This change recognizes assets and archives as 1st class resource
property values. This is necessary to support them in the new bridge
work, and lays the foundation for fixing pulumi/lumi#153.
I also took the opportunity to clean up some old cruft in the
resource properties area.
This renames the basemost resource properties, id and urn, to
names that are less likely to conflict with properties that real
resources will want to use, pid and upn (provider ID and Universal
Pulumi Name, respectively).
I actually ran into this with the current bridge work. An alternative
solution would be to require derived resources to pick different names,
however this is unfortunate because usually they are more "user-facing"
than ours. Another alternative is to not hijack the object properties
at all, but that too is problematic because we use these properties
during the evaluation of plans and deployments.
This seems like a reasonable middle ground.
This adds a ReadLocations RPC function to the engine interface, alongside
the singular ReadLocation. The plural function takes a single token that
represents a module or class and we will then return all of the module
or class (static) properties that are currently known.
This adds a handy MapReplace function on pkg/resource's PropertyMap and
PropertyValue types. This is just like the existing Mappable function,
except that it permits easy replacement of elements as the map transformation
occurs. We need this to perform float64=>int transformations.
We fail very late in the process of plan application, should a duplicate
URN arise. This change fails as early in the process as possible and
ensures that it does so with good line number information.
This properly unwinds the interpreter should something happen that
results in cancellation. This occurs, for example, when the planning
engine encounters an error and decides that it doesn't need to proceed
further with evaluation before it simply goes ahead and exits.
This adds a few missing closes for the plugin host/context. This
should fixpulumi/lumi#261. Eventually when we have more robust
nightly test options, and want to spend the time, we should think
about doing more rigorous stress testing that kills processes at
inopportune times and guarantees we don't leak. I've filed
pulumi/lumi#263 to do that.
This change fixes a few things:
* Most importantly, we need to place a leading "." in the paths
to Gometalinter, otherwise some sub-linters just silently skip
the directory altogether. errcheck is one such linter, which
is a very important one!
* Use an explicit Gometalinter.json file to configure the various
settings. This flips on a few additional linters that aren't
on by default (line line length checking). Sadly, a few that
I'd like to enable take waaaay too much time, so in the future
we may consider a nightly job (this includes code similarity,
unused parameters, unused functions, and others that generally
require global analysis).
* Now that we're running more, however, linting takes a while!
The core Lumi project now takes 26 seconds to lint on my laptop.
That's not terrible, but it's long enough that we don't want to
do the silly "run them twice" thing our Makefiles were previously
doing. Instead, we shall deploy some $$($${PIPESTATUS[1]}-1))-fu
to rely on the fact that grep returns 1 on "zero lines".
* Finally, fix the many issues that this turned up.
I think(?) we are done, except, of course, for needing to drive
down some of the cyclomatic complexity issues (which I'm possibly
going to punt on; see pulumi/lumi#259 for more details).
We were not propagating the error from `deployLatest` through
to the CLI error result. Despite out recent efforts to integrate
gometalinter, there were also several additional similar cases of
ignored error results reported by `errcheck`. Not yet clear why
these are not being reported via gometalinter.
Fixes#262.
After 233c5a8 landed, I noticed there are a few things to be fixed up:
* Run gometalinter in all the right places. We need to run both in
lint and lint_quiet targets. I've also cleaned up some of the logic
around what to suppress so there's less repetition.
* We currently @ meaningful commands, which is unfortunate, since it
makes debugging Makefiles tough (especially when looking at CI build
logs). Going forward, we should only use @ for meaningless commands,
like @echo.
* The AWS project wasn't actually running tslint, because it needs to
say `tslint './pack/**/*.ts' --exclude='./pack/node_modules/**'`.
The current script of `tslint lib/aws/pack/...` wasn't actually
running lint, hence we missed a lot of AWS lint issues.
* Fix up the issues that these fixes uncovered. Mostly err shadowing.
This continues the previous commit and establishes the interpreter
context so that we can use the new host interface. In summary:
* Instead of using the NullSource for destructions -- which
doesn't hook up an interpreter and so any reads of configuration
variables will fail -- we will enlighten the EvalSource to know
how to orchestrate destruction interpretation. The primary
difference is that we don't actually run the code, but *we do*
perform all of the necessary configuration and variable init.
* Associate the active interpreter with the plugin context as
we are executing, so that the host object can actually read the
state from the heap as requested to do so by attached plugins.
* Rename anything "engine" related to use the term "host"; this
avoids introducing unnecesarily new terminology.
* Add a new pkg/resource/provider/ package where we can begin
consolidating helper functionality for resource providers.
Right now, this includes a wrapper interface atop the gRPC
machinery necessary to contact the host, in addition to a
Main function that hides some boilerplate entrypoint code.
* Add a rpcutil.IsBenignCloseErr routine to let us ignore
"benign" gRPC errors that are knowingly returned at shutdown.
This commit completes pulumi/lumi#117.
This addresses CR feedback from @lukehoban; namely, that we should
be going through the Read API for location reads in the plugin host
to ensure that getters are invoked as appropriate.
I also made Location's various fields private so that we aren't
tempted to make this mistake elsewhere, effectively "forcing" us
to go through the accessor methods.
This change adds an engine gRPC interface, and associated implementation,
so that plugins may do interesting things that require "phoning home".
Previously, the engine would fire up plugins and talk to them directly,
but there was no way for a plugin to ask the engine to do anything.
The motivation here is so that plugins can read evaluator state, such
as config information, but this change also allows richer logging
functionality than previously possible. We will still auto-log any
stdout/stderr writes; however, explicit errors, warnings, informational,
and even debug messages may be written over the Log API.
This change implements the `get` function for resources. Per pulumi/lumi#83,
this allows Lumi scripts to actually read from the target environment.
For example, we can now look up a SecurityGroup from its ARN:
let group = aws.ec2.SecurityGroup.get(
"arn:aws:ec2:us-west-2:153052954103:security-group:sg-02150d79");
The returned object is a fully functional resource object. So, we can then
link it up with an EC2 instance, for example, in the usual ways:
let instance = new aws.ec2.Instance(..., {
securityGroups: [ group ],
});
This didn't require any changes to the RPC or provider model, since we
already implement the Get function.
There are a few loose ends; two are short term:
1) URNs are not rehydrated.
2) Query is not yet implemented.
One is mid-term:
3) We probably want a URN-based lookup function. But we will likely
wait until we tackle pulumi/lumi#109 before adding this.
And one is long term (and subtle):
4) These amount to I/O and are not repeatable! A change in the target
environment may cause a script to generate a different plan
intermittently. Most likely we want to apply a different kind of
deployment "policy" for such scripts. These are inching towards the
scripting model of pulumi/lumi#121, which is an entirely different
beast than the repeatable immutable infrastructure deployments.
Finally, it is worth noting that with this, we have some of the fundamental
underpinnings required to finally tackle "inference" (pulumi/lumi#142).
This change simplifies the generated Check interface for providers.
Instead of
Check(ctx context.Context, obj *T) ([]error, error)
where T is the resource type, we have
Check(ctx context.Context, obj *T, property string) error
This is done so that we can drive the calls to Check one property
at a time, allowing us to skip any that are computed. (Otherwise,
we may fail the verification erroneously.)
This has the added advantage that the Check implementations are
simpler and can simply return a single error. Furthermore, the
generated RPC code handles wrapping the result, so we can just do
return errors.New("bad");
rather than the previous reflection-laden junk
return resource.NewFieldError(
reflect.TypeOf(obj), awsservice.AWSResource_Property,
errors.New("bad"))
This change implements showing a summary of the current environment.
All you need to do is run
$ lumi env
and the current environment's information will be printed.
This makes it convenient to grab resource information that might be
required, for instance, to correlate with logs (e.g., lambda ARNs).
Eventually, as per pulumi/lumi#184, we want to print details about
all of the resources too.
Tests all of our commonly used examples.
Also sets test parallelism to 10 by default
since we are I/O bound on API calls to
the resource providers.
Also avoids using larger EC2 examples in
our samples so that we can keep our test
costs lower :-).
On the first turn, we want to distinguish between a coroutine
running that owns its turn, and a coroutine that knows it doesn't
own the turn and is simply awaiting its turn. The old Meet logic
wasn't quite right; instead, we'll have the caller tell us this.
We now have enough output properties implementation
working to change our API gateway examples and API
wrapper to correctly wire the API routes to the ARNs of
lambdas passed in to them.
We both wire up the lambda to the route, but also create
a permission specific to each route to assign to the
corresponding lambda - providing least privelege needed
for the API definition.
Also adds `string#toUpperCase` and fixes NewUniqueHex
to match how we are using it.
This change overwrites output property slots in runtime objects
after performing a CRUD operation, in addition to null or missing
slots, fixing #251. The problem is that we sometimes have output
property values pre-populated in an object, and sometimes don't,
depending on various things (both are legal). We should handle both.
The recent change to run the interpreter and planner on separate goroutines
created the need to perform rendezvous-style synchronization between them.
Although the case of an invoked function properly tore down the synchronization
by communicating the error, we seldom directly invoke functions for JavaScript
programs because the way module entrypoint code ends up in initializers.
This requires that we propagate errors correctly out of module and class
initializers, in the standard way, so that the unwind makes its way to the top.
This fixespulumi/lumi#246.
The primary purposes of this change is to mark only immediate ouptuts
on a resource object as "output" and categories the rest as computed.
It also contains a few minor things:
* Rebase atop the latest in master.
* Always marshal unknows as their default value.
* Permit computed as the existing ID property, in addition to null.
* Tidy up some asserts.
This change updates the ID/output propagation logic to properly handle
the case of replacements, in addition to accurately conveying the fact
that an update may change the values of output properties (but not the ID).
Also fixes a formatting issue with the replacement diffing displays.
This change introduces an OpSame planning step. The reason we need
this is so that we can apply the necessary output properties, including
the ID, even as we are simply walking the plan (i.e., when we aren't
actually performing a deployment). This ensures that the object state
evolves as required to let reads of output properties propagate in the
ways necessary to reproduce past executions of the program.
We need to run the post-construction hook *before* freezing an object's
readonly properties, since the hook will actually mutate the object in
the case of a deployment (it stores the output properties). In a sense,
this hook simply becomes an extension of the object's constructor.
* Assert new things in new places.
* Log more interesting tidbits during evaluation.
* Invoke the OnStart hook before triggering initializers.
* Tolerate nil prev snapshots during deletion calculation.
* Handle and serialize missing resource IDs as output props.
* Return "done" flag from Rendezvous.Meet.
This change refactors a number of aspects of the CLI's treatment of
steps, in line with the new scheme, and a number of other miscellaneous
and minor fixes. It also regenerates all RPC code impacted by recent renames.
This change restructures a lot more pertaining to deployments, snapshots,
environments, and the like.
The most notable change is that the notion of a deploy.Source is introduced,
which splits the responsibility between the deploy.Plan -- which simply
understands how to compute and carry out deployment plans -- and the idea
of something that can produce new objects on-demand during deployment.
The primary such implementation is evalSource, which encapsulates an
interpreter and takes a package, args, and config map, and proceeds to run
the interpreter in a distinct goroutine. It synchronizes as needed to
poke and prod the interpreter along its path to create new resource objects.
There are two other sources, however. First, a nullSource, which simply
refuses to create new objects. This can be handy when writing isolated
tests but is also used to simulate the "empty" environment as necessary to
do a complete teardown of the target environment. Second, a fixedSource,
which takes a pre-computed array of objects, and hands those, in order, to
the planning engine; this is mostly useful as a testing technique.
Boatloads of code is now changed and updated in the various CLI commands.
This further chugs along towards pulumi/lumi#90. The end is in sight.
This change guts the deployment planning and execution process, a
necessary component of pulumi/lumi#90.
The major effect of this change is that resources are actually
connected to the live objects, instead of being snapshots taken at
inopportune moments in time.
This change, part of pulumi/lumi#90, overhauls quite a bit of the
core resource, planning, environments, and related areas.
The biggest amount of movement comes from the splitting of pkg/resource
into multiple sub-packages. This results in:
- pkg/resource: just the core resource data structures.
- pkg/resource/deployment: all planning and deployment logic.
- pkg/resource/environment: all environment, configuration, and
serialized checkpoint structures and logic.
- pkg/resource/plugin: all dynamically loaded analyzer and
provider logic, including the actual loading and RPC mechanisms.
This also splits the resource abstraction up. We now have:
- resource.Resource: a shared interface.
- resource.Object: a resource that is connected to a live object
that will periodically observe mutations due to ongoing
evaluation of computations. Snapshots of its state may be
taken; however, this is purely a "pre-planning" abstraction.
- resource.State: a snapshot of a resource's state that is frozen.
In other words, it is no longer connected to a live object.
This is what will store provider outputs (ID and properties),
and is what may be serialized into a deployment record.
The branch is in a half-baked state as of this change; more changes
are to come...
LumiJS lambdas can now be serialized when they include calls to other LumiJS lambdas. The chain of lambda dependencies is jointly serialized into the target Lambda.
Also, LumiJS lambdas now include `node_modules` automatically in the AWS Lambda, ensuring the the runtime execution environment more closely matches the deployment time environment.
An early version of the gh-cicd example supporting #134 is added which uses these capabilities, currently including a mocked GitHub resource provider.
This change slightly refactors the way resources are created and
implemented. We now have two implementations of the Resource interface:
* `resource` (in resource_value.go), which is a snapshot of a resource's
state. All values are resolved and there is no live reference to any
heap state or objects. This will be used when serializing and/or
deserializing snapshots of deployments.
* `objectResource` (in resource_object.go), which is an implementation
of the Resource interface that wraps an underlying, live runtime object.
This currently introduces no functional difference, as fetching Inputs()
amounts to taking a snapshot of the full state. But this at least
gives us a leg to stand on in making sure that output properties are
read at the right times during evaluation.
This is a fundamental part of pulumi/lumi#90.
This change begins to track objects that are implicated in the
creation of computed values. This ultimately translates into the
resource URNs which are used during dependency analysis and
serialization. This is part of pulumi/lumi#90.
This change fixes the serialization of resource properties during
deployment checkpoints. We erroneously serialized empty arrays and
empty maps as though they were nil; instead, we want to keep them
serialized as non-nil empty collections, since the presence of a
value might be semantically meaningful. (We still skip nils.)
Also added some test cases.
This change implements `mapper.Encode` "for real" (that is, in a way
that isn't a complete embarrassment). It uses the obvious reflection
trickery to encode a tagged struct and its values as a JSON-like
in-memory map and collection of keyed values.
During this, I took the opportunity to also clean up a few other things
that had been bugging me. Namely, the presence of `mapper.Object` was
always error prone, since it isn't a true "typedef" in the sence that
it carries extra RTTI. Instead of doing that, let's just use the real
`map[string]interface{}` "JSON-map-like" object type. Even better, we
no longer require resource providers to deal with the mapper
infrastructure. Instead, the `Check` function can simply return an
array of errors. It's still best practice to return field-specific errors
to facilitate better diagnostics, but it's no longer required; and I've
added `resource.NewFieldError` to eliminate the need to import mapper.
As of this change, we can also consistently emit RPC structs with `lumi`
tags, rather than `lumi` tags on the way in and `json` on the way out.
This completes pulumi/lumi#183.
This changes the resource model to persist input and output properties
distinctly, so that when we diff changes, we only do so on the programmer-
specified input properties. This eliminates problems when the outputs
differ slightly; e.g., when the provider normalizes inputs, adds its own
values, or fails to produce new values that match the inputs.
This change simultaneously makes progress on pulumi/lumi#90, by beginning
tracking the resource objects implicated in a computed property's value.
I believe this fixes both #189 and #198.
This change alters diag.Message to not format strings and, instead,
encourages developers to use the Infof, Errorf, and Warningf varargs
functions. It also tests that arguments are never interepreted as
format strings.
The AssumeRolePolicyDocument property returned by the AWS IAM GetRole API returns
a URL-encoded JSON string, so we need to decode this before JSON unmarshalling.
The Code property returned by AWS Lambda GetFunction provides a pre-signed S3 URL,
which changes on each call, and is of a different format to what is provided by the user.
For now, we'll not store this back into the Function object.
Add additional output properties to AWS Lambda Function that are stable values returned
from GetFunction.
Also corrects a gap where some property delete operations were not being correctly reported.
This is a minor refactoring to introduce a ProviderHost interface
that is associated with the context and can be swapped in and out for
custom plugin behavior. This is required to write tests that mock
certain aspects, like loading packages from the filesystem.
In theory, this change incurs zero behavioral changes.
This change fixes up a few things so that updates correctly deal
with output properties. This involves a few things:
1) All outputs stored on the pre snapshot need to get propagated
to the post snapshot during planning at various points. This
ensures that the diffing logic doesn't need to be special cased
everywhere, including both the Lumi and the provider sides.
2) Names are changed to "input" properties (using a new `lumi` tag
option, `in`). These are properties that providers are expected
to know nothing about, which we must treat with care during diffs.
3) We read back properties, via Get, after doing an Update just like
we do after performing a Create. This ensures that if an update
has a cascading impact on other properties, it will be detected.
4) Inspecting a change, prior to updating, must be done using the
computed property set instead of the real one. This is to avoid
mutating the resource objects ahead of actually applying a plan,
which would be wrong and misleading.
This change remembers which properties were computed as outputs,
or even just read back as default values, during a deployment. This
information is required in the before/after comparison in order to
perform an intelligent diff that doesn't flag, for example, the absence
of "default" values in the after image as deletions (among other things).
As I was in here, I also cleaned up the way the provider interface
works, dealing with concrete resource types, making it feel a little
richer and less like we're doing in-memory RPC.
This change makes progress on a few things with respect to properly
receiving properties on the engine side, coming from the provider side,
of the RPC boundary. The issues here are twofold:
1. Properties need to get unmapped using a JSON-tag-sensitive
marshaler, so that they are cased properly, etc. For that, we
have a new mapper.Unmap function (which is ultra lame -- see
pulumi/lumi#138).
2. We have the reverse problem with respect to resource IDs: on
the send side, we must translate from URNs (which the engine
knows about) and provider IDs (which the provider knows about);
similarly, then, on the receive side, we must translate from
provider IDs back into URNs.
As a result of these getting fixed, we can now properly marshal the
resulting properties back into the resource object during the plan
execution, alongside propagating and memoizing its ID.
The change to flow logging to plugins is nice, however, it can be
annoying because all writes to stderr are interepreted on the Lumi
side as errors. After this change, we will only flow if
--logflow is passed, e.g. as in
$ lumi --logtostderr --logflow -v=9 deploy ...
This change modifies the existing resource provider RPC interface slightly.
Instead of the Create API returning the bag of output properties, we will
rely on the Get API to do so. As a result, this change takes an initial
whack at implementing Get on all existing AWS resources. The Get API needs
to return a fully populated structure containing all inputs and outputs.
Believe it or not, this is actually part of pulumi/lumi#90.
This was done because just returning output properties is insufficient.
Any input properties that weren't supplied may have default values, for
example, and it is wholly reasonable to expect Lumi scripts to depend on
those values in addition to output values.
This isn't fully functional in its current form, because doing this
change turned up many other related changes required to enable output
properties. For instance, at the moment resource properties are defined
in terms of `resource.URN`s, and yet unfortunately the provider side
knows nothing of URNs (instead preferring to deal in `resource.ID`s).
I am going to handle that in a subsequent isolated change, since it will
have far-reaching implications beyond just modifying create and get.
This change introduces the notion of a computed versus an output
property on resources. Technically, output is a subset of computed,
however it is a special kind that we want to treat differently during
the evaluation of a deployment plan. Specifically:
* An output property is any property that is populated by the resource
provider, not code running in the Lumi type system. Because these
values aren't available during planning -- since we have not yet
performed the deployment operations -- they will be latent values in
our runtime and generally missing at the time of a plan. This is no
problem and we just want to avoid marshaling them in inopportune places.
* A computed property, on the other hand, is a different beast altogehter.
Although true one of these is missing a value -- by virtue of the fact
that they too are latent values, bottoming out in some manner on an
output property -- they will appear in serializable input positions.
Not only must we treat them differently during the RPC handshake and
in the resource providers, but we also want to guarantee they are gone
by the time we perform any CRUD operations on a resource. They are
purely a planning-time-only construct.
This change includes approximately 1/3rd of the change necessary
to support output properties, as per pulumi/lumi#90.
In short, the runtime now has a new hidden type, Latent<T>, which
represents a "speculative" value, whose eventual type will be T,
that we can use during evaluation in various ways. Namely,
operations against Latent<T>s generally produce new Latent<U>s.
During planning, any Latent<T>s that end up in resource properties
are transformed into "unknown" property values. An unknown property
value is legal only during planning-time activities, such as Check,
Name, and InspectChange. As a result, those RPC interfaces have
been updated to include lookaside maps indicating which properties
have unknown values. My intent is to add some helper functions to
make dealing with this circumstance more correct-by-construction.
For now, using an unresolved Latent<T> in a conditional will lead
to an error. See pulumi/lumi#67. Speculating beyond these -- by
supporting iterative planning and application -- is something we
want to support eventually, but it makes sense to do that as an
additive change beyond this initial support. That is a missing 1/3.
Finally, the other missing 1/3rd which will happen much sooner
than the rest is restructuing plan application so that it will
correctly observe resolution of Latent<T> values. Right now, the
evaluation happens in one single pass, prior to the application, and
so Latent<T>s never actually get witnessed in a resolved state.
This change flows --logtostderr and -v=x settings to any dynamically
loaded plugins so that running Lumi's command line with these flags
will also result in the plugins logging at the requested levels. I've
found this handy for debugging purposes.
Resolves#137.
This is an initial pass for supporting JavaScript lambda syntax for defining an AWS Lambda Function.
A higher level API for defining AWS Lambda Function objects `aws.lambda.FunctionX` is added which accepts a Lumi lambda as an argument, and uses that lambda to generate the AWS Lambda Function code package.
LumiJS lambdas are serialized as the JavaScript text of the lambda body, along with a serialized version of the environment that is deserialized at runtime and used as the context for the body of the lambda.
Remaining work to further improve support for lambdas is being tracked in #173, #174, #175, and #177.
The storing of output properties won't work correctly until pulumi/lumi#90
is completed. The update logic sees properties that weren't supplied by the
developer and thinks this means an update is required; this is easy to fix
but better to just roll into the overall pending change that will land soon.
We need a stable object key enumeration order and we might as well leverage
ECMAScript's definition for this. As of ES6, key ordering is specified; see
https://tc39.github.io/ecma262/#sec-ordinaryownpropertykeys.
I haven't fully implemented the "numbers come first part" (we can do this as
soon as we have support for Object.keys()), but the chronological part works.
Our initial implementation of assets was intentionally naive, because
they were limited to single-file assets. However, it turns out that for
real scenarios (like lambdas), we want to support multi-file assets.
In this change, we introduce the concept of an Archive. An archive is
what the term classically means: a collection of files, addressed as one.
For now, we support three kinds: tarfile archives (*.tar), gzip-compressed
tarfile archives (*.tgz, *.tar), and normal zipfile archives (*.zip).
There is a fair bit of library support for manipulating Archives as a
logical collection of Assets. I've gone to great length to avoid making
copies, however, sometimes it is unavoidable (for example, when sizes
are required in order to emit offsets). This is also complicated by the
fact that the AWS libraries often want seekable streams, if not actual
raw contiguous []byte slices.
Unfortunately, this wasn't a great name. The old one stunk, but the
new one was misleading at best. The thing is, this isn't about performing
an update -- it's about NOT doing an update, depending on its return value.
Further, it's not just previewing the changes, it is actively making a
decision on what to do in response to them. InspectUpdate seems to convey
this and I've unified the InspectUpdate and Update routines to take a
ChangeRequest, instead of UpdateRequest, to help imply the desired behavior.
This is an initial implementation of the Coconut IDL Compiler (CIDLC).
This is described further in
https://github.com/pulumi/coconut/blob/master/docs/design/idl.md,
and the work is tracked by coconut/pulumi#133.
I've been kicking the tires with this locally enough to checkpoint the
current version. There are quite a few loose ends not yet implemented,
most of them minor, with the exception of the RPC stub generation which
I need to flesh out more before committing.
In order to support output properties (pulumi/coconut#90), we need to
modify the Create gRPC interface for resource providers slightly. In
addition to returning the ID, we need to also return any properties
computed by the AWS provider itself. For instance, this includes ARNs
and IDs of various kinds. This change simply propagates the resources
but we don't actually support reading the outputs just yet.
This change renames two provider methods:
* Read becomes Get.
* UpdateImpact becomes PreviewUpdate.
These just read a whole lot nicer than the old names.
The order of operations for stderr/stdout monitoring with plugins
managed to hide some important errors. For example, if something
was written to stderr *before* the port was parsed from stdout, a
very possible scenario if the plugin fails before it has even
properly sarted, then we would silently drop the stderr on the floor
leaving behind no indication of what went wrong. The new ordering
ensures that stderr is never ignored with some minor improvements
in the case that part of the port is parsed from stdout but it
ultimately ends in an error (e.g., if an EOF occurs prematurely).
