5 files changed, 75 insertions, 0 deletions

diff --git a/shells/README.md b/shells/README.md
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+++ b/shells/README.md
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+This directory regroups regularly-accessed nix-shells that require (or
+not) a bit of configuration to run and may not be trivial to write from
+scratch.
diff --git a/shells/ipython.nix b/shells/ipython.nix
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+++ b/shells/ipython.nix
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+with import <nixpkgs> {};
+mkShell {
+  buildInputs = [ (python3.withPackages (ps: [ ps.ipython ])) ];
+}
diff --git a/shells/mysql.nix b/shells/mysql.nix
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+++ b/shells/mysql.nix
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+with import <nixpkgs> {};
+  mkShell {
+    buildInputs = [ mariadb ];
+    shellHook = ''
+      export MARIADBHOST=$PWD/mysql
+      export LANG=en_US.UTF-8;
+      export LOCALE_ARCHIVE=${glibcLocales}/lib/locale/locale-archive;
+      export MYSQL_UNIX_PORT=$MARIADBHOST/mysql.sock
+      mkdir -p $MARIADBHOST
+      cat > $MARIADBHOST/my.cnf <<EOF
+      [mysqld]
+      skip-networking
+      datadir=$MARIADBHOST
+      socket=$MARIADBHOST/mysql.sock
+      EOF
+      echo 'Initializing mysql database...'
+      mysql_install_db --defaults-file=$MARIADBHOST/my.cnf --datadir=$MARIADBHOST --basedir=${mariadb} > $MARIADBHOST/LOG 2>&1
+      mysqld --defaults-file=$MARIADBHOST/my.cnf --datadir=$MARIADBHOST --basedir=${mariadb} --pid-file=$MARIADBHOST/mariadb.pid >> $MARIADBHOST/LOG 2>&1 &
+      finish() {
+          mysqladmin shutdown
+          rm -rf "$MARIADBHOST";
+      }
+      trap finish EXIT
+    '';
+  }
+
diff --git a/shells/postgresql.nix b/shells/postgresql.nix
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+++ b/shells/postgresql.nix
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+with import <nixpkgs> {};
+  mkShell {
+    buildInputs = [ postgresql_11 glibcLocales ];
+    shellHook = ''
+            export PGDB="dummy";
+            export PGDATA=$PWD/postgres
+            export PGHOST=$PWD/postgres
+            export PGPORT=5432
+            export LOG_PATH=$PWD/postgres/LOG
+            export PGDATABASE=postgres
+            export DATABASE_URL="postgresql:///postgres?host=$PGDATA"
+            export LANG=en_US.UTF-8;
+            export LOCALE_ARCHIVE=${glibcLocales}/lib/locale/locale-archive;
+            mkdir -p $PGDATA
+            echo 'Initializing postgresql database...'
+            initdb $PGDATA --auth=trust >/dev/null
+            pg_ctl start -w -l $LOG_PATH -o "-c synchronous_commit=off -c listen_addresses= -c unix_socket_directories=$PGDATA"
+            createdb "$PGDB";
+            finish() {
+                pg_ctl stop -m fast;
+                rm -rf "$PGDATA";
+            }
+            trap finish EXIT
+    '';
+  }
+
diff --git a/shells/sub_bash.nix b/shells/sub_bash.nix
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+++ b/shells/sub_bash.nix
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+# run with
+# nix-shell shell.nix --run 'touch in ; tail -f in | bash & echo $! > pid'
+# and then send commands with
+# echo 'compute_me "1 + 3"' >> in
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.mkShell {
+  buildInputs = [ pkgs.bc ];
+  shellHook = ''
+    compute_me() {
+      echo "$1" | bc;
+    }
+    export -f compute_me
+
+    echo "I’m ready"
+    '';
+}