WiP! Synit support

README.md

@@ -34,6 +34,7 @@ Currently, the following process managers are supported:
 * `cygrunsrv`: Cygwin's [cygrunsrv](http://web.mit.edu/cygwin/cygwin_v1.3.2/usr/doc/Cygwin/cygrunsrv.README)
 * `s6-rc`: [s6-rc](https://skarnet.org/software/s6-rc) for managing services
   supervised by [s6](https://skarnet.org/software/s6)
+* `synit`: [Synit](https://synit.org/)
 
 It can also work with the following solutions that are technically not
 categorized as process managers (but can still be used as such):

nixproc/backends/synit/build-synit-env.nix

@@ -0,0 +1,37 @@
+{ pkgs ? import <nixpkgs> { inherit system; }
+, system ? builtins.currentSystem
+, stateDir ? "/var"
+, runtimeDir ? "${stateDir}/run"
+, logDir ? "${stateDir}/log"
+, cacheDir ? "${stateDir}/cache"
+, spoolDir ? "${stateDir}/spool"
+, lockDir ? "${stateDir}/lock"
+, libDir ? "${stateDir}/lib"
+, tmpDir ? (if stateDir == "/var" then "/tmp" else "${stateDir}/tmp")
+, forceDisableUserChange ? false
+, callingUser ? null
+, callingGroup ? null
+, extraParams ? {}
+, exprFile ? null
+}@args:
+
+let
+  processesFun = import exprFile;
+
+  processesFormalArgs = builtins.functionArgs processesFun;
+
+  processesArgs = builtins.intersectAttrs processesFormalArgs (args // {
+    processManager = "synit";
+  } // extraParams);
+
+  processes = if exprFile == null then {} else processesFun processesArgs;
+in
+pkgs.buildEnv {
+  name = "synit";
+  paths = map (processName:
+    let
+      process = builtins.getAttr processName processes;
+    in
+    process.pkg
+  ) (builtins.attrNames processes);
+}

nixproc/backends/synit/generate-synit-service.nix

@@ -0,0 +1,30 @@
+{ stdenv, lib, execline, writeTextFile }:
+
+{ name, description, initialize, daemon, daemonArgs, instanceName, pidFile
+, foregroundProcess, foregroundProcessArgs, path, environment, directory, umask
+, nice, user, dependencies, credentials, overrides, postInstall }:
+
+let
+  util = import ../util { inherit lib; };
+
+  generator = import ./preserves-generator.nix { inherit lib; };
+  toPreserves = generator.toPreserves { };
+
+  escapeArgs = args:
+    lib.concatMapStringsSep " "
+    (arg: ''"${lib.replaceStrings [ ''"'' ] [ ''\"'' ] (toString arg)}"'') args;
+
+  processSpec = {
+    argv = "${daemon} ${toString daemonArgs}";
+    env = environment;
+  } // (lib.attrsets.optionalAttrs (directory != null) { dir = directory; });
+
+in writeTextFile {
+  name = "services-${name}";
+  destination = "/services/${name}.pr";
+  text = ''
+    <metadata <daemon ${name}> { description: "${description}" }>
+    <require-service <daemon ${name}>>
+    <daemon ${name} ${toPreserves processSpec}>
+  '';
+}

nixproc/backends/synit/preserves-generator.nix

@@ -0,0 +1,52 @@
+{ lib }:
+
+let inherit (lib) isAttrs isBool isFunction isList;
+in rec {
+  /* Generates text-encoded Preserves from an arbitrary value.
+
+     Records are generated for lists with a final element in
+     the form of `{ record = «label»; }`.
+
+     Type: toPreserves :: a -> string
+
+     Example:
+       toPreserves { } [{ a = 0; b = 1; } "c" [ true false ] { record = "foo"; }]
+       => "<foo { a: 0 b: 1 } \"c\" [ #t #f ]>"
+  */
+  toPreserves = { }@args:
+    let
+      toPreserves' = toPreserves args;
+      concatItems = toString;
+      recordLabel = list:
+        with builtins;
+        let len = length list;
+        in if len == 0 then
+          null
+        else
+          let end = elemAt list (len - 1);
+          in if (isAttrs end) && (attrNames end) == [ "record" ] then
+            end
+          else
+            null;
+    in v:
+    if isAttrs v then
+      "{ ${
+        concatItems
+        (lib.attrsets.mapAttrsToList (key: val: "${key}: ${toPreserves' val}")
+          v)
+      } }"
+    else if isList v then
+      let label = recordLabel v;
+      in if label == null then
+        "[ ${concatItems (map toPreserves' v)} ]"
+      else
+        "<${label.record} ${concatItems (map toPreserves' (lib.lists.init v))}>"
+    else if isBool v then
+      (if v then "#t" else "#f")
+    else if isFunction v then
+      abort "generators.toPreserves: cannot convert a function to Preserves"
+    else if isNull v then
+      "null"
+    else
+      builtins.toJSON v;
+}

nixproc/create-managed-process/universal/create-managed-process-universal.nix

@@ -113,6 +113,11 @@ let
     inherit (pkgs) stdenv writeTextFile lib execline s6;
     inherit s6-rc basePackages tmpDir runtimeDir forceDisableUserChange;
   };
+
+  generateSynitService = import ../../backends/synit/generate-synit-service.nix {
+    inherit (pkgs) stdenv lib execline writeTextFile;
+  };
+
 in
 import ../agnostic/create-managed-process.nix {
   inherit processManager;
@@ -128,5 +133,6 @@ import ../agnostic/create-managed-process.nix {
     supervisord = generateSupervisordProgram;
     systemd = generateSystemdService;
     sysvinit = generateSystemVInitScript;
+    synit = generateSynitService;
   };
 }

tools/default.nix

@@ -47,6 +47,10 @@ rec {
     inherit (pkgs) stdenv getopt;
   };
 
+  synit = import ./synit {
+    inherit (pkgs) stdenv getopt;
+  };
+
   systemd = import ./systemd {
     inherit (pkgs) stdenv getopt;
   };

tools/synit/default.nix

@@ -0,0 +1,20 @@
+{ stdenv, getopt }:
+
+stdenv.mkDerivation {
+  name = "nixproc-synit-tools";
+  buildCommand = ''
+    mkdir -p $out/bin
+
+    sed -e "s|/bin/bash|$SHELL|" \
+      -e "s|@getopt@|${getopt}/bin/getopt|" \
+      -e "s|@commonchecks@|${../commonchecks}|" \
+      ${./nixproc-synit-switch.in} > $out/bin/nixproc-synit-switch
+    chmod +x $out/bin/nixproc-synit-switch
+
+    sed -e "s|/bin/bash|$SHELL|" \
+      -e "s|@getopt@|${getopt}/bin/getopt|" \
+      -e "s|@commonchecks@|${../commonchecks}|" \
+      ${./nixproc-synit-deploy.in} > $out/bin/nixproc-synit-deploy
+    chmod +x $out/bin/nixproc-synit-deploy
+  '';
+}

tools/synit/nixproc-synit-deploy.in

@@ -0,0 +1,132 @@
+#!/bin/bash -e
+
+showUsage()
+{
+    me="$(basename "$0")"
+
+    cat <<EOF
+Usage: $me [OPTION] PATH
+
+Deploys a prebuilt Synit configuration profile.
+
+Options:
+  -p, --profile=NAME    Name of the Nix profile that stores the sysvinit scripts
+                        (defaults to: processes)
+  -o, --old-profile=PATH
+                        Path to the previously deployed Nix profile (by default,
+                        it gets auto detected)
+      --state-dir       Changes the directory in which the state of the
+                        processes are stored
+      --runtime-dir     Changes the directory in which the PID files are stored
+      --log-dir         Changes the directory in which the log files are stored
+      --tmp-dir         Changes the directory in which temp files are stored
+      --cache-dir       Changes the directory in which cache files are stored
+      --spool-dir       Changes the directory in which spool files are stored
+      --lock-dir        Changes the directory in which lock files are stored
+      --lib-dir         Changes the directory in which state files are stored
+      --force-disable-user-change
+                        Forces to not create users, groups or change user
+                        permissions
+      --runlevel=LEVEL  Specifies which runlevel to activate (defaults to the
+                        runlevel of the system)
+  -h, --help            Shows the usage of this command
+
+Environment:
+  NIX_STATE_DIR        Overrides the location of the Nix state directory
+  NIXPROC_STATE_DIR    Changes the directory in which the state of the
+                       processes is stored
+  NIXPROC_RUNTIME_DIR  Changes the directory in which the PID files are stored
+  NIXPROC_LOG_DIR      Changes the directory in which log files are stored
+  NIXPROC_TMP_DIR      Changes the directory in which temp files are stored
+  NIXPROC_CACHE_DIR    Changes the directory in which cache files are stored
+  NIXPROC_SPOOL_DIR    Changes the directory in which spool files are stored
+  NIXPROC_LOCK_DIR     Changes the directory in which lock files are stored
+  NIXPROC_LIB_DIR      Changes the directory in which state files are stored
+  NIXPROC_FORCE_DISABLE_USER_CHANGE
+                       Forces to not create users, groups or change user
+                       permissions
+EOF
+}
+
+# Parse valid argument options
+
+PARAMS=`@getopt@ -n $0 -o p:o:h -l profile:,old-profile:,state-dir:,runtime-dir:,log-dir:,tmp-dir:,cache-dir:,spool-dir:,lock-dir:,lib-dir:,force-disable-user-change,runlevel:,help -- "$@"`
+
+if [ $? != 0 ]
+then
+    showUsage
+    exit 1
+fi
+
+# Evaluate valid options
+
+eval set -- "$PARAMS"
+
+while [ "$1" != "--" ]
+do
+    case "$1" in
+        -p|--profile)
+            profile="$2"
+            ;;
+        -o|--old-profile)
+            oldProfilePath="$2"
+            ;;
+        --state-dir)
+            stateDirArg="--state-dir $2"
+            ;;
+        --runtime-dir)
+            runtimeDirArg="--runtime-dir $2"
+            ;;
+        --log-dir)
+            logDirArg="--log-dir $2"
+            ;;
+        --tmp-dir)
+            tmpDirArg="--tmp-dir $2"
+            ;;
+        --cache-dir)
+            cacheDirArg="--cache-dir $2"
+            ;;
+        --spool-dir)
+            spoolDirArg="--spool-dir $2"
+            ;;
+        --lock-dir)
+            lockDirArg="--lock-dir $2"
+            ;;
+        --lib-dir)
+            libDirArg="--lib-dir $2"
+            ;;
+        --force-disable-user-change)
+            forceDisableUserChangeArg="--force-disable-user-change"
+            ;;
+        --runlevel)
+            runlevel="$2"
+            ;;
+        -h|--help)
+            showUsage
+            exit 0
+            ;;
+    esac
+
+    shift
+done
+
+shift
+
+profilePath="$1"
+
+# Validate the given options
+
+source @commonchecks@
+
+checkNixStateDir
+checkProfile
+composeOldProfilePath
+
+# TODO
+
+# Delete obsolete users and groups
+deleteObsoleteUsers
+deleteObsoleteGroups
+
+# Set new profile
+setNixProfile

tools/synit/nixproc-synit-switch.in

@@ -0,0 +1,192 @@
+#!/bin/bash
+set -e
+shopt -s nullglob
+
+# Shows the usage of this command to the user
+
+showUsage()
+{
+    me="$(basename "$0")"
+
+    cat <<EOF
+Usage: $me [OPTION] [PATH]
+  or: $me --undeploy [OPTION]
+  or: $me --rollback [OPTION]
+  or: $me --switch-generation NUM [OPTION]
+  or: $me --list-generations [OPTION]
+  or: $me --delete-generations NUM [OPTION]
+  or: $me --delete-all-generations NUM [OPTION]
+
+This command repopulates a folder with Synit configuration files and updates
+the configuration so that obsolete services will be stoppped and new services
+will be started.
+
+If the provided path is a file then it is considered a Nix expression that
+produces a Nix profile. If the provided path is a directory, then it is
+considered a pre-built Nix profile.
+
+Options:
+      --undeploy        Undeploys all previously deployed processes
+      --rollback        Rolls back to the previous deployment
+      --switch-generation=NUM
+                        Switches to a previous deployment generation
+      --list-generations
+                        Lists all profile generations of the current deployment
+      --delete-generations=NUM
+                        Deletes the specified generations. The number can
+                        correspond to generation numbers, days (d postfix) or
+                        'old'.
+      --delete-all-generations
+                        Deletes all profile generations. This is useful when a
+                        deployment has been discarded
+  -p, --profile=NAME    Name of the Nix profile that stores the sysvinit scripts
+                        (defaults to: processes)
+  -o, --old-profile=PATH
+                        Path to the previously deployed Nix profile (by default,
+                        it gets auto detected)
+      --runlevel=LEVEL  Specifies which runlevel to activate (defaults to the
+                        runlevel of the system)
+      --state-dir       Changes the directory in which the state of the
+                        processes are stored
+      --runtime-dir     Changes the directory in which the PID files are stored
+      --log-dir         Changes the directory in which the log files are stored
+      --tmp-dir         Changes the directory in which temp files are stored
+      --cache-dir       Changes the directory in which cache files are stored
+      --spool-dir       Changes the directory in which spool files are stored
+      --lock-dir        Changes the directory in which lock files are stored
+      --lib-dir         Changes the directory in which state files are stored
+      --force-disable-user-change
+                        Forces to not create users, groups or change user
+                        permissions
+      --show-trace      Shows a trace of the output
+      --extra-params=PARAMS
+                        A string with an attribute set in the Nix expression
+                        language propagating extra parameters to the input models
+  -h, --help            Shows the usage of this command
+
+Environment:
+  NIX_STATE_DIR        Overrides the location of the Nix state directory
+  NIXPROC_PROCESSES    Path to a processes model
+  NIXPROC_STATE_DIR    Changes the directory in which the state of the
+                       processes is stored
+  NIXPROC_RUNTIME_DIR  Changes the directory in which the PID files are stored
+  NIXPROC_LOG_DIR      Changes the directory in which log files are stored
+  NIXPROC_TMP_DIR      Changes the directory in which temp files are stored
+  NIXPROC_CACHE_DIR    Changes the directory in which cache files are stored
+  NIXPROC_SPOOL_DIR    Changes the directory in which spool files are stored
+  NIXPROC_LOCK_DIR     Changes the directory in which lock files are stored
+  NIXPROC_LIB_DIR      Changes the directory in which state files are stored
+  NIXPROC_FORCE_DISABLE_USER_CHANGE
+                       Forces to not create users, groups or change user
+                       permissions
+EOF
+}
+
+# Parse valid argument options
+
+PARAMS=`@getopt@ -n $0 -o p:o:h -l undeploy,rollback,switch-generation:,list-generations,delete-generations:,delete-all-generations,profile:,old-profile:,state-dir:,runtime-dir:,log-dir:,tmp-dir:,cache-dir:,spool-dir:,lock-dir:,lib-dir:,force-disable-user-change,runlevel:,show-trace,extra-params:,help -- "$@"`
+
+if [ $? != 0 ]
+then
+    showUsage
+    exit 1
+fi
+
+# Evaluate valid options
+
+eval set -- "$PARAMS"
+
+while [ "$1" != "--" ]
+do
+    case "$1" in
+        --undeploy)
+            undeploy=1
+            ;;
+        --rollback)
+            operation="switchGenerations"
+            ;;
+        --switch-to-generation)
+            operation="switchGenerations"
+            generationId=$2
+            ;;
+        --list-generations)
+            operation="listGenerations"
+            ;;
+        --delete-generations)
+            operation="deleteGenerations"
+            generations="$2"
+            ;;
+        --delete-all-generations)
+            operation="deleteAllGenerations"
+            ;;
+        -p|--profile)
+            profileArg="-p $2"
+            ;;
+        -o|--old-profile)
+            oldProfileArg="-o $2"
+            ;;
+        --state-dir)
+            stateDirArg="--state-dir $2"
+            ;;
+        --runtime-dir)
+            runtimeDirArg="--runtime-dir $2"
+            ;;
+        --log-dir)
+            logDirArg="--log-dir $2"
+            ;;
+        --tmp-dir)
+            tmpDirArg="--tmp-dir $2"
+            ;;
+        --cache-dir)
+            cacheDirArg="--cache-dir $2"
+            ;;
+        --spool-dir)
+            spoolDirArg="--spool-dir $2"
+            ;;
+        --lock-dir)
+            lockDirArg="--lock-dir $2"
+            ;;
+        --lib-dir)
+            libDirArg="--lib-dir $2"
+            ;;
+        --force-disable-user-change)
+            forceDisableUserChangeArg="--force-disable-user-change"
+            ;;
+        --runlevel)
+            runlevel="$2"
+            runlevelArg="--runlevel $runlevel"
+            ;;
+        --show-trace)
+            showTraceArg="--show-trace"
+            ;;
+        --extra-params)
+            extraParamsArg=("--extra-params" "$2")
+            ;;
+        -h|--help)
+            showUsage
+            exit 0
+            ;;
+    esac
+
+    shift
+done
+
+shift
+
+# Validate the given options
+
+source @commonchecks@
+
+checkProcessesFile "$1"
+checkNixStateDir
+checkProfile
+composeProfileBaseDir
+
+# Execute the deployment
+
+deploy()
+{
+    nixproc-synit-deploy $runlevelArg $profileArg $oldProfileArg $profilePath $stateDirArg $runtimeDirArg $logDirArg $tmpDirArg $cacheDirArg $spoolDirArg $lockDirArg $libDirArg $forceDisableUserChange
+}
+
+executeDeploymentOperation synit