Re: [PATCH 2/4] pakfire.cgi: Implement JavaScript log message display

[Michael Tremer <michael.tremer@ipfire.org>]

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Hello,

> On 2 Dec 2021, at 15:39, Leo-Andres Hofmann <hofmann(a)leo-andres.de> wrote:
> 
> Currently the page becomes unresponsive while Pakfire is busy.
> This patch implements a AJAX/JSON driven log output, to provide
> continuous information to the user while Pakfire is running.
> 
> The output is updated 1x per second, if the load should be too high,
> the interval can be change by writing to "pakfire.refreshInterval".
> 
> Signed-off-by: Leo-Andres Hofmann <hofmann(a)leo-andres.de>
> ---
> html/cgi-bin/pakfire.cgi     | 153 ++++++++++++++++++----
> html/html/include/pakfire.js | 241 +++++++++++++++++++++++++++++++++++
> 2 files changed, 368 insertions(+), 26 deletions(-)
> create mode 100644 html/html/include/pakfire.js
> 
> diff --git a/html/cgi-bin/pakfire.cgi b/html/cgi-bin/pakfire.cgi
> index 7957bc154..e5f5f7d6a 100644
> --- a/html/cgi-bin/pakfire.cgi
> +++ b/html/cgi-bin/pakfire.cgi
> @@ -36,8 +36,11 @@ my %color = ();
> my %pakfiresettings = ();
> my %mainsettings = ();
> 
> -&Header::showhttpheaders();
> +# Load general settings
> +&General::readhash("${General::swroot}/main/settings", \%mainsettings);
> +&General::readhash("/srv/web/ipfire/html/themes/ipfire/include/colors.txt", \%color);
> 
> +# Get CGI request data
> $cgiparams{'ACTION'} = '';
> $cgiparams{'VALID'} = '';
> 
> @@ -46,12 +49,102 @@ $cgiparams{'DELPAKS'} = '';
> 
> &Header::getcgihash(\%cgiparams);
> 
> -&General::readhash("${General::swroot}/main/settings", \%mainsettings);
> -&General::readhash("/srv/web/ipfire/html/themes/ipfire/include/colors.txt", \%color);
> +### Process AJAX/JSON request ###
> +if($cgiparams{'ACTION'} eq 'json-getstatus') {
> +	# Send HTTP headers
> +	_start_json_output();
> +
> +	# Collect Pakfire status and log messages
> +	my %status = (
> +		'running' => &_is_pakfire_busy() || "0",
> +		'running_since' => &General::age("$Pakfire::lockfile") || "0s",
> +		'reboot' => (-e "/var/run/need_reboot") || "0"
> +	);
> +	my @messages = `tac /var/log/messages | sed -n '/pakfire:/{p;/Pakfire.*started/q}'`;
> +
> +	# Start JSON file
> +	print "{\n";
> +
> +	foreach my $key (keys %status) {
> +		my $value = $status{$key};
> +		print qq{\t"$key": "$value",\n};
> +	}
> +
> +	# Print sanitized messages in reverse order to undo previous "tac"
> +	print qq{\t"messages": [\n};
> +	for my $index (reverse (0 .. $#messages)) {
> +		my $line = $messages[$index];
> +		$line =~ s/[[:cntrl:]<>&\\]+//g;
> +
> +		print qq{\t\t"$line"};
> +		print ",\n" unless $index < 1;
> +	}
> +	print "\n\t]\n";

What is the reason to “tac” the log file first and then reverse the order again?

Is it just to limit the length of the JSON array?

It might be faster to read the entire file, grep out what we need and then throw away most of the array. Or push a line to the end of the array and remove one from the beginning if it is longer than a certain threshold.

> +
> +	# Finalize JSON file & stop
> +	print "}";
> +	exit;
> +}
> +
> +### Start pakfire page ###
> +&Header::showhttpheaders();
> +
> +###--- HTML HEAD ---###
> +my $extraHead = <<END
> +<style>
> +	/* Pakfire log viewer */
> +	section#pflog-header {
> +		width: 100%;
> +		display: flex;
> +		text-align: left;
> +		align-items: center;
> +		column-gap: 20px;
> +	}
> +	#pflog-header > div:last-child {
> +		margin-left: auto;
> +		margin-right: 20px;
> +	}
> +	#pflog-header span {
> +		line-height: 1.3em;
> +	}
> +	#pflog-header span:empty::before {
> +		content: "\\200b"; /* zero width space */
> +	}
> +
> +	pre#pflog-messages {
> +		margin-top: 0.7em;
> +		padding-top: 0.7em;
> +		border-top: 0.5px solid $Header::bordercolour;
> 
> -&Header::openpage($Lang::tr{'pakfire configuration'}, 1);
> +		text-align: left;
> +		min-height: 15em;
> +		overflow-x: auto;
> +	}
> +</style>
> +
> +<script src="/include/pakfire.js"></script>
> +<script>
> +	// Translations
> +	pakfire.i18n.load({
> +		'working': '$Lang::tr{'pakfire working'}',
> +		'finished': 'Pakfire is finished! Please check the log output.',
> +		'since': '$Lang::tr{'since'} ', //(space is intentional)
> +
> +		'link_return': '<a href="$ENV{'SCRIPT_NAME'}">Return to Pakfire</a>',
> +		'link_reboot': '<a href="/cgi-bin/shutdown.cgi">$Lang::tr{'needreboot'}</a>'
> +	});
> +	
> +	// AJAX auto refresh interval
> +	pakfire.refreshInterval = 1000;
> +</script>
> +END
> +;
> +###--- END HTML HEAD ---###
> +
> +&Header::openpage($Lang::tr{'pakfire configuration'}, 1, $extraHead);
> &Header::openbigbox('100%', 'left', '', $errormessage);
> 
> +# Process Pakfire commands
> if (($cgiparams{'ACTION'} eq 'install') && (! &_is_pakfire_busy())) {
> 	my @pkgs = split(/\|/, $cgiparams{'INSPAKS'});
> 	if ("$cgiparams{'FORCE'}" eq "on") {
> @@ -170,29 +263,30 @@ if ($errormessage) {
> 	&Header::closebox();
> }
> 
> -# Check if pakfire is already running.
> -if (&_is_pakfire_busy()) {
> -	&Header::openbox( 'Waiting', 1, "<meta http-equiv='refresh' content='10;'>" );
> -	print <<END;
> -	<table>
> -		<tr><td>
> -				<img src='/images/indicator.gif' alt='$Lang::tr{'active'}' title='$Lang::tr{'active'}' />&nbsp;
> -			<td>
> -				$Lang::tr{'pakfire working'}
> -		<tr><td colspan='2' align='center'>
> -			<form method='post' action='$ENV{'SCRIPT_NAME'}'>
> -				<input type='image' alt='$Lang::tr{'reload'}' title='$Lang::tr{'reload'}' src='/images/view-refresh.png' />
> -			</form>
> -		<tr><td colspan='2' align='left'><code>
> -END
> -	my @output = `grep pakfire /var/log/messages | tail -20`;
> -	foreach (@output) {
> -		print "$_<br>";
> -	}
> -	print <<END;
> -			</code>
> -		</table>
> +# Show log output while Pakfire is running
> +if(&_is_pakfire_busy()) {
> +	&Header::openbox("100%", "center", "Pakfire");
> +
> +	print <<END
> +<section id="pflog-header">
> +	<div><img src="/images/indicator.gif" alt="$Lang::tr{'active'}" title="$Lang::tr{'pagerefresh'}"></div>
> +	<div>
> +		<span id="pflog-status">$Lang::tr{'pakfire working'}</span><br>
> +		<span id="pflog-time"></span><br>
> +		<span id="pflog-action"></span>
> +	</div>
> +	<div><a href="$ENV{'SCRIPT_NAME'}"><img src="/images/view-refresh.png" alt="$Lang::tr{'refresh'}" title="$Lang::tr{'refresh'}"></a></div>
> +</section>
> +
> +<!-- Pakfire log messages -->
> +<pre id="pflog-messages"></pre>
> +<script>
> +	pakfire.running = true;
> +</script>
> +
> END
> +;
> +
> 	&Header::closebox();
> 	&Header::closebigbox();
> 	&Header::closepage();
> @@ -320,3 +414,10 @@ sub _is_pakfire_busy {
> 	# Test presence of PID or lockfile
> 	return (($pakfire_pid) || (-e "$Pakfire::lockfile"));
> }
> +
> +# Send HTTP headers
> +sub _start_json_output {
> +	print "Cache-Control: no-cache, no-store\n";
> +	print "Content-Type: application/json\n";
> +	print "\n"; # End of HTTP headers
> +}
> diff --git a/html/html/include/pakfire.js b/html/html/include/pakfire.js
> new file mode 100644
> index 000000000..0950870e0
> --- /dev/null
> +++ b/html/html/include/pakfire.js
> @@ -0,0 +1,241 @@
> +/*#############################################################################
> +#                                                                             #
> +# IPFire.org - A linux based firewall                                         #
> +# Copyright (C) 2007-2021  IPFire Team  <info(a)ipfire.org>                     #
> +#                                                                             #
> +# This program is free software: you can redistribute it and/or modify        #
> +# it under the terms of the GNU General Public License as published by        #
> +# the Free Software Foundation, either version 3 of the License, or           #
> +# (at your option) any later version.                                         #
> +#                                                                             #
> +# This program is distributed in the hope that it will be useful,             #
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
> +# GNU General Public License for more details.                                #
> +#                                                                             #
> +# You should have received a copy of the GNU General Public License           #
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
> +#                                                                             #
> +#############################################################################*/
> +
> +"use strict";
> +
> +// Pakfire Javascript functions (requires jQuery)
> +class PakfireJS {
> +	constructor() {
> +		//--- Public properties ---
> +		// Translation strings
> +		this.i18n = new PakfireI18N();
> +
> +		//--- Private properties ---
> +		// Status flags (access outside constructor only with setter/getter)
> +		this._states = Object.create(null);
> +		this._states.running = false;
> +		this._states.reboot = false;
> +
> +		// Status refresh helper
> +		this._autoRefresh = {
> +			delay: 1000, //Delay between requests (default: 1s)
> +			jsonAction: 'getstatus', //CGI POST action parameter
> +			timeout: 5000, //XHR timeout (5s)
> +
> +			delayTimer: null, //setTimeout reference
> +			jqXHR: undefined, //jQuery.ajax promise reference
> +			get runningDelay() { //Waiting for end of delay
> +				return (this.delayTimer !== null);
> +			},
> +			get runningXHR() { //Waiting for CGI response
> +				return (this.jqXHR && (this.jqXHR.state() === 'pending'));
> +			},
> +			get isRunning() {
> +				return (this.runningDelay || this.runningXHR);
> +			}
> +		};
> +	}
> +
> +	//### Public properties ###
> +
> +	// Pakfire is running (true/false)
> +	set running(state) {
> +		if(this._states.running !== state) {
> +			this._states.running = state;
> +			this._states_onChange('running');
> +		}
> +	}
> +	get running() {
> +		return this._states.running;
> +	}
> +
> +	// Reboot needed (true/false)
> +	set reboot(state) {
> +		if(this._states.reboot !== state) {
> +			this._states.reboot = state;
> +			this._states_onChange('reboot');
> +		}
> +	}
> +	get reboot() {
> +		return this._states.reboot;
> +	}
> +
> +	// Status refresh interval in ms
> +	set refreshInterval(delay) {
> +		if(delay < 500) {
> +			delay = 500; //enforce reasonable minimum
> +		}
> +		this._autoRefresh.delay = delay;
> +	}
> +	get refreshInterval() {
> +		return this._autoRefresh.delay;
> +	}
> +
> +	// Document loaded (call once from jQuery.ready)
> +	documentReady() {
> +		// Status refresh late start
> +		if(this.running && (! this._autoRefresh.isRunning)) {
> +			this._autoRefresh_runNow();
> +		}
> +	}
> +
> +	//### Private properties ###
> +
> +	// Pakfire status change handler
> +	// property: Affected status (running, reboot, ...)
> +	_states_onChange(property) {
> +		// Always update UI
> +		if(this.running) {
> +			$('#pflog-status').text(this.i18n.get('working'));
> +			$('#pflog-action').empty();
> +		} 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'));
> +			} else {
> +				$('#pflog-action').html(this.i18n.get('link_return'));
> +			}
> +		}
> +
> +		// Start/stop status refresh if Pakfire started/stopped
> +		if(property === 'running') {
> +			if(this.running) {
> +				this._autoRefresh_runNow();
> +			} else {
> +				this._autoRefresh_clearSchedule();
> +			}
> +		}
> +	}
> +
> +	//--- Status refresh scheduling functions ---
> +
> +	// Immediately perform AJAX status refresh request
> +	_autoRefresh_runNow() {
> +		if(this._autoRefresh.runningXHR) {
> +			return; // Don't send multiple requests
> +		}
> +		this._autoRefresh_clearSchedule(); // Stop scheduled refresh, will send immediately
> +
> +		// Send AJAX request, attach listeners
> +		this._autoRefresh.jqXHR = this._JSON_get(this._autoRefresh.jsonAction, this._autoRefresh.timeout);
> +		this._autoRefresh.jqXHR.done(function() { // Request succeeded
> +			if(this.running) { // Keep refreshing while Pakfire is running
> +				this._autoRefresh_scheduleRun();
> +			}
> +		});
> +		this._autoRefresh.jqXHR.fail(function() { // Request failed
> +			this._autoRefresh_scheduleRun(); // Try refreshing until valid status is received
> +		});
> +	}
> +
> +	// Schedule next refresh
> +	_autoRefresh_scheduleRun() {
> +		if(this._autoRefresh.runningDelay || this._autoRefresh.runningXHR) {
> +			return; // Refresh already scheduled or in progress
> +		}
> +		this._autoRefresh.delayTimer = window.setTimeout(function() {
> +			this._autoRefresh.delayTimer = null;
> +			this._autoRefresh_runNow();
> +		}.bind(this), this._autoRefresh.delay);
> +	}
> +
> +	// Stop scheduled refresh (can still be refreshed up to 1x if XHR is already sent)
> +	_autoRefresh_clearSchedule() {
> +		if(this._autoRefresh.runningDelay) {
> +			window.clearTimeout(this._autoRefresh.delayTimer);
> +			this._autoRefresh.delayTimer = null;
> +		}
> +	}
> +
> +	//--- JSON request & data handling ---
> +
> +	// Load JSON data from Pakfire CGI, using a POST request
> +	// action: POST paramter "json-[action]"
> +	// maxTime: XHR timeout, 0 = no timeout
> +	_JSON_get(action, maxTime = 0) {
> +		return $.ajax({
> +			url: '/cgi-bin/pakfire.cgi',
> +			method: 'POST',
> +			timeout: maxTime,
> +			context: this,
> +			data: {'ACTION': `json-${action}`},
> +			dataType: 'json' //automatically check and convert result
> +		})
> +			.done(function(response) {
> +				this._JSON_process(action, response);
> +			});
> +	}
> +
> +	// Process successful response from Pakfire CGI
> +	// action: POST paramter "json-[action]" used to send request
> +	// data: JSON data object
> +	_JSON_process(action, data) {
> +		// Pakfire status refresh
> +		if(action === this._autoRefresh.jsonAction) {
> +			// Update status flags
> +			this.running = (data['running'] != '0');
> +			this.reboot = (data['reboot'] != '0');
> +
> +			// Update timer display
> +			if(this.running && data['running_since']) {
> +				$('#pflog-time').text(this.i18n.get('since') + data['running_since']);
> +			} else {
> +				$('#pflog-time').empty();
> +			}
> +
> +			// Print log messages
> +			let messages = "";
> +			data['messages'].forEach(function(line) {
> +				messages += `${line}\n`;
> +			});
> +			$('#pflog-messages').text(messages);
> +		}
> +	}
> +}
> +
> +// Simple translation strings helper
> +// Format: {key: "translation"}
> +class PakfireI18N {
> +	constructor() {
> +		this._strings = Object.create(null); //Object without prototypes
> +	}
> +
> +	// Get translation
> +	get(key) {
> +		if(Object.prototype.hasOwnProperty.call(this._strings, key)) {
> +			return this._strings[key];
> +		}
> +		return `(undefined string '${key}')`;
> +	}
> +
> +	// Load key/translation object
> +	load(translations) {
> +		if(translations instanceof Object) {
> +			Object.assign(this._strings, translations);
> +		}
> +	}
> +}
> +
> +//### Initialize Pakfire ###
> +const pakfire = new PakfireJS();
> +
> +$(function() {
> +	pakfire.documentReady();
> +});
> -- 
> 2.27.0.windows.1
>