codenkeg

January 6, 2017February 5, 2017

Setting up MongoDB on Ubuntu

(MongoDB: Install MongoDB Community Edition on Ubuntu)
(Linode: Install MongoDB on Ubuntu 16.04 (Xenial))
(Digital Ocean: How To Install MongoDB on Ubuntu 14.04)

Before You Begin

Check for updates
sudo apt-get update && sudo apt-get upgrade

Add the MongoDB repository

Import the MongoDB public GPG key for package signing
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6
Add the MongoDB repository to your sources.list.d directory
echo "deb [ arch=amd64,arm64 ] http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list
Update your repositories. This allows apt to read from the newly added MongoDB repo
sudo apt-get update
Install MongoDB
sudo apt-get install mongodb-org
Enable auto-start on reboot
sudo systemctl enable mongod.service
Open a port in ufw
sudo ufw allow 27017

Running MongoDB

Start MongoDB
sudo service mongod start
Verify MongoDB started
sudo nano /var/log/mongodb/mongod.log
and look for
[initandlisten] waiting for connections on port 27017
Stop MongoDB
sudo service mongod stop
Restart MongoDB
sudo service mongod restart

Setup MongoDB users

Open MongoDB
mongo --port 27017
Create an admin database
use admin
Add a mongodbAdminUsername and mongodbAdminPassword (letters and numbers, no funny characters)
db.createUser({user: "mongodbAdminUsername", pwd: "mongodbAdminPassword", roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]})
Exit
exit
Restart MongoDB
sudo service mongod restart

Mini series

January 4, 2017January 24, 2017

Getting started

(Linode: Getting Started)
(Digital Ocean: Additional Recommended Steps for New Ubuntu 14.04 Servers)

Sign up
Add a Linode
- Select
  Linode 2048
- Select
  Location
- Click
  Add this Linode!
Click linodexxxxxxx
Click Deploy an Image
Cofigure deployment
- Image Ubuntu 16.04 LTS
- Deployment Disk Size max
- Swap Disk 512MB
- Root Password ••••••••
- Click Deploy
Boot
- Click Boot
- Confirm boot
SSH
- Click Remote Access tab
- Click SSH Access link ssh root@xxx.xxx.xxx.xxx
- Click Allow to open in Terminal
- Terminal should open (first run has some additional Allows and yeses)
- Enter password in Terminal
Update software via ssh apt-get update && apt-get upgrade
Choose a newhostname and set it hostnamectl set-hostname newhostname
Update /etc/hosts
- nano /etc/hosts
- Add IP address and newhostname separated by a tab below:
  127.0.0.1 localhost127.0.1.1 ubuntu.members.linode.com
  xxx.xxx.xxx.xxx newhostname
- Exit ^X
- Save y
- File Name to Write: /etc/hosts ↩︎
Setup timezone (I like UTC)
- dpkg-reconfigure tzdata
- Arrow around, ↩︎, ⎋
Setup NTP network time synchronisation
- sudo apt-get install ntp

Securing the server

(Linode: Securing Your Server)

Login
- ssh root@xxx.xxx.xxx.xxx
- Password
Add a limited user account
- adduser example_user
- Password
- Retype password
- Enter Full name
- Room number
- Work phone number
- Home phone number
- Other
- Is the info correct? Y
Add user to admin group
- adduser example_user sudo
Logout exit
Login again, but as the new user
- ssh example_user@xxx.xxx.xxx.xxx
- Password
Harden SSH access
- Create an ssh directory on the Linode machine
  mkdir -p ~/.ssh && sudo chmod -R 700 ~/.ssh/
- (open a new Terminal window)
- Check if you have an RSA key-pair on your local Mac
  ls ~/.ssh/id_rsa*
  If NOT,
  ssh-keygen -b 4096
- Copy the public key from your Mac to the Linode machine
  scp ~/.ssh/id_rsa.pub example_user@xxx.xxx.xxx.xxx:~/.ssh/authorized_keys
- Swap back to linode terminal
- Set permissions on the Linode machine
  sudo chmod 700 -R ~/.ssh && chmod 600 ~/.ssh/authorized_keys
- Logout
  exit
- Login again, as the new user
  ssh example_user@xxx.xxx.xxx.xxx
  (no password required)
Edit SSH Daemon Options
- sudo nano /etc/ssh/sshd_config
- Password
- Disallow root logins over SSH: change PermitRootLogin yes to PermitRootLogin no
- Maybe disable SSH password authentication: change PasswordAuthentication yes to PasswordAuthentication no
- Restart SSH Daemon sudo systemctl restart sshd
Automatic updates (Ubuntu: Automatic Updates)
- Install package sudo apt install unattended-upgrades
- Make schedule sudo nano /etc/apt/apt.conf.d/10periodic
  Add lines:
  APT::Periodic::Update-Package-Lists "1";
  APT::Periodic::Download-Upgradeable-Packages "1";
  APT::Periodic::AutocleanInterval "7";
  APT::Periodic::Unattended-Upgrade "1";
  Exit ^X
  Save y
  Write ↩︎
- Setup notifications sudo apt install apticron
Enable firewall
sudo ufw allow proto tcp from any to any port 22
sudo ufw enable
Use Fail2Ban to block multiple unsuccessful login attempts
(Linode: Using Fail2ban to Secure Your Server)
Install Fail2ban
sudo apt-get install fail2ban
Configure fail2ban
- cd /etc/fail2ban
- Copy fail2ban.conf file and # all lines
  sed 's/$^[[:alpha:]]$/# \1/' fail2ban.conf | sudo tee fail2ban.local &> /dev/null
- Copy jail.conf file and # all lines
  sed 's/$^[a-z tab]$/# \1/' jail.conf | sudo tee jail.local &> /dev/null

Point a domain name at your new IP

(Linode: DNS Manager Overview)
(Linode: Common DNS Configurations)

Login to your domain registrar and change the zone file (DNS management) to point to Linode’s name servers.
- ns1.linode.com
- ns2.linode.com
- ns3.linode.com
- ns4.linode.com
- ns5.linode.com
Create a new domain zone
- Login to Linode Manager
- Click on DNS Manager tab
- Click Add a domain zone
- Domain your domain
- SOA Email A good email address
- Insert Default Records Yes, ...
- Click Add a Master Zone

Mini series

November 19, 2016November 19, 2016

Setting up a new domain (registrar different from host)

Registrar: Register domain
Host: Add domain to host
Registrar: Change registrar’s nameservers to host’s nameservers
Wait

October 3, 2016October 18, 2016

Shortcut characters

command ⌘
option ⌥
control ⌃
function fn
shift ⇧
caps lock ⇪
tab ⇥
back tab ⇤
escape ⎋
power ⌽
eject ⏏
delete ⌫
forward delete ⌦
return ↩︎
enter ⌤
arrows ← ↑ ↓ →
page up/down ⇞ ⇟
home/end ↖︎ ↘︎
space space
apple 
refresh ↻

October 3, 2016October 4, 2016

Copy Spotify playlist to text

To get song title and artist:

Select a Spotify playlist, ⌘A, ⌘C
New rich text TextEdit file, ⌘V, ⇧⌘T

To get song links:

Select a Spotify playlist, ⌘A, ⌘C
New rich text TextEdit file, ⇧⌘T, ⌘V

September 26, 2016September 28, 2016

Shorthand if statement (Ternary Conditional Operator)

I never remember the syntax, or name, for Ternary Conditional Operator.

let contentHeight = 40
let hasHeader = true
let rowHeight: Int
if hasHeader {
    rowHeight = contentHeight + 50
} else {
    rowHeight = contentHeight + 20
}
// rowHeight is equal to 90

let contentHeight = 40

let hasHeader = true

let rowHeight: Int

if hasHeader {

rowHeight = contentHeight + 50

} else {

rowHeight = contentHeight + 20

}

// rowHeight is equal to 90

becomes

let contentHeight = 40
let hasHeader = true
let rowHeight = contentHeight + (hasHeader ? 50 : 20)
// rowHeight is equal to 90

let contentHeight = 40

let hasHeader = true

let rowHeight = contentHeight + (hasHeader ? 50 : 20)

// rowHeight is equal to 90

Apple documentation here.

September 25, 2016September 25, 2016

Transparently redirect your root directory to a subdirectory

DreamHost has instructions here.
Make a text file called .htaccess with the following code and upload it to the domain’s root directory.

RewriteEngine on
RewriteBase /

RewriteCond %{REQUEST_URI} !^/blog/

# Rewrites all URLS [Replace "domain" with the actual domain, without the TLD (.com, .net, .biz, etc)]
RewriteCond %{HTTP_HOST} ^(www\.)?domain\.

# Rewrite all those to insert /folder
RewriteRule ^(.*)$ /blog/$1 [L]

RewriteEngine on

RewriteBase /

RewriteCond %{REQUEST_URI} !^/blog/

# Rewrites all URLS [Replace "domain" with the actual domain, without the TLD (.com, .net, .biz, etc)]

RewriteCond %{HTTP_HOST} ^(www\.)?domain\.

# Rewrite all those to insert /folder

RewriteRule ^(.*)$ /blog/$1 [L]

Alternatively.

RewriteEngine on
RewriteCond %{HTTP_HOST} example\.com [NC]
RewriteCond %{REQUEST_URI} ^/$
RewriteRule ^(.*)$ /blog/$1 [L]

RewriteEngine on

RewriteCond %{HTTP_HOST} example\.com [NC]

RewriteCond %{REQUEST_URI} ^/$

RewriteRule ^(.*)$ /blog/$1 [L]

September 24, 2016September 25, 2016

How to do a lightweight Core Data migration in Swift

Here’s a stack overflow post on the topic.
Define migrationOptions to be used in persistentStoreCoordinator

let migrationOptions = [NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true]

1	let migrationOptions = [NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true]

Inclue options in:

try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: migrationOptions)

1	try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: migrationOptions)

It should end up like this:

    lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
        // The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
        // Create the coordinator and store
        let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
        let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("SingleViewCoreData.sqlite")
        let migrationOptions = [NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true] // Migration options added to standard Core Data stack
        var failureReason = "There was an error creating or loading the application's saved data."
        do {
            try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: migrationOptions)
        } catch {
            // Report any error we got.
            var dict = [String: AnyObject]()
            dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
            dict[NSLocalizedFailureReasonErrorKey] = failureReason

            dict[NSUnderlyingErrorKey] = error as NSError
            let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
            // Replace this with code to handle the error appropriately.
            // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
            NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
            abort()
        }
        
        return coordinator
    }()

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {

// The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.

// Create the coordinator and store

let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)

let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("SingleViewCoreData.sqlite")

let migrationOptions = [NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true] // Migration options added to standard Core Data stack

var failureReason = "There was an error creating or loading the application's saved data."

do {

try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: migrationOptions)

} catch {

// Report any error we got.

var dict = [String: AnyObject]()

dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"

dict[NSLocalizedFailureReasonErrorKey] = failureReason

dict[NSUnderlyingErrorKey] = error as NSError

let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)

// Replace this with code to handle the error appropriately.

// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.

NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")

abort()

}

return coordinator

}()

Similarly in Objective C. Thanks @rockvotes

NSDictionary *migrationOptions = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];

1	NSDictionary *migrationOptions = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];

September 23, 2016September 23, 2016

iOS minimum set of required icons

There are 4 icon sizes required to submit a universal iOS app to the App Store:

76px (iPad 1x)
120px (iPhone 2x)
152px (iPad 2x)
167px (iPad Pro 2x)

Download placeholder icons here.

September 23, 2016November 19, 2016

Submitting apps to the App Store with Dynamic Libraries

I was trying to submit a proof of concept app to the app store for TestFlight distribution. Submission failed.
Looked up Mapbox to see if there was a new version. No.
Looked up Mapbox to see if I was missing something in their instructions. No
A quick google search, lead me to a stack overflow post, which linked to another, which linked to this: Stripping Unwanted Architectures From Dynamic Libraries In Xcode
Copy, paste,

APP_PATH="${TARGET_BUILD_DIR}/${WRAPPER_NAME}"

# This script loops through the frameworks embedded in the application and
# removes unused architectures.
find "$APP_PATH" -name '*.framework' -type d | while read -r FRAMEWORK
do
    FRAMEWORK_EXECUTABLE_NAME=$(defaults read "$FRAMEWORK/Info.plist" CFBundleExecutable)
    FRAMEWORK_EXECUTABLE_PATH="$FRAMEWORK/$FRAMEWORK_EXECUTABLE_NAME"
    echo "Executable is $FRAMEWORK_EXECUTABLE_PATH"

    EXTRACTED_ARCHS=()

    for ARCH in $ARCHS
    do
        echo "Extracting $ARCH from $FRAMEWORK_EXECUTABLE_NAME"
        lipo -extract "$ARCH" "$FRAMEWORK_EXECUTABLE_PATH" -o "$FRAMEWORK_EXECUTABLE_PATH-$ARCH"
        EXTRACTED_ARCHS+=("$FRAMEWORK_EXECUTABLE_PATH-$ARCH")
    done

    echo "Merging extracted architectures: ${ARCHS}"
    lipo -o "$FRAMEWORK_EXECUTABLE_PATH-merged" -create "${EXTRACTED_ARCHS[@]}"
    rm "${EXTRACTED_ARCHS[@]}"

    echo "Replacing original executable with thinned version"
    rm "$FRAMEWORK_EXECUTABLE_PATH"
    mv "$FRAMEWORK_EXECUTABLE_PATH-merged" "$FRAMEWORK_EXECUTABLE_PATH"

done

APP_PATH="${TARGET_BUILD_DIR}/${WRAPPER_NAME}"

# This script loops through the frameworks embedded in the application and

# removes unused architectures.

find "$APP_PATH" -name '*.framework' -type d | while read -r FRAMEWORK

FRAMEWORK_EXECUTABLE_NAME=$(defaults read "$FRAMEWORK/Info.plist" CFBundleExecutable)

FRAMEWORK_EXECUTABLE_PATH="$FRAMEWORK/$FRAMEWORK_EXECUTABLE_NAME"

echo "Executable is $FRAMEWORK_EXECUTABLE_PATH"

EXTRACTED_ARCHS=()

for ARCH in $ARCHS

echo "Extracting $ARCH from $FRAMEWORK_EXECUTABLE_NAME"

lipo -extract "$ARCH" "$FRAMEWORK_EXECUTABLE_PATH" -o "$FRAMEWORK_EXECUTABLE_PATH-$ARCH"

EXTRACTED_ARCHS+=("$FRAMEWORK_EXECUTABLE_PATH-$ARCH")

done

echo "Merging extracted architectures: ${ARCHS}"

lipo -o "$FRAMEWORK_EXECUTABLE_PATH-merged" -create "${EXTRACTED_ARCHS[@]}"

rm "${EXTRACTED_ARCHS[@]}"

echo "Replacing original executable with thinned version"

rm "$FRAMEWORK_EXECUTABLE_PATH"

mv "$FRAMEWORK_EXECUTABLE_PATH-merged" "$FRAMEWORK_EXECUTABLE_PATH"

done

(might need to follow step 0 from here)
Archive, submit.

codenkeg

Posts

Setting up MongoDB on Ubuntu

Before You Begin

Add the MongoDB repository

Running MongoDB

Setup MongoDB users

Mini series

Setting up a server at Linode

Getting started

Securing the server

Point a domain name at your new IP

Mini series

Setting up a new domain (registrar different from host)

Shortcut characters

Copy Spotify playlist to text

Shorthand if statement (Ternary Conditional Operator)

Transparently redirect your root directory to a subdirectory

How to do a lightweight Core Data migration in Swift

iOS minimum set of required icons

Submitting apps to the App Store with Dynamic Libraries