Node.js certificate issues

When you encountered certificate issues when using node.js, there are some workaround that can be tried:

1) Add custom CA certs

    $ export NODE_EXTRA_CA_CERTS=[your CA certificate file path]

2) Disable certificate checking

    NODE_TLS_REJECT_UNAUTHORIZED

Keep current log file when using logrotate

When using logrotate in Linux, you might encounter a situation where your log file gone when the log rotated. One of the flag that you may need to notice is the copytruncate flag. It did not remove the current log file, instead it copy the log file and then truncate it:

File name: /etc/logrotate.d/your-application

 /var/log/your-application/output.log {
    copytruncate
    rotate 5
    daily 
    compress
    delaycompress
    notifempty
    missingok
}

Quasar failed to proxy pass via https

When failed to proxy pass with https in Quasar framework, it is very likely that the target-host HTTPS are configured incorrectly.  As a workaround, you can modify the quasar.conf.js with secure:false as following:

        "/context/path1/": {
          target: "https://target-host/path1/",
          secure: false,
          changeOrigin: true,
          pathRewrite: {
            "^/context/path1/": "",
          },
        },

Limit CPU and Memory usage in Linux Slack

The Linux Slack consumes a lot of CPU and memory in Linux environment. To limit its resource usages, you can apply a quote via the snap command:

sudo snap set-quota slacklimit --memory=2GB --cpu=20% slack

Sync multiple git repo at once

Use the following command in Linux will do the job:

 ls -d RepoNames* | xargs -I{} git -C {} pull

ffmpeg to convert MPEG4 to Animated GIF

In short, use the following command to do the conversion:

ffmpeg -i source_file.m4v -filter_complex "[0:v] split [a][b];[a] palettegen [p];[b][p] paletteuse" output_trimmed_enhanced.gif

Reference: https://www.bannerbear.com/blog/how-to-make-a-gif-from-a-video-using-ffmpeg/

Using Conda behind firewall

 To use conda behind firewall, in Windows:

1) Edit the .condarc

channels:

- defaults

proxy_servers:

  http: <proxy_host>:8080

  https: <proxy_host>:8080

ssl_verify: False

NOTE: Beware doing something like this:

http: http://proxyhost:8080

https: http://proxyhost:8080

Don't add "http://" above, it's wrong!

2) Using pip (need to trust the hosts)

pip install --trusted-host pypi.org --trusted-host pypi.python.org --trusted-host files.pythonhosted.org pandas

Some other better methods exist, the above is just one of the options that works.

Bind port 80 for normal user in Linux

To bind port 80 for normal user in Linux, use 'authbind'

Steps:

1. sudo apt get authbind

2. sudo touch /etc/authbind/byport/80

3. sudo chown user:user /etc/authbind/byport/80

4. chmod 500 /etc/authbind/byport/80

5. authbind --deep <command to run> (e.g. quasar dev)

Favourite LS_COLORS

Just wanna have my script files (Python script, Shell script) shows color in ls:

LS_COLORS=$LS_COLORS:'*.py=0;94:*.sh=0;94' ; export LS_COLORS 

Watch git log automatically

Linux one-liner to watch and refresh git log every 30 secs:

watch --color -n 30 "git fetch; git log origin/master -30 --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit --color=always"