flow php

Symfony Filesystem Bundle

Symfony bundle integrating Flow PHP's Filesystem library with Symfony applications, providing a typed FilesystemTable service that mounts multiple filesystems under URI protocols, pluggable factories, console commands for managing files across mounted protocols, and first-class OpenTelemetry integration.

Installation

For detailed installation instructions, see the installation page.

Register the bundle in config/bundles.php:

return [
    // ...
    Flow\Bridge\Symfony\FilesystemBundle\FlowFilesystemBundle::class => ['all' => true],
];

Overview

This bundle integrates Flow PHP's Filesystem library with Symfony applications. It provides:

  • Mount-protocol routing — mount filesystems under URI protocols of your choice (file, memory, aws-s3, warehouse, archive, …) and resolve them at runtime via $table->for(...)
  • Pluggable filesystem factories — register custom backends with the #[AsFilesystemFactory] attribute or a DI tag
  • Built-in factoriesfile, memory, stdout, aws_s3, and azure_blob ship out of the box
  • Console commandsflow:filesystem:* (alias flow:fs:*) for ls, cat, cp, mv, rm, stat, touch against any configured filesystem
  • Telemetry integration — wrap every filesystem in TraceableFilesystem via OpenTelemetry
  • Multi-fstab support (advanced) — configure several independent FilesystemTable services when you really need them

Quick Start

A minimal configuration mounts one or more filesystems inside a single fstab. The fstab name is arbitrary — the bundle auto-detects the only fstab and exposes it as Flow\Filesystem\FilesystemTable:

# config/packages/flow_filesystem.yaml
flow_filesystem:
  fstabs:
    default:
      filesystems:
        file:
          type: file
        memory:
          type: memory

The YAML key under filesystems: (file, memory) is the mount protocol the filesystem will be registered under. The type: field identifies which built-in (or custom) factory builds it.

Inject the table anywhere via autowiring:

use Flow\Filesystem\FilesystemTable;

final class ReportBuilder
{
    public function __construct(private readonly FilesystemTable $fstab)
    {
    }

    public function read(string $uri) : string
    {
        return $this->fstab->for('file')->readFrom(/* path */)->content();
    }
}

FilesystemTable::for() accepts either a raw protocol string ('file', 'aws-s3', 'warehouse') or a Path — when given a Path, the table resolves the filesystem by the path's URI scheme.

Most applications need exactly one fstab with multiple filesystems mounted under it. Multi-fstab support exists for advanced cases — see Multi-Fstab Support.

Configuration Reference

Fstabs

At least one fstab is required. Each fstab declares a set of filesystems. The YAML key under filesystems: is the mount protocol and must match the regex /^[a-zA-Z][a-zA-Z0-9+.-]+$/ (letters, digits, ., -, +). The type: field picks the factory that builds the filesystem.

flow_filesystem:
  fstabs:
    default:
      filesystems:
        file:
          type: file
        memory:
          type: memory
        warehouse:                  # mount protocol
          type: aws_s3              # factory lookup key
          bucket: '%env(S3_BUCKET)%'

Because protocol and type are independent, one fstab can mount the same backend multiple times under different protocols — two S3 buckets as warehouse and archive, for example. Mount each explicitly:

flow_filesystem:
  fstabs:
    default:
      filesystems:
        warehouse:
          type: aws_s3
          bucket: '%env(S3_WAREHOUSE_BUCKET)%'
          client_service_id: app.s3_client
        archive:
          type: aws_s3
          bucket: '%env(S3_ARCHIVE_BUCKET)%'
          client_service_id: app.s3_client

The fstab is wired as a private .flow_filesystem.fstab.<name> service and aliased to Flow\Filesystem\FilesystemTable for autowiring.

Default Fstab

When you only have one fstab, the bundle picks it as the default automatically — no default_fstab key needed, and the fstab name does not have to be default. Set default_fstab explicitly only when you have multiple fstabs and the one you want as the default is not literally named default.

Telemetry

Enable telemetry per fstab to wrap every mounted filesystem with Flow\Filesystem\Telemetry\TraceableFilesystem. You must wire a Flow\Telemetry\Telemetry service and a Psr\Clock\ClockInterface service yourself — the bundle does NOT provide defaults.

flow_filesystem:
  fstabs:
    default:
      telemetry:
        enabled: true
        telemetry_service_id: app.flow_telemetry   # Required: Telemetry service ID
        clock_service_id: app.system_clock         # Required: PSR-20 clock service
        options:
          trace_streams: true                       # Record stream open/close in traces
          collect_metrics: true                     # Collect read/write metrics
      filesystems:
        file:
          type: file
        memory:
          type: memory

With telemetry.enabled: false (the default) the fstab is wired without any telemetry overhead.

Built-in Filesystems

The bundle ships with factories for these types out of the box:

type Options Notes
file none Local filesystem via native PHP calls.
memory none In-memory filesystem, lifetime of the kernel.
stdout none Write-only sink that targets STDOUT.
aws_s3 bucket, client*, options Requires flow-php/filesystem-async-aws-bridge.
azure_blob container, client*, options Requires flow-php/filesystem-azure-bridge.

Each entry under filesystems: is resolved against a registered FilesystemFactory by its type() value. To introduce a new type, register your own factory (see Custom Filesystem Factory).

AWS S3

Install the bridge:

composer require flow-php/filesystem-async-aws-bridge

Mode A — bring your own AsyncAws\S3\S3Client:

flow_filesystem:
  fstabs:
    default:
      filesystems:
        aws-s3:
          type: aws_s3
          bucket: my-bucket
          client_service_id: app.async_aws_s3_client

Mode B — inline client config:

flow_filesystem:
  fstabs:
    default:
      filesystems:
        aws-s3:
          type: aws_s3
          bucket: my-bucket
          client:
            region: '%env(AWS_REGION)%'
            access_key_id: '%env(AWS_ACCESS_KEY_ID)%'
            access_key_secret: '%env(AWS_SECRET_ACCESS_KEY)%'
            endpoint: ~                # optional, MinIO/R2/Scaleway/LocalStack
            path_style_endpoint: false
            profile: ~
            debug: false
            http_client_service_id: ~
            logger_service_id: ~
          options:
            block_size: 6291456

Any null client.* key is omitted from the underlying AsyncAws resolution chain, so environment-based credential discovery still works.

Azure Blob Storage

Install the bridge:

composer require flow-php/filesystem-azure-bridge

Mode A — bring your own Flow\Azure\SDK\BlobServiceInterface:

flow_filesystem:
  fstabs:
    default:
      filesystems:
        azure-blob:
          type: azure_blob
          container: my-container
          client_service_id: app.azure_blob_service

Mode B — inline client config (shared key auth):

flow_filesystem:
  fstabs:
    default:
      filesystems:
        azure-blob:
          type: azure_blob
          container: my-container
          client:
            account_name: '%env(AZURE_ACCOUNT_NAME)%'
            auth:
              shared_key: '%env(AZURE_ACCOUNT_KEY)%'
            url_factory:                  # optional, e.g. Azurite
              host: 127.0.0.1
              port: '10000'
              https: false
            http_client_service: ~        # optional PSR-18 client
            request_factory_service: ~    # optional PSR-17 request factory
            stream_factory_service: ~     # optional PSR-17 stream factory
            logger_service_id: ~          # optional PSR-3 logger
          options:
            block_size: 4194304
            list_blob_max_results: 100

SAS token auth is not supported yet.

Console Commands

The bundle ships a small set of flow:filesystem:* console commands that operate on any mounted filesystem. Unlike league/flysystem-bundle, which does not provide any CLI tools, these commands are a Flow-specific differentiator: you can inspect, read, write, copy, move, and delete files across mounted protocols straight from bin/console.

Each command also has a shorter flow:fs:* alias (e.g. flow:fs:ls).

Filesystem Commands

Command Description
flow:filesystem:ls List entries under a directory URI
flow:filesystem:cat Stream a file URI to STDOUT
flow:filesystem:cp Copy a file between two URIs
flow:filesystem:mv Move a file between two URIs (copy + delete source)
flow:filesystem:rm Remove a file or directory
flow:filesystem:stat Print metadata about a file or directory URI
flow:filesystem:touch Create an empty file at a URI

Common options:

Option Description
--fstab (-f) (advanced) Target a specific fstab when more than one is configured; defaults to the bundle default fstab

Per-command options:

Command Options
ls --recursive (-r), --short (-s), --limit=N, --offset=N, --page-size=N, --format=json
rm --recursive (-r) — required for directories
stat --format=json
touch --force (-F) — overwrite existing file with empty content

ls output

By default ls prints a table with Type, Size, Modified, URI columns. Size is formatted with binary units (3.12 MiB, 2.50 KiB, raw bytes below 1 KiB). Modified is ISO-8601. Both come from the backend's listing response — no per-file HEAD or GET is issued.

  • --short drops the metadata columns, leaves only URI.
  • --format=json emits newline-delimited JSON (NDJSON), one object per line — pipe-friendly for scripting.

Results are always paginated in tables of --page-size rows (default 10). When stdout is attached to an interactive terminal, ls prompts between pages with "Show next N entries? [yes/no] (yes)" — Enter continues, no stops. Piped or redirected output flows all pages continuously without prompting.

--limit=N caps total entries (no cap by default). When limit is reached, the command emits a truncated warning and skips the page prompt. --offset=N skips the first N entries before listing; note that offset is client-side, so on S3 the backend still walks the skipped keys — deep offsets on huge buckets are slow.

stat output

stat prints a definition list with URI, Protocol, Path, Type, Size (human-readable), and Modified. Same metadata source as ls --long (now default) — the backend's single status() call, no extra stream opened. Pattern paths (memory://*.txt, **/*.parquet) are rejected with a clear error.

URI Format

Path arguments are full URIs in the form <protocol>://<path>. When a protocol is omitted, the bundle assumes the local filesystem (file://) and resolves relative paths against the current working directory:

bin/console flow:filesystem:ls ./reports          # → file:///<cwd>/reports
bin/console flow:filesystem:ls /var/log           # → file:///var/log
bin/console flow:filesystem:ls memory://reports   # explicit protocol

Examples

# Paginated table with type/size/modified; press Enter to go through pages
bin/console flow:filesystem:ls aws-s3://bucket/

# Top 50 entries only, skipping the first 20
bin/console flow:filesystem:ls aws-s3://bucket/ --offset=20 --limit=50

# Larger pages for a bigger terminal
bin/console flow:filesystem:ls aws-s3://bucket/ --page-size=50

# URI-only output, piped into another command
bin/console flow:filesystem:ls aws-s3://bucket/ --short --limit=1000 | sort

# NDJSON for scripts
bin/console flow:filesystem:ls aws-s3://bucket/ --format=json | jq '.uri'

bin/console flow:filesystem:cat file:///tmp/dump.csv
bin/console flow:filesystem:cp memory://staging/out.parquet file:///var/lib/flow/out.parquet
bin/console flow:filesystem:mv memory://tmp/result.json aws-s3://bucket/result.json
bin/console flow:filesystem:rm file:///var/cache/flow --recursive
bin/console flow:filesystem:stat aws-s3://bucket/key.bin --format=json
bin/console flow:filesystem:touch file:///tmp/.flow_smoke_test

cp / mv work across protocols, not across fstabs

cp and mv happily copy between any two protocols mounted in the same fstab — e.g. memory://… → aws-s3://… or file:///… → azure-blob://…. Internally they use the Flow\Filesystem\Operations\Copy / Move operations which stream in 8 KiB chunks by default, so large files don't blow up memory. Same-filesystem moves (e.g. aws-s3://a → aws-s3://b) use the backend's native mv for server-side optimizations (rename on local, CopyObject+DeleteObject on S3, CopyBlob+DeleteBlob on Azure).

Cross-filesystem mv is not atomic: if the source removal fails after a successful write, the destination is present and the source remains; re-running is idempotent.

What these commands do not do is bridge two separate fstabs: source and destination must resolve through the same FilesystemTable. Since most apps use a single fstab with everything mounted under it, this is rarely a real constraint. If you genuinely need to move data between two fstabs, run two commands and stage through a temporary location:

bin/console flow:filesystem:cp aws-s3://bucket/file.csv file:///tmp/file.csv --fstab=warehouse
bin/console flow:filesystem:cp file:///tmp/file.csv azure-blob://container/file.csv --fstab=archive

mkdir is intentionally absent

Remote object stores (S3, Azure Blob, …) do not have a real concept of directories — they expose flat keyspaces with / as a convention. Rather than emulate mkdir inconsistently across backends, the bundle omits the command entirely. Directories appear when files appear inside them.

Multi-Fstab Support

Advanced. Most applications should stick to a single fstab with multiple filesystems mounted under it. Reach for multi-fstab only when you need fully isolated tables — e.g. strict separation between read-only archive storage and a read/write working area, or two completely independent configurations that should never bleed across to one another.

The bundle supports multiple independent fstabs, each with its own protocol keyspace:

flow_filesystem:
  default_fstab: primary
  fstabs:
    primary:
      filesystems:
        file:
          type: file

    analytics:
      filesystems:
        memory:
          type: memory
        file:
          type: file

    archive:
      filesystems:
        aws-s3:
          type: aws_s3
          bucket: '%env(ARCHIVE_BUCKET)%'

Each fstab gets its own .flow_filesystem.fstab.<name> service. The default fstab is automatically aliased to Flow\Filesystem\FilesystemTable, allowing direct type-hint injection without specifying a fstab name. Each named fstab is also aliased as Flow\Filesystem\FilesystemTable $<camelCasedName>Fstab for named-argument autowiring:

use Flow\Filesystem\FilesystemTable;

final class ReportBuilder
{
    public function __construct(
        private readonly FilesystemTable $fstab,           // → primary (default)
        private readonly FilesystemTable $analyticsFstab,  // → analytics
        private readonly FilesystemTable $archiveFstab,    // → archive
    ) {
    }

    public function read() : string
    {
        return $this->fstab->for('file')->readFrom(/* path */)->content();
    }
}

Target a specific fstab with any console command:

bin/console flow:filesystem:ls aws-s3://bucket/reports --fstab=archive

Custom Filesystem Factory

The bundle has no concept of "custom" filesystems — every filesystem is created by a FilesystemFactory. To plug in your own backend, implement Flow\Bridge\Symfony\FilesystemBundle\Filesystem\FilesystemFactory:

namespace App\Flow;

use Flow\Bridge\Symfony\FilesystemBundle\Filesystem\FilesystemFactory;
use Flow\Filesystem\Filesystem;

final class MyFilesystemFactory implements FilesystemFactory
{
    public function type() : string
    {
        return 'my_backend';
    }

    public function create(string $protocol, array $config) : Filesystem
    {
        // $protocol is the YAML key (mount protocol) the user chose.
        // $config is the array under filesystems.<protocol> in YAML with `type` already stripped.
    }
}

type() returns the factory lookup key — it's what users put under type: in YAML. The mount protocol is a separate concept and comes from the YAML key (passed to create() as $protocol).

There are two ways to register the factory.

Attribute-Based Discovery

Annotate the factory class with #[AsFilesystemFactory] for automatic discovery:

namespace App\Flow;

use Flow\Bridge\Symfony\FilesystemBundle\Attribute\AsFilesystemFactory;
use Flow\Bridge\Symfony\FilesystemBundle\Filesystem\FilesystemFactory;
use Flow\Filesystem\Filesystem;

#[AsFilesystemFactory(type: 'my_backend')]
final class MyFilesystemFactory implements FilesystemFactory
{
    public function type() : string { return 'my_backend'; }
    public function create(string $protocol, array $config) : Filesystem { /* ... */ }
}

As long as your service is autoconfigured (the default in services.yaml for everything under your App\ namespace), the bundle automatically attaches the flow_filesystem.factory tag with the right type attribute.

Explicit Tag

Useful if your factory lives in a service that doesn't have autoconfigure enabled (e.g. third-party namespaces, manual definitions):

services:
  app.flow_filesystem.factory.my_backend:
    class: App\Flow\MyFilesystemFactory
    tags:
      - { name: flow_filesystem.factory, type: my_backend }

Either way, you can then mount the backend under any protocol in any fstab:

flow_filesystem:
  fstabs:
    default:
      filesystems:
        my-mount:
          type: my_backend
          foo: bar    # arbitrary options handed to the factory's create()

Notes:

  • The type attribute on the tag (or on #[AsFilesystemFactory]) must match type() exactly.
  • A type can be served by exactly one factory; registering two factories for the same type fails at compile time.
  • Within a single fstab, a mount protocol (the YAML key under filesystems:) can be used exactly once — this is enforced by FilesystemTable itself. To mount the same backend twice with different options (e.g. two S3 buckets), use two distinct mount protocols pointing to the same type.

Comparison with league/flysystem-bundle

  • Multi-fstab: each fstab is an independent FilesystemTable service with its own protocol keyspace. Flysystem Bundle wires individual filesystems keyed only by name.
  • Mount-protocol routing: filesystems inside a fstab are resolved at runtime via $table->for('warehouse') / $table->for($path), so application code can hand-off across protocols without knowing service ids.
  • Factory tag: filesystem types are pluggable via a standard flow_filesystem.factory DI tag; third-party libraries can ship their own factory without bundle changes.
  • CLI commands: flow:filesystem:* ship with the bundle and operate on any configured fstab. Flysystem Bundle does not ship any console commands.
  • Telemetry first-class: OTel TraceableFilesystem is wired by simply toggling telemetry.enabled: true per fstab.
  • No autoconfigure magic: every tagged service and compiler-pass action is explicit, matching the Symfony 6.4+/7.4+/8.0+ bundle best practices.

Complete Example

A typical single-fstab setup with local + S3 mounts and telemetry enabled:

# config/packages/flow_filesystem.yaml
flow_filesystem:
  fstabs:
    default:
      telemetry:
        enabled: true
        telemetry_service_id: app.flow_telemetry
        clock_service_id: app.system_clock
        options:
          trace_streams: true
          collect_metrics: true
      filesystems:
        file:
          type: file
        memory:
          type: memory
        aws-s3:
          type: aws_s3
          bucket: '%env(S3_BUCKET)%'
          client:
            region: '%env(AWS_REGION)%'
            access_key_id: '%env(AWS_ACCESS_KEY_ID)%'
            access_key_secret: '%env(AWS_SECRET_ACCESS_KEY)%'
          options:
            block_size: 6291456

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