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postgres_binaries.txt (4723B)

      1 ===============================================================================
      2 POSTGRES BINARIES
      3 ===============================================================================
      4 
      5 -------------------------------------------------------------------------------
      6 1. POSTGRES BINARIES & FILE STRUCTURE
      7 -------------------------------------------------------------------------------
      8 
      9 +------------------------------------------------------------------+
     10 |                        Docker Container                          |
     11 |  +------------------------------------------------------------+  |
     12 |  |                            OS                              |  |
     13 |  |                                                            |  |
     14 |  |   /usr/lib/postgresql/                                     |  |
     15 |  |                                                            |  |
     16 |  |   +-----------------------------------------------------+  |  |
     17 |  |   |  data                                               |  |  |
     18 |  |   |  ------------------> /var/lib/postgresql/data       |  |  |
     19 |  |   +-----------------------------------------------------+  |  |
     20 |  |                                                            |  |
     21 |  |   +-----------------------------------------------------+  |  |
     22 |  |   |  lib                                                |  |  |
     23 |  |   |  ------------------> *.so shared libraries          |  |  |
     24 |  |   +-----------------------------------------------------+  |  |
     25 |  |                                                            |  |
     26 |  |   +-----------------------------------------------------+  |  |
     27 |  |   |  bin  --> Postgres executables:                     |  |  |
     28 |  |   |           postgres  (server daemon)                 |  |  |
     29 |  |   |           psql      (CLI, libpq)                    |  |  |
     30 |  |   |           initdb    (init data dir)                 |  |  |
     31 |  |   |           pg_ctl    (server control)                |  |  |
     32 |  |   |           createdb / dropdb                         |  |  |
     33 |  |   |           createuser / dropuser                     |  |  |
     34 |  |   |           pg_dump, pg_dumpall, pg_restore           |  |  |
     35 |  |   |           (backup/restore utilities)                |  |  |
     36 |  |   |           ...                                       |  |  |
     37 |  |   +-----------------------------------------------------+  |  |
     38 |  +------------------------------------------------------------+  |
     39 +------------------------------------------------------------------+
     40 
     41 
     42 -------------------------------------------------------------------------------
     43 2. SERVICE VS. SUPPORTING TOOLS
     44 -------------------------------------------------------------------------------
     45 
     46                     +--------------+
     47                     |   postgres   |  <-- one service, PID 1
     48                     |  (the thing  |      (what the container is about)
     49                     | container is |
     50                     |  all about)  |
     51                     +------+-------+
     52            +---------+--------+---------+---------+
     53            |         |        |         |         |
     54       +----+----+ +--+-----+ +--+-----+ +--+-----+
     55       |  psql   | | pg_dump| |pg_upgrade| |vacuumdb|
     56       +---------+ +--------+ +----------+ +--------+
     57 
     58   many binaries - supporting tools
     59 
     60 Traditional Unix packaging carried into containers.
     61 
     62 
     63 -------------------------------------------------------------------------------
     64 3. COMPARATIVE PHILOSOPHY
     65 -------------------------------------------------------------------------------
     66 
     67 Typical Docker: "one binary per container"
     68   - small image, minimal attack surface
     69   - "this container runs exactly this one app"
     70   - you lose built-in tools, need lots of sidecars
     71 
     72 Postgres Docker:
     73   - "single concern" != "literally one executable on disk"
     74   - you can, and often should, ship a toolbox with the main service
     75 
     76 
     77 -------------------------------------------------------------------------------
     78 4. EXAMPLE RUST APP
     79 -------------------------------------------------------------------------------
     80 
     81 +------------------------------------------------------------------+
     82 |                        Docker Container                          |
     83 |                                                                  |
     84 |   main binary --> Running as PID 1          +--------------+   |
     85 |   ops binary                                |  CLI TOOL    |   |
     86 |                                             |  debug binary|   |
     87 |         |                                   +--------------+   |
     88 |         |         pipe                                           |
     89 |         +------------------------------->  maintenance binaries  |
     90 +------------------------------------------------------------------+