(Express) server.js

const app = require('express')()

app.use(require('cors')())

app.get('/verycoolguy/posts/1',
    (req, res) => res.sendFile(__dirname + '/post.json')
)

app.get('/cdn/verycoolguy/posts/1/img.jpg',
    (req, res) => res.sendFile(__dirname + '/img.jpg'))

app.listen(4000)

(React) index.js

import React from 'react'
import { hydrate } from 'react-dom'
import Post from './Post'

hydrate(
    <div>
        <Post/>
</div>, document.getElementById('root')
)

(React) Post.js

import React, { Component } from 'react'
import axios from 'axios'
import ReactMarkdown from 'react-markdown'
import Img from 'react-image'

export default class Post extends Component {
    constructor () {
        super()
        this.state = {
            content: '',
            likes: '',
            comments: []
        }
    }
    componentDidMount(){
        axios.get('http://localhost:4000/verycoolguy/posts/1')
        .then(res => {
            this.setState({
            text: res.data.text,
            likes: res.data.likes,
            comments: res.data.comments,
            image: res.data.image
        });
            console.log(this.state.image)
    })
    }
    render = () => (
        <div>
            <Img src={this.state.image}/>
            <ReactMarkdown source={this.state.text}/>
            <span>Likes: {this.state.likes}</span>
            <div className="comments">
            {this.state.comments.map(e => (
                <div>
                    <p><b>{e.author}</b> {e.text}</p>
                </div>
            ))}
            </div>
        </div>
    )
}

post.json

{
    "image": "localhost:4000/cdn/verycoolguy/posts/1/img.jpg",
    "text": "**bold**",
    "likes": "30",
    "comments": [
    {
            "author": "supadupasuser",
            "text": "md rocks",
            "likes": "10"
    },
    {
            "author": "anothercooluser",
            "text": "html is better",
            "likes": "0"
    }
    ]
}