Add INI config utility to common/util module

modules/common/util/ini.go

@@ -0,0 +1,104 @@
+/*
+Copyright 2025 Red Hat
+
+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 util
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// IniOption -
+type IniOption struct {
+	Section string
+	Key     string
+	Value   string
+	Unique  bool
+}
+
+// Define static errors
+var (
+	ErrKeyAlreadyExists     = errors.New("key already exists in section")
+	ErrCouldNotPatchSection = errors.New("could not patch target section")
+)
+
+// repr - print key: value in .ini format
+func (i *IniOption) repr() string {
+	return fmt.Sprintf("%s = %s", i.Key, i.Value)
+}
+
+// ExtendCustomServiceConfig - customServiceConfig is tokenized and parsed in a
+// loop where we keep track of two indexes:
+//   - index: keep track of the current extracted token
+//   - sectionIndex: when we detect a [<section>] within a token, we save the index
+//     and we update it with the next section when is detected. This way we can
+//     make sure to evaluate only the keys of the target section
+//
+// when an invalid case is detected, we return the customServiceConfig string
+// unchanged, otherwise the new key=value is appended as per the IniOption struct
+func ExtendCustomServiceConfig(
+	iniString string,
+	customServiceConfigExtend IniOption,
+) (string, error) {
+	// customServiceConfig is empty
+	if len(iniString) == 0 {
+		return iniString, nil
+	}
+	// Position where insert new option (-1 = target section not found)
+	index := -1
+	// Current section header position (-1 = no section found)
+	sectionIndex := -1
+	svcConfigLines := strings.Split(iniString, "\n")
+	sectionName := ""
+	for idx, rawLine := range svcConfigLines {
+		line := strings.TrimSpace(rawLine)
+		token := strings.TrimSpace(strings.SplitN(line, "=", 2)[0])
+
+		if token == "" || strings.HasPrefix(token, "#") {
+			// Skip blank lines and comments
+			continue
+		}
+		if strings.HasPrefix(token, "[") && strings.HasSuffix(token, "]") {
+			// Note the section name before looking for a backend_name
+			sectionName = strings.Trim(token, "[]")
+			sectionIndex = idx
+			// increment the index (as an offset) only when a section is found
+			if sectionName == customServiceConfigExtend.Section {
+				index = idx + 1
+			}
+		}
+		// Check if key already exists in target section
+		if customServiceConfigExtend.Unique && token == customServiceConfigExtend.Key && sectionIndex > -1 &&
+			sectionName == customServiceConfigExtend.Section {
+			errMsg := fmt.Errorf("%w: key %s in section %s", ErrKeyAlreadyExists, token, sectionName)
+			return iniString, errMsg
+		}
+	}
+	// index didn't progress during the customServiceConfig scan:
+	// return unchanged, but no error
+	if index == -1 {
+		errMsg := fmt.Errorf("%w: %s", ErrCouldNotPatchSection, customServiceConfigExtend.Section)
+		return iniString, errMsg
+	}
+	// index has a valid value and it is used as a pivot to inject the new ini
+	// option right after the section
+	var svcExtended []string
+	svcExtended = append(svcExtended, svcConfigLines[:index]...)
+	svcExtended = append(svcExtended, []string{customServiceConfigExtend.repr()}...)
+	svcExtended = append(svcExtended, svcConfigLines[index:]...)
+	return strings.Join(svcExtended, "\n"), nil
+}

modules/common/util/ini_test.go

@@ -0,0 +1,221 @@
+package util // nolint:revive
+
+import (
+	"testing"
+
+	. "github.com/onsi/gomega" // nolint:revive
+)
+
+var (
+	defaultTestIniOption = IniOption{
+		Section: "foo",
+		Key:     "s3_store_cacert",
+		Value:   "/etc/pki/tls/certs/ca-bundle.crt",
+		Unique:  true,
+	}
+
+	aliasKeyIniOption = IniOption{
+		Section: "pci",
+		Key:     "alias",
+		Value:   "{ \"device_type\": \"type-VF\", \"resource_class\": \"CUSTOM_A16_16A\", \"name\": \"A16_16A\" }",
+		Unique:  false,
+	}
+
+	deviceSpecIniOption = IniOption{
+		Section: "pci",
+		Key:     "device_spec",
+		Value:   "{ \"vendor_id\": \"10de\", \"product_id\": \"25b6\", \"address\": \"0000:25:00.6\", \"resource_class\": \"CUSTOM_A16_8A\", \"managed\": \"yes\" }",
+		Unique:  false,
+	}
+)
+
+var tests = []struct {
+	name     string
+	input    string
+	option   IniOption
+	expected string
+	err      string
+}{
+	{
+		name:     "empty customServiceConfig",
+		input:    "",
+		option:   defaultTestIniOption,
+		expected: "",
+		err:      "",
+	},
+	{
+		name: "field to non-existing section",
+		input: `[DEFAULT]
+debug=true
+enabled_backends = backend:s3
+[foo]
+bar = bar
+foo = foo
+[backend]
+option1 = value1`,
+		option: IniOption{
+			Section: "bar",
+			Key:     "foo",
+			Value:   "foo",
+		},
+		expected: `[DEFAULT]
+debug=true
+enabled_backends = backend:s3
+[foo]
+bar = bar
+foo = foo
+[backend]
+option1 = value1`,
+		err: "could not patch target section: bar",
+	},
+	{
+		name: "add new ini line to a section in the middle",
+		input: `[DEFAULT]
+debug=true
+enabled_backends = backend:s3
+[foo]
+bar = bar
+foo = foo
+[backend]
+option1 = value1`,
+		option: defaultTestIniOption,
+		expected: `[DEFAULT]
+debug=true
+enabled_backends = backend:s3
+[foo]
+s3_store_cacert = /etc/pki/tls/certs/ca-bundle.crt
+bar = bar
+foo = foo
+[backend]
+option1 = value1`,
+		err: "",
+	},
+	{
+		name: "section is not found, return it unchanged",
+		input: `[DEFAULT]
+debug=true
+enabled_backends = backend:s3
+[backend]
+s3_store_cacert = /etc/pki/tls/certs/ca-bundle.crt `,
+		option: defaultTestIniOption,
+		expected: `[DEFAULT]
+debug=true
+enabled_backends = backend:s3
+[backend]
+s3_store_cacert = /etc/pki/tls/certs/ca-bundle.crt `,
+		err: "could not patch target section: foo",
+	},
+	{
+		name: "Add option to a section at the very beginning of customServiceConfig",
+		input: `[foo]
+bar = bar
+foo = foo
+[backend]
+option1 = value1 `,
+		option: defaultTestIniOption,
+		expected: `[foo]
+s3_store_cacert = /etc/pki/tls/certs/ca-bundle.crt
+bar = bar
+foo = foo
+[backend]
+option1 = value1 `,
+		err: "",
+	},
+	{
+		name: "Add option to a section at the very bottom of customServiceConfig",
+		input: `[DEFAULT]
+debug=true
+enabled_backends = backend:s3
+[backend]
+# this is a comment
+option1 = value1
+[foo]
+# this is a comment
+bar = bar
+foo = foo`,
+		option: defaultTestIniOption,
+		expected: `[DEFAULT]
+debug=true
+enabled_backends = backend:s3
+[backend]
+# this is a comment
+option1 = value1
+[foo]
+s3_store_cacert = /etc/pki/tls/certs/ca-bundle.crt
+# this is a comment
+bar = bar
+foo = foo`,
+		err: "",
+	},
+	{
+		name: "Add option to an empty target section",
+		input: `[DEFAULT]
+debug=true
+[foo]`,
+		option: defaultTestIniOption,
+		expected: `[DEFAULT]
+debug=true
+[foo]
+s3_store_cacert = /etc/pki/tls/certs/ca-bundle.crt`,
+		err: "",
+	},
+	{
+		name: "key/value already present in the target section",
+		input: `[DEFAULT]
+debug=true
+[foo]
+s3_store_cacert = /my/custom/path/ca-bundle.crt`,
+		option: defaultTestIniOption,
+		expected: `[DEFAULT]
+debug=true
+[foo]
+s3_store_cacert = /my/custom/path/ca-bundle.crt`,
+		err: "key already exists in section: key s3_store_cacert in section foo",
+	},
+	{
+		name: "add new ini line anyway even though a section contains the same key ",
+		input: `[pci]
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.4", "resource_class": "CUSTOM_A16_16A", "managed": "no" }
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.5", "resource_class": "CUSTOM_A16_8A", "managed": "no" }
+alias = { "device_type": "type-VF", "resource_class": "CUSTOM_A16_8A", "name": "A16_8A" }`,
+		option: aliasKeyIniOption,
+		expected: `[pci]
+alias = { "device_type": "type-VF", "resource_class": "CUSTOM_A16_16A", "name": "A16_16A" }
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.4", "resource_class": "CUSTOM_A16_16A", "managed": "no" }
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.5", "resource_class": "CUSTOM_A16_8A", "managed": "no" }
+alias = { "device_type": "type-VF", "resource_class": "CUSTOM_A16_8A", "name": "A16_8A" }`,
+		err: "",
+	},
+	{
+		name: "add new ini line anyway even though a section contains the same key ",
+		input: `[pci]
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.4", "resource_class": "CUSTOM_A16_16A", "managed": "no" }
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.5", "resource_class": "CUSTOM_A16_8A", "managed": "no" }
+alias = { "device_type": "type-VF", "resource_class": "CUSTOM_A16_16A", "name": "A16_16A" }
+alias = { "device_type": "type-VF", "resource_class": "CUSTOM_A16_8A", "name": "A16_8A" }`,
+		option: deviceSpecIniOption,
+		expected: `[pci]
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.6", "resource_class": "CUSTOM_A16_8A", "managed": "yes" }
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.4", "resource_class": "CUSTOM_A16_16A", "managed": "no" }
+device_spec = { "vendor_id": "10de", "product_id": "25b6", "address": "0000:25:00.5", "resource_class": "CUSTOM_A16_8A", "managed": "no" }
+alias = { "device_type": "type-VF", "resource_class": "CUSTOM_A16_16A", "name": "A16_16A" }
+alias = { "device_type": "type-VF", "resource_class": "CUSTOM_A16_8A", "name": "A16_8A" }`,
+		err: "",
+	},
+}
+
+func TestExtendCustomServiceConfig(t *testing.T) {
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			g := NewWithT(t)
+			output, err := ExtendCustomServiceConfig(tt.input, tt.option)
+			g.Expect(output).To(Equal(tt.expected))
+			if err != nil {
+				// check the string matches the expected error message
+				g.Expect(err.Error()).To(Equal(tt.err))
+			} else {
+				g.Expect(err).ToNot(HaveOccurred())
+			}
+		})
+	}
+}