behavior changes: UserAgent configurable, test cookies, check errors

fetch cookies from 1st response and use them in subsequent requests.

CODE_OF_CONDUCT.md

@@ -0,0 +1,114 @@
+# No Code of Conduct
+
+*TL;DR:* This project  does **NOT** have a so called  Code of Conduct,
+nor will it ever have one.
+
+## The Rant
+
+The reasons are somewhat complicated and  I'll try my best to document
+them here.
+
+Ethical codes  or rules come  along like laws.  But how is  ethical or
+moral behavior defined? And who  defines which behavior is ethical and
+which is not? Certainly not me.
+
+Unless  you  live  in  a  dictatorship (and  more  than  half  of  the
+population on  planet earth  do as  of this  writing), laws  come into
+existence by democratic procedures. Laws  cover almost every aspect of
+live in  a society. Laws allow  and forbid behavior and  laws sanction
+infringements.
+
+A software project like  this one on the other hand  is not a society.
+There   are   not   enough   people  involved   to   form   democratic
+structures. And there will always be  a minority of users who have the
+right to commit or reject code. How could any maintainer of a software
+project dare to decree rules upon  others? Actually, am I, the current
+maintainer of this very project authorized to do so?
+
+I think the anser to this question clearly is NO.
+
+The  issue  is  being  complicated  by  the  fact,  that  open  source
+development these days  happens on a planetary scale.  And this planet
+houses hundreds if not  thousands of different cultures, philosophies,
+ideologies and worldviews.  The answer  to many ethical questions will
+in most cases be vague and nebulous.
+
+Ones joke will always be another ones insult.
+
+Then there  is the  problem of  language. I myself  am not  an english
+native, but I publish everyting using  the english language. I am able
+to communicate with  most people in the open  source community because
+of that.   But I am  certainly not  able to understand  everything and
+everyone. There  might be nuances to  a sentence I don't  sense, there
+might be  sarcastic connotations I  don't understand or  references to
+historical figures, events  or traditions I don't know  and never have
+heard of.
+
+Judging over other  peoples online behavior looks like  a titanic task
+to me. It is just not my job  to judge others, I am not legitimized or
+authorized to do so and I am not interested in this kind of business.
+
+Another huge  problem with ethical rules  is that you need  to outline
+and enforce sanctions  on those who violate the rules.  But since I am
+not an  elected authority  how would I  be able to  do this?   I don't
+know.  And  what happens if  someone complains about myself?   Shall I
+remove myself from my own project? Come on!
+
+Last but  not least there's  the law. So,  let's say someone  in india
+writes something  insulting to some  other developer in an  issue.  Of
+course  german law  does not  apply  to indian  people. Moreover,  the
+insult might actually not be an  insult in india.  In the end, nothing
+would   happen.   Under   normal   circumstances,  maintainers   would
+eventually delete the posting, ban  the user or remove push privileges
+etc.
+
+But then, is there a way for  the offending user to defend himself? Of
+course not, since neither indian or german law alone applies. I cannot
+go to  a german court  and sue the  guy and he  cannot do the  same in
+india. Or -  we possibly could but the judges  in both countries would
+just laugh and close the case.
+
+That  being said,  I  don't have  the  power nor  the  tools, nor  the
+authority to enforce serious sanctions  of any meaningful kind against
+others. Therefore I cannot outline any rules whatsoever.
+
+And let's not  even start talking about  these undemocratic "comitees"
+many projects are  forming to circumvent this  problem.  Some projects
+even  include  external entities  like  a  lawyer or  some  bureaucrat
+somewhere  just to  have the  ability  to complain  against a  comitee
+member. What a mess!
+
+
+
+## So, what are the ethical rules within this project then?
+
+Well, there are none.
+
+This project is  about code, not society. It doesn't  matter where you
+come from,  how you look,  how you think,  what you believe,  who your
+friends are, whay you  said or did sometime in the  past. I don't even
+care if you are a human being. You are an alien so bored that you need
+to submit code on github? Fine with me. You're a convicted criminal? I
+don't give a shit!
+
+**The only thing I am interested here is Code and only Code.**
+
+So if anyhing happens  here I don't like or I  am obliged by (german!)
+law to act on, I will decide on  a case to case basis what to do.  And
+unfortunately,  since this  is the  nature  of a  github project,  you
+cannot complain, object or protest. I am very sorry!
+
+If you will, let's at least  outline these:
+
+- Please - just please -  behave towards others as you'd expect others
+  to behave towards yourself.
+
+- Don't judge others for any reason.
+
+- Only judge the code.
+
+But these are not rules, only a  friendly appeal to you as a developer
+and user.
+
+
+Thanks a lot!

CONTRIBUTING.md

@@ -0,0 +1,93 @@
+## Project Goals
+
+The goal  of this  project is  to build  a small  tool which  helps in
+maintaining backups of the german  ad site kleinanzeigen.de. It should
+be  small,  fast and  easy  to  understand.
+
+There will be no GUI, no web interface, no public API of some sort, no
+builtin interpreter.
+
+The  programming  language  used  for  this  project  will  always  be
+[GOLANG](https://go.dev/)  with  the  exception of  the  documentation
+([Perl POD](https://perldoc.perl.org/perlpod)) and the Makefile.
+
+# Contributing
+
+You can contribute to this project in various ways:
+
+## Open an issue
+
+If you encounter  a problem or don't understand how  the program works
+or if you think the documentation is unclear, please don't hesitate to
+open an issue.
+
+Please add as much information about the case as possible, such as:
+
+- Your environment (operating system etc)
+- kleingebaeck version (`kleingebaeck --version`)
+- Commandline used. Please replace sensitive information with mock data!
+- Repeat the command with debugging enabled (`-d` flag)
+- Actual program output, Please replace sensitive information with mock data!
+- Expected program output.
+- Error message - if any.
+
+Be aware  that I am  working on this (and  some others) project  in my
+spare  time which  is scarce.   Therefore  please don't  expect me  to
+respond to  your query within  hours or even  days. Be patient,  but I
+WILL respond.
+
+## Pull Requests
+
+Code and documentation help is  always much appreciated! Please follow
+thes guidelines to successfully contribute:
+
+-  Every  pull   request  shall  be  based   on  latest  `development`
+  branch. `main` is only used for releases.
+  
+- Execute the  unit tests before committing: `make  test`. There shall
+  be no errors.
+  
+- Strive  to be  backwards compatible  so that  users who  are already
+  using the program  don't have to change their habits  - unless it is
+  really neccessary.
+
+- Try to add a unit test for your fix, addition or modification.
+
+- Don't ever change existing unit tests!
+
+- Add a meaningful and comprehensive rationale about your contribution:
+  - Why do you think it might be useful for others?
+  - What did you actually change or add?
+  - Is there an open issue which  this PR fixes and if so, please link
+    to that issue.
+
+- [Re-]format your code with `gofmt -s`.
+
+- Avoid unneccesary dependencies, especially for very small functions.
+
+- **If** a  new dependency is being added, it  must be compatible with
+  our [license agreement](LICENSE).
+  
+- You  need to accept  that the  code or documentation  you contribute
+  will be redistributed under the  terms of said license agreement. If
+  your  contribution  is  considerably  large  or  if  you  contribute
+  regularly, then  feel free  to add  your name (and  if you want your
+  email    address)     to    the    *AUTHORS*    section    of    the
+  [manpage](kleingebaeck.pod).
+
+- Adhere to the above mentioned project goals.
+
+- If   you are  unsure if  your addition or  change will  be accepted,
+  better ask before starting coding. Open an issue about your proposal
+  and let's  discuss it! That way  we avoid doing unnessesary  work on
+  both sides.
+    
+Each pull  request will be  carefully reviewed and  if it is  a useful
+addition  it  will  be  accepted. However,  please  be  prepared  that
+sometimes a  PR will be  rejected.  The reasons  may vary and  will be
+documented.   Perhaps the  above guidelines  are not  matched, or  the
+addition seems  to be not so  useful from my perspective,  maybe there
+are  too  much  changes  or  there  might  be  changes  I  don't  even
+understand.
+
+But whatever happens: your contribution is always welcome!

config.go

@@ -35,19 +35,27 @@ import (
 )
 
 const (
-	VERSION         string = "0.3.0"
+	VERSION    string = "0.3.1"
 	Baseuri    string = "https://www.kleinanzeigen.de"
 	Listuri    string = "/s-bestandsliste.html"
 	Defaultdir string = "."
+
 	DefaultTemplate string = "Title: {{.Title}}\nPrice: {{.Price}}\nId: {{.Id}}\n" +
 		"Category: {{.Category}}\nCondition: {{.Condition}}\n" +
 		"Created: {{.Created}}\nExpire: {{.Expire}}\n\n{{.Text}}\n"
+
 	DefaultTemplateWin string = "Title: {{.Title}}\r\nPrice: {{.Price}}\r\nId: {{.Id}}\r\n" +
 		"Category: {{.Category}}\r\nCondition: {{.Condition}}\r\n" +
 		"Created: {{.Created}}\r\nExpires: {{.Expire}}\r\n\r\n{{.Text}}\r\n"
-	Useragent string = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) " +
+
+	DefaultUserAgent string = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) " +
 		"AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"
+
 	DefaultAdNameTemplate string = "{{.Slug}}"
+
+	// for image download throttling
+	MinThrottle int = 2
+	MaxThrottle int = 20
 )
 
 const Usage string = `This is kleingebaeck, the kleinanzeigen.de backup tool.
@@ -84,6 +92,7 @@ type Config struct {
 	Limit            int    `koanf:"limit"`
 	IgnoreErrors     bool   `koanf:"ignoreerrors"`
 	ForceDownload    bool   `koanf:"force"`
+	UserAgent        string `koanf:"useragent"` // conf only
 	Adlinks          []string
 	StatsCountAds    int
 	StatsCountImages int
@@ -114,6 +123,7 @@ func InitConfig(w io.Writer) (*Config, error) {
 		"loglevel":       "notice",
 		"userid":         0,
 		"adnametemplate": DefaultAdNameTemplate,
+		"useragent":      DefaultUserAgent,
 	}, "."), nil); err != nil {
 		return nil, err
 	}

fetch.go

@@ -22,21 +22,32 @@ import (
 	"io"
 	"log/slog"
 	"net/http"
+	"net/http/cookiejar"
+	"net/url"
 )
 
 // convenient wrapper to fetch some web content
 type Fetcher struct {
 	Config  *Config
 	Client  *http.Client
-	Useragent string // FIXME: make configurable
+	Cookies []*http.Cookie
 }
 
-func NewFetcher(c *Config) *Fetcher {
-	return &Fetcher{
-		Client:    &http.Client{Transport: &loggingTransport{}}, // implemented in http.go
-		Useragent: Useragent,                                    // default in config.go
-		Config:    c,
+func NewFetcher(c *Config) (*Fetcher, error) {
+	jar, err := cookiejar.New(nil)
+	if err != nil {
+		return nil, err
 	}
+
+	return &Fetcher{
+			Client: &http.Client{
+				Transport: &loggingTransport{}, // implemented in http.go
+				Jar:       jar,
+			},
+			Config:  c,
+			Cookies: []*http.Cookie{},
+		},
+		nil
 }
 
 func (f *Fetcher) Get(uri string) (io.ReadCloser, error) {
@@ -45,7 +56,16 @@ func (f *Fetcher) Get(uri string) (io.ReadCloser, error) {
 		return nil, err
 	}
 
-	req.Header.Set("User-Agent", f.Useragent)
+	req.Header.Set("User-Agent", f.Config.UserAgent)
+
+	if len(f.Cookies) > 0 {
+		uriobj, _ := url.Parse(Baseuri)
+		slog.Debug("have cookies, sending them",
+			"sample-cookie-name", f.Cookies[0].Name,
+			"sample-cookie-expire", f.Cookies[0].Expires,
+		)
+		f.Client.Jar.SetCookies(uriobj, f.Cookies)
+	}
 
 	res, err := f.Client.Do(req)
 	if err != nil {
@@ -56,6 +76,9 @@ func (f *Fetcher) Get(uri string) (io.ReadCloser, error) {
 		return nil, errors.New("could not get page via HTTP")
 	}
 
+	slog.Debug("got cookies?", "cookies", res.Cookies())
+	f.Cookies = res.Cookies()
+
 	return res.Body, nil
 }
 

kleingebaeck.1

@@ -133,7 +133,7 @@
 .\" ========================================================================
 .\"
 .IX Title "KLEINGEBAECK 1"
-.TH KLEINGEBAECK 1 "2024-01-22" "1" "User Commands"
+.TH KLEINGEBAECK 1 "2024-01-24" "1" "User Commands"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
@@ -174,10 +174,11 @@ well.   We    use   \s-1TOML\s0   as   our    configuration   language.   See
 .PP
 Format is pretty simple:
 .PP
-.Vb 10
+.Vb 11
 \&    user = 1010101
 \&    loglevel = verbose
 \&    outdir = "test"
+\&    useragent = "Mozilla/5.0"
 \&    template = """
 \&    Title: {{.Title}}
 \&    Price: {{.Price}}

kleingebaeck.go

@@ -39,6 +39,7 @@ CONFIGURATION
         user = 1010101
         loglevel = verbose
         outdir = "test"
+        useragent = "Mozilla/5.0"
         template = """
         Title: {{.Title}}
         Price: {{.Price}}

kleingebaeck.pod

@@ -39,6 +39,7 @@ Format is pretty simple:
     user = 1010101
     loglevel = verbose
     outdir = "test"
+    useragent = "Mozilla/5.0"
     template = """
     Title: {{.Title}}
     Price: {{.Price}}

main.go

@@ -22,8 +22,10 @@ import (
 	"fmt"
 	"io"
 	"log/slog"
+	"math/rand"
 	"os"
 	"runtime/debug"
+	"time"
 
 	"github.com/lmittmann/tint"
 	"github.com/tlinden/yadu"
@@ -111,7 +113,13 @@ func Main(w io.Writer) int {
 	}
 
 	// used for all HTTP requests
-	fetch := NewFetcher(conf)
+	fetch, err := NewFetcher(conf)
+	if err != nil {
+		return Die(err)
+	}
+
+	// randomization needed here and there
+	rand.Seed(time.Now().UnixNano())
 
 	if len(conf.Adlinks) >= 1 {
 		// directly backup ad listing[s]

main_test.go

@@ -21,6 +21,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"net/http"
 	"os"
 	"strings"
 	"testing"
@@ -446,19 +447,22 @@ func GetImage(path string) []byte {
 
 // setup httpmock
 func SetIntercept(ads []Adsource) {
+	ch := http.Header{}
+	ch.Add("Set-Cookie", "session=permanent")
+
 	for _, ad := range ads {
 		if ad.status == 0 {
 			ad.status = 200
 		}
 
 		httpmock.RegisterResponder("GET", ad.uri,
-			httpmock.NewStringResponder(ad.status, ad.content))
+			httpmock.NewStringResponder(ad.status, ad.content).HeaderAdd(ch))
 	}
 
 	// we just use 2 images, put this here
 	for _, image := range []string{"t/1.jpg", "t/2.jpg"} {
 		httpmock.RegisterResponder("GET", image,
-			httpmock.NewBytesResponder(200, GetImage(image)))
+			httpmock.NewBytesResponder(200, GetImage(image)).HeaderAdd(ch))
 	}
 
 }

scrape.go

@@ -24,6 +24,7 @@ import (
 	"log/slog"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"astuart.co/goq"
 	"golang.org/x/sync/errgroup"
@@ -150,6 +151,11 @@ func ScrapeImages(fetch *Fetcher, ad *Ad, addir string) error {
 		imguri := imguri
 		file := filepath.Join(adpath, fmt.Sprintf("%d.jpg", img))
 		g.Go(func() error {
+			// wait a little
+
+			t := GetThrottleTime()
+			time.Sleep(t)
+
 			body, err := fetch.Getimage(imguri)
 			if err != nil {
 				return err
@@ -163,7 +169,7 @@ func ScrapeImages(fetch *Fetcher, ad *Ad, addir string) error {
 
 			buf2 := buf.Bytes() // needed for image writing
 
-			image := NewImage(buf, "", imguri)
+			image := NewImage(buf, file, imguri)
 			err = image.CalcHash()
 			if err != nil {
 				return err
@@ -181,7 +187,7 @@ func ScrapeImages(fetch *Fetcher, ad *Ad, addir string) error {
 				return err
 			}
 
-			slog.Debug("wrote image", "image", image, "size", len(buf2))
+			slog.Debug("wrote image", "image", image, "size", len(buf2), "throttle", t)
 			return nil
 		})
 		img++

store_test.go

@@ -0,0 +1,37 @@
+/*
+Copyright © 2023-2024 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package main
+
+import (
+	"testing"
+)
+
+// this is  a weird thing.  WriteImage() is being called  in scrape.go
+// which is  being tested by  TestMain() in main_test.go.  However, it
+// doesn't  show up  in the  coverage report  for unknown  reasons, so
+// here's a single test for it
+func TestWriteImage(t *testing.T) {
+	buf := []byte{1, 2, 3, 4, 5, 6, 7, 8}
+	file := "t/out/t.jpg"
+
+	err := WriteImage(file, buf)
+	if err != nil {
+		t.Errorf("Could not write mock image to %s: %s", file, err.Error())
+	}
+
+}

util.go

@@ -20,9 +20,11 @@ package main
 import (
 	"bytes"
 	"errors"
+	"math/rand"
 	"os"
 	"os/exec"
 	"runtime"
+	"time"
 
 	"github.com/mattn/go-isatty"
 )
@@ -66,3 +68,7 @@ func IsNoTty() bool {
 	// it is a tty
 	return false
 }
+
+func GetThrottleTime() time.Duration {
+	return time.Duration(rand.Intn(MaxThrottle-MinThrottle+1)+MinThrottle) * time.Millisecond
+}