minio/cmd/notify-postgresql.go
Frank Wessels 46897b1100 Name return values to prevent the need (and unnecessary code bloat) (#4576)
This is done to explicitly instantiate objects for every return statement.
2017-06-21 19:53:09 -07:00

354 lines
9.3 KiB
Go

/*
* Minio Cloud Storage, (C) 2014-2016 Minio, 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.
*/
// PostgreSQL Notifier implementation. Two formats, "namespace" and
// "access" are supported.
//
// * Namespace format
//
// On each create or update object event in Minio Object storage
// server, a row is created or updated in the table in Postgres. On
// each object removal, the corresponding row is deleted from the
// table.
//
// A table with a specific structure (column names, column types, and
// primary key/uniqueness constraint) is used. The user may set the
// table name in the configuration. A sample SQL command that creates
// a table with the required structure is:
//
// CREATE TABLE myminio (
// key VARCHAR PRIMARY KEY,
// value JSONB
// );
//
// PostgreSQL's "INSERT ... ON CONFLICT ... DO UPDATE ..." feature
// (UPSERT) is used here, so the minimum version of PostgreSQL
// required is 9.5.
//
// * Access format
//
// On each event, a row is appended to the configured table. There is
// no deletion or modification of existing rows.
//
// A different table schema is used for this format. A sample SQL
// commant that creates a table with the required structure is:
//
// CREATE TABLE myminio (
// event_time TIMESTAMP WITH TIME ZONE NOT NULL,
// event_data JSONB
// );
package cmd
import (
"database/sql"
"encoding/json"
"fmt"
"io/ioutil"
"strings"
"time"
"github.com/Sirupsen/logrus"
// Register postgres driver
_ "github.com/lib/pq"
)
const (
// Queries for format=namespace mode. Here the `key` column is
// the bucket and object of the event. When objects are
// deleted, the corresponding row is deleted in the
// table. When objects are created or over-written, rows are
// inserted or updated respectively in the table.
upsertRowForNS = `INSERT INTO %s (key, value)
VALUES ($1, $2)
ON CONFLICT (key)
DO UPDATE SET value = EXCLUDED.value;`
deleteRowForNS = ` DELETE FROM %s
WHERE key = $1;`
createTableForNS = `CREATE TABLE %s (
key VARCHAR PRIMARY KEY,
value JSONB
);`
// Queries for format=access mode. Here the `event_time`
// column of the table, stores the time at which the event
// occurred in the Minio server.
insertRowForAccess = `INSERT INTO %s (event_time, event_data)
VALUES ($1, $2);`
createTableForAccess = `CREATE TABLE %s (
event_time TIMESTAMP WITH TIME ZONE NOT NULL,
event_data JSONB
);`
// Query to check if a table already exists.
tableExists = `SELECT 1 FROM %s;`
)
var (
pgErrFunc = newNotificationErrorFactory("PostgreSQL")
errPGFormatError = pgErrFunc(`"format" value is invalid - it must be one of "%s" or "%s".`, formatNamespace, formatAccess)
errPGTableError = pgErrFunc("Table was not specified in the configuration.")
)
type postgreSQLNotify struct {
Enable bool `json:"enable"`
Format string `json:"format"`
// Pass connection string in config directly. This string is
// formatted according to
// https://godoc.org/github.com/lib/pq#hdr-Connection_String_Parameters
ConnectionString string `json:"connectionString"`
// specifying a table name is required.
Table string `json:"table"`
// The values below, if non-empty are appended to
// ConnectionString above. Default values are shown in
// comments below (implicitly used by the library).
Host string `json:"host"` // default: localhost
Port string `json:"port"` // default: 5432
User string `json:"user"` // default: user running minio
Password string `json:"password"` // default: no password
Database string `json:"database"` // default: same as user
}
func (p *postgreSQLNotify) Validate() error {
if !p.Enable {
return nil
}
if p.Format != formatNamespace && p.Format != formatAccess {
return errPGFormatError
}
if p.ConnectionString == "" {
if _, err := checkURL(p.Host); err != nil {
return err
}
}
if p.Table == "" {
return errPGTableError
}
return nil
}
type pgConn struct {
connStr string
table string
format string
preparedStmts map[string]*sql.Stmt
*sql.DB
}
func dialPostgreSQL(pgN postgreSQLNotify) (pc pgConn, e error) {
if !pgN.Enable {
return pc, errNotifyNotEnabled
}
// collect connection params
params := []string{pgN.ConnectionString}
if pgN.Host != "" {
params = append(params, "host="+pgN.Host)
}
if pgN.Port != "" {
params = append(params, "port="+pgN.Port)
}
if pgN.User != "" {
params = append(params, "user="+pgN.User)
}
if pgN.Password != "" {
params = append(params, "password="+pgN.Password)
}
if pgN.Database != "" {
params = append(params, "dbname="+pgN.Database)
}
connStr := strings.Join(params, " ")
db, err := sql.Open("postgres", connStr)
if err != nil {
return pc, pgErrFunc(
"Connection opening failure (connectionString=%s): %v",
connStr, err)
}
// ping to check that server is actually reachable.
err = db.Ping()
if err != nil {
return pc, pgErrFunc("Ping to server failed with: %v",
err)
}
// check that table exists - if not, create it.
_, err = db.Exec(fmt.Sprintf(tableExists, pgN.Table))
if err != nil {
createStmt := createTableForNS
if pgN.Format == formatAccess {
createStmt = createTableForAccess
}
// most likely, table does not exist. try to create it:
_, errCreate := db.Exec(fmt.Sprintf(createStmt, pgN.Table))
if errCreate != nil {
// failed to create the table. error out.
return pc, pgErrFunc(
"'Select' failed with %v, then 'Create Table' failed with %v",
err, errCreate,
)
}
}
// create prepared statements
stmts := make(map[string]*sql.Stmt)
switch pgN.Format {
case formatNamespace:
// insert or update statement
stmts["upsertRow"], err = db.Prepare(fmt.Sprintf(upsertRowForNS,
pgN.Table))
if err != nil {
return pc, pgErrFunc(
"create UPSERT prepared statement failed with: %v", err)
}
// delete statement
stmts["deleteRow"], err = db.Prepare(fmt.Sprintf(deleteRowForNS,
pgN.Table))
if err != nil {
return pc, pgErrFunc(
"create DELETE prepared statement failed with: %v", err)
}
case formatAccess:
// insert statement
stmts["insertRow"], err = db.Prepare(fmt.Sprintf(insertRowForAccess,
pgN.Table))
if err != nil {
return pc, pgErrFunc(
"create INSERT prepared statement failed with: %v", err)
}
}
return pgConn{connStr, pgN.Table, pgN.Format, stmts, db}, nil
}
func newPostgreSQLNotify(accountID string) (*logrus.Logger, error) {
pgNotify := serverConfig.Notify.GetPostgreSQLByID(accountID)
// Dial postgres
pgC, err := dialPostgreSQL(pgNotify)
if err != nil {
return nil, err
}
pgLog := logrus.New()
pgLog.Out = ioutil.Discard
pgLog.Formatter = new(logrus.JSONFormatter)
pgLog.Hooks.Add(pgC)
return pgLog, nil
}
func (pgC pgConn) Close() {
// first close all prepared statements
for _, v := range pgC.preparedStmts {
_ = v.Close()
}
// close db connection
_ = pgC.DB.Close()
}
func jsonEncodeEventData(d interface{}) ([]byte, error) {
// json encode the value for the row
value, err := json.Marshal(map[string]interface{}{
"Records": d,
})
if err != nil {
return nil, pgErrFunc(
"Unable to encode event %v to JSON: %v", d, err)
}
return value, nil
}
func (pgC pgConn) Fire(entry *logrus.Entry) error {
// get event type by trying to convert to string
entryEventType, ok := entry.Data["EventType"].(string)
if !ok {
// ignore event if converting EventType to string
// fails.
return nil
}
switch pgC.format {
case formatNamespace:
// Check for event delete
if eventMatch(entryEventType, []string{"s3:ObjectRemoved:*"}) {
// delete row from the table
_, err := pgC.preparedStmts["deleteRow"].Exec(entry.Data["Key"])
if err != nil {
return pgErrFunc(
"Error deleting event with key=%v: %v",
entry.Data["Key"], err,
)
}
} else {
value, err := jsonEncodeEventData(entry.Data["Records"])
if err != nil {
return err
}
// upsert row into the table
_, err = pgC.preparedStmts["upsertRow"].Exec(entry.Data["Key"], value)
if err != nil {
return pgErrFunc(
"Unable to upsert event with key=%v and value=%v: %v",
entry.Data["Key"], entry.Data["Records"], err,
)
}
}
case formatAccess:
// eventTime is taken from the first entry in the
// records.
events, ok := entry.Data["Records"].([]NotificationEvent)
if !ok {
return pgErrFunc("unable to extract event time due to conversion error of entry.Data[\"Records\"]=%v", entry.Data["Records"])
}
eventTime, err := time.Parse(timeFormatAMZ, events[0].EventTime)
if err != nil {
return pgErrFunc("unable to parse event time \"%s\": %v",
events[0].EventTime, err)
}
value, err := jsonEncodeEventData(entry.Data["Records"])
if err != nil {
return err
}
_, err = pgC.preparedStmts["insertRow"].Exec(eventTime, value)
if err != nil {
return pgErrFunc("Unable to insert event with value=%v: %v",
value, err)
}
}
return nil
}
func (pgC pgConn) Levels() []logrus.Level {
return []logrus.Level{
logrus.InfoLevel,
}
}