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// Copyright 2019-2025 The Wait4X Authors
//
// 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 postgresql provides the PostgreSQL checker for the Wait4X application.
package postgresql
import (
"context"
"database/sql"
"fmt"
"net/url"
"regexp"
"wait4x.dev/v3/checker"
// Needed for the PostgreSQL driver
_ "github.com/lib/pq"
)
var hidePasswordRegexp = regexp.MustCompile(`^(postgres://[^/:]+):[^:@]+@`)
const (
expectTableQuery = "SELECT EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = '%s')"
)
// Option is a function that configures the PostgreSQL checker
type Option func(p *PostgreSQL)
// PostgreSQL is a PostgreSQL checker
type PostgreSQL struct {
dsn string
expectTable string
}
// New creates a new PostgreSQL checker
func New(dsn string, opts ...Option) checker.Checker {
p := &PostgreSQL{
dsn: dsn,
}
// apply the list of options to PostgreSQL
for _, opt := range opts {
opt(p)
}
return p
}
// WithExpectTable configures the table existence check
func WithExpectTable(table string) Option {
return func(p *PostgreSQL) {
p.expectTable = table
}
}
// Identity returns the identity of the PostgreSQL checker
func (p *PostgreSQL) Identity() (string, error) {
u, err := url.Parse(p.dsn)
if err != nil {
return "", fmt.Errorf("can't retrieve the checker identity: %w", err)
}
return u.Host, nil
}
// Check checks the PostgreSQL connection
func (p *PostgreSQL) Check(ctx context.Context) (err error) {
db, err := sql.Open("postgres", p.dsn)
if err != nil {
return err
}
defer func(db *sql.DB) {
if dberr := db.Close(); dberr != nil {
err = dberr
}
}(db)
err = db.PingContext(ctx)
if err != nil {
if checker.IsConnectionRefused(err) {
return checker.NewExpectedError(
"failed to establish a connection to the postgresql server", err,
"dsn", hidePasswordRegexp.ReplaceAllString(p.dsn, `$1:***@`),
)
}
return err
}
// check if the table exists if option has been set
if p.expectTable != "" {
query := fmt.Sprintf(expectTableQuery, p.expectTable)
var exists bool
err = db.QueryRowContext(ctx, query).Scan(&exists)
if err != nil {
return err
}
if !exists {
return checker.NewExpectedError(
"table does not exist", nil,
"table", p.expectTable,
)
}
}
return nil
}
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