The image dropped to a fixed non-root user (uid 10001) and pointed HOME at
/out. On native Linux Docker a bind-mounted /out is owned by whoever created
it on the host, so uid 10001 cannot write into it. Two things then failed:
kage's output and resume state under $HOME/data/kage hit "mkdir /out:
permission denied", and Chrome launched chrome_crashpad_handler with an empty
crash database path, which aborts the whole browser with
"chrome_crashpad_handler: --database is required" and fails every render.
The earlier attempt set HOME=/out, but that only helps when /out is writable,
which it is not for a non-root uid against a host-owned mount. The crash-reporter
flags in the launcher did not help either: they do not stop Chrome from spawning
the handler, so the abort stayed.
Run as root instead. Container root writes a host-owned bind mount whatever its
ownership, so both /out and HOME stay writable and the documented one-liner just
works. This does not loosen the sandbox: Chrome's sandbox is already off inside
any container (kage drops it on container detection), so root here changes
nothing that was holding.
Verified end to end in an Alpine + chromium container: the non-root image
reproduces both the crashpad abort and the permission-denied exactly as
reported, and the root image clones example.com cleanly, writing index.html and
resume state into a host-owned mounted volume.
Two failures stopped a docker run from producing anything. Chrome
aborted on launch with 'chrome_crashpad_handler: --database is
required', because its crash reporter cannot start in a minimal
container, so disable the crash reporter on the container launch path.
kage never uploads Chrome crash dumps, so nothing is lost.
The image also created the kage user without a home directory, so HOME
was an unwritable /home/kage. kage writes its default output and resume
state under $HOME/data/kage and Chrome puts its profile and crash
database under HOME too, so both failed with a permission error and the
mounted /out volume captured nothing. Point HOME at the /out volume so
all of it lands somewhere writable that the mount picks up.
kage renders every page in headless Chrome, snapshots the final
DOM, strips all JavaScript, and localises CSS, images, and fonts
so a site can be browsed offline as a plain folder of files.
The engine is split into small packages:
urlx deterministic URL to local-path mapping and scope rules
sanitize remove scripts, on* handlers, and javascript: URLs
asset rewrite HTML and CSS references, download assets
browser headless Chrome pool over the DevTools protocol
robots robots.txt matcher
clone the orchestrator: a polite resumable breadth-first crawl
The cli package wires a cobra and fang command surface with two
commands, clone and serve. Every pure package has table tests; the
browser and clone packages add Chrome-driven end-to-end tests that
skip when no browser is present or under -short.
CI runs gofmt, vet, build, race tests, golangci-lint, govulncheck,
and a tidy check on Linux and macOS. A goreleaser config fans one
tag out to archives, deb/rpm/apk, a Chromium-bundled GHCR image,
and the package managers. A tago docs site builds to Pages and
Cloudflare.
Tam Nguyen Duc