From cc07466f25ad76904b3c05c0b876ff78e5ea7f41 Mon Sep 17 00:00:00 2001
From: Frank Denis <124872+jedisct1@users.noreply.github.com>
Date: Sun, 21 Jul 2019 02:05:29 +0200
Subject: [PATCH] Make the script a bit more reliable

---
 Updates.md | 76 ++++++++++++++----------------------------------------
 1 file changed, 20 insertions(+), 56 deletions(-)

diff --git a/Updates.md b/Updates.md
index d063e81..9424d6f 100644
--- a/Updates.md
+++ b/Updates.md
@@ -1,69 +1,33 @@
-# Automatic Update For Linux
-The script below will check to see if dnscrypt-proxy needs updating by comparing the installed version with the latest git version.
+#! /bin/sh
 
-If the installed version is older, then the script will update to the newest version.
-
-Tested on: Ubuntu 18.04
-
-## Requirements
-This script requires dnscrypt-proxy to be installed as a service using,`./dnscrypt-proxy -service install` and for dnscrypt-proxy to be installed in `/opt/dnscrypt-proxy` and for the configuration file to be named `dnscrypt-proxy.toml`.
-
-If dnscrypt-proxy is not run as root then, change `sudo chown root:root -R /opt/dnscrypt-proxy` to the user dnscrypt-proxy is run as.
-
-## Configuration
-
-Initially make sure all the above requirements are met.
-
-Then to get this script to automatically run add this as a cron job under root using `sudo crontab -e` but, change the file path to the file path the script is saved.
-
-`0 */12 * * * /path/dnscrypt-proxy-update.sh`
-
-Also, this script needs to be run as root.
-
-```sh
-#!/bin/sh
+INSTALL_DIR="/opt/dnscrypt-proxy"
+LATEST_URL="https://api.github.com/repos/jedisct1/dnscrypt-proxy/releases/latest"
 
 Update() {
-    cd /opt/dnscrypt-proxy
-    sudo mv dnscrypt-proxy.toml /opt/
-    cd /opt
-    sudo curl -L -O $( curl -s https://api.github.com/repos/jedisct1/dnscrypt-proxy/releases/latest | grep dnscrypt-proxy-linux_x86_64- | grep browser_download_url | head -1 | cut -d \" -f 4 )
-    sudo service dnscrypt-proxy stop
-    sudo rm -rf /opt/dnscrypt-proxy
-    sudo tar xvzf dnscrypt-proxy-linux_x86_64-*.tar.gz
-    cd linux-x86_64
-    sudo mkdir /opt/dnscrypt-proxy
-    sudo mv * /opt/dnscrypt-proxy
-    sudo mv -f /opt/dnscrypt-proxy.toml /opt/dnscrypt-proxy
-    sudo chown root:root -R /opt/dnscrypt-proxy
-    sudo chmod 775 /opt/dnscrypt-proxy
-    sudo cp -f /etc/resolv.conf /etc/resolv.conf.backup
-    cd /opt
-    sudo rm -rf dnscrypt-proxy-linux_x86_*
-    sudo rm -rf linux-x86_64
-    sudo service dnscrypt-proxy start
-    sudo service dnscrypt-proxy status
+    workdir="$(mktemp -d)"
+    curl -sL $(curl -sL ${LATEST_URL} |
+        grep dnscrypt-proxy-linux_x86_64- | grep browser_download_url | head -1 | cut -d \" -f 4) |
+        tar xz -C "$workdir" -f - linux-x86_64/dnscrypt-proxy &&
+        [ -x linux-x86_64/dnscrypt-proxy ] &&
+        mv -f "${INSTALL_DIR}/dnscrypt-proxy" "${INSTALL_DIR}/dnscrypt-proxy.old" || : &&
+        mv -f "${workdir}/linux-x86_64/dnscrypt-proxy" "${INSTALL_DIR}/" &&
+        cd "$INSTALL_DIR" && rm -fr "$workdir" &&
+        ./dnscrypt-proxy -check && ./dnscrypt-proxy -service install 2>/dev/null || : &&
+        ./dnscrypt-proxy -service restart || ./dnscrypt-proxy -service start
 }
 
-lversion=$(
-    cd /opt/dnscrypt-proxy
-    ./dnscrypt-proxy -version
-)
-
-rmersion=$(
-    curl -s https://api.github.com/repos/jedisct1/dnscrypt-proxy/releases/latest | grep "tag_name" | head -1 | cut -d \" -f 4
-)
+lversion=$("${INSTALL_DIR}/dnscrypt-proxy" -version)
+rmersion=$(curl -sL ${LATEST_URL} | grep "tag_name" | head -1 | cut -d \" -f 4)
+[ -z "$lversion" || -z "$rmersion" ] && exit 1
 
 echo locally installed
-echo $lversion
+echo "$lversion"
 
 echo remote git version
-echo $rmersion
+echo "$rmersion"
 
-if [[ "$rmersion" > "$lversion" ]]
-then
+if [ "$rmersion" != "$lversion" ]; then
     echo Updating && Update
 else
     echo No Update Needed
-fi
-```
\ No newline at end of file
+fi
\ No newline at end of file