Symmetric with the existing CPProvisionerAPI interface. Closes the
asymmetry where the SaaS provisioner field was an interface (mockable
in tests) but the Docker provisioner field was a concrete pointer
(not).
## Changes
- New ``provisioner.LocalProvisionerAPI`` interface — the 7 methods
WorkspaceHandler / TeamHandler call on h.provisioner today: Start,
Stop, IsRunning, ExecRead, RemoveVolume, VolumeHasFile,
WriteAuthTokenToVolume. Compile-time assertion confirms *Provisioner
satisfies it. Mirror of cp_provisioner.go's CPProvisionerAPI block.
- ``WorkspaceHandler.provisioner`` and ``TeamHandler.provisioner``
re-typed from ``*provisioner.Provisioner`` to
``provisioner.LocalProvisionerAPI``. Constructor parameter type is
unchanged — the assignment widens to the interface, so the 200+
callers of ``NewWorkspaceHandler`` / ``NewTeamHandler`` are
unaffected.
- Constructors gain a ``if p != nil`` guard before assigning to the
interface field. Without this, ``NewWorkspaceHandler(..., nil, ...)``
(the test fixture pattern across 200+ tests) yields a typed-nil
interface value where ``h.provisioner != nil`` evaluates *true*,
and the SaaS-vs-Docker fork incorrectly routes nil-fixture tests
into the Docker code path. Documented inline with reference to
the Go FAQ.
- Hardened the 5 Provisioner methods that lacked nil-receiver guards
(Start, ExecRead, WriteAuthTokenToVolume, RemoveVolume,
VolumeHasFile) — return ErrNoBackend on nil receiver instead of
panicking on p.cli dereference. Symmetric with Stop/IsRunning
(already hardened in #1813). Defensive cleanup so a future caller
that bypasses the constructor's nil-elision still degrades
cleanly.
- Extended TestZeroValuedBackends_NoPanic with 5 new sub-tests
covering the newly-hardened nil-receiver paths. Defense-in-depth:
a future refactor that drops one of the nil-checks fails red here
before reaching production.
## Why now
- Provisioner orchestration has been touched in #2366 / #2368 — the
interface symmetry is the natural follow-up captured in #2369.
- Future work (CP fleet redeploy endpoint, multi-backend
provisioners) wants this in place. Memory note
``project_provisioner_abstraction.md`` calls out pluggable
backends as a north-star.
- Memory note ``feedback_long_term_robust_automated.md`` —
compile-time gates + ErrNoBackend symmetry > runtime panics.
## Verification
- ``go build ./...`` clean.
- ``go test ./...`` clean — 1300+ tests pass, including the
previously-flaky Create-with-nil-provisioner paths that now
exercise the constructor's nil-elision correctly.
- ``go test ./internal/provisioner/ -run TestZeroValuedBackends_NoPanic
-v`` — all 11 nil-receiver subtests green (was 6, +5 for the
newly-hardened methods).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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