webserver

A simple HTTP server in C with:

• static resources
• in-memory dynamic resources
• optional distributed lookup/routing over a small DHT ring

Requirements

• GCC or Clang
• CMake ≥ 3.5
• Python 3 + pip (for tests)
• POSIX-compatible OS (Linux, macOS)

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Build

cmake -B build && make -C build

The binary is placed at build/webserver.

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Test

Install the test dependencies once:

pip install -r requirements.txt

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Run

Single-node mode

./build/webserver <hostname> <port>

Example — listen on all interfaces, port 8080:

./build/webserver 0.0.0.0 8080

Example — localhost only:

./build/webserver 127.0.0.1 4000

DHT mode

PRED_ID=<id> PRED_IP=<ip> PRED_PORT=<port> \
SUCC_ID=<id> SUCC_IP=<ip> SUCC_PORT=<port> \
./build/webserver <hostname> <port> <node-id>

Example 3-node ring:

Node 0

PRED_ID=50000 PRED_IP=127.0.0.1 PRED_PORT=4002 \
SUCC_ID=20000 SUCC_IP=127.0.0.1 SUCC_PORT=4001 \
./build/webserver 127.0.0.1 4000 0

Node 20000

PRED_ID=0     PRED_IP=127.0.0.1 PRED_PORT=4000 \
SUCC_ID=50000 SUCC_IP=127.0.0.1 SUCC_PORT=4002 \
./build/webserver 127.0.0.1 4001 20000

Node 50000

PRED_ID=20000 PRED_IP=127.0.0.1 PRED_PORT=4001 \
SUCC_ID=0     SUCC_IP=127.0.0.1 SUCC_PORT=4000 \
./build/webserver 127.0.0.1 4002 50000

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Endpoints

Static resources

Method	Path	Response
GET	/static/foo	200 Foo
GET	/static/bar	200 Bar
GET	/static/baz	200 Baz

Dynamic resources

Method	Path	Behaviour
PUT	/dynamic/<name>	Creates the resource (201) or updates it (204)
GET	/dynamic/<name>	Returns the stored content (200) or 404
DELETE	/dynamic/<name>	Deletes the resource (204) or 404 if not found

Attempting PUT or DELETE on a non-/dynamic/ path returns 403.
Any other HTTP method returns 501.

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Usage examples

Single-node / local examples

# Create a resource
curl -i -X PUT http://127.0.0.1:4000/dynamic/hello \
     -H "Content-Length: 11" \
     -d "hello world"

# Read it back
curl -i http://127.0.0.1:4000/dynamic/hello

# Update it
curl -i -X PUT http://127.0.0.1:4000/dynamic/hello \
     -H "Content-Length: 5" \
     -d "world"

# Delete it
curl -i -X DELETE http://127.0.0.1:4000/dynamic/hello

# Static resource
curl -i http://127.0.0.1:4000/static/foo

DHT examples

curl -i -X PUT http://127.0.0.1:4000/dynamic/hello \
     -d "hello world"

curl -i -L http://127.0.0.1:4000/dynamic/hello

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Notes

• Dynamic resources are stored in memory only and are lost when the server stops.
• In DHT mode, a node stores a dynamic resource only if it is responsible for that resource.
• DHT lookups are performed over UDP.
• Only one TCP client is handled at a time.
• BUFFER_SIZE is set to 1024 bytes in networking.h. Larger requests are received across multiple recv calls and reassembled.