		BufferItems: 64,
+	})
+	if err != nil {
+		panic(err)
+	}
+	ristrettoStore := store.NewRistretto(ristrettoCache, nil)
+	cacheManager := cache.New(ristrettoStore)
+
+	return cacheManager
+}
+func setupCron(l *zap.Logger, cm *cache.Cache, cc *client.Client) {
+	l.Info("Setting up job scheduler (cron)")
+
+	s := gocron.NewScheduler(time.UTC)
+
+	s.Every(10).Second().Do(func() {
+		l.Debug("getting container list")
+		list, err := cc.ContainerList(context.Background(), types.ContainerListOptions{})
+		if err != nil {
+			l.Warn(err.Error())
+			return
+		}
+
+		err = cm.Set("docker-containers", list, &store.Options{
+			Cost: 2,
+		})
+		if err != nil {
+			l.Warn(err.Error())
+			return
+		}
+	})
+
+	s.StartAsync()
+}
+func setupDatabase(l *zap.Logger) *pgxpool.Pool {
+	l.Info("Setting up database connection")
+	dbUrl := os.Getenv("DATABASE_URL")
+	if dbUrl == "" {
+		panic(errors.New("DATABASE_URL is not set"))
+	}
+	dbpool, err := pgxpool.Connect(context.Background(), dbUrl)
+	if err != nil {
+		panic(err)
+	}
+
+	var greeting string
+	err = dbpool.QueryRow(context.Background(), "select 'Hello, world!'").Scan(&greeting)
+	if err != nil {
+		panic(err)
+	}
+
+	l.Info("Database successfully connected")
+
+	return dbpool
+}
+
+func main() {
+	logger := setupLogger()
+	logger.Info("Starting serverctl")
+
+	cacheM := setupCache(logger)
+	containerClient := setupDocker(logger)
+	setupCron(logger, cacheM, containerClient)
+	dbpool := setupDatabase(logger)
+
+	setupApi(logger, cacheM)
 }

migrations/001_create_users.sql

@@ -0,0 +1,9 @@
+create table users(
+  id serial primary key,
+  email varchar(320) not null,
+  password_hash varchar(256) not null
+);
+
+---- create above / drop below ----
+
+drop table users;

migrations/tern.conf

@@ -0,0 +1,34 @@
+[database]
+# host is required (network host or path to Unix domain socket)
+host = localhost
+port = 5432
+# database is required
+database = serverctl
+# user defaults to OS user
+user = serverctl
+password = serverctlsecret
+version_table = public.schema_version
+#
+# sslmode generally matches the behavior described in:
+# http://www.postgresql.org/docs/9.4/static/libpq-ssl.html#LIBPQ-SSL-PROTECTION
+#
+# There are only two modes that most users should use:
+# prefer - on trusted networks where security is not required
+# verify-full - require SSL connection
+sslmode = prefer
+#
+# sslrootcert is generally used with sslmode=verify-full
+# sslrootcert = /path/to/root/ca
+
+# Proxy the above database connection via SSH
+# [ssh-tunnel]
+# host =
+# port = 22
+# user defaults to OS user
+# user =
+# password is not required if using SSH agent authentication
+# password =
+
+[data]
+# Any fields in the data section are available in migration templates
+# prefix = foo