Currently Wasm modules are limited to a 32bit address space (until at
least the memory64 work is completed). All the counters etc in the
request structure were u32's. Which matched with 32bit memory
limitation.
However there is really no need to not allow >4GiB uploads that can be
saved off to disk or some such.
To do this we just need to increase the ->content_len &
->total_content_sent members to u64's.
However because we need the request structure to have the exact same
layout on 32bit (for Wasm modules) as it does on 64bit we need to re-jig
the order of some of these members and add a four-byte padding member.
Thus the request structure now looks like on 64bit (as shown by
pahole(1))
struct nxt_wasm_request_s {
uint32_t method_off; /* 0 4 */
uint32_t method_len; /* 4 4 */
uint32_t version_off; /* 8 4 */
uint32_t version_len; /* 12 4 */
uint32_t path_off; /* 16 4 */
uint32_t path_len; /* 20 4 */
uint32_t query_off; /* 24 4 */
uint32_t query_len; /* 28 4 */
uint32_t remote_off; /* 32 4 */
uint32_t remote_len; /* 36 4 */
uint32_t local_addr_off; /* 40 4 */
uint32_t local_addr_len; /* 44 4 */
uint32_t local_port_off; /* 48 4 */
uint32_t local_port_len; /* 52 4 */
uint32_t server_name_off; /* 56 4 */
uint32_t server_name_len; /* 60 4 */
/* --- cacheline 1 boundary (64 bytes) --- */
uint64_t content_len; /* 64 8 */
uint64_t total_content_sent; /* 72 8 */
uint32_t content_sent; /* 80 4 */
uint32_t content_off; /* 84 4 */
uint32_t request_size; /* 88 4 */
uint32_t nfields; /* 92 4 */
uint32_t tls; /* 96 4 */
char __pad[4]; /* 100 4 */
nxt_wasm_http_field_t fields[]; /* 104 0 */
/* size: 104, cachelines: 2, members: 25 */
/* last cacheline: 40 bytes */
};
and the same structure (taken from unit-wasm) compiled as 32bit
struct luw_req {
u32 method_off; /* 0 4 */
u32 method_len; /* 4 4 */
u32 version_off; /* 8 4 */
u32 version_len; /* 12 4 */
u32 path_off; /* 16 4 */
u32 path_len; /* 20 4 */
u32 query_off; /* 24 4 */
u32 query_len; /* 28 4 */
u32 remote_off; /* 32 4 */
u32 remote_len; /* 36 4 */
u32 local_addr_off; /* 40 4 */
u32 local_addr_len; /* 44 4 */
u32 local_port_off; /* 48 4 */
u32 local_port_len; /* 52 4 */
u32 server_name_off; /* 56 4 */
u32 server_name_len; /* 60 4 */
/* --- cacheline 1 boundary (64 bytes) --- */
u64 content_len; /* 64 8 */
u64 total_content_sent; /* 72 8 */
u32 content_sent; /* 80 4 */
u32 content_off; /* 84 4 */
u32 request_size; /* 88 4 */
u32 nr_fields; /* 92 4 */
u32 tls; /* 96 4 */
char __pad[4]; /* 100 4 */
struct luw_hdr_field fields[]; /* 104 0 */
/* size: 104, cachelines: 2, members: 25 */
/* last cacheline: 40 bytes */
};
We can see the structures have the same layout, same size and no
padding.
We need the __pad member as otherwise I saw gcc and clang on Alpine
Linux automatically add the 'packed' attribute to the structure which
made the two structures not match.
Link: <https://github.com/WebAssembly/memory64>
Link: <https://github.com/nginx/unit-wasm>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
NGINX Unit
Universal Web App Server
NGINX Unit is a lightweight and versatile open-source server that has two primary capabilities:
- serves static media assets,
- runs application code in seven languages.
Unit compresses several layers of the modern application stack into a potent, coherent solution with a focus on performance, low latency, and scalability. It is intended as a universal building block for any web architecture regardless of its complexity, from enterprise-scale deployments to your pet's homepage.
Its native RESTful JSON API enables dynamic updates with zero interruptions and flexible configuration, while its out-of-the-box productivity reliably scales to production-grade workloads. We achieve that with a complex, asynchronous, multithreading architecture comprising multiple processes to ensure security and robustness while getting the most out of today's computing platforms.
Quick Installation
macOS
$ brew install nginx/unit/unit
For details and available language packages, see the docs.
Docker
$ docker pull unit
For a description of image tags, see the docs.
Amazon Linux, Fedora, RedHat
$ wget https://raw.githubusercontent.com/nginx/unit/master/tools/setup-unit && chmod +x setup-unit
# ./setup-unit repo-config && yum install unit
# ./setup-unit welcome
For details and available language packages, see the docs.
Debian, Ubuntu
$ wget https://raw.githubusercontent.com/nginx/unit/master/tools/setup-unit && chmod +x setup-unit
# ./setup-unit repo-config && apt install unit
# ./setup-unit welcome
For details and available language packages, see the docs.
Running a Hello World App
Unit runs apps in a variety of languages. Let's consider a basic example, choosing PHP for no particular reason.
Suppose you saved a PHP script as /www/helloworld/index.php:
<?php echo "Hello, PHP on Unit!"; ?>
To run it on Unit with the unit-php module installed, first set up an
application object. Let's store our first config snippet in a file called
config.json:
{
"helloworld": {
"type": "php",
"root": "/www/helloworld/"
}
}
Saving it as a file isn't necessary, but can come in handy with larger objects.
Now, PUT it into the /config/applications section of Unit's control API,
usually available by default via a Unix domain socket:
# curl -X PUT --data-binary @config.json --unix-socket \
/path/to/control.unit.sock http://localhost/config/applications
{
"success": "Reconfiguration done."
}
Next, reference the app from a listener object in the /config/listeners
section of the API. This time, we pass the config snippet straight from the
command line:
# curl -X PUT -d '{"127.0.0.1:8000": {"pass": "applications/helloworld"}}' \
--unix-socket /path/to/control.unit.sock http://localhost/config/listeners
{
"success": "Reconfiguration done."
}
Now Unit accepts requests at the specified IP and port, passing them to the application process. Your app works!
$ curl 127.0.0.1:8080
Hello, PHP on Unit!
Finally, query the entire /config section of the control API:
# curl --unix-socket /path/to/control.unit.sock http://localhost/config/
Unit's output should contain both snippets, neatly organized:
{
"listeners": {
"127.0.0.1:8080": {
"pass": "applications/helloworld"
}
},
"applications": {
"helloworld": {
"type": "php",
"root": "/www/helloworld/"
}
}
}
For full details of configuration management, see the docs.
OpenAPI Specification
Our OpenAPI specification aims to simplify configuring and integrating NGINX Unit deployments and provide an authoritative source of knowledge about the control API.
Although the specification is still in the early beta stage, it is a promising step forward for the NGINX Unit community. While working on it, we kindly ask you to experiment and provide feedback to help improve its functionality and usability.
Community
-
The go-to place to start asking questions and share your thoughts is our Slack channel.
-
Our GitHub issues page offers space for a more technical discussion at your own pace.
-
The project map on GitHub sheds some light on our current work and plans for the future.
-
Our official website may provide answers not easily found otherwise.
-
Get involved with the project by contributing! See the contributing guide for details.
-
To reach the team directly, subscribe to the mailing list.
-
For security issues, email us, mentioning NGINX Unit in the subject and following the CVSS v3.1 spec.