Add HTTP upload configuration support

docs/config.md

@@ -10,7 +10,7 @@ If `--config` is omitted, `run` uses:
 /usr/local/etc/distributor/config.yml
 ```
 
-Config parsing rejects unknown YAML fields. The executable backends are `local`, `ssh`, and `s3`.
+Config parsing rejects unknown YAML fields. The executable `run` backends are `local`, `ssh`, and `s3`. The schema also accepts `http_upload` as a source-only ingestion backend configuration.
 
 ## Minimal Local Config
 
@@ -31,6 +31,14 @@ This publishes source files only. It uses the default validation and transfer po
 ## Production-Oriented Local Config
 
 ```yaml
+server:
+  http:
+    bind: 127.0.0.1:8080
+    staging_root: /var/spool/distributor
+    max_upload_size: 20MB
+    queue_size: 16
+    max_concurrency: 1
+    retention: 24h
 pipelines:
   - id: reports
     source:
@@ -52,6 +60,38 @@ pipelines:
           on_conflict: fail
 ```
 
+## HTTP Upload Source Configuration
+
+HTTP upload sources are configured as pipeline sources only. They are not valid destination backends.
+
+```yaml
+server:
+  http:
+    bind: 127.0.0.1:8080
+    staging_root: /var/spool/distributor
+    max_upload_size: 20MB
+    queue_size: 16
+    max_concurrency: 1
+    retention: 24h
+pipelines:
+  - id: weather-daily
+    source:
+      backend: http_upload
+      token_env: WEATHER_DAILY_UPLOAD_TOKEN
+      staging_path: /var/spool/distributor/weather-daily
+      max_upload_size: 20MB
+    destinations:
+      - id: archive
+        backend: local
+        path: /srv/reports/archive
+```
+
+`source.token_env` is required and names the environment variable or `secrets.directory` file that provides the bearer token. Literal upload tokens are not supported in YAML.
+
+`source.staging_path` is optional. When omitted, it defaults to `<server.http.staging_root>/<pipeline id>`.
+
+`source.max_upload_size` is optional. When omitted, it defaults to `server.http.max_upload_size`.
+
 ## HTML Publication
 
 To publish generated sidecar HTML from Markdown files:
@@ -143,6 +183,12 @@ Output URLs are built from `links.base_url`, the destination bundle path, and th
 
 Top level:
 
+- `server.http.bind`: optional HTTP bind address; defaults to `127.0.0.1:8080`.
+- `server.http.staging_root`: optional root for default HTTP upload staging paths; defaults to `/var/spool/distributor`.
+- `server.http.max_upload_size`: optional default upload size limit; defaults to `20MB`.
+- `server.http.queue_size`: optional HTTP upload admission queue size; defaults to `16`.
+- `server.http.max_concurrency`: optional HTTP upload worker concurrency; defaults to `1`.
+- `server.http.retention`: optional completed upload retention duration; defaults to `24h`.
 - `secrets.directory`: optional credential secrets directory.
 - `pipelines`: required non-empty list.
 
@@ -170,6 +216,9 @@ Source backend:
 - `force_path_style`: optional for `s3`; defaults to `true`. Set `false` only for services that require virtual-host addressing.
 - `credentials.access_key_id_env`: optional S3 credential environment variable name.
 - `credentials.secret_access_key_env`: optional S3 credential environment variable name.
+- `token_env`: required for `http_upload`; names the token environment variable or secret-file name.
+- `staging_path`: optional for `http_upload`; defaults below `server.http.staging_root` using the pipeline id.
+- `max_upload_size`: optional for `http_upload`; defaults to `server.http.max_upload_size`.
 
 Destination:
 
@@ -187,6 +236,20 @@ Accepted backend names:
 - `local`: executable; requires `path`.
 - `ssh`: executable; requires `host` and `path`.
 - `s3`: executable; requires `endpoint` and `bucket`.
+- `http_upload`: source-only configuration; requires `token_env`.
+
+## Size And Duration Values
+
+Upload size fields use an integer plus one of the supported binary-size suffixes:
+
+- `B`
+- `KB`
+- `MB`
+- `GB`
+
+Suffix multipliers use powers of 1024. Size values must be greater than zero after defaults are applied.
+
+HTTP retention uses Go-style duration strings such as `24h`, `90m`, or `168h`. Retention must be greater than zero after defaults are applied.
 
 ## SSH Backend
 
@@ -266,6 +329,14 @@ Defaults are applied after YAML decoding and before validation:
 - SSH `host_key_policy: accept-new`
 - S3 `region: us-east-1`
 - S3 `force_path_style: true`
+- `server.http.bind: 127.0.0.1:8080`
+- `server.http.staging_root: /var/spool/distributor`
+- `server.http.max_upload_size: 20MB`
+- `server.http.queue_size: 16`
+- `server.http.max_concurrency: 1`
+- `server.http.retention: 24h`
+- `source.staging_path: /var/spool/distributor/<pipeline id>` for `http_upload`
+- `source.max_upload_size: server.http.max_upload_size` for `http_upload`
 - `transform.markdown_to_html.mode: sidecar` when a Markdown-to-HTML transform block is present and mode is omitted
 - `publish.source: true`
 - `publish.html: false`

docs/internal/config.md

@@ -6,7 +6,7 @@
 
 ## Inputs and outputs
 
-Input is a YAML file containing optional `secrets` and required `pipelines`. Output is a `Config` value with defaults applied and validation completed. Load failures include the config path and whether the failure occurred during file loading, YAML parsing, or validation.
+Input is a YAML file containing optional `server`, optional `secrets`, and required `pipelines`. Output is a `Config` value with defaults applied and validation completed. Load failures include the config path and whether the failure occurred during file loading, YAML parsing, or validation.
 
 ## Loading flow
 
@@ -20,6 +20,14 @@ Known-field checking rejects misspelled or unknown YAML keys before defaults and
 
 Defaults are applied in `ApplyDefaults`:
 
+- HTTP server `bind` defaults to `127.0.0.1:8080`;
+- HTTP server `staging_root` defaults to `/var/spool/distributor`;
+- HTTP server `max_upload_size` defaults to `20MB`;
+- HTTP server `queue_size` defaults to `16`;
+- HTTP server `max_concurrency` defaults to `1`;
+- HTTP server `retention` defaults to `24h`;
+- `http_upload` source `staging_path` defaults to `<server.http.staging_root>/<pipeline id>`;
+- `http_upload` source `max_upload_size` defaults to `server.http.max_upload_size`;
 - pipeline validation defaults `on_digest_mismatch` to `fail`;
 - SSH backend `port` defaults to `22`;
 - SSH backend `host_key_policy` defaults to `accept-new`;
@@ -34,7 +42,11 @@ Defaults are applied in `ApplyDefaults`:
 
 ## Validation responsibilities
 
-Validation requires at least one pipeline, slug-like unique pipeline ids, one source per pipeline, at least one destination, slug-like unique destination ids within each pipeline, backend-specific required fields, valid validation policy, valid publish and transform combinations, valid destination path mapping mode, valid destination link config, and valid transfer actions.
+Validation requires positive HTTP server limits and retention, at least one pipeline, slug-like unique pipeline ids, one source per pipeline, at least one destination, slug-like unique destination ids within each pipeline, backend-specific required fields, valid validation policy, valid publish and transform combinations, valid destination path mapping mode, valid destination link config, and valid transfer actions.
+
+HTTP upload sources require `token_env`, a staging path after defaults, and a positive maximum upload size. Literal token fields are not part of the YAML schema. The `http_upload` backend is accepted only for sources and rejected for destinations.
+
+Upload size values are parsed from strings with `B`, `KB`, `MB`, or `GB` suffixes using 1024 multipliers. Retention values are parsed with `time.ParseDuration`. Explicit zero values fail validation; omitted values receive defaults before validation.
 
 Transfer validation accepts `replace` for `on_destination_newer` and `on_conflict`, but publish planning honors those destructive actions only when the current run explicitly requests force.
 
@@ -46,12 +58,14 @@ Destination links are optional. When a `links` block is present, `base_url` is r
 
 ## Executable support boundary
 
-Config validation accepts `local`, `ssh`, and `s3` backend shapes. Runtime execution opens all three through `internal/app`.
+Config validation accepts `local`, `ssh`, `s3`, and source-only `http_upload` backend shapes. Runtime execution opens `local`, `ssh`, and `s3` through `internal/app`.
 
 SSH config uses structured fields: `host`, optional `user`, optional `port`, `path`, optional `ssh_key_file`, optional `known_hosts`, and optional `host_key_policy`. `host_key_policy` accepts YAML booleans and strings and normalizes `true`/`strict`, `accept-new`, and `false`/`off`.
 
 S3 config requires `endpoint` and `bucket`, normalizes optional `prefix`, defaults `region` to `us-east-1`, and defaults omitted `force_path_style` to `true` while preserving explicit `false`.
 
+HTTP upload config is source-only. Config owns its YAML shape, defaulting, size and duration parsing, and validation. The config package does not resolve `token_env`, authenticate requests, stage uploads, or execute HTTP upload sources.
+
 ## Secrets and credential resolution
 
 `secrets.directory` points to a directory of credential files. `LoadSecretEnvironment` reads regular files and symlinks to regular files, rejects invalid filenames, trims exactly one trailing LF or CRLF, and returns an `Environment` resolver plus conflict metadata.

internal/config/config.go

@@ -1,10 +1,24 @@
 package config
 
 type Config struct {
+	Server    Server     `yaml:"server"`
 	Secrets   Secrets    `yaml:"secrets"`
 	Pipelines []Pipeline `yaml:"pipelines"`
 }
 
+type Server struct {
+	HTTP HTTPServer `yaml:"http"`
+}
+
+type HTTPServer struct {
+	Bind           string    `yaml:"bind"`
+	StagingRoot    string    `yaml:"staging_root"`
+	MaxUploadSize  *ByteSize `yaml:"max_upload_size"`
+	QueueSize      int       `yaml:"queue_size"`
+	MaxConcurrency int       `yaml:"max_concurrency"`
+	Retention      *Duration `yaml:"retention"`
+}
+
 type Secrets struct {
 	Directory string `yaml:"directory"`
 }
@@ -50,6 +64,13 @@ type Backend struct {
 	ForcePath *bool       `yaml:"force_path_style"`
 	Creds     Credentials `yaml:"credentials"`
 	SSH       SSH         `yaml:",inline"`
+	Upload    HTTPUpload  `yaml:",inline"`
+}
+
+type HTTPUpload struct {
+	TokenEnv      string    `yaml:"token_env"`
+	StagingPath   string    `yaml:"staging_path"`
+	MaxUploadSize *ByteSize `yaml:"max_upload_size"`
 }
 
 type SSH struct {

internal/config/defaults.go

@@ -1,13 +1,19 @@
 package config
 
-import "gitea.maximumdirect.net/eric/distributor/internal/transform"
+import (
+	"path/filepath"
+	"time"
+
+	"gitea.maximumdirect.net/eric/distributor/internal/transform"
+)
 
 const DefaultConfigPath = "/usr/local/etc/distributor/config.yml"
 
 const (
-	BackendLocal = "local"
+	BackendLocal      = "local"
-	BackendSSH   = "ssh"
+	BackendSSH        = "ssh"
-	BackendS3    = "s3"
+	BackendS3         = "s3"
+	BackendHTTPUpload = "http_upload"
 )
 
 const (
@@ -38,10 +44,23 @@ const (
 
 const DefaultS3Region = "us-east-1"
 
+const (
+	DefaultHTTPBind           = "127.0.0.1:8080"
+	DefaultHTTPStagingRoot    = "/var/spool/distributor"
+	DefaultHTTPMaxUploadSize  = ByteSize(20 * 1024 * 1024)
+	DefaultHTTPQueueSize      = 16
+	DefaultHTTPMaxConcurrency = 1
+	DefaultHTTPRetention      = Duration(24 * time.Hour)
+)
+
 func ApplyDefaults(cfg *Config) {
+	applyHTTPServerDefaults(&cfg.Server.HTTP)
 	for pipelineIndex := range cfg.Pipelines {
 		pipeline := &cfg.Pipelines[pipelineIndex]
 		applyBackendDefaults(&pipeline.Source)
+		if pipeline.Source.Backend == BackendHTTPUpload {
+			applyHTTPUploadDefaults(&pipeline.Source.Upload, pipeline.ID, cfg.Server.HTTP)
+		}
 		if pipeline.Validation.OnDigestMismatch == "" {
 			pipeline.Validation.OnDigestMismatch = ValidationActionFail
 		}
@@ -76,6 +95,44 @@ func ApplyDefaults(cfg *Config) {
 	}
 }
 
+func applyHTTPServerDefaults(server *HTTPServer) {
+	if server.Bind == "" {
+		server.Bind = DefaultHTTPBind
+	}
+	if server.StagingRoot == "" {
+		server.StagingRoot = DefaultHTTPStagingRoot
+	}
+	if server.MaxUploadSize == nil {
+		server.MaxUploadSize = byteSize(DefaultHTTPMaxUploadSize)
+	}
+	if server.QueueSize == 0 {
+		server.QueueSize = DefaultHTTPQueueSize
+	}
+	if server.MaxConcurrency == 0 {
+		server.MaxConcurrency = DefaultHTTPMaxConcurrency
+	}
+	if server.Retention == nil {
+		server.Retention = duration(DefaultHTTPRetention)
+	}
+}
+
+func applyHTTPUploadDefaults(upload *HTTPUpload, pipelineID string, server HTTPServer) {
+	if upload.StagingPath == "" && pipelineID != "" {
+		upload.StagingPath = filepath.Join(server.StagingRoot, pipelineID)
+	}
+	if upload.MaxUploadSize == nil && server.MaxUploadSize != nil {
+		upload.MaxUploadSize = byteSize(*server.MaxUploadSize)
+	}
+}
+
+func byteSize(value ByteSize) *ByteSize {
+	return &value
+}
+
+func duration(value Duration) *Duration {
+	return &value
+}
+
 func applyBackendDefaults(backend *Backend) {
 	if backend.Backend == BackendSSH {
 		if backend.Port == 0 {

internal/config/load_test.go

@@ -208,6 +208,123 @@ pipelines:
 	}
 }
 
+func TestLoadFileDefaultsHTTPServerConfig(t *testing.T) {
+	cfg := loadConfig(t, `
+pipelines:
+  - id: reports
+    source:
+      backend: local
+      path: /source
+    destinations:
+      - id: archive
+        backend: local
+        path: /archive
+`)
+
+	server := cfg.Server.HTTP
+	if got, want := server.Bind, DefaultHTTPBind; got != want {
+		t.Fatalf("server.http.bind = %q, want %q", got, want)
+	}
+	if got, want := server.StagingRoot, DefaultHTTPStagingRoot; got != want {
+		t.Fatalf("server.http.staging_root = %q, want %q", got, want)
+	}
+	if got, want := *server.MaxUploadSize, DefaultHTTPMaxUploadSize; got != want {
+		t.Fatalf("server.http.max_upload_size = %s, want %s", got, want)
+	}
+	if got, want := server.QueueSize, DefaultHTTPQueueSize; got != want {
+		t.Fatalf("server.http.queue_size = %d, want %d", got, want)
+	}
+	if got, want := server.MaxConcurrency, DefaultHTTPMaxConcurrency; got != want {
+		t.Fatalf("server.http.max_concurrency = %d, want %d", got, want)
+	}
+	if got, want := *server.Retention, DefaultHTTPRetention; got != want {
+		t.Fatalf("server.http.retention = %s, want %s", got, want)
+	}
+}
+
+func TestLoadFileAcceptsHTTPUploadSourceConfig(t *testing.T) {
+	cfg := loadConfig(t, `
+server:
+  http:
+    bind: 127.0.0.1:9090
+    staging_root: /srv/distributor/staging
+    max_upload_size: 64MB
+    queue_size: 32
+    max_concurrency: 2
+    retention: 48h
+pipelines:
+  - id: weather-daily
+    source:
+      backend: http_upload
+      token_env: WEATHER_DAILY_UPLOAD_TOKEN
+      staging_path: /srv/distributor/staging/weather-daily
+      max_upload_size: 32MB
+    destinations:
+      - id: archive
+        backend: local
+        path: /archive
+`)
+
+	server := cfg.Server.HTTP
+	if got, want := server.Bind, "127.0.0.1:9090"; got != want {
+		t.Fatalf("server.http.bind = %q, want %q", got, want)
+	}
+	if got, want := server.StagingRoot, "/srv/distributor/staging"; got != want {
+		t.Fatalf("server.http.staging_root = %q, want %q", got, want)
+	}
+	if got, want := *server.MaxUploadSize, ByteSize(64*1024*1024); got != want {
+		t.Fatalf("server.http.max_upload_size = %s, want %s", got, want)
+	}
+	if got, want := server.QueueSize, 32; got != want {
+		t.Fatalf("server.http.queue_size = %d, want %d", got, want)
+	}
+	if got, want := server.MaxConcurrency, 2; got != want {
+		t.Fatalf("server.http.max_concurrency = %d, want %d", got, want)
+	}
+	if got, want := server.Retention.String(), "48h0m0s"; got != want {
+		t.Fatalf("server.http.retention = %s, want %s", got, want)
+	}
+
+	source := cfg.Pipelines[0].Source
+	if got, want := source.Backend, BackendHTTPUpload; got != want {
+		t.Fatalf("source.backend = %q, want %q", got, want)
+	}
+	if got, want := source.Upload.TokenEnv, "WEATHER_DAILY_UPLOAD_TOKEN"; got != want {
+		t.Fatalf("source.token_env = %q, want %q", got, want)
+	}
+	if got, want := source.Upload.StagingPath, "/srv/distributor/staging/weather-daily"; got != want {
+		t.Fatalf("source.staging_path = %q, want %q", got, want)
+	}
+	if got, want := *source.Upload.MaxUploadSize, ByteSize(32*1024*1024); got != want {
+		t.Fatalf("source.max_upload_size = %s, want %s", got, want)
+	}
+}
+
+func TestLoadFileDefaultsHTTPUploadSourceConfig(t *testing.T) {
+	cfg := loadConfig(t, `
+server:
+  http:
+    max_upload_size: 12MB
+pipelines:
+  - id: weather-daily
+    source:
+      backend: http_upload
+      token_env: WEATHER_DAILY_UPLOAD_TOKEN
+    destinations:
+      - id: archive
+        backend: local
+        path: /archive
+`)
+
+	source := cfg.Pipelines[0].Source
+	if got, want := source.Upload.StagingPath, "/var/spool/distributor/weather-daily"; got != want {
+		t.Fatalf("source.staging_path = %q, want %q", got, want)
+	}
+	if got, want := *source.Upload.MaxUploadSize, ByteSize(12*1024*1024); got != want {
+		t.Fatalf("source.max_upload_size = %s, want %s", got, want)
+	}
+}
+
 func TestLoadFileValidBackendConfigs(t *testing.T) {
 	tests := map[string]string{
 		"local": `
@@ -396,6 +513,26 @@ func TestLoadFileRejectsInvalidS3Config(t *testing.T) {
 	}
 }
 
+func TestLoadFileRejectsInvalidHTTPUploadConfig(t *testing.T) {
+	tests := map[string]string{
+		"server size":             `server: {http: {max_upload_size: 20XB}}`,
+		"source size":             `pipelines: [{id: reports, source: {backend: http_upload, token_env: UPLOAD_TOKEN, max_upload_size: 20XB}, destinations: [{id: archive, backend: local, path: /archive}]}]`,
+		"zero source size":        `pipelines: [{id: reports, source: {backend: http_upload, token_env: UPLOAD_TOKEN, max_upload_size: 0B}, destinations: [{id: archive, backend: local, path: /archive}]}]`,
+		"server duration":         `server: {http: {retention: forever}}`,
+		"zero server duration":    `server: {http: {retention: 0s}}`,
+		"missing token env":       `pipelines: [{id: reports, source: {backend: http_upload}, destinations: [{id: archive, backend: local, path: /archive}]}]`,
+		"destination http upload": `pipelines: [{id: reports, source: {backend: local, path: /source}, destinations: [{id: ingest, backend: http_upload}]}]`,
+		"literal token":           `pipelines: [{id: reports, source: {backend: http_upload, token: secret, token_env: UPLOAD_TOKEN}, destinations: [{id: archive, backend: local, path: /archive}]}]`,
+		"unknown server field":    `server: {http: {surprise: true}}`,
+		"unknown source field":    `pipelines: [{id: reports, source: {backend: http_upload, token_env: UPLOAD_TOKEN, surprise: true}, destinations: [{id: archive, backend: local, path: /archive}]}]`,
+	}
+	for name, body := range tests {
+		t.Run(name, func(t *testing.T) {
+			assertLoadError(t, body, "")
+		})
+	}
+}
+
 func TestLoadFileDefaultsSSHConfig(t *testing.T) {
 	cfg := loadConfig(t, `
 pipelines:

internal/config/quantity.go

@@ -0,0 +1,117 @@
+package config
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+type ByteSize int64
+
+type Duration time.Duration
+
+func (size *ByteSize) UnmarshalYAML(value *yaml.Node) error {
+	if value.Kind != yaml.ScalarNode || value.Tag != "!!str" {
+		return fmt.Errorf("size must be a string with B, KB, MB, or GB suffix")
+	}
+
+	var raw string
+	if err := value.Decode(&raw); err != nil {
+		return err
+	}
+	parsed, err := ParseByteSize(raw)
+	if err != nil {
+		return err
+	}
+	*size = parsed
+	return nil
+}
+
+func (size ByteSize) String() string {
+	value := int64(size)
+	if value == 0 {
+		return "0B"
+	}
+	units := []struct {
+		suffix     string
+		multiplier int64
+	}{
+		{suffix: "GB", multiplier: 1024 * 1024 * 1024},
+		{suffix: "MB", multiplier: 1024 * 1024},
+		{suffix: "KB", multiplier: 1024},
+		{suffix: "B", multiplier: 1},
+	}
+	for _, unit := range units {
+		if value%unit.multiplier == 0 {
+			return strconv.FormatInt(value/unit.multiplier, 10) + unit.suffix
+		}
+	}
+	return strconv.FormatInt(value, 10) + "B"
+}
+
+func ParseByteSize(raw string) (ByteSize, error) {
+	value := strings.TrimSpace(raw)
+	if value == "" {
+		return 0, fmt.Errorf("size is required")
+	}
+
+	units := []struct {
+		suffix     string
+		multiplier int64
+	}{
+		{suffix: "GB", multiplier: 1024 * 1024 * 1024},
+		{suffix: "MB", multiplier: 1024 * 1024},
+		{suffix: "KB", multiplier: 1024},
+		{suffix: "B", multiplier: 1},
+	}
+	for _, unit := range units {
+		number, ok := strings.CutSuffix(value, unit.suffix)
+		if !ok {
+			continue
+		}
+		if strings.TrimSpace(number) != number || number == "" {
+			return 0, fmt.Errorf("size must be an integer followed by B, KB, MB, or GB")
+		}
+		parsed, err := strconv.ParseInt(number, 10, 64)
+		if err != nil {
+			return 0, fmt.Errorf("size must be an integer followed by B, KB, MB, or GB")
+		}
+		if parsed < 0 {
+			return 0, fmt.Errorf("size must be non-negative")
+		}
+		const maxInt64 = int64(1<<63 - 1)
+		if parsed > 0 && parsed > maxInt64/unit.multiplier {
+			return 0, fmt.Errorf("size is too large")
+		}
+		return ByteSize(parsed * unit.multiplier), nil
+	}
+	return 0, fmt.Errorf("size must use B, KB, MB, or GB suffix")
+}
+
+func (duration *Duration) UnmarshalYAML(value *yaml.Node) error {
+	if value.Kind != yaml.ScalarNode || value.Tag != "!!str" {
+		return fmt.Errorf("duration must be a string duration")
+	}
+
+	var raw string
+	if err := value.Decode(&raw); err != nil {
+		return err
+	}
+	parsed, err := time.ParseDuration(raw)
+	if err != nil {
+		return fmt.Errorf("duration must be a valid duration: %w", err)
+	}
+	*duration = Duration(parsed)
+	return nil
+}
+
+func (duration Duration) String() string {
+	return time.Duration(duration).String()
+}
+
+func (duration Duration) AsDuration() time.Duration {
+	return time.Duration(duration)
+}

internal/config/validate.go

@@ -22,6 +22,8 @@ func (e ValidationErrors) Error() string {
 func Validate(cfg Config) error {
 	var errs ValidationErrors
 
+	errs = validateHTTPServer(errs, "server.http", cfg.Server.HTTP)
+
 	if len(cfg.Pipelines) == 0 {
 		errs = append(errs, "pipelines is required")
 	}
@@ -72,14 +74,56 @@ func Validate(cfg Config) error {
 	return nil
 }
 
+func validateHTTPServer(errs ValidationErrors, context string, server HTTPServer) ValidationErrors {
+	if server.Bind == "" {
+		errs = append(errs, context+".bind is required")
+	}
+	if server.StagingRoot == "" {
+		errs = append(errs, context+".staging_root is required")
+	}
+	if server.MaxUploadSize == nil || *server.MaxUploadSize <= 0 {
+		errs = append(errs, context+".max_upload_size must be greater than zero")
+	}
+	if server.QueueSize <= 0 {
+		errs = append(errs, context+".queue_size must be greater than zero")
+	}
+	if server.MaxConcurrency <= 0 {
+		errs = append(errs, context+".max_concurrency must be greater than zero")
+	}
+	if server.Retention == nil || *server.Retention <= 0 {
+		errs = append(errs, context+".retention must be greater than zero")
+	}
+	return errs
+}
+
 func validateSourceBackend(errs ValidationErrors, context string, backend Backend) ValidationErrors {
+	if backend.Backend == BackendHTTPUpload {
+		return validateHTTPUploadSource(errs, context, backend.Upload)
+	}
 	return validateBackend(errs, context, backend.Backend, backend.Host, backend.Port, backend.Path, backend.Endpoint, backend.Bucket, backend.Prefix, backend.SSH.HostKeyPolicy, backend.Creds)
 }
 
 func validateDestinationBackend(errs ValidationErrors, context string, destination Destination) ValidationErrors {
+	if destination.Backend == BackendHTTPUpload {
+		errs = append(errs, context+".backend "+BackendHTTPUpload+" is only supported for sources")
+		return errs
+	}
 	return validateBackend(errs, context, destination.Backend, destination.Host, destination.Port, destination.Path, destination.Endpoint, destination.Bucket, destination.Prefix, destination.SSH.HostKeyPolicy, destination.Creds)
 }
 
+func validateHTTPUploadSource(errs ValidationErrors, context string, upload HTTPUpload) ValidationErrors {
+	if upload.TokenEnv == "" {
+		errs = append(errs, context+".token_env is required for http_upload backend")
+	}
+	if upload.StagingPath == "" {
+		errs = append(errs, context+".staging_path is required for http_upload backend")
+	}
+	if upload.MaxUploadSize == nil || *upload.MaxUploadSize <= 0 {
+		errs = append(errs, context+".max_upload_size must be greater than zero")
+	}
+	return errs
+}
+
 func validateBackend(errs ValidationErrors, context, backend, host string, port int, path, endpoint, bucket, prefix string, hostKeyPolicy HostKeyPolicy, creds Credentials) ValidationErrors {
 	switch backend {
 	case "":