[1/2] pakfire: Implement feedback from mailing list discussion

  - Improve lockfile test: Return immediately if lockfile is present,
to prevent unnecessary and expensive "pidof" calls

- Add better explanation to the log file reading command and JS

- Change user interface: If no errors occurred, the page returns to
the main screen (after a short delay). If an error occurred, the log
output remains and a message is shown.

Signed-off-by: Leo-Andres Hofmann <hofmann@leo-andres.de>
---
 html/cgi-bin/pakfire.cgi     | 42 ++++++++++++----
 html/html/include/pakfire.js | 96 ++++++++++++++++++++++++++++++++++--
 langs/de/cgi-bin/de.pl       |  3 +-
 langs/en/cgi-bin/en.pl       |  3 +-
 4 files changed, 127 insertions(+), 17 deletions(-)
  

Acked-by: Peter Müller <peter.mueller@ipfire.org>


> - Improve lockfile test: Return immediately if lockfile is present,
> to prevent unnecessary and expensive "pidof" calls
> 
> - Add better explanation to the log file reading command and JS
> 
> - Change user interface: If no errors occurred, the page returns to
> the main screen (after a short delay). If an error occurred, the log
> output remains and a message is shown.
> 
> Signed-off-by: Leo-Andres Hofmann <hofmann@leo-andres.de>
> ---
>  html/cgi-bin/pakfire.cgi     | 42 ++++++++++++----
>  html/html/include/pakfire.js | 96 ++++++++++++++++++++++++++++++++++--
>  langs/de/cgi-bin/de.pl       |  3 +-
>  langs/en/cgi-bin/en.pl       |  3 +-
>  4 files changed, 127 insertions(+), 17 deletions(-)
> 
> diff --git a/html/cgi-bin/pakfire.cgi b/html/cgi-bin/pakfire.cgi
> index e14658ffb..8516b07b1 100644
> --- a/html/cgi-bin/pakfire.cgi
> +++ b/html/cgi-bin/pakfire.cgi
> @@ -20,6 +20,7 @@
>  ###############################################################################
>  
>  use strict;
> +use List::Util qw(any);
>  
>  # enable only the following on debugging purpose
>  #use warnings;
> @@ -54,13 +55,20 @@ if($cgiparams{'ACTION'} eq 'json-getstatus') {
>  	# Send HTTP headers
>  	_start_json_output();
>  
> -	# Collect Pakfire status and log messages
> +	# Read /var/log/messages backwards until a "Pakfire started" header is found,
> +	# to capture all messages of the last (i.e. current) Pakfire run
> +	my @messages = `tac /var/log/messages | sed -n '/pakfire:/{p;/Pakfire.*started/q}'`;
> +
> +	# Test if the log contains an error message (fastest implementation, stops at first match)
> +	my $failure = any{ index($_, 'ERROR') != -1 } @messages;
> +
> +	# Collect Pakfire status
>  	my %status = (
>  		'running' => &_is_pakfire_busy() || "0",
>  		'running_since' => &General::age("$Pakfire::lockfile") || "0s",
> -		'reboot' => (-e "/var/run/need_reboot") || "0"
> +		'reboot' => (-e "/var/run/need_reboot") || "0",
> +		'failure' => $failure || "0"
>  	);
> -	my @messages = `tac /var/log/messages | sed -n '/pakfire:/{p;/Pakfire.*started/q}'`;
>  
>  	# Start JSON file
>  	print "{\n";
> @@ -128,14 +136,18 @@ my $extraHead = <<END
>  	pakfire.i18n.load({
>  		'working': '$Lang::tr{'pakfire working'}',
>  		'finished': '$Lang::tr{'pakfire finished'}',
> -		'since': '$Lang::tr{'since'} ', //(space is intentional)
> +		'finished error': '$Lang::tr{'pakfire finished error'}',
> +		'since': '$Lang::tr{'since'}',
>  
>  		'link_return': '<a href="$ENV{'SCRIPT_NAME'}">$Lang::tr{'pakfire return'}</a>',
>  		'link_reboot': '<a href="/cgi-bin/shutdown.cgi">$Lang::tr{'needreboot'}</a>'
>  	});
> -	
> -	// AJAX auto refresh interval
> -	pakfire.refreshInterval = 1000;
> +
> +	// AJAX auto refresh interval (in ms, default: 1000)
> +	//pakfire.refreshInterval = 1000;
> +
> +	// Enable returning to main screen (delay in ms)
> +	pakfire.setupPageReload(true, 3000);
>  </script>
>  END
>  ;
> @@ -276,6 +288,7 @@ if(&_is_pakfire_busy()) {
>  <!-- Pakfire log messages -->
>  <pre id="pflog-messages"></pre>
>  <script>
> +	// Start automatic log refresh
>  	pakfire.running = true;
>  </script>
>  
> @@ -401,13 +414,22 @@ END
>  
>  # Check if pakfire is already running (extend test here if necessary)
>  sub _is_pakfire_busy {
> -	# Get PID of a running pakfire instance
> +	# Return immediately if lockfile is present
> +	if(-e "$Pakfire::lockfile") {
> +		return 1;
> +	}
> +
> +	# Check if a PID of a running pakfire instance is found
>  	# (The system backpipe command is safe, because no user input is computed.)
>  	my $pakfire_pid = `pidof -s /usr/local/bin/pakfire`;
>  	chomp($pakfire_pid);
>  
> -	# Test presence of PID or lockfile
> -	return (($pakfire_pid) || (-e "$Pakfire::lockfile"));
> +	if($pakfire_pid) {
> +		return 1;
> +	}
> +
> +	# Pakfire isn't running
> +	return 0;
>  }
>  
>  # Send HTTP headers
> diff --git a/html/html/include/pakfire.js b/html/html/include/pakfire.js
> index 0950870e0..44a40c75f 100644
> --- a/html/html/include/pakfire.js
> +++ b/html/html/include/pakfire.js
> @@ -32,12 +32,13 @@ class PakfireJS {
>  		this._states = Object.create(null);
>  		this._states.running = false;
>  		this._states.reboot = false;
> +		this._states.failure = false;
>  
>  		// Status refresh helper
>  		this._autoRefresh = {
> -			delay: 1000, //Delay between requests (default: 1s)
> +			delay: 1000, //Delay between requests (minimum: 500, default: 1s)
>  			jsonAction: 'getstatus', //CGI POST action parameter
> -			timeout: 5000, //XHR timeout (5s)
> +			timeout: 5000, //XHR timeout (0 to disable, default: 5s)
>  
>  			delayTimer: null, //setTimeout reference
>  			jqXHR: undefined, //jQuery.ajax promise reference
> @@ -51,10 +52,32 @@ class PakfireJS {
>  				return (this.runningDelay || this.runningXHR);
>  			}
>  		};
> +
> +		// Return to main screen helper
> +		this._pageReload = {
> +			delay: 1000, //Delay before page reload (default: 1s)
> +			enabled: false, //Reload disabled by default
> +
> +			delayTimer: null, //setTimeout reference
> +			get isTriggered() { //Reload timer started
> +				return (this.delayTimer !== null);
> +			}
> +		};
>  	}
>  
>  	//### Public properties ###
>  
> +	// Note on using the status flags
> +	// running: Pakfire is performing a task.
> +	//    Writing "true" activates the periodic AJAX/JSON status polling, writing "false" stops polling.
> +	//    When the task has been completed, status polling stops and this returns to "false".
> +	//    The page can then be reloaded to go back to the main screen. Writing "false" does not trigger a reload.
> +	//    "refreshInterval" and "setupPageReload" can be used to adjust the respective behaviour.
> +	// reboot: An update requires a reboot.
> +	//    If set to "true", a link to the reboot menu is shown after the task is completed.
> +	// failure: An error has occured.
> +	//    To display the error log, the page does not return to the main screen.
> +
>  	// Pakfire is running (true/false)
>  	set running(state) {
>  		if(this._states.running !== state) {
> @@ -77,6 +100,17 @@ class PakfireJS {
>  		return this._states.reboot;
>  	}
>  
> +	// Error encountered (true/false)
> +	set failure(state) {
> +		if(this._states.failure !== state) {
> +			this._states.failure = state;
> +			this._states_onChange('failure');
> +		}
> +	}
> +	get failure() {
> +		return this._states.failure;
> +	}
> +
>  	// Status refresh interval in ms
>  	set refreshInterval(delay) {
>  		if(delay < 500) {
> @@ -88,6 +122,16 @@ class PakfireJS {
>  		return this._autoRefresh.delay;
>  	}
>  
> +	// Configure page reload after successful task (returns to main screen)
> +	// delay: In ms
> +	setupPageReload(enabled, delay) {
> +		if(delay < 0) {
> +			delay = 0;
> +		}
> +		this._pageReload.delay = delay;
> +		this._pageReload.enabled = enabled;
> +	}
> +
>  	// Document loaded (call once from jQuery.ready)
>  	documentReady() {
>  		// Status refresh late start
> @@ -96,6 +140,12 @@ class PakfireJS {
>  		}
>  	}
>  
> +	// Reload entire CGI page (clears POST/GET data from history)
> +	documentReload() {
> +		let url = window.location.origin + window.location.pathname;
> +		window.location.replace(url);
> +	}
> +
>  	//### Private properties ###
>  
>  	// Pakfire status change handler
> @@ -106,9 +156,13 @@ class PakfireJS {
>  			$('#pflog-status').text(this.i18n.get('working'));
>  			$('#pflog-action').empty();
>  		} else {
> -			$('#pflog-status').text(this.i18n.get('finished'));
> +			if(this.failure) {
> +				$('#pflog-status').text(this.i18n.get('finished error'));
> +			} else {
> +				$('#pflog-status').text(this.i18n.get('finished'));
> +			}
>  			if(this.reboot) { //Enable return or reboot links in UI
> -				$('#pflog-action').html(this.i18n.get('link_reboot'));
> +				$('#pflog-action').html(this.i18n.get('link_return') + " &bull; " + this.i18n.get('link_reboot'));
>  			} else {
>  				$('#pflog-action').html(this.i18n.get('link_return'));
>  			}
> @@ -122,6 +176,13 @@ class PakfireJS {
>  				this._autoRefresh_clearSchedule();
>  			}
>  		}
> +
> +		// Always stay in the log viewer if Pakfire failed
> +		if(property === 'failure') {
> +			if(this.failure) {
> +				this._pageReload_cancel();
> +			}
> +		}
>  	}
>  
>  	//--- Status refresh scheduling functions ---
> @@ -164,6 +225,25 @@ class PakfireJS {
>  		}
>  	}
>  
> +	// Start delayed page reload to return to main screen
> +	_pageReload_trigger() {
> +		if((! this._pageReload.enabled) || this._pageReload.isTriggered) {
> +			return; // Disabled or already started
> +		}
> +		this._pageReload.delayTimer = window.setTimeout(function() {
> +			this._pageReload.delayTimer = null;
> +			this.documentReload();
> +		}.bind(this), this._pageReload.delay);
> +	}
> +
> +	// Stop scheduled reload
> +	_pageReload_cancel() {
> +		if(this._pageReload.isTriggered) {
> +			window.clearTimeout(this._pageReload.delayTimer);
> +			this._pageReload.delayTimer = null;
> +		}
> +	}
> +
>  	//--- JSON request & data handling ---
>  
>  	// Load JSON data from Pakfire CGI, using a POST request
> @@ -192,10 +272,11 @@ class PakfireJS {
>  			// Update status flags
>  			this.running = (data['running'] != '0');
>  			this.reboot = (data['reboot'] != '0');
> +			this.failure = (data['failure'] != '0');
>  
>  			// Update timer display
>  			if(this.running && data['running_since']) {
> -				$('#pflog-time').text(this.i18n.get('since') + data['running_since']);
> +				$('#pflog-time').text(this.i18n.get('since') + " " + data['running_since']);
>  			} else {
>  				$('#pflog-time').empty();
>  			}
> @@ -206,6 +287,11 @@ class PakfireJS {
>  				messages += `${line}\n`;
>  			});
>  			$('#pflog-messages').text(messages);
> +
> +			// Pakfire finished without errors, return to main screen
> +			if((! this.running) && (! this.failure)) {
> +				this._pageReload_trigger();
> +			}
>  		}
>  	}
>  }
> diff --git a/langs/de/cgi-bin/de.pl b/langs/de/cgi-bin/de.pl
> index 490879c90..dd946081d 100644
> --- a/langs/de/cgi-bin/de.pl
> +++ b/langs/de/cgi-bin/de.pl
> @@ -1974,7 +1974,8 @@
>  'pakfire configuration' => 'Pakfire Konfiguration',
>  'pakfire core update auto' => 'Core- und Addon-Updates automatisch installieren:',
>  'pakfire core update level' => 'Core-Update-Level',
> -'pakfire finished' => 'Pakfire ist fertig!. Bitte überprüfen Sie die Log Ausgabe.',
> +'pakfire finished' => 'Pakfire ist fertig! Kehre zurück...',
> +'pakfire finished error' => 'Pakfire ist fertig! Fehler sind aufgetreten, bitte überprüfen Sie die Log-Ausgabe, bevor Sie fortfahren.',
>  'pakfire health check' => 'Mirrors auf Erreichbarkeit prüfen (Ping):',
>  'pakfire install description' => 'Wählen Sie ein oder mehrere Pakete zur Installation aus und drücken Sie auf das plus-Symbol.',
>  'pakfire install package' => 'Sie möchten folgende Pakete installieren: ',
> diff --git a/langs/en/cgi-bin/en.pl b/langs/en/cgi-bin/en.pl
> index 4442ea772..fc5a57cb0 100644
> --- a/langs/en/cgi-bin/en.pl
> +++ b/langs/en/cgi-bin/en.pl
> @@ -2009,7 +2009,8 @@
>  'pakfire configuration' => 'Pakfire Configuration',
>  'pakfire core update auto' => 'Install core and addon updates automatically:',
>  'pakfire core update level' => 'Core-Update-Level',
> -'pakfire finished' => 'Pakfire is finished! Please check the log output.',
> +'pakfire finished' => 'Pakfire has finished! Returning...',
> +'pakfire finished error' => 'Pakfire has finished! Errors occurred, please check the log output before proceeding.',
>  'pakfire health check' => 'Check if mirror is reachable (ping):',
>  'pakfire install description' => 'Please choose one or more items from the list below and click the plus to install.',
>  'pakfire install package' => 'You want to install the following packages: ',
>