/
template.go
145 lines (122 loc) · 4.06 KB
/
template.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
// Copyright 2023 Greenmask
//
// 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 transformers
import (
"bytes"
"context"
"fmt"
"text/template"
"github.com/greenmaskio/greenmask/internal/db/postgres/transformers/utils"
templateToolkit "github.com/greenmaskio/greenmask/internal/db/postgres/transformers/utils/template"
"github.com/greenmaskio/greenmask/pkg/toolkit"
)
var TemplateTransformerDefinition = utils.NewDefinition(
utils.NewTransformerProperties(
"Template",
"Modify the value using gotemplate",
),
NewTemplateTransformer,
toolkit.MustNewParameter(
"column",
"column name",
).SetIsColumn(toolkit.NewColumnProperties().
SetAffected(true),
).SetRequired(true),
toolkit.MustNewParameter(
"template",
"gotemplate string",
).SetRequired(true),
toolkit.MustNewParameter(
"validate",
"validate template result via PostgreSQL driver decoding",
).SetRequired(false).
SetDefaultValue(toolkit.ParamsValue("false")),
)
type TemplateTransformer struct {
columnName string
template string
validate bool
columnIdx int
affectedColumns map[int]string
tmpl *template.Template
buf *bytes.Buffer
tctx *ColumnContext
}
func NewTemplateTransformer(ctx context.Context, driver *toolkit.Driver, parameters map[string]*toolkit.Parameter) (utils.Transformer, toolkit.ValidationWarnings, error) {
var columnName, templateStr string
p := parameters["column"]
if _, err := p.Scan(&columnName); err != nil {
return nil, nil, fmt.Errorf("unable to scan \"column\" param: %w", err)
}
idx, c, ok := driver.GetColumnByName(columnName)
if !ok {
return nil, nil, fmt.Errorf("column with name %s is not found", columnName)
}
affectedColumns := make(map[int]string)
affectedColumns[idx] = columnName
p = parameters["template"]
if _, err := p.Scan(&templateStr); err != nil {
return nil, nil, fmt.Errorf("unable to scan \"templateStr\" param: %w", err)
}
t := template.New("tmpl").Funcs(templateToolkit.FuncMap())
tmpl, err := t.Parse(templateStr)
if err != nil {
return nil, nil, fmt.Errorf("error parsing template: %w", err)
}
return &TemplateTransformer{
columnName: columnName,
template: templateStr,
columnIdx: idx,
affectedColumns: affectedColumns,
tmpl: tmpl,
buf: bytes.NewBuffer(nil),
tctx: NewColumnContext(c.TypeName, columnName),
}, nil, nil
}
func (sut *TemplateTransformer) GetAffectedColumns() map[int]string {
return sut.affectedColumns
}
func (sut *TemplateTransformer) Init(ctx context.Context) error {
return nil
}
func (sut *TemplateTransformer) Done(ctx context.Context) error {
return nil
}
func (sut *TemplateTransformer) Transform(ctx context.Context, r *toolkit.Record) (*toolkit.Record, error) {
sut.tctx.setRecord(r)
if err := sut.tmpl.Execute(sut.buf, sut.tctx); err != nil {
return nil, fmt.Errorf("error executing template: %w", err)
}
data := sut.buf.Bytes()
var res *toolkit.RawValue
if len(data) == 2 && data[0] == '\\' && data[1] == 'N' {
res = toolkit.NewRawValue(nil, true)
} else {
if sut.validate {
if _, err := r.Driver.DecodeValueByColumnIdx(sut.columnIdx, res.Data); err != nil {
return nil, fmt.Errorf("error validating template output via driver: %w", err)
}
}
res = toolkit.NewRawValue(data, false)
}
if err := r.SetRawColumnValueByIdx(sut.columnIdx, res); err != nil {
return nil, fmt.Errorf("error setting raw value: %w", err)
}
sut.buf.Reset()
sut.tctx.clean()
return r, nil
}
func init() {
utils.DefaultTransformerRegistry.MustRegister(TemplateTransformerDefinition)
}