Communication between containers on Docker - c

Question

I have 3 services in C and I want they communicate toghether with a docker compose but I can't.
I tried with a two simples images and they connected but not in a docker compose.
The problem are the function connect(). He return -1 beaucause in the inet_addr(), I want to include the image who the message will be sent.
I use 3 images with gcc for to compile C files.
# FILE : service1.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
//#define PORT_SERV 4443
#define PORT_CLI 4443
time_t t;
static void * client(){
int clientSocket, ret;
struct sockaddr_in serverAddr;
char buffer[256];
clientSocket = socket(AF_INET, SOCK_STREAM, 0);
if (clientSocket < 0) {
printf("[Client -] Error in Client Socket \n");
fflush(stdout);
exit(1);
}
memset(&serverAddr, '\0', sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_port = htons(PORT_CLI);
serverAddr.sin_addr.s_addr = inet_addr("image1");
ret = connect(clientSocket, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
while (ret < 0) {
printf("[Client -] Erreur de connexion. Nouvel essai ! %d\n", ret);
fflush(stdout);
sleep(3);
ret = connect(clientSocket, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
}
printf("[Client +] Connected to Server.\n");
fflush(stdout);
while(1){
time(&t);
strcpy(buffer, "Bonjour depuis le service 1");
sleep(5);
send(clientSocket, buffer, strlen(buffer), 0);
if (strcmp(buffer, ": exit") == 0) {
printf("[Client -] Disconnected from server.\n");
fflush(stdout);
exit(1);
}
if (recv(clientSocket, buffer, 256, 0) < 0) {
printf("[Client -] Error in receiving data. \n");
fflush(stdout);
} else {
printf("%sService 1 : %s \n", ctime(&t), buffer);
fflush(stdout);
}
}
}
int main(void){
//pthread_t s,
pthread_t c;
int ret = 0;
ret = pthread_create(&c, NULL, &client, NULL);
/*ret = pthread_create(&s, NULL, &server, NULL);
if (! ret) {
ret = pthread_create(&c, NULL, &client, NULL);
}*/
//pthread_join(s, NULL);
pthread_join(c, NULL);
return 0;
}
FILE = service2.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
#define PORT_SERV 4442
#define PORT_CLI 4443
time_t t;
time_t t2;
static void * server(){
int sockfd, ret;
struct sockaddr_in serverAddr;
int newSocket;
struct sockaddr_in newAddr;
char buffer[256];
pid_t childpid;
socklen_t addr_size;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
printf("[-] Error in Client Socket\n");
fflush(stdout);
exit(1);
}
memset(&serverAddr, '\0', sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_port = htons(PORT_SERV);
serverAddr.sin_addr.s_addr = inet_addr("image1");
ret = bind(sockfd, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
if (ret < 0) {
printf("[-] Error in binding\n");
fflush(stdout);
exit(1);
}
printf("[+] Bind to port %d\n", PORT_CLI);
fflush(stdout);
if (listen(sockfd, 10) == 0) {
printf("[+] Listening...\n");
fflush(stdout);
} else {
printf("[-] Error in binding\n");
fflush(stdout);
}
while(1)
{
newSocket = accept(sockfd, (struct sockaddr*)&newAddr, &addr_size);
if(newSocket < 0) {
exit(1);
}
printf("Connection accepted from %s:%d\n", inet_ntoa(newAddr.sin_addr), ntohs(newAddr.sin_port));
fflush(stdout);
if ((childpid = fork()) == 0)
{
close(sockfd);
while (1)
{
time(&t2);
recv(newSocket, buffer, 256, 0);
if(strcmp(buffer, ": exit") == 0){
printf("Disconnected from %s:%d\n", inet_ntoa(newAddr.sin_addr), ntohs(newAddr.sin_port));
fflush(stdout);
break;
} else {
printf("%sClient : %s\n", ctime(&t2), buffer);
fflush(stdout);
send(newSocket, buffer, strlen(buffer), 0);
bzero(buffer, sizeof(buffer));
}
}
}
}
close(newSocket);
}
static void * client(){
int clientSocket, ret;
struct sockaddr_in serverAddr;
char buffer[256];
clientSocket = socket(AF_INET, SOCK_STREAM, 0);
if (clientSocket < 0) {
printf("[-] Error in connection\n");
fflush(stdout);
exit(1);
}
memset(&serverAddr, '\0', sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_port = htons(PORT_CLI);
serverAddr.sin_addr.s_addr = inet_addr("image3");
ret = connect(clientSocket, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
while (ret < 0) {
printf("[-] Erreur de connexion. Nouvelle tentative !\n");
fflush(stdout);
sleep(3);
ret = connect(clientSocket, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
}
printf("[+] Connected to Server.\n");
while(1){
time(&t);
strcpy(buffer, "Bonjour depuis le service 2");
sleep(5);
send(clientSocket, buffer, strlen(buffer), 0);
if (strcmp(buffer, ": exit") == 0) {
printf("[Client -] Disconnected from server.\n");
fflush(stdout);
exit(1);
}
if (recv(clientSocket, buffer, 256, 0) < 0) {
printf("[Client -] Error in receiving data. \n");
fflush(stdout);
} else {
printf("%sService 2: %s \n", ctime(&t), buffer);
fflush(stdout);
}
}
}
int main(void){
pthread_t s, c;
int ret = 0;
ret = pthread_create(&s, NULL, &server, NULL);
if (! ret) {
ret = pthread_create(&c, NULL, &client, NULL);
}
pthread_join(s, NULL);
pthread_join(c, NULL);
return 0;
}
FILE = service3.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
#define PORT_SERV 4444
//#define PORT_CLI 4443
time_t t;
time_t t2;
static void * server(){
printf("Hello World!\n");
int sockfd, ret;
struct sockaddr_in serverAddr;
int newSocket;
struct sockaddr_in newAddr;
char buffer[256];
pid_t childpid;
socklen_t addr_size;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
printf("[-] Error in connection\n");
exit(1);
}
printf("[+] Client Socket is created !\n");
memset(&serverAddr, '\0', sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_port = htons(PORT_SERV);
serverAddr.sin_addr.s_addr = inet_addr("image2");
ret = bind(sockfd, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
if (ret < 0) {
printf("[-] Error in binding\n");
exit(1);
}
printf("[+] Bind to port %d\n", 4444);
if (listen(sockfd, 10) == 0) {
printf("[+] Listening...\n");
} else {
printf("[-] Error in binding\n");
}
while(1)
{
newSocket = accept(sockfd, (struct sockaddr*)&newAddr, &addr_size);
if(newSocket < 0) {
exit(1);
}
printf("Connection accepted from %s:%d\n", inet_ntoa(newAddr.sin_addr), ntohs(newAddr.sin_port));
fflush(stdout);
if ((childpid = fork()) == 0)
{
close(sockfd);
while (1)
{
time(&t2);
recv(newSocket, buffer, 256, 0);
if(strcmp(buffer, ": exit") == 0){
printf("Disconnected from %s:%d\n", inet_ntoa(newAddr.sin_addr), ntohs(newAddr.sin_port));
break;
} else {
printf("%sClient : %s\n", ctime(&t2), buffer);
send(newSocket, buffer, strlen(buffer), 0);
bzero(buffer, sizeof(buffer));
}
}
}
}
close(newSocket);
}
int main(void){
printf("Hello World!\n");
fflush(stdout);
pthread_t s;
//pthread_t c;
int ret = 0;
printf("Thread du server\n");
ret = pthread_create(&s, NULL, &server, NULL);
/*if (! ret) {
printf("Thread du client\n");
ret = pthread_create(&c, NULL, &client, NULL);
}*/
pthread_join(s, NULL);
//pthread_join(c, NULL);
return 0;
}
File = docker-compose.yml
version: "3.8"
services:
image1:
build: ./image1
image: service1:1.0
networks:
- mynet
ports:
- 127.0.0.1:4441:4441
image2:
build: ./image2
image: service2:1.0
networks:
- mynet
ports:
- 127.0.0.1:4442:4442
image3:
build: ./image3
image: service3:1.0
networks:
- mynet
ports:
- 127.0.0.1:4443:4443
networks:
mynet:
I build and run with docker compose build docker compose up -d and the images don't connect toghether.
Thanks !