= caddyv2-upload :toc: :source-highlighter: rouge

This repo holds a simple caddyserver v2 upload handler

WARNING: You have to secure the upload URL as the nature of this handler/plugin is to save uploaded artifacts on the disc.

In this handler are the following modules in use.

• templates
• file_server
• github.com/caddyserver/jsonc-adapter
• upload :-)

== Configuration

IMPORTANT: The relative paths are relative to the current web root directory http.vars.root!

=== Environment Variables

.Parameters [cols="2,6",options=header] |=== |Name |Description

|APPPORT |The Port on which Caddyserver should listen. The format depends which Configuration file format you use. See the official Caddyserver documentation for the format https://caddyserver.com/docs/conventions#network-addresses[Network addresses]

|SKIP_LOG |With this variable can you control if the health check will be logged or not. This feature was implemented as part of the vars handler.

|===

=== Parameters

.Parameters [cols="2,6",options=header] |=== |Name |Description

|dest_dir |The directory in which the files will be uploaded

|root_dir |The root directory for this module. When not set will the root directory be evaluated at runtime from this variable http.vars.root.

|file_field_name |The field name for the multi-part form upload

|fixed_file_name |When set, all uploaded files will be renamed to the provided file name.

|response_template |The response template after a upload was successfully

|max_form_buffer |The maximum buffer size for https://pkg.go.dev/net/http#Request.ParseMultipartForm[ParseMultipartForm]. It accepts all size values supported by https://pkg.go.dev/github.com/dustin/go-humanize#pkg-constants[go-humanize]. Here can also be used a https://caddyserver.com/docs/conventions#placeholders[Placeholder] + JSON: "{env.MAXBUFFSIZE}" + Caddyfile: {$MAXBUFFSIZE} +

The default size is 1G.

|max_form_buffer_int |The maximum buffer size for https://pkg.go.dev/net/http#Request.ParseMultipartForm[ParseMultipartForm]. + The default size is 1G.

|max_filesize |is the maximum size in bytes allowed for the upload. It accepts all size values supported by https://pkg.go.dev/github.com/dustin/go-humanize#pkg-constants[go-humanize]. Reads of more bytes will return an error with HTTP status 413. Here can also be used a https://caddyserver.com/docs/conventions#placeholders[Placeholder] + JSON: "{env.MAXFILESIZE}" + Caddyfile: {$MAXFILESIZE} +

The default size is 1G.

|max_filesize_int |is the maximum size in bytes allowed for the upload. Reads of more bytes will return an error with HTTP status 413. + The default size is 1G.

|notify_url |After a successful upload will this URL be called. The only supported schema is https.

|notify_method |The default method is GET. If you need to make a POST request please open a feature issue as for now is a request body handling not implemented

|insecure |This boolean flag configure the InsecureSkipVerify in the https://pkg.go.dev/crypto/tls#Config[tls-config] . Default is false which implies that a valid CA must be used

|capath |This is the Parameter where you can define the CA filename for the notify_url.

|create_uuid_dir |If set to true, each file will get a unique directory with a UUID as its name.

|dest_dir_field_name |If set, the dest_dir will be set from the specified form value.

|===

=== Caddy Variables

The following Variables will be added to the request flow

.variables [cols="2,6",options=header] |=== |Name |Description

|http.upload.filename |The uploaded filename

|http.upload.filesize |The uploaded filesize

|http.upload.directory |The directory where the file is uploaded

|http.upload.uuiddir |The name of the random directory created if create_uuid_dir is enabled

|===

=== JSON

Because I prefer the https://caddyserver.com/docs/json/[JSON Config ] will I write here the configuration snipplet in JSON Syntax.

[source,json]

"handle": [
	{
		"MyTlsSetting": {},
		"dest_dir": "upload", <1>
		"handler": "upload",
		"max_filesize": "5GB", <2>
		"max_form_buffer_int": 1000000, <3>
		"response_template": "upload-resp.txt" <4>
	}
]

---

<1> Destination Directory on the Server site <2> Maximal possible upload size <3> Maximal buffer for uploading <4> the response template which will be used for response after upload

A full working example is in docker-files/opt/webroot/config/Caddyfile-upload.json

=== Caddyfile

Here a example Caddyfile which expects that the environment variable APPPORT is set.

[source]

{ order upload before file_server log { level DEBUG } }

{$APPPORT} { root .

file_server browse
templates

@mypost method POST
upload @mypost {
	dest_dir tmp-upl
	max_form_buffer 1G
	max_filesize 4MB
	response_template templates/upload-resp-template.txt
}

log {
	output file access.log
}

}

== build

=== local [source,shell]

xcaddy build --with github.com/kirsch33/realip
--with github.com/git001/caddyv2-upload

=== docker [source,shell]

buildah bud --tag caddyv2-upload .

or

docker build --tag caddyv2-upload .

== run

=== cli

[source,shell]

APPPORT=:2011 ./caddy run
-config Caddyfile-upload.json

=== docker

You can get this image from docker hub

The default listen port must be defined with this variable

APPPORT=:2011

https://hub.docker.com/r/me2digital/caddyv2-upload

[source,shell]

podman run --rm --network host --name caddy-test
--env APPPORT=:8888 -it
docker.io/me2digital/caddyv2-upload:latest

or

docker run --name caddy-test --rm
docker.io/me2digital/caddyv2-upload:latest

=== OpenShift / kubernetes

You can use the examples in the directory openshift to deploy the caddy uploader into your OpenShift or kubernetes Cluster.

[source,shell]

oc new-project caddyupload oc -n caddyupload apply -f openshift/

To adopt the used Caddyfile then can you easily do this with a configmap. The commands below show the steps.

[source,shell]

add configure change trigger

oc -n caddyupload
set triggers
deployment.apps/caddy-upload
--from-config

create configmap

oc -n caddyupload
create configmap
caddyfile-json
--from-file=Caddyfile-upload.json=<PATH_TO_LOCAL>/Caddyfile-upload.json

add configmap to caddy deployment

oc -n caddyupload
set volumes
deployment.apps/caddy-upload
--add --configmap-name=caddyfile-json
--mount-path=/opt/webroot/config/Caddyfile-upload.json
--name=caddyfile-json
--sub-path=Caddyfile-upload.json
--type=configmap

In case the first shot of the configuration file does not work can you use the following commands to recreate the configuration file.

[source,shell]

oc -n caddyupload-nis delete configmap caddyfile-json
&& oc -n caddyupload-nis create configmap caddyfile-json --from-file=Caddyfile-upload.json=<PATH_TO_LOCAL>/Caddyfile-upload.json

output of the commands

configmap "caddyfile-json" deleted configmap/caddyfile-json created

== Health probe

There is a builtin health handler with the path /health which just returns 200 and Okay. The log output can be controled via the environment variable SKIP_LOG.

== example cli

When you run the Image with port 8888 can you use curl or any other tool to post (upload) files

It's not necessary to use -X POST as written in this Blog post https://daniel.haxx.se/blog/2015/09/11/unnecessary-use-of-curl-x/[UNNECESSARY USE OF CURL -X]

Here a example call with curl

[source,shell]

curl -v --form [email protected] http://localhost:8888/templates/upload-template.html

• Trying 127.0.0.1:8888...
• TCP_NODELAY set
• Connected to localhost (127.0.0.1) port 8888 (#0)

POST /templates/upload-template.html HTTP/1.1 Host: localhost:8888 User-Agent: curl/7.68.0 Accept: / Content-Length: 2492 Content-Type: multipart/form-data; boundary=------------------------58b770bc61c0e691 Expect: 100-continue

• Mark bundle as not supporting multiuse < HTTP/1.1 100 Continue
• We are completely uploaded and fine
• Mark bundle as not supporting multiuse < HTTP/1.1 200 OK < Accept-Ranges: bytes < Content-Length: 299 < Etag: "rbb1gx8b" < Last-Modified: Tue, 03 May 2022 11:34:09 GMT < Server: Caddy < Date: Thu, 19 May 2022 21:45:07 GMT <

http.request.uri.path: {{placeholder "http.request.uri.path"}}

http.request.uuid {{placeholder "http.request.uuid" }} http.request.host {{placeholder "http.request.host" }}

http.upload.filename: {{placeholder "http.upload.filename"}} http.upload.filesize: {{placeholder "http.upload.filesize"}}

== Background informations

The max_form_buffer paramater will be directly passed to https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/mime/multipart/formdata.go;l=34;drc=7791e934c882fd103357448aee0fd577b20013ce[readForm] function and is used to check if the uploaded file should be saved temporarly on disk or keep it in the memory. This have dicret impact into the performance and disk usage of that module. Keep in mind when this paramter is low and the upload is a big file then will be there a lot of disk io. +

INFO: The observation from https://github.com/etherwvlf in issue https://github.com/git001/caddyv2-upload/issues/2[Memory issues on large uploads] was that the initial memory usage is 7-8 times higher then the configured max_form_buffer size.