Behind a TLS-terminating corporate proxy every HTTPS call inside a container
fails — npm, pip, git, curl, the browser-view pane, and Claude Code's own API
requests. There was no mechanism at all: installing the certificate by hand
inside a container is lost on Reset and had to be repeated per project.
A global CA path in AppSettings with a per-project override on Project, taking
either a single certificate file or a directory. It is bind-mounted read-only
at /tmp/.host-ca (mirroring /tmp/.host-ssh and /tmp/.host-aws) and applied by
entrypoint.sh on every start, so it survives recreation, migration and Reset.
Four things this gets right that are easy to get wrong:
* update-ca-certificates globs *.crt case-sensitively, so a .pem that is merely
copied in is ignored in silence. Certificates are renamed, by
container_cert_name() in Rust and a mirrored few lines of shell.
* The system store only serves curl/git/apt. Node — and so Claude Code itself —
needs NODE_EXTRA_CA_CERTS, Python needs REQUESTS_CA_BUNDLE/SSL_CERT_FILE, and
Chromium reads neither: it wants ~/.pki/nssdb, seeded with certutil
(libnss3-tools, added to the image).
* Those vars are set from Rust at creation, never exported by the entrypoint —
a terminal is a docker exec and sees nothing the entrypoint exported. They are
emitted empty when no CA is configured, since docker commit bakes env into the
snapshot image.
* triple-c.ca-fingerprint hashes the certificate bytes as well as the path, so
a CA rotated in at the same location still forces a recreation.
Verified end to end against a real container and a self-signed CA: curl, node,
python and git all complete a TLS handshake against a server signed by it and
all three fail in the same container without it; the env vars are visible from
a docker exec session; the store is cleaned when the setting is cleared.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KSP2KNPhuWKQ4DL5TZEn3k
