# HG changeset patch
# User Oleksandr Gavenko <gavenkoa@gmail.com>
# Date 1546546398 -7200
# Node ID c44e4331713c571f62ea4e623f9ec0c94a62779e
# Parent  3a371f9736447444d7433d1e8e0375a344e968dc# Parent  c3baf557ff0c3f74a73c01af3b15d9d8a0e22938
merged

diff -r c3baf557ff0c -r c44e4331713c alpine.rst
--- a/alpine.rst	Tue Aug 01 01:00:35 2017 +0300
+++ b/alpine.rst	Thu Jan 03 22:13:18 2019 +0200
@@ -56,8 +56,27 @@
 Install package::
 
   $ sudo apk add bash
+
+Install local package::
+
   $ sudo apk add --allow-untrusted /path/to/file.apk
 
+To install package from specific Alpine release tag extra repository URL in
+``/etc/apk/repositories``::
+
+  @edge http://nldl-cdn.alpinelinux.org/alpine/edge/main
+
+and pin dependencies to tag::
+
+  $ sudo apk add bash@edge
+
+To avoid registering repository in ``/etc/apk/repositories`` pass repository URL and fixate package
+version::
+
+  $ sudo apk add postgresql==9.6.10-r0 --no-cache --repository=http://dl-cdn.alpinelinux.org/alpine/v3.6/main
+
+To select Alpine release, package and package version use https://pkgs.alpinelinux.org/packages
+
 Do not grab package index with ``--no-cache`` option to reduce installation size::
 
   $ apk add --no-cache bash
diff -r c3baf557ff0c -r c44e4331713c cygwin.rst
--- a/cygwin.rst	Tue Aug 01 01:00:35 2017 +0300
+++ b/cygwin.rst	Thu Jan 03 22:13:18 2019 +0200
@@ -124,8 +124,10 @@
   $ apt-cyg cache ~/net
   Cache set to C:\home\net.
 
+https://github.com/kou1okada/apt-cyg
+  Still maintained project with extra features.
 https://github.com/transcode-open/apt-cyg/
-  Home page.
+  Home page of abandoned project.
 https://github.com/transcode-open/apt-cyg/issues/19
   Request to support multiply sources.
 http://stackoverflow.com/questions/22411162/how-to-add-a-repository-using-apt-cyg/
@@ -134,6 +136,22 @@
   Depricated way to install from several sources with ``-m`` option using shell
   aliases as a trick.
 
+Cygwin bash completion
+======================
+
+Cygwin ``bash`` has extra patch that adds ``completion_strip_exe`` option::
+
+  shopt -s completion_strip_exe
+
+If you complete executable ``.exe`` suffix is stripped if any. That halps with ``bash-completion``
+because usually comletion defined for base name without ``.exe`` suffix, like::
+
+  complete -F _figlet figlet
+
+https://github.com/cygwinports/bash
+  7b. completion_strip_exe - using 'shopt -s completion_strip_exe'
+  makes completion strip .exe suffixes.
+
 Cygwin file permission
 ======================
 
diff -r c3baf557ff0c -r c44e4331713c debian-apt.rst
--- a/debian-apt.rst	Tue Aug 01 01:00:35 2017 +0300
+++ b/debian-apt.rst	Thu Jan 03 22:13:18 2019 +0200
@@ -65,6 +65,34 @@
 https://www.google.com/linuxrepositories/
   Links to Google repositories and verification key.
 
+Enable/disable recommends and suggestions
+=========================================
+
+To disable installation of recommended packages (which is by default) create file
+``/etc/apt/apt.conf.d/01no-recommends``::
+
+  APT::Install-Recommends "0";
+  APT::AutoRemove::RecommendsImportant "1";
+
+  APT::Install-Suggests "0";
+
+Alternatively pass corresponding option to installation utility to suppress installation of
+recommended packages::
+
+  apt --no-install-recommends
+  aptitude --without-recommends
+  aptitude -R
+
+To install suggested packages::
+
+  apt --install-suggests
+  aptitude --install-suggests
+
+Verify  settings::
+
+  apt-config dump | fgrep -i recommend
+  apt-config dump | fgrep -i suggest
+
 Find nearest mirror
 ===================
 
@@ -300,3 +328,10 @@
   $ sudo apt-get upgrade -s
   $ sudo aptitude upgrade -s
 
+Making aptitude forget changes
+==============================
+
+Following removes or override (like "hold" status) ``aptitude`` package state DB::
+
+  sudo rm /var/lib/aptitude/pkgstates
+  sudo aptitude keep-all
diff -r c3baf557ff0c -r c44e4331713c elasticsearch.rst
--- a/elasticsearch.rst	Tue Aug 01 01:00:35 2017 +0300
+++ b/elasticsearch.rst	Thu Jan 03 22:13:18 2019 +0200
@@ -11,6 +11,63 @@
 https://amsterdam.luminis.eu/2016/10/18/elasticsearch-5-is-coming-what-is-new-and-improved/
   New features of ES 5.
 
+Releases
+========
+
+https://github.com/elastic/elasticsearch/releases
+  Git releases & tags.
+https://www.elastic.co/support/eol
+  Elastic Product End of Life Dates.
+
+Installing & configuring
+========================
+
+https://www.elastic.co/guide/en/elasticsearch/reference/current/deb.html
+  Install Elasticsearch with Debian Package.
+
+Basic config
+============
+
+Common cluster name inside given intranet::
+
+  cluster.name: mycluster
+
+Unique node name within claser::
+
+  node.name: "node1"
+
+Node types::
+
+  node.master: true
+  node.ingest: true
+  node.data: true
+
+Network interfaces to bind to::
+
+  network.host: [_local_, node1.example.com]
+
+Port definitions::
+
+  http.port : 9200
+  tcp.port : 9300
+
+Override default locations::
+
+  path.data: /path/to/data1,/path/to/data2
+  path.logs: /path/to/logs
+  path.plugins: /path/to/plugins
+
+Explicit list of seed nodes in cluster::
+
+  discovery.zen.ping.unicast.hosts: ["master1.example.com", "master2.example.com:9300"]
+
+https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-node.html
+  Node types.
+https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-discovery-zen.html
+  Discovery settings.
+https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-transport.html
+  Transport definitions.
+
 REST syntax conventions
 =======================
 
@@ -41,6 +98,7 @@
 List cluster state::
 
   GET /_cluster/state?pretty
+  GET /_cluster/allocation/explain
 
 List of tasks executed in cluster::
 
@@ -66,6 +124,8 @@
 
 https://www.elastic.co/guide/en/elasticsearch/reference/current/_cluster_health.html
   Cluster Health.
+https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-allocation-explain.html
+  Cluster Allocation Explain API
 https://www.elastic.co/guide/en/elasticsearch/reference/current/_list_all_indices.html
   List All Indices.
 https://www.elastic.co/guide/en/elasticsearch/reference/current/cat.html
diff -r c3baf557ff0c -r c44e4331713c lxc.rst
--- a/lxc.rst	Tue Aug 01 01:00:35 2017 +0300
+++ b/lxc.rst	Thu Jan 03 22:13:18 2019 +0200
@@ -6,12 +6,34 @@
 .. contents::
    :local:
 
+LXC releases
+============
+
+https://discuss.linuxcontainers.org/tags/release
+  Announces of LXC & LXD releases.
+https://discuss.linuxcontainers.org/t/lxc-3-0-0-has-been-released/1449
+  LXC 3.0.0 has been released.
+
+Supported templates
+===================
+
+https://github.com/lxc/lxc-templates
+  Old style template scripts for LXC (prefer distrobuilder).
+https://github.com/lxc/distrobuilder
+  System container image builder for LXC and LXD.
+https://brauner.github.io/2018/02/27/lxc-removes-legacy-template-build-system.html
+  Details about replacing template stripts.
+
 Install LXC under Debian
 ========================
 ::
 
   $ sudo apt-get install lxc
 
+Verify your host/kernel satisfy LXC requirements::
+
+  $ sudo lxc-checkconfig
+
 To make network bridge install supplement packages::
 
   $ sudo apt-get install bridge-utils dnsmasq
@@ -34,30 +56,52 @@
 
   $ sudo service lxc-net start
 
-Check installation with::
-
-  $ sudo lxc-checkconfig
-
 Create new container in LXC
 ===========================
 
-``-t`` defines distro name, ``-n`` gives name for container for further
-referencing, ``--`` allow pass options to template script, ``-r`` specifies
-Debian release::
+Create container from template::
+
+  $ sudo lxc-create -t $TMPL -n $NAME -- $EXTRA_ARGS
 
-  $ sudo lxc-create -t debian -n debtest -- -r sid
+.. note::
+   * ``-t`` defines distro name
+   * ``-n`` gives name for container for further referencing
+   * everything after ``--`` is passed to template script
+
+Template name is based on file name from ``/usr/share/lxc/templates`` directory without ``lxc-``
+prefix.
 
-In order to use another miror::
+List available templates with::
+
+  $ ls -alh /usr/share/lxc/templates/
+
+Examples of container creation command::
 
-  $ MIRROR=http://httpredir.debian.org/debian sudo lxc-create -t debian -n debtest -- -r sid
+  $ sudo lxc-create -t debian -n deb-sid --  -r sid --enable-non-free
+  $ sudo lxc-create -t debian -n deb-testing --  -r testing
+  $ sudo lxc-create -t debian -n deb-stable --  -r stable -a amd64
 
-Getting help for template specific options::
+  $ sudo lxc-create -t alpine -n alpine-3.7 --  -r 3.7
+
+Each template has own options, which can be passed after ``--``. To get help on template specific
+options run::
 
   $ /usr/share/lxc/templates/lxc-ubuntu -h
   $ /usr/share/lxc/templates/lxc-debian -h
   $ /usr/share/lxc/templates/lxc-alpine -h
   ...
 
+For Debian in order to use another miror::
+
+  $ MIRROR=http://httpredir.debian.org/debian sudo lxc-create -t debian -n debtest -- -r sid
+
+Since LXC v3.0 sh-templates moved to separate project and only 4 are left supported::
+
+  $ lxc-create my-busybox -t busybox
+  $ lxc-create my-x -t download
+  $ lxc-create c1 -t local -- --metadata /path/to/meta.tar.xz --fstree /path/to/rootfs.tar.xz
+  $ lxc-create c2 -t oci -- --url docker://alpine
+
 Put ``veth`` network configuration into container config ``/var/lib/lxc/$NAME/config``::
 
   lxc.network.type = veth
@@ -83,7 +127,7 @@
 
   $ sudo lxc-start -n $NAME
 
-Safely stop VM (with honer of init system)::
+Safely stop VM (honoring init system)::
 
   $ sudo lxc-halt -n $NAME
 
diff -r c3baf557ff0c -r c44e4331713c mumble.rst
--- a/mumble.rst	Tue Aug 01 01:00:35 2017 +0300
+++ b/mumble.rst	Thu Jan 03 22:13:18 2019 +0200
@@ -13,8 +13,14 @@
 https://wiki.mumble.info/wiki/Running_Murmur
   Running Murmur.
 https://wiki.mumble.info/wiki/Murmurguide
-  Setting Up a Murmur Server.
+  Setting Up a Murmur Server and managing ACL.
+https://wiki.mumble.info/wiki/Authentication
+  Authentication
+https://wiki.mumble.info/wiki/3rd_Party_Applications
+  3rd Party Applications.
 https://wiki.mumble.info/wiki/FAQ/English
   FAQ.
+https://wiki.mumble.info/wiki/Obtaining_a_Let%27s_Encrypt_Murmur_Certificate
+  Obtaining a Let's Encrypt Murmur Certificate.
 https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-mumble-server-murmur-on-ubuntu-14-04
   How To Install and Configure Mumble Server (Murmur) on Ubuntu 14.04
diff -r c3baf557ff0c -r c44e4331713c postgres.rst
--- a/postgres.rst	Tue Aug 01 01:00:35 2017 +0300
+++ b/postgres.rst	Thu Jan 03 22:13:18 2019 +0200
@@ -35,6 +35,19 @@
 https://wiki.debian.org/PostgreSql
   Debian wiki instructions.
 
+Check version
+=============
+
+By SQL query::
+
+  SELECT version();
+  SHOW server_version;
+  SHOW server_version_num;
+
+From executable::
+
+  $ postgres -V
+
 Check locations
 ===============
 ::
@@ -42,6 +55,55 @@
   SHOW hba_file;
   SHOW config_file;
 
+Check settings
+==============
+::
+
+   SELECT name, setting FROM pg_settings;
+
+Check extensions
+================
+::
+
+   SELECT * FROM pg_available_extensions;
+
+Grant role options
+==================
+::
+
+   ALTER USER me WITH SUPERUSER;
+   ALTER USER me WITH CREATEDB CREATEROLE LOGIN;
+
+https://www.postgresql.org/docs/current/sql-createrole.html
+  ``CREATE ROLE``.
+
+Change password
+===============
+::
+
+   ALTER USER me WITH PASSWORD 'PassWord';
+
+Monitor connections
+===================
+::
+
+   select * from pg_stat_activity;
+
+https://www.postgresql.org/docs/current/monitoring-stats.html
+  The Statistics Collector.
+
+Profile queries
+===============
+
+Stats on query execution time::
+
+  SELECT * FROM pg_stat_statements;
+
+https://www.postgresql.org/docs/current/pgstatstatements.html
+  ``pg_stat_statements``.
+https://www.postgresql.org/docs/current/indexes-examine.html
+  Examining Index Usage.
+
 List databases, schemas and tables
 ==================================
 
@@ -62,14 +124,14 @@
 
 Schemas::
 
-  => select schema_name from information_schema.schemata;
-  => select nspname from pg_catalog.pg_namespace;
-  => \dn *
+  \dn *
+  select schema_name from information_schema.schemata;
+  select nspname from pg_catalog.pg_namespace;
 
 To list all tables in the current database::
 
-  => SELECT table_schema,table_name FROM information_schema.tables ORDER BY table_schema,table_name;
-  => \dt
+  \dt
+  SELECT table_schema, table_name FROM information_schema.tables ORDER BY table_schema, table_name;
 
 or in all schemas::
 
@@ -91,6 +153,68 @@
 List indexes::
 
   \di
+  select * from pg_indexes;
+  select * from pg_indexes where schemaname = '...';
+  select * from pg_indexes where schemaname = '...' and tablename = '...';
+  select * from pg_indexes where schemaname = '...' and indexname = '...';
+
+  select
+    t.relname as table_name,
+    i.relname as index_name,
+    a.attname as column_name
+  from
+    pg_class t,
+    pg_class i,
+    pg_index ix,
+    pg_attribute a
+  where
+    t.oid = ix.indrelid
+    and i.oid = ix.indexrelid
+    and a.attrelid = t.oid
+    and a.attnum = ANY(ix.indkey)
+    and t.relkind = 'r'
+    and t.relname like 'test%'
+  order by
+    t.relname,
+    i.relname;
+
+  select
+    t.relname as table_name,
+    i.relname as index_name,
+    array_to_string(array_agg(a.attname), ', ') as column_names
+  from
+    pg_class t,
+    pg_class i,
+    pg_index ix,
+    pg_attribute a
+  where
+    t.oid = ix.indrelid
+    and i.oid = ix.indexrelid
+    and a.attrelid = t.oid
+    and a.attnum = ANY(ix.indkey)
+    and t.relkind = 'r'
+    and t.relname like 'test%'
+  group by
+    t.relname,
+    i.relname
+  order by
+    t.relname,
+    i.relname;
+
+List index usage::
+
+  SELECT * FROM pg_stat_all_indexes;
+  SELECT * FROM pg_stat_all_tables;
+  SELECT * FROM pg_stat_user_indexes;
+  SELECT * FROM pg_stat_user_tables;
+
+List constraints::
+
+  SELECT * FROM pg_constraint;
+  SELECT * FROM pg_constraint WHERE conrelid = (SELECT oid FROM pg_class WHERE relname LIKE 'tblName');
+
+https://www.postgresql.org/docs/current/catalog-pg-constraint.html
+  pg_constraint.
 
 List functions::
 
@@ -100,7 +224,6 @@
 
   \dy
 
-
 List misc info::
 
   select current_database();
@@ -148,6 +271,22 @@
 
   SELECT relname, relpages FROM pg_class ORDER BY relpages DESC;
 
+MVCC and transaction id
+=======================
+
+As being MVCC Postgres doesn't delete or update existing rows. Row visibility is controled by
+transaction id (monotonous incremented number): ``xmin`` - first transaction that can see row,
+``xmax`` - last transaction that can see row:::
+
+  SELECT xmin, xmax, * FROM foo WHERE id < 5 ORDER BY id;
+
+Vacuum
+======
+
+Stats on vacuum oprtations per table::
+
+  select * from pg_stat_user_tables;
+
 Using psql client
 =================
 
@@ -202,3 +341,32 @@
 
   $ psql -U $USER -h $HOST $DB -c "\\copy tbl_name from 'my.csv' csv"
 
+JDBC driver
+===========
+
+https://jdbc.postgresql.org/about/about.html
+  The current version of the driver should be compatible with PostgreSQL 8.2 and higher, and Java 6
+  (JDBC 4.0), Java 7 (JDBC 4.1), Java 8 (JDBC 4.2) and Java 9.
+https://jdbc.postgresql.org/download.html
+  Java/JDBC/Postgres compatibility table.
+
+plpgsql
+=======
+
+Simple function::
+
+  CREATE OR REPLACE FUNCTION incx(x INTEGER)
+  RETURNS INTEGER STABLE AS $$
+    BEGIN
+      RETURN x + 1;
+    END;
+  $$ LANGUAGE plpgsql;
+
+Support for procedures is added only in Postgres v11.
+
+https://www.postgresql.org/docs/current/sql-createfunction.html
+  ``CREATE FUNCTION``.
+https://www.postgresql.org/docs/current/plpgsql-control-structures.html
+  plpgsql control structures.
+https://www.postgresql.org/docs/current/errcodes-appendix.html
+  PostgreSQL Error Codes.
\ No newline at end of file
diff -r c3baf557ff0c -r c44e4331713c systemd.rst
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/systemd.rst	Thu Jan 03 22:13:18 2019 +0200
@@ -0,0 +1,38 @@
+
+=========
+ Systemd
+=========
+
+Managing services
+=================
+
+Display service details/status::
+
+  $ sudo systemctl show   my.service
+  $ sudo systemctl status my.service
+
+Start/stop service::
+
+  $ sudo systemctl start   repricer-server.service
+  $ sudo systemctl stop    repricer-server.service
+  $ sudo systemctl restart repricer-server.service
+
+Enabling/disabling service::
+
+  $ sudo systemctl enable  my.service
+  $ sudo systemctl disable my.service
+
+Systemd journal
+===============
+
+Get service console output::
+
+  $ journalctl -u repricer-server.service
+
+Like ``tail -n 20``::
+
+  $ journalctl -n 20 ...
+
+Like ``tail -f``::
+
+  $ journalctl -f ...