Port Mapping (-p vs -P)
"-p HOST_PORT:CONTAINER_PORT" flag, se, HOST, machine, ke, EK, SPECIFIC, PORT, ko, container, ke, ANDAR, ke, EK, PORT, se, MAP, kiya, jaata hai — jaise, "-p 8080:80" HOST, ke, port, 8080, ko, container, ke, port, 80, se, CONNECT, kar, deta, hai.
"-P" (CAPITAL, P) Dockerfile, mein, EXPOSE, ki, GAYI, saari, ports, ko, HOST, ke, RANDOM, AVAILABLE, PORTS, PAR, AUTOMATICALLY, MAP, kar, deta hai — MANUALLY, HAR, PORT, SPECIFY, karne, ki, ZAROORAT, NAHI, PADTI.
# Specific mapping: host 8080 -> container 80
docker run -d -p 8080:80 nginx
# Multiple ports map karo
docker run -d -p 8080:80 -p 8443:443 nginx
# Auto-map saari EXPOSEd ports (random host ports)
docker run -d -P nginx
# Kaunse ports actually mapped hain, dekho:
docker port my-nginx- -p HOST:CONTAINER se specific port mapping ki jaati hai
- -P se saari EXPOSEd ports random host ports par auto-map hoti hain
- docker port command se actual mappings check kiye ja sakte hain
DEFAULT, RUP, se, port, mapping, TCP, ke, liye, hota hai — UDP, PORTS, MAP, karne, ke, liye, "/udp" suffix, ZAROORI, hai, jaise, "-p 53:53/udp" (DNS, jaisi, services, ke, liye).
docker run -d -p 53:53/udp -p 53:53/tcp dns-server"-p HOST_IP:HOST_PORT:CONTAINER_PORT" se, port, mapping, ko, EK, SPECIFIC, HOST, NETWORK, INTERFACE, tak, LIMIT, kiya, ja, sakta hai — jaise, sirf, "127.0.0.1" (localhost, only, EXTERNAL, access, NAHI).
docker run -d -p 127.0.0.1:8080:80 nginx
# Sirf localhost se access, outside network se NAHI