krz/skunky-art

Alternative privacy frontend for DeviantArt. deviantart frontend privacy web https://art.krz.sh

Commit 5b2c8a11b2

5b2c8a11b2195cecc635ba205c7f001452d842c7

parent: ec6fbe95a9

Verified · cmc ci/build: success ci/lint: success ci/test: success

cmc <hello@cleberg.net> · 2026-09-11 19:04 UTC 

Make the upstream throttle configurable

upstream.min-interval-ms (default 400) and upstream.max-concurrent
(default 2) replace the source constants, so an instance that
DeviantArt bans can slow its own requests down without a rebuild.

Layout: unified · split

SETUP.md +6
@@ -50,6 +50,12 @@ below apply. A file named with `-c` must exist.
50 `0` turns the limit off. 50 `0` turns the limit off.
51 * `burst` — How many requests a client can make at once before the rate 51 * `burst` — How many requests a client can make at once before the rate
52 applies, default 20. 52 applies, default 20.
53* `upstream` — How fast the instance itself talks to DeviantArt, whichever
54 client asked. DeviantArt bans an address that asks too often, so an
55 instance that gets banned should slow this down before anything else.
56 * `min-interval-ms` — Minimum gap between two requests to DeviantArt, in
57 milliseconds. Default 400.
58 * `max-concurrent` — Requests to DeviantArt in flight at once. Default 2.
53* `static-path` — Directory of templates, styles and catalogues, read into 59* `static-path` — Directory of templates, styles and catalogues, read into
54 memory at startup. Default `static`. Ignored by a binary built with the 60 memory at startup. Default `static`. Ignored by a binary built with the
55 `embed` tag. 61 `embed` tag.
app/config.go +16
@@ -40,6 +40,12 @@ type rateLimitConfig struct {
40 Burst int `json:"burst"` 40 Burst int `json:"burst"`
41} 41}
42 42
43// upstreamConfig paces the instance's own requests to DeviantArt.
44type upstreamConfig struct {
45 MinIntervalMS int `json:"min-interval-ms"`
46 MaxConcurrent int `json:"max-concurrent"`
47}
48
43type config struct { 49type config struct {
44 cfg string 50 cfg string
45 Listen string `json:"listen"` 51 Listen string `json:"listen"`
@@ -47,6 +53,7 @@ type config struct {
47 Cache cacheConfig `json:"cache"` 53 Cache cacheConfig `json:"cache"`
48 APICache apiCacheConfig `json:"api-cache"` 54 APICache apiCacheConfig `json:"api-cache"`
49 RateLimit rateLimitConfig `json:"rate-limit"` 55 RateLimit rateLimitConfig `json:"rate-limit"`
56 Upstream upstreamConfig `json:"upstream"`
50 Proxy bool `json:"proxy"` 57 Proxy bool `json:"proxy"`
51 Nsfw bool `json:"nsfw"` 58 Nsfw bool `json:"nsfw"`
52 HideAI bool `json:"hide-ai"` 59 HideAI bool `json:"hide-ai"`
@@ -82,6 +89,10 @@ var CFG = config{
82 PerMinute: 60, 89 PerMinute: 60,
83 Burst: 20, 90 Burst: 20,
84 }, 91 },
92 Upstream: upstreamConfig{
93 MinIntervalMS: 400,
94 MaxConcurrent: 2,
95 },
85 StaticPath: "static", 96 StaticPath: "static",
86 UserAgent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36", 97 UserAgent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36",
87 Proxy: true, 98 Proxy: true,
@@ -234,6 +245,11 @@ func ExecuteConfig() {
234 daLimiter = newRateLimiter(CFG.RateLimit.PerMinute, max(CFG.RateLimit.Burst, 1)) 245 daLimiter = newRateLimiter(CFG.RateLimit.PerMinute, max(CFG.RateLimit.Burst, 1))
235 } 246 }
236 247
248 // Read here so InstallDAThrottle, which runs next, builds the throttle
249 // from the file rather than the source defaults.
250 daMinInterval = time.Duration(max(CFG.Upstream.MinIntervalMS, 0)) * time.Millisecond
251 daMaxConcurrent = max(CFG.Upstream.MaxConcurrent, 1)
252
237 static.StaticPath = CFG.StaticPath 253 static.StaticPath = CFG.StaticPath
238 devianter.UserAgent = CFG.UserAgent 254 devianter.UserAgent = CFG.UserAgent
239} 255}
app/config_test.go +27
@@ -1,6 +1,7 @@
1package app 1package app
2 2
3import ( 3import (
4 "os"
4 "testing" 5 "testing"
5 "time" 6 "time"
6) 7)
@@ -80,3 +81,29 @@ func TestExecuteConfigExitsOnAMissingExplicitFile(t *testing.T) {
80 t.Error("a missing file named with -c started the instance, want an exit") 81 t.Error("a missing file named with -c started the instance, want an exit")
81 } 82 }
82} 83}
84
85func TestUpstreamDefaults(t *testing.T) {
86 if CFG.Upstream.MinIntervalMS != 400 || CFG.Upstream.MaxConcurrent != 2 {
87 t.Errorf("defaults are %+v, want 400 ms and 2 in flight", CFG.Upstream)
88 }
89}
90
91// TestUpstreamConfigSetsTheThrottle pins that the file's values reach the
92// throttle: the tunables used to be source constants.
93func TestUpstreamConfigSetsTheThrottle(t *testing.T) {
94 dir := t.TempDir()
95 path := dir + "/config.json"
96 if err := os.WriteFile(path, []byte(`{"upstream": {"min-interval-ms": 1500, "max-concurrent": 1}}`), 0600); err != nil {
97 t.Fatal(err)
98 }
99 withScratchConfig(t, path, true)
100 interval, concurrent := daMinInterval, daMaxConcurrent
101 t.Cleanup(func() { daMinInterval, daMaxConcurrent = interval, concurrent })
102 captureExit(t)
103
104 ExecuteConfig()
105
106 if daMinInterval != 1500*time.Millisecond || daMaxConcurrent != 1 {
107 t.Errorf("throttle is %v / %d, want 1.5s / 1 from the file", daMinInterval, daMaxConcurrent)
108 }
109}
app/httpclient.go +3 −1
@@ -18,7 +18,9 @@ import (
18// 18//
19// http.ProxyFromEnvironment is preserved, so HTTPS_PROXY (VPN egress) still applies. 19// http.ProxyFromEnvironment is preserved, so HTTPS_PROXY (VPN egress) still applies.
20 20
21// Tunables (kept in source; safe defaults). Lower is gentler on the DA IP. 21// Tunables, set from the upstream config block by ExecuteConfig; these are
22// the defaults for a config that omits it. Slower is gentler on the egress
23// address, which DeviantArt bans when it asks too often.
22var ( 24var (
23 daMinInterval = 400 * time.Millisecond // minimum gap between DA request starts 25 daMinInterval = 400 * time.Millisecond // minimum gap between DA request starts
24 daMaxConcurrent = 2 // max simultaneous in-flight DA requests 26 daMaxConcurrent = 2 // max simultaneous in-flight DA requests
config.example.json +4
@@ -18,6 +18,10 @@
18 "per-minute": 60, 18 "per-minute": 60,
19 "burst": 20 19 "burst": 20
20 }, 20 },
21 "upstream": {
22 "min-interval-ms": 400,
23 "max-concurrent": 2
24 },
21 "static-path": "static", 25 "static-path": "static",
22 "download-proxy": "", 26 "download-proxy": "",
23 "user-agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36", 27 "user-agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36",