Files
pmg/docs/proxy-mode.md
T
c47776db27 feat(proxy): persistent proxy server mode (#351)
* refactor(flows): extract SetupCACertificate for reuse

Move the CA load/generate/merge logic out of proxyFlow into an exported
flows.SetupCACertificate so the persistent proxy server can reuse it.

* feat(proxy): add persistent proxy server with start/stop/env/status

Introduces 'pmg proxy' commands backed by internal/proxyserver: a long-lived
MITM proxy that intercepts package managers via env vars (no shims). Supports
--daemon (Unix), --state, --port; generic 'env' output that skips cert vars
when the CA is OS-trusted; opt-in 'stop --fail-on-violation' (fail-closed on
crash) with a synchronous cloud event flush; and the malysis analysis cache.

* feat(action): add server-mode for persistent proxy

When server-mode=true the action starts the proxy daemon and injects proxy
env vars into the job instead of installing shims.

* test(proxy): add persistent proxy server E2E workflow

* docs(readme): document persistent proxy server mode

* fix(proxy): create cache dir before writing state file and daemon log

On a fresh CI runner the cache directory does not exist yet; os.OpenFile and
os.WriteFile do not create parent dirs, so 'pmg proxy start --daemon' failed
with 'no such file or directory'. MkdirAll the parent before writing.

* docs: add persistent proxy server architecture doc

* refactor proxyserver

* fix(proxy): always emit cert env vars instead of skipping on OS-trust status

npm/pip/yarn/requests trust the MITM CA inconsistently across tools, versions,
and configs; many still use bundled CA stores. Always emitting the cert-path
env vars is the conservative choice that works regardless, and is harmless for
tools that read the OS store (they ignore the vars). Skipping them when a
system CA exists would silently break any tool still on a bundled store.

* refactor(proxy): drop redundant audit init in daemon; rely on main.go

main.go's PersistentPreRun already initializes the audit pipeline for every
command (including the daemon's re-exec'd child) and closes it at process exit.
Re-initializing in proxyserver.Run created a second auditor and a second
cloud-sync WAL connection, orphaning the first. Removing it makes the daemon
consistent with the normal proxy flow, which never self-initializes audit.

* fix(proxy): bypass proxy env when flushing events to cloud on stop

pmg proxy stop inherits HTTP(S)_PROXY (injected by 'pmg proxy env') pointing at
the PMG proxy it just shut down. The cloud sync gRPC client honored those vars
and routed api.safedep.io through the dead proxy, failing with 'connection
refused' so no events were delivered. Clear the proxy env vars before the sync
so PMG's own cloud traffic goes direct.

* chore(proxy): address review feedback

- configurable bind host via proxy.server.listen_host (default loopback)
- proxy commands use ui.ErrorExit instead of returning errors to cobra
- rename errcode to ProxyPolicyViolation (covers malware + cooldown)
- share cloud sync via audit.DrainToCloud (de-dup with cmd/cloud/sync)
- centralize proxy CA bundle path in certmanager
- docs: persistent proxy cert trust + bind address

* fix(proxy): show real message on fail-on-violation error

stopExitError set only WithMsg, but ui.ErrorExit renders HumanError, so the
framed error showed 'no human-readable message available'. Set both from one
string, and emit the framed error before the stdout summary so the blocked
count is stated once.

* fix(proxy): flush cloud events from the daemon, not stop

The stop process inherits HTTP_PROXY (from 'pmg proxy env'), so its cloud
client routed api.safedep.io through the already-stopped proxy and failed with
connection refused. Move the flush into the daemon's shutdown, which has no
proxy env (it started before env injection) and dials SafeDep directly.

- daemon flushes on shutdown via audit.DrainToCloud and records the result in
  the state file; stop surfaces it (on both success and fail-on-violation
  paths) since the daemon's own logs aren't visible to stop
- coordinate stop's wait with the daemon shutdown budget; on timeout, error
  out without reading stale state or deleting the file (fail-closed)
- persist blocked count before the flush so the gate stays correct if the
  flush hangs or the daemon is killed mid-flush
- remove now-redundant cloud_flush.go

* disable auto-sync for proxy cmds

* feat(proxy): periodic cloud sync + move proxy env vars to packagemanager

- daemon runs a periodic cloud-sync ticker so the shutdown flush stays small;
  the run total is reported by stop, and shutdown timeouts are coordinated
- move EnvVarForProxy from config to packagemanager (it is package-manager
  knowledge); the shared function now builds the proxy URL and NO_PROXY itself,
  removing the duplicated construction in the per-command and persistent paths
- relocate the #319 yarn and #339 IPv6 regression tests alongside the function
- enable cloud sync in the persistent-proxy E2E workflow and fix the stale
  internal/proxystate path filter

* refactor(proxy): rename cloudFlushLockTimeout to cloudFlushLockWait

Consistent timeout naming: *LockWait is the lock-acquire bound, *Timeout is
the sync-RPC bound. Previously the final-flush pair was cloudFlushLockTimeout
vs cloudFlushTimeout — two lookalike names for different operations.

* refactor(proxy): extract cloudFlush and trim duplicate shutdown comments

The shutdown's final-flush block is now a cloudFlush helper, symmetric with
startCloudSyncLoop (one-shot vs loop). Removed the triplicated ticker/lock
contention comments, keeping the contract on the function doc and one-line
pointers at the call sites.

* docs: update persistent proxy cloud sync to daemon-owned model

The daemon now owns cloud delivery (periodic sync while serving + final flush
on shutdown); stop signals it, waits, and reports the result. Rewrite the Cloud
event sync section, fix stop attributions, add the cloud_sync state field, and
update the sequence diagram.

* docs: move Usage section up below How it works

Put the copy-paste recipes near the top so users find them before the internals.

* refactor(proxy): address PR review feedback

- configurable bind host/port via --host/--port flags + config (listen_host,
  listen_port), bound directly to config fields per PMG's flag pattern
- daemon log path via --log-file and readiness timeout in ProxyDaemonConfig;
  Daemonize no longer owns path policy (caller validates, fails fast)
- gate periodic cloud sync on auto_sync; suppress detached background sync for
  proxy commands instead of flipping the flag
- pmg proxy env --export emits shell-quoted lines for eval (spaces survive)
- extract shared flows.BuildCachedMalysisAnalyzer, dropping the analyzer+cache
  duplication between proxy flow and proxy server
- add internal/proxyserver/doc.go documenting the package + boundary vs flows
- E2E: assert malicious installs are blocked (drop continue-on-error)
- docs: trim Commands/State-file to user contracts; refresh bind address

* refactor(proxy): proactive alignment fixes from whole-PR review

- gate the shutdown cloud flush on auto_sync too, matching the periodic ticker
  (auto_sync consistently controls all daemon-driven cloud delivery)
- ResolveStatePath takes cacheDir instead of *RuntimeConfig, keeping state.go
  free of config dependency
- drop the empty-host comment in listenAddr; keep the loopback guard so a blank
  host never silently binds all interfaces

* fix: Decouple localdb with malysis analyser construction

* fix: Persist global args before proxy server daemon exec

* fix: GitHub Action for cloud auto-sync in server mode

---------

Co-authored-by: Abhisek Datta <abhisek.datta@gmail.com>
2026-06-26 11:19:28 +05:30

2.4 KiB

Proxy Mode

PMG supports proxy based interception as an alternative to the current optimistic dependency resolution. When enabled:

  • PMG starts a micro-proxy server on a random localhost port
  • Runs npm and other supported package managers configured to use the proxy
  • Intercepts package registry requests and analyzes packages as they are downloaded
  • Blocks malicious packages and allows trusted packages to be installed

Usage

pmg npm install lodash

Configuration

Proxy behavior is configured under the proxy: section in config.yml:

proxy:
  enabled: true
Key Default Description
enabled true Enable proxy-based interception. When false, PMG falls back to guard-based analysis.
install_only false When true, only install commands are proxied. Other commands (e.g., npm ls, pip list) bypass the proxy and execute directly.
skip_commands {} Per-package-manager commands to bypass the proxy. Only applies when install_only is true.

Per-package-manager skip commands

The skip_commands map lets you define additional commands that should bypass the proxy for specific package managers. This only takes effect when install_only is true:

proxy:
  install_only: true
  skip_commands:
    npm: ["dev", "my-script"]
    pip: ["list", "show"]

Commands in skip_commands are matched against the first non-flag argument. For example, npm dev would match dev, but npm install dev would not since install is the first non-flag argument.

CLI flags

Use --proxy-mode to override proxy.enabled at runtime.

Environment variables

Variable Description
PMG_PROXY_ENABLED Override proxy.enabled
PMG_PROXY_INSTALL_ONLY Override proxy.install_only

Legacy variables PMG_PROXY_MODE and PMG_PROXY_INSTALL_ONLY (for the old flat config keys) are still supported when the proxy: section does not exist in the config file.

Supported Package Managers

Package Manager Status
npm
npx
pnpm
pnpx
bun
yarn
pip
uv
poetry

References