Revision history for API-Docker

0.003     2026-08-27 03:37:00Z
  - t/containers.t: the registered cleanup tolerates the container the
    happy path already removed, so a live run no longer warns "Cleanup
    failed: ... no such container" on every pass. The safety net still
    warns on any other failure.
  - The `>= 400` croak now falls back to `errorDetail.message` and then to
    the flat `error` key when the JSON error body carries no `message`.
    Docker answers `{"message":...}`; Podman answers a failed push with
    the stream shape instead -- `{"errorDetail":{"message":...},"error":
    ...}` and no `message` at all -- so the whole JSON object used to be
    the croak text and the reason had to be dug out of it by eye. A body
    that is not an object still surfaces verbatim.
  - `images->build`, `->pull` and `->push` now croak when the engine
    reports a failure inside the event stream, instead of returning the
    stream and leaving the check to the caller. A failed build, pull or
    push is answered with HTTP 200 -- the status line is committed
    before the operation is attempted -- and the failure arrives as an
    `errorDetail` object among the progress events, so nothing about the
    response says the operation broke. Measured against the rootless
    Podman socket (5.4.2, API 1.41): a Dockerfile of `FROM alpine:3` /
    `RUN exit 7` answers `200 OK` and ends the stream with
    `{"errorDetail":{"message":"building at STEP \"RUN exit 7\": while
    running runtime: exit status 7\n"},"error":"..."}`, the flat `error`
    key carrying the same text. Callers that never scanned for it -- the
    documented shape until now -- reported a broken build as a success.
    The exception is an `API::Docker::Error::Stream`, a new class whose
    whole purpose is that the progress output is not lost with the
    return value: `$err->events` is the complete event list, error event
    included. It overloads stringification and produces exactly what the
    plain croak it replaces produced, reason plus Carp's ` at FILE line
    N.` suffix, so existing eval-and-inspect-$@ code needs no change;
    `$@ =~ s/...//` on it yields a plain string as it would for any
    overloaded object. The trigger is the `errorDetail` key alone, never
    the word "error" in payload text.
    Which of the three actually takes that route depends on the engine,
    and Podman is not Docker here -- measured on the same socket, all
    three cases: only `build` answers 200 with the failure in the
    stream. A pull of a missing repository answers `403 Forbidden` with
    `{"message":"denied: requested access to the resource is denied"}`,
    a missing tag answers `404 Not Found` with `{"message":"manifest
    unknown: manifest unknown"}`, and a push to an unreachable registry
    answers `500 Internal Server Error` with an `errorDetail` body and
    no `message` key at all. The first two never reach the stream; the
    third has its whole JSON body used as the croak text, because the
    >= 400 path looks for `message`. So on Podman the new check fires
    for `build` and the pre-existing status check catches the other two.
    All three are loud either way, but catching
    `API::Docker::Error::Stream` specifically is not a reliable way to
    catch a failed pull or push -- inspect $@ as a string, which both
    routes satisfy. The POD on each method says which engine does what.
    `system->events` is explicitly exempt and never croaks on stream
    content: it is a feed, so an object in it records something that
    happened on the engine rather than the outcome of this call. The
    check is on by default for the transport's `ndjson` option and
    exempting an endpoint is deliberate (`croak_on_error => 0`), because
    the operation-shaped streaming endpoints are open-ended while the
    feed-shaped ones are `/events` and nothing else.
  - `tls => 1` now croaks with "not implemented" instead of being
    accepted and ignored. `tls` and `cert_path` were attributes no code
    read: `API::Docker::Role::HTTP` builds a plain IO::Socket::INET and
    speaks HTTP over it, so a `tcp://` daemon was always addressed in
    cleartext and a caller who asked for TLS got an unencrypted
    connection with no indication of it -- anyone passing the option was
    by definition sending credentials in the clear while believing
    otherwise. TLS is still not implemented; the croak names the reason
    and the way round it, which is to terminate TLS in front of the
    daemon (stunnel, socat, `ssh -N -L`) and point `host` at the local
    end. Both attributes are kept. `cert_path` on its own does not
    croak: it defaults from `DOCKER_CERT_PATH`, which is exported on
    plenty of machines that also run the docker CLI, so croaking on it
    would break constructions over a value the caller never passed, and
    on its own it transmits nothing and makes an unencrypted connection
    look no different. The POD called TLS "experimental", as though it
    partly worked; it never worked at all.
  - A header name passed through the transport's `headers` option is now
    validated against the RFC 9110 token grammar and rejected if it does
    not match. Only values were sanitised before, so a caller-supplied
    key carrying CR/LF could open a header line of its own. Not
    reachable from this distribution -- the one caller, `push`, passes
    the literal `X-Registry-Auth` -- but the option is public. Names are
    rejected rather than stripped, unlike values: a value can pick up a
    stray newline honestly (`encode_base64` wraps its output by
    default), and flattening it keeps what the caller meant, while a
    name is a literal the programmer wrote and rewriting
    "X-Foo\r\nX-Bar" into "X-FooX-Bar" would put a header on the wire
    under a name nobody asked for. The check also catches spaces and
    colons, which corrupt the request without injecting anything.
  - `containers->logs` and `exec->start` now demultiplex the Docker
    stream format and return an ArrayRef of frames, each a HashRef with
    `stream` and `data`:
      [ { stream => 'stdout', data => "OUT\n" },
        { stream => 'stderr', data => "ERR\n" } ]
    Both used to hand the caller the framed bytes, so the 8-byte frame
    header of every frame landed inside the log text. Measured against
    the rootless Podman socket (5.4.2, API 1.41) with a container
    running `echo OUT; echo ERR 1>&2`: without a TTY the body is
    `01 00 00 00 00 00 00 04 "OUT\n" 02 00 00 00 00 00 00 04 "ERR\n"`,
    and the same exec produces byte-identical output. With a TTY there
    is no framing at all -- the body is `"OUT\r\n" "ERR\r\n"` -- which
    is why hand-testing interactively never showed the defect. TTY
    output comes back as one frame with `stream => 'raw'`, so the shape
    never varies and `$_->{stream} eq 'stderr'` is safe on any frame.
    Callers wanting plain text use
    `join '', map { $_->{data} } @$frames`.
    Framing is decided from the response bytes, not from `Content-Type`.
    Measured on Podman: `GET /containers/{id}/logs` sends no
    `Content-Type` whatsoever, for either kind of container, and
    `POST /exec/{id}/start` sends
    `application/vnd.docker.raw-stream` for both -- including the
    non-TTY exec whose body is in fact multiplexed. Trusting that header
    would put frame headers back into the caller's output on that
    engine. Instead the body is walked as frames and is only treated as
    framed when the walk consumes it exactly; the one way to fool it,
    and the `tty => 1` option that overrides it, are documented on
    `API::Docker::Role::HTTP::stream_frames`.
    `exec->start` also gained POD saying where the exit status actually
    comes from -- `exec->inspect($id)->{ExitCode}`, a separate call --
    which the method's documentation never mentioned.
  - `images->build`, `->pull` and `->push` now always return an ArrayRef
    of events. `_request` used to try `decode_json` on the whole body
    first and only fall back to line-by-line parsing, so a stream that
    carried exactly one JSON object came back as a HashRef while a
    multi-event stream came back as an ArrayRef, and every caller had to
    check `ref` before iterating. Measured on Podman: `POST /build?q=1`
    emits exactly one object, which is the case that used to change
    shape. The ordinary single-JSON-object endpoints (`/version`,
    `/containers/{id}/json`, ...) are untouched and still return a
    HashRef -- the streaming behaviour is now requested explicitly with
    the new `ndjson => 1` transport option rather than guessed from the
    body. The option is named for the format and not `stream`, which is
    already a query parameter of `/events` and
    `/containers/{id}/stats`.
    `system->events` takes the same option. It was reaching an ArrayRef
    only through the implicit fallback that has now gone, so without it
    the endpoint would have quietly started returning an undecoded
    string. Measured on Podman for one container create/init/start/
    died/remove cycle: five newline-delimited objects, and the body is
    not valid JSON as a whole. Its POD now also says to always pass
    `until`, since the transport buffers the whole response and an
    unbounded event stream therefore never returns.
    Note for anyone scanning these events: a failed build is still HTTP
    200 with the failure carried as an `errorDetail` object inside the
    stream, confirmed on Podman for a Dockerfile whose `RUN` exits 7.
    A failed *pull* differs there -- Podman answers 404 with a plain
    `{"message":...}` body where Docker streams `errorDetail` on a 200 --
    so `pull` can croak as well as report an error event.
  - Bring the cpanfile in line with what the code loads. `URI` was
    required and is used nowhere in `lib/` or `t/`, so every consumer
    installed it for nothing; it is gone. `Carp` (loaded by eight of the
    twelve modules) and `IO::Socket::INET` (loaded by
    API::Docker::Role::HTTP beside its already-declared `IO::Socket::UNIX`
    sibling) were undeclared and are now required, as is `Exporter`
    under `on test` for the mock helper. Nothing else in the tree loads
    an undeclared module: `SOCK_STREAM` in the HTTP role comes from
    IO::Socket, which IO::Socket::UNIX and IO::Socket::INET both
    re-export, and `Path::Tiny` appears in `lib/` only inside the
    API::Docker::API::Images SYNOPSIS, so it stays a test dependency.
  - Fix every image push failing with a 400. The X-Registry-Auth header
    was encoded as base64url with the padding stripped; the engine
    decodes it with Go's `base64.URLEncoding`, which requires padding
    and answers `failed to parse "X-Registry-Auth" header ... unexpected
    EOF` without it. That hit authenticated and anonymous pushes alike
    -- the anonymous payload is `{}`, which encodes to three characters
    and one `=`. Measured against a local registry: before, all three
    tags of a test image came back 400 and nothing reached the registry;
    after, all three are there.
    The test that covered this could not have caught it. Its decode
    helper computed the missing padding and appended it before decoding,
    so the assertions passed either way. It now decodes what the engine
    would get, and a separate case pins the exact padded header.
  - Document that this client speaks the Docker Engine HTTP API over a
    socket and never shells out to the `docker` binary, so any engine
    serving that API works -- Podman's rootless socket needs nothing
    but `DOCKER_HOST`. The new CONTAINER ENGINES section also states
    what socket discovery deliberately does not do: Docker contexts
    (`currentContext`, `~/.docker/contexts/meta/*/meta.json`) are never
    consulted, unlike the `docker` CLI, docker-java or Testcontainers.

0.002     2026-05-17 05:36:20Z
  - HTTP role: `_request` now accepts a `headers => {}` option to set
    extra HTTP request headers. Headers are sanitised against CR/LF
    injection. Used by `images->push` to send `X-Registry-Auth`, and
    available to any caller that needs custom headers.
  - `images->push` now always sends an `X-Registry-Auth` header — the
    Docker Engine refuses pushes without it (`HTTP 400: missing
    X-Registry-Auth: invalid X-Registry-Auth header: EOF`). A new `auth`
    option accepts a hashref of credentials (`username`, `password`,
    `serveraddress`, or `identitytoken`) which is JSON-encoded and
    base64url-wrapped per the Docker Engine spec. Without `auth` the
    header carries an empty JSON object so unauthenticated/public
    pushes succeed where they previously failed at the HTTP layer.

0.001     2026-04-29 00:40:43Z
    - Initial release as API::Docker
    - Docker Engine API client with Unix socket and TCP support
    - Auto-negotiate API version from daemon
    - Container, Image, Network, Volume, System, and Exec APIs
    - Pure Perl implementation with minimal dependencies (no LWP)
    - HTTP/1.1 transport with chunked transfer encoding support
