Sergei Basharov's questions

I am working on an app which can start and stop a service (lnd) with different options for different users:

• Service Instance 1 for Alice using config 1
• Service Instance 2 for Bob using config 2
• Service Instance 3 for Carol using config 3
• ...
• Service Instance n for Neil using config n

So, as a quick solution to see if it works at all I just start the service in separate terminal windows. It works.

Now, to prepare it for production, I am thinking of a process manager which could spawn, start/stop, monitor etc with the lnd.

In the past I used to succesfully run PM2 for this purpose but as it's more from my NodeJS experience, I wonder if there are other process managers which could be more general, not NodeJS-oriented or just may be better at something than PM2.

I have SVG images in a folder and also a single PNG file to make sure these images are shown on the page.

My nginx config is basically this:

server {
    listen 80;

    location / {
        root www;
    }

}

The images are in www/images folder.

What I see is with the same structure in the page:

<img src="images/logo.svg">
<img src="images/logo.png">

PNG file is shown on the page just as expected, but not SVG. It shows in network tab of the browser code 200, though, but empty body.

When I try to open it directly, like http://localhost/images/logo.svg, it just downloads it as a file.

Do I need to add some special config to make SVG files showable on a page like PNG/JPG files?

I am new to SSL certificates and trying to install one from https://letsencrypt.org with certbot.

I see that I need to prove I own the domain by putting a file accessible from the web that to hosting running that domain.

When I get the certificate, will it be somehow locked to the hosting I use or can I just put the files somewhere on my computer then upload them once I deploy on this or that hosting environment?

I am creating and image to reuse in my projects which I want to push to Docker Hub.

I initially thought that I just had to make a folder, put a right Dockerfile with some additional files like configs and push it.

Then I realized that I also had to create an image based on this Dockerfile first.

So, I suppose, Docker Hub keeps the image that I created locally? Thus, images can be quite large, like gigabytes?

Please shed light on what's exactly is being pushed when I run docker push name/repo.

I have a fleet service in file nginx.service which I am trying to launch on CoreOS:

[Unit]
Description=nginx

[Service]
User=core
TimeoutStartSec=0
EnvironmentFile=/etc/environment

ExecStartPre=-/usr/bin/docker stop nginx
ExecStartPre=-/usr/bin/docker rm nginx

ExecStart=/usr/bin/docker run --rm --name nginx -v /home/core/nginx/conf:/etc/nginx/conf:ro -p 80:80 nginx:latest
#
ExecStop=-/usr/bin/docker stop nginx
ExecStopPost=-/usr/bin/docker rm nginx

Restart=always
RestartSec=10s

[X-Fleet]

When I launch it with fleetctl start nginx.service, it shows no erros, but then in the journal I see this when I try to visit the site:

Aug 24 15:00:09 core-01 docker[2839]: 172.17.8.1 - - [24/Aug/2016:15:00:09 +0000] "GET / HTTP/1.1" 403 571 "-" "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36" "-"
Aug 24 15:00:09 core-01 docker[2839]: 2016/08/24 15:00:09 [error] 5#5: *1 directory index of "/usr/share/nginx/html/" is forbidden, client: 172.17.8.1, server: localhost, request: "GET / HTTP/1.1", host: "172.17.8.101"
Aug 24 15:00:09 core-01 docker[2839]: 2016/08/24 15:00:09 [error] 5#5: *1 open() "/usr/share/nginx/html/favicon.ico" failed (2: No such file or directory), client: 172.17.8.1, server: localhost, request: "GET /favicon.ico HTTP/1.1", host: "172.17.8.101", referrer: "http://172.17.8.101/"
Aug 24 15:00:09 core-01 docker[2839]: 172.17.8.1 - - [24/Aug/2016:15:00:09 +0000] "GET /favicon.ico HTTP/1.1" 404 571 "http://172.17.8.101/" "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36" "-"

But if I start docker command from the fleet file:

/usr/bin/docker run --rm --name nginx -v /home/core/nginx/conf:/etc/nginx/conf:ro -p 80:80 nginx:latest

It runs properly and shows the correct pages.

What am I doing wrong and how to fix it?

I configured nginx as a reverse proxy for some app urls, like /auth, /api, /users and others. I want nginx to reject all the other requests and show 404 or do something else.

I have this in my config now:

server {
    listen 80;

    error_page  404  /404.html;

    location /404.html {
        root static;
    }

    location /auth$ {
        proxy_pass http://localhost:8080/auth;
        proxy_redirect off;
    }

    location /api$ {
        proxy_pass http://localhost:8080/api;
        proxy_redirect off;
    }

    location /users$ {
        proxy_pass http://localhost:8080/users;
        proxy_redirect     off;
    }
}

When I visit any of matched urls, all works good, but when I enter something like /abrakadabra, it shows a loading spinner, trying to load something, then shows empty page even though I have the file for it, and in console I see it's 404 error.

I see these requests in access.log.

What am I doing wrong and how to fix it?

I have default Listen 80 in httpd.conf. Sometimes I need my own webapp to run on that port so I run it with sudo. So, first I need to change Apache port to something else. What I am looking for is a quick one click action to switch in forth and back.

Please advise.

I googled and found a hint that I should set debug mode in Tornado so that it could reload files automatically on update. But I didn't find an exact string to insert. I tried different combinations similar to this application.settings = {"Debug": True} but it doesn't help.