forgejo/go.mod
Mathieu Fenniak 77fafbe578 Add a "summary card" to issues & PRs for consumption by OpenGraph clients (#6053)
## Overview

Hi all, I'm a first-time contributor to Forgejo.  I was looking for something interesting to contribute and the first thing that caught my attention was https://codeberg.org/forgejo/forgejo/issues/6043, a request for an enhancement to include "issue previews" when publishing links to social media platforms.  As a bit of background, the way these platforms work is that they search for meta tags in the posted link's content, and if they find a meta `og:image` (along with other meta tags) they'll pull the image to include in the social media post.  Forgejo currently provides an `og:image` tag but it just renders the repository or repository-owner's avatar.

This PR will render `og:image` for an issue or PR into a link to `{...}/summary-card`, which is a dynamically generated image that contains a summary of the issue.

## Design Notes

### Rendering / Rasterization

The tricky part of solving this problem is rendering an image that combines some text, some images, and some layout elements.  To address this, I've created a `card` module which allows for a handful of operations:
- Create a new rendered image (a "Card")
- Add a margin to a card
- Split the card, horizontally or vertically, into two pieces with a proportional layout (eg. 70%/30%, as desired), each of which are "Cards" that render into the same root image
- Render text into a card, with line-wrapping and text-alignment capabilities
- Render an image onto a card
- Fetches an external image as safely as possible (for server-side fetch of Gravatar, etc.)

The card module can be reused to create `og:image` summary cards for any object in the future, although obviously it's capabilities are limited.  The current implementation is on issues/PRs.

I considered a few alternative approaches before taking this approach, and here's why I rejected those options:
- Provide the summary card as an SVG object which could be rendered much more easily with a template file -- however, support for SVG isn't defined as positive for OpenGraph, and a quick look through some existing implementations suggest that it is not widely supported, if at all
- Rendering as HTML/CSS, or SVG, and then using an external tool to convert into a PNG (or other static) image -- this would be much nicer and easier to implement, but would require tying in some very heavy-weight dependencies
- Rendering using a more sophisticated graphics library, eg. cairo -- also would be nicer and easier to implement, but again a heavy dependency for a small functionality

As a result of the limited capabilities of the new card module, summary cards don't have icons on them (which would require SVG rasterization) or pretty status badges with colors and rounded rects.  In the future if better drawing capabilities were added, the graphics could be improved, but it doesn't seem too important.

### External Avatars

In order to rasterize a user's avatar onto the summary card, it might have to be retrieved by the server from the external source (eg. Gravatar).  A `fetchExternalImage` routine attempts to do this in the safest way possible to protect the server from any possible security exposure from this; (a) verifying that the content-types are acceptable, (b) ensuring that the file-size and image-size are within the safe bounds that are used for custom avatars, (c) using a very-short timeout to avoid stalling the server if an external dependency is offline.

### Caching

Summary cards are cached after rendered.  This has the downside of causing updates to statuses, avatars, titles, etc. being stale on the summary card for the cache TTL.  However, during testing I found that some social media engines like Mastodon will cause the summary card to be accessed a significant number of times after being referenced by a post, causing a mini-tornado of requests.  The cache compensates for this to avoid server load in this situation.

### Scope

I'm considering out-of-scope:
- Summary cards on other objects (eg. repos, users) can be left for future implementation

## Checklist

The [contributor guide](https://forgejo.org/docs/next/contributor/) contains information that will be helpful to first time contributors. There also are a few [conditions for merging Pull Requests in Forgejo repositories](https://codeberg.org/forgejo/governance/src/branch/main/PullRequestsAgreement.md). You are also welcome to join the [Forgejo development chatroom](https://matrix.to/#/#forgejo-development:matrix.org).

### Tests

- I added test coverage for Go changes...
  - [x] in their respective `*_test.go` for unit tests.
  - [x] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- ~~I added test coverage for JavaScript changes...~~ n/a, no JS changes
  - [x] ~~in `web_src/js/*.test.js` if it can be unit tested.~~
  - [x] ~~in `tests/e2e/*.test.e2e.js` if it requires interactions with a live Forgejo server (see also the [developer guide for JavaScript testing](https://codeberg.org/forgejo/forgejo/src/branch/forgejo/tests/e2e/README.md#end-to-end-tests)).~~
- Manual testing
  - [x] Access & attach screenshots of both an issue and a pull-request's summary card; see below
  - [x] Ensure reasonable (non-crash) behavior of rendering text with glyphs outside the font -- correctly rendered as replacement unicode chars
  - [x] Using a public test instance, verify that og:image behavior looks good on platforms like Mastodon and BlueSky
    - [x] Bluesky: 
    - [x] Mastodon:    (Note that the summary card will be requested many times as the post is federated; either each server, or each client, will fetch it itself)
    - [x] OpenGraph test site (https://www.opengraph.xyz/): 
    - [x] Discord: Looks OK ; needs "twitter:card" to be set to "summary_large_image" to display the large-scale image, but (a) that's probably annoying to use, (b) probably wrong because it doesn't match Twitter Card's spec for a "photographic image", and (c) don't want to encourage/continue use of vendor-specific tag
  - [x] Verify cases with user avatar missing (or autogen), and repo avatar missing (falls back to repo owner avatar)

Pull request summary card:
![image](/attachments/b64283e3-9a3c-4f19-9d00-961662ffe86b)

Issue summary card:
![image](/attachments/318ce589-02e0-493e-b10c-5b2cb2627db2)

(images to the right are the custom repo avatar, w/ fallback to the repo owner avatar)

### Documentation

- [ ] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
- [x] I did not document these changes and I do not expect someone else to do it.
  - OpenGraph capabilities are expected to work in the background without user awareness, and so there is no need for documentation to explain the capabilities for users.

### Release notes

- [ ] I do not want this change to show in the release notes.
- [x] I want the title to show in the release notes with a link to this pull request.
- [ ] I want the content of the `release-notes/<pull request number>.md` to be be used for the release notes instead of the title.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6053
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: Mathieu Fenniak <mathieu@fenniak.net>
Co-committed-by: Mathieu Fenniak <mathieu@fenniak.net>
2024-11-29 15:02:03 +00:00

301 lines
14 KiB
Modula-2

module code.gitea.io/gitea
go 1.23.3
require (
code.forgejo.org/f3/gof3/v3 v3.7.0
code.forgejo.org/forgejo-contrib/go-libravatar v0.0.0-20191008002943-06d1c002b251
code.forgejo.org/forgejo/reply v1.0.2
code.forgejo.org/go-chi/binding v1.0.0
code.forgejo.org/go-chi/cache v1.0.0
code.forgejo.org/go-chi/captcha v1.0.0
code.forgejo.org/go-chi/session v1.0.0
code.gitea.io/actions-proto-go v0.4.0
code.gitea.io/gitea-vet v0.2.3
code.gitea.io/sdk/gitea v0.17.1
codeberg.org/gusted/mcaptcha v0.0.0-20220723083913-4f3072e1d570
connectrpc.com/connect v1.17.0
gitea.com/lunny/levelqueue v0.4.2-0.20230414023320-3c0159fe0fe4
github.com/42wim/sshsig v0.0.0-20211121163825-841cf5bbc121
github.com/Azure/go-ntlmssp v0.0.0-20221128193559-754e69321358
github.com/ProtonMail/go-crypto v1.0.0
github.com/PuerkitoBio/goquery v1.10.0
github.com/SaveTheRbtz/zstd-seekable-format-go/pkg v0.7.2
github.com/alecthomas/chroma/v2 v2.14.0
github.com/blakesmith/ar v0.0.0-20190502131153-809d4375e1fb
github.com/blevesearch/bleve/v2 v2.4.3
github.com/buildkite/terminal-to-html/v3 v3.16.4
github.com/caddyserver/certmagic v0.21.4
github.com/chi-middleware/proxy v1.1.1
github.com/djherbis/buffer v1.2.0
github.com/djherbis/nio/v3 v3.0.1
github.com/dsnet/compress v0.0.2-0.20230904184137-39efe44ab707
github.com/dustin/go-humanize v1.0.1
github.com/editorconfig/editorconfig-core-go/v2 v2.6.2
github.com/emersion/go-imap v1.2.1
github.com/felixge/fgprof v0.9.5
github.com/fsnotify/fsnotify v1.8.0
github.com/gliderlabs/ssh v0.3.7
github.com/go-ap/activitypub v0.0.0-20231114162308-e219254dc5c9
github.com/go-ap/jsonld v0.0.0-20221030091449-f2a191312c73
github.com/go-chi/chi/v5 v5.1.0
github.com/go-chi/cors v1.2.1
github.com/go-co-op/gocron v1.37.0
github.com/go-enry/go-enry/v2 v2.9.1
github.com/go-fed/httpsig v1.1.1-0.20201223112313-55836744818e
github.com/go-git/go-git/v5 v5.11.0
github.com/go-ldap/ldap/v3 v3.4.6
github.com/go-openapi/spec v0.20.14
github.com/go-sql-driver/mysql v1.8.1
github.com/go-swagger/go-swagger v0.30.5
github.com/go-testfixtures/testfixtures/v3 v3.12.0
github.com/go-webauthn/webauthn v0.11.2
github.com/gobwas/glob v0.2.3
github.com/gogs/chardet v0.0.0-20211120154057-b7413eaefb8f
github.com/gogs/go-gogs-client v0.0.0-20210131175652-1d7215cd8d85
github.com/golang-jwt/jwt/v5 v5.2.1
github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
github.com/google/go-github/v64 v64.0.0
github.com/google/pprof v0.0.0-20241017200806-017d972448fc
github.com/google/uuid v1.6.0
github.com/gorilla/feeds v1.2.0
github.com/gorilla/sessions v1.4.0
github.com/h2non/gock v1.2.0
github.com/hashicorp/go-version v1.6.0
github.com/hashicorp/golang-lru/v2 v2.0.7
github.com/huandu/xstrings v1.5.0
github.com/jaytaylor/html2text v0.0.0-20230321000545-74c2419ad056
github.com/jhillyerd/enmime/v2 v2.0.0
github.com/json-iterator/go v1.1.12
github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
github.com/klauspost/compress v1.17.11
github.com/klauspost/cpuid/v2 v2.2.8
github.com/lib/pq v1.10.9
github.com/markbates/goth v1.80.0
github.com/mattn/go-isatty v0.0.20
github.com/mattn/go-sqlite3 v1.14.24
github.com/meilisearch/meilisearch-go v0.29.0
github.com/mholt/archiver/v3 v3.5.1
github.com/microcosm-cc/bluemonday v1.0.27
github.com/minio/minio-go/v7 v7.0.78
github.com/msteinert/pam v1.2.0
github.com/nektos/act v0.2.52
github.com/niklasfasching/go-org v1.7.0
github.com/olivere/elastic/v7 v7.0.32
github.com/opencontainers/go-digest v1.0.0
github.com/opencontainers/image-spec v1.1.0
github.com/pquerna/otp v1.4.0
github.com/prometheus/client_golang v1.20.5
github.com/redis/go-redis/v9 v9.7.0
github.com/robfig/cron/v3 v3.0.1
github.com/santhosh-tekuri/jsonschema/v6 v6.0.1
github.com/sassoftware/go-rpmutils v0.4.0
github.com/sergi/go-diff v1.3.1
github.com/shurcooL/vfsgen v0.0.0-20230704071429-0000e147ea92
github.com/stretchr/testify v1.10.0
github.com/syndtr/goleveldb v1.0.0
github.com/ulikunitz/xz v0.5.12
github.com/urfave/cli/v2 v2.27.5
github.com/valyala/fastjson v1.6.4
github.com/xanzy/go-gitlab v0.109.0
github.com/yohcop/openid-go v1.0.1
github.com/yuin/goldmark v1.7.8
github.com/yuin/goldmark-highlighting/v2 v2.0.0-20230729083705-37449abec8cc
go.uber.org/mock v0.4.0
golang.org/x/crypto v0.29.0
golang.org/x/image v0.21.0
golang.org/x/net v0.31.0
golang.org/x/oauth2 v0.23.0
golang.org/x/sys v0.27.0
golang.org/x/text v0.20.0
golang.org/x/tools v0.26.0
google.golang.org/grpc v1.68.0
google.golang.org/protobuf v1.35.1
gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df
gopkg.in/ini.v1 v1.67.0
gopkg.in/yaml.v3 v3.0.1
mvdan.cc/xurls/v2 v2.5.0
xorm.io/builder v0.3.13
xorm.io/xorm v1.3.9
)
require (
cloud.google.com/go/compute/metadata v0.5.0 // indirect
dario.cat/mergo v1.0.0 // indirect
filippo.io/edwards25519 v1.1.0 // indirect
git.sr.ht/~mariusor/go-xsd-duration v0.0.0-20220703122237-02e73435a078 // indirect
github.com/ClickHouse/ch-go v0.61.5 // indirect
github.com/ClickHouse/clickhouse-go/v2 v2.26.0 // indirect
github.com/DataDog/zstd v1.5.5 // indirect
github.com/Masterminds/goutils v1.1.1 // indirect
github.com/Masterminds/semver/v3 v3.2.1 // indirect
github.com/Masterminds/sprig/v3 v3.2.3 // indirect
github.com/Microsoft/go-winio v0.6.1 // indirect
github.com/RoaringBitmap/roaring v1.9.3 // indirect
github.com/andybalholm/brotli v1.1.0 // indirect
github.com/andybalholm/cascadia v1.3.2 // indirect
github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be // indirect
github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2 // indirect
github.com/aymerick/douceur v0.2.0 // indirect
github.com/beorn7/perks v1.0.1 // indirect
github.com/bits-and-blooms/bitset v1.13.0 // indirect
github.com/blevesearch/bleve_index_api v1.1.12 // indirect
github.com/blevesearch/geo v0.1.20 // indirect
github.com/blevesearch/go-faiss v1.0.23 // indirect
github.com/blevesearch/go-porterstemmer v1.0.3 // indirect
github.com/blevesearch/gtreap v0.1.1 // indirect
github.com/blevesearch/mmap-go v1.0.4 // indirect
github.com/blevesearch/scorch_segment_api/v2 v2.2.16 // indirect
github.com/blevesearch/segment v0.9.1 // indirect
github.com/blevesearch/snowballstem v0.9.0 // indirect
github.com/blevesearch/upsidedown_store_api v1.0.2 // indirect
github.com/blevesearch/vellum v1.0.10 // indirect
github.com/blevesearch/zapx/v11 v11.3.10 // indirect
github.com/blevesearch/zapx/v12 v12.3.10 // indirect
github.com/blevesearch/zapx/v13 v13.3.10 // indirect
github.com/blevesearch/zapx/v14 v14.3.10 // indirect
github.com/blevesearch/zapx/v15 v15.3.16 // indirect
github.com/blevesearch/zapx/v16 v16.1.8 // indirect
github.com/boombuler/barcode v1.0.1 // indirect
github.com/bradfitz/gomemcache v0.0.0-20230905024940-24af94b03874 // indirect
github.com/caddyserver/zerossl v0.1.3 // indirect
github.com/cention-sany/utf7 v0.0.0-20170124080048-26cad61bd60a // indirect
github.com/cespare/xxhash/v2 v2.3.0 // indirect
github.com/cloudflare/circl v1.3.8 // indirect
github.com/cpuguy83/go-md2man/v2 v2.0.5 // indirect
github.com/cyphar/filepath-securejoin v0.2.4 // indirect
github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
github.com/davidmz/go-pageant v1.0.2 // indirect
github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
github.com/dlclark/regexp2 v1.11.0 // indirect
github.com/emersion/go-sasl v0.0.0-20231106173351-e73c9f7bad43 // indirect
github.com/emirpasic/gods v1.18.1 // indirect
github.com/fatih/color v1.16.0 // indirect
github.com/felixge/httpsnoop v1.0.4 // indirect
github.com/fxamacker/cbor/v2 v2.7.0 // indirect
github.com/go-ap/errors v0.0.0-20231003111023-183eef4b31b7 // indirect
github.com/go-asn1-ber/asn1-ber v1.5.5 // indirect
github.com/go-enry/go-oniguruma v1.2.1 // indirect
github.com/go-faster/city v1.0.1 // indirect
github.com/go-faster/errors v0.7.1 // indirect
github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 // indirect
github.com/go-git/go-billy/v5 v5.5.0 // indirect
github.com/go-ini/ini v1.67.0 // indirect
github.com/go-openapi/analysis v0.22.2 // indirect
github.com/go-openapi/errors v0.21.0 // indirect
github.com/go-openapi/inflect v0.19.0 // indirect
github.com/go-openapi/jsonpointer v0.20.2 // indirect
github.com/go-openapi/jsonreference v0.20.4 // indirect
github.com/go-openapi/loads v0.21.5 // indirect
github.com/go-openapi/runtime v0.26.2 // indirect
github.com/go-openapi/strfmt v0.22.0 // indirect
github.com/go-openapi/swag v0.22.7 // indirect
github.com/go-openapi/validate v0.22.6 // indirect
github.com/go-webauthn/x v0.1.14 // indirect
github.com/goccy/go-json v0.10.3 // indirect
github.com/golang-jwt/jwt/v4 v4.5.0 // indirect
github.com/golang/geo v0.0.0-20230421003525-6adc56603217 // indirect
github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
github.com/golang/protobuf v1.5.4 // indirect
github.com/golang/snappy v0.0.4 // indirect
github.com/google/btree v1.1.2 // indirect
github.com/google/go-cmp v0.6.0 // indirect
github.com/google/go-querystring v1.1.0 // indirect
github.com/google/go-tpm v0.9.1 // indirect
github.com/gorilla/css v1.0.1 // indirect
github.com/gorilla/handlers v1.5.2 // indirect
github.com/gorilla/mux v1.8.1 // indirect
github.com/gorilla/securecookie v1.1.2 // indirect
github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 // indirect
github.com/hashicorp/go-cleanhttp v0.5.2 // indirect
github.com/hashicorp/go-retryablehttp v0.7.7 // indirect
github.com/hashicorp/hcl v1.0.0 // indirect
github.com/imdario/mergo v0.3.16 // indirect
github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
github.com/jessevdk/go-flags v1.5.0 // indirect
github.com/josharian/intern v1.0.0 // indirect
github.com/kevinburke/ssh_config v1.2.0 // indirect
github.com/klauspost/pgzip v1.2.6 // indirect
github.com/kr/pretty v0.3.1 // indirect
github.com/kr/text v0.2.0 // indirect
github.com/libdns/libdns v0.2.2 // indirect
github.com/magiconair/properties v1.8.7 // indirect
github.com/mailru/easyjson v0.7.7 // indirect
github.com/markbates/going v1.0.3 // indirect
github.com/mattn/go-colorable v0.1.13 // indirect
github.com/mattn/go-runewidth v0.0.16 // indirect
github.com/mholt/acmez/v2 v2.0.3 // indirect
github.com/miekg/dns v1.1.62 // indirect
github.com/minio/md5-simd v1.1.2 // indirect
github.com/mitchellh/copystructure v1.2.0 // indirect
github.com/mitchellh/mapstructure v1.5.0 // indirect
github.com/mitchellh/reflectwalk v1.0.2 // indirect
github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
github.com/modern-go/reflect2 v1.0.2 // indirect
github.com/mrjones/oauth v0.0.0-20190623134757-126b35219450 // indirect
github.com/mschoch/smat v0.2.0 // indirect
github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
github.com/nwaples/rardecode v1.1.3 // indirect
github.com/oklog/ulid v1.3.1 // indirect
github.com/olekukonko/tablewriter v0.0.5 // indirect
github.com/onsi/ginkgo v1.16.5 // indirect
github.com/paulmach/orb v0.11.1 // indirect
github.com/pelletier/go-toml/v2 v2.1.1 // indirect
github.com/pierrec/lz4/v4 v4.1.21 // indirect
github.com/pjbgf/sha1cd v0.3.0 // indirect
github.com/pkg/errors v0.9.1 // indirect
github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
github.com/prometheus/client_model v0.6.1 // indirect
github.com/prometheus/common v0.55.0 // indirect
github.com/prometheus/procfs v0.15.1 // indirect
github.com/rhysd/actionlint v1.6.27 // indirect
github.com/rivo/uniseg v0.4.7 // indirect
github.com/rogpeppe/go-internal v1.12.0 // indirect
github.com/rs/xid v1.6.0 // indirect
github.com/russross/blackfriday/v2 v2.1.0 // indirect
github.com/sagikazarmark/locafero v0.4.0 // indirect
github.com/sagikazarmark/slog-shim v0.1.0 // indirect
github.com/segmentio/asm v1.2.0 // indirect
github.com/shopspring/decimal v1.4.0 // indirect
github.com/shurcooL/httpfs v0.0.0-20230704072500-f1e31cf0ba5c // indirect
github.com/sirupsen/logrus v1.9.3 // indirect
github.com/skeema/knownhosts v1.2.1 // indirect
github.com/sourcegraph/conc v0.3.0 // indirect
github.com/spf13/afero v1.11.0 // indirect
github.com/spf13/cast v1.6.0 // indirect
github.com/spf13/pflag v1.0.5 // indirect
github.com/spf13/viper v1.18.2 // indirect
github.com/ssor/bom v0.0.0-20170718123548-6386211fdfcf // indirect
github.com/subosito/gotenv v1.6.0 // indirect
github.com/toqueteos/webbrowser v1.2.0 // indirect
github.com/x448/float16 v0.8.4 // indirect
github.com/xanzy/ssh-agent v0.3.3 // indirect
github.com/xi2/xz v0.0.0-20171230120015-48954b6210f8 // indirect
github.com/xrash/smetrics v0.0.0-20240521201337-686a1a2994c1 // indirect
github.com/zeebo/blake3 v0.2.4 // indirect
go.etcd.io/bbolt v1.3.9 // indirect
go.mongodb.org/mongo-driver v1.13.1 // indirect
go.opentelemetry.io/otel v1.26.0 // indirect
go.opentelemetry.io/otel/trace v1.26.0 // indirect
go.uber.org/atomic v1.11.0 // indirect
go.uber.org/multierr v1.11.0 // indirect
go.uber.org/zap v1.27.0 // indirect
golang.org/x/exp v0.0.0-20240119083558-1b970713d09a // indirect
golang.org/x/mod v0.21.0 // indirect
golang.org/x/sync v0.9.0 // indirect
golang.org/x/time v0.5.0 // indirect
google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1 // indirect
gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
gopkg.in/warnings.v0 v0.1.2 // indirect
gopkg.in/yaml.v2 v2.4.0 // indirect
)
replace github.com/hashicorp/go-version => github.com/6543/go-version v1.3.1
replace github.com/shurcooL/vfsgen => github.com/lunny/vfsgen v0.0.0-20220105142115-2c99e1ffdfa0
replace github.com/nektos/act => code.forgejo.org/forgejo/act v1.22.0
replace github.com/mholt/archiver/v3 => code.forgejo.org/forgejo/archiver/v3 v3.5.1
replace github.com/goccy/go-json => github.com/grafana/go-json v0.0.0-20241115232854-f14426c40ff2