feat: implement imprint/impressum support (#706)

* feat: implement imprint/impressum support

Closes #362

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(docs/anubis): enable an imprint

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: fix the end of the sentence, comment out a default impressum

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: link back to impressum page

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/policy/config/config.go

@@ -327,6 +327,7 @@ type fileConfig struct {
 	Bots        []BotOrImport       `json:"bots"`
 	DNSBL       bool                `json:"dnsbl"`
 	OpenGraph   openGraphFileConfig `json:"openGraph,omitempty"`
+	Impressum   *Impressum          `json:"impressum,omitempty"`
 	StatusCodes StatusCodes         `json:"status_codes"`
 	Thresholds  []Threshold         `json:"thresholds"`
 }
@@ -421,6 +422,14 @@ func Load(fin io.Reader, fname string) (*Config, error) {
 		}
 	}
 
+	if c.Impressum != nil {
+		if err := c.Impressum.Valid(); err != nil {
+			validationErrs = append(validationErrs, err)
+		}
+
+		result.Impressum = c.Impressum
+	}
+
 	if len(c.Thresholds) == 0 {
 		c.Thresholds = DefaultThresholds
 	}
@@ -445,6 +454,7 @@ type Config struct {
 	Bots        []BotConfig
 	Thresholds  []Threshold
 	DNSBL       bool
+	Impressum   *Impressum
 	OpenGraph   OpenGraph
 	StatusCodes StatusCodes
 }

lib/policy/config/impressum.go

@@ -0,0 +1,71 @@
+package config
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+)
+
+var ErrMissingValue = errors.New("config: missing value")
+
+type Impressum struct {
+	Footer string        `json:"footer" yaml:"footer"`
+	Page   ImpressumPage `json:"page" yaml:"page"`
+}
+
+func (i Impressum) Render(_ context.Context, w io.Writer) error {
+	if _, err := fmt.Fprint(w, i.Footer); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (i Impressum) Valid() error {
+	var errs []error
+
+	if len(i.Footer) == 0 {
+		errs = append(errs, fmt.Errorf("%w: impressum footer must be defined", ErrMissingValue))
+	}
+
+	if err := i.Page.Valid(); err != nil {
+		errs = append(errs, err)
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(errs...)
+	}
+
+	return nil
+}
+
+type ImpressumPage struct {
+	Title string `json:"title" yaml:"title"`
+	Body  string `json:"body" yaml:"body"`
+}
+
+func (ip ImpressumPage) Render(_ context.Context, w io.Writer) error {
+	if _, err := fmt.Fprint(w, ip.Body); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (ip ImpressumPage) Valid() error {
+	var errs []error
+
+	if len(ip.Title) == 0 {
+		errs = append(errs, fmt.Errorf("%w: impressum page title must be defined", ErrMissingValue))
+	}
+
+	if len(ip.Body) == 0 {
+		errs = append(errs, fmt.Errorf("%w: impressum body title must be defined", ErrMissingValue))
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(errs...)
+	}
+
+	return nil
+}

lib/policy/config/impressum_test.go

@@ -0,0 +1,62 @@
+package config
+
+import (
+	"bytes"
+	"errors"
+	"testing"
+)
+
+func TestImpressumValid(t *testing.T) {
+	for _, cs := range []struct {
+		name string
+		inp  Impressum
+		err  error
+	}{
+		{
+			name: "basic happy path",
+			inp: Impressum{
+				Footer: "<p>Website hosted by Techaro.<p>",
+				Page: ImpressumPage{
+					Title: "Techaro Imprint",
+					Body:  "<p>This is an imprint page.</p>",
+				},
+			},
+			err: nil,
+		},
+		{
+			name: "no footer",
+			inp: Impressum{
+				Footer: "",
+				Page: ImpressumPage{
+					Title: "Techaro Imprint",
+					Body:  "<p>This is an imprint page.</p>",
+				},
+			},
+			err: ErrMissingValue,
+		},
+		{
+			name: "page not valid",
+			inp: Impressum{
+				Footer: "test page please ignore",
+			},
+			err: ErrMissingValue,
+		},
+	} {
+		t.Run(cs.name, func(t *testing.T) {
+			if err := cs.inp.Valid(); !errors.Is(err, cs.err) {
+				t.Logf("want: %v", cs.err)
+				t.Logf("got:  %v", err)
+				t.Error("validation failed")
+			}
+
+			var buf bytes.Buffer
+			if err := cs.inp.Render(t.Context(), &buf); err != nil {
+				t.Errorf("can't render footer: %v", err)
+			}
+
+			if err := cs.inp.Page.Render(t.Context(), &buf); err != nil {
+				t.Errorf("can't render page: %v", err)
+			}
+		})
+	}
+}

lib/policy/config/testdata/bad/impressum-no-footer.yaml

@@ -0,0 +1,11 @@
+bots:
+  - name: simple-weight-adjust
+    action: WEIGH
+    user_agent_regex: Mozilla
+    weight:
+      adjust: 5
+
+impressum:
+  page:
+    title: Test
+    body: <p>This is a test</p>

lib/policy/config/testdata/bad/impressum-no-page-contents.yaml

@@ -0,0 +1,10 @@
+bots:
+  - name: simple-weight-adjust
+    action: WEIGH
+    user_agent_regex: Mozilla
+    weight:
+      adjust: 5
+
+impressum:
+  footer: "Hi there these are WORDS on the INTERNET."
+  page: {}

lib/policy/config/testdata/good/impressum.yaml

@@ -0,0 +1,10 @@
+bots:
+  - name: simple
+    action: CHALLENGE
+    user_agent_regex: Mozilla
+
+impressum:
+  footer: "Hi these are WORDS on the INTERNET."
+  page:
+    title: Test
+    body: <p>This is a test</p>