import migrations and don't require diesel_cli for admins (#555)

* import migrations via macro

* panic on database not to the latest migration

* add subcommand to plm

* create migration that run tantivy index creation

* remove diesel_cli from places it was

* use our migration system for tests

* create table __diesel_schema_migrations if needed

plume-models/src/migrations.rs

@@ -0,0 +1,122 @@
+use Connection;
+use Error;
+use Result;
+
+use diesel::connection::{Connection as Conn, SimpleConnection};
+use migrations_internals::{setup_database, MigrationConnection};
+
+use std::path::Path;
+
+#[allow(dead_code)] //variants might not be constructed if not required by current migrations
+enum Action {
+    Sql(&'static str),
+    Function(&'static Fn(&Connection, &Path) -> Result<()>),
+}
+
+impl Action {
+    fn run(&self, conn: &Connection, path: &Path) -> Result<()> {
+        match self {
+            Action::Sql(sql) => conn.batch_execute(sql).map_err(Error::from),
+            Action::Function(f) => f(conn, path),
+        }
+    }
+}
+
+struct ComplexMigration {
+    name: &'static str,
+    up: &'static [Action],
+    down: &'static [Action],
+}
+
+impl ComplexMigration {
+    fn run(&self, conn: &Connection, path: &Path) -> Result<()> {
+        println!("Running migration {}", self.name);
+        for step in self.up {
+            step.run(conn, path)?
+        }
+        Ok(())
+    }
+
+    fn revert(&self, conn: &Connection, path: &Path) -> Result<()> {
+        println!("Reverting migration {}", self.name);
+        for step in self.down {
+            step.run(conn, path)?
+        }
+        Ok(())
+    }
+}
+
+pub struct ImportedMigrations(&'static [ComplexMigration]);
+
+impl ImportedMigrations {
+    pub fn run_pending_migrations(&self, conn: &Connection, path: &Path) -> Result<()> {
+        use diesel::dsl::sql;
+        use diesel::sql_types::Bool;
+        use diesel::{select, RunQueryDsl};
+        #[cfg(feature = "postgres")]
+        let schema_exists: bool = select(sql::<Bool>(
+            "EXISTS \
+             (SELECT 1 \
+             FROM information_schema.tables \
+             WHERE table_name = '__diesel_schema_migrations')",
+        ))
+        .get_result(conn)?;
+        #[cfg(feature = "sqlite")]
+        let schema_exists: bool = select(sql::<Bool>(
+            "EXISTS \
+             (SELECT 1 \
+             FROM sqlite_master \
+             WHERE type = 'table' \
+             AND name = '__diesel_schema_migrations')",
+        ))
+        .get_result(conn)?;
+
+        if !schema_exists {
+            setup_database(conn)?;
+        }
+
+        let latest_migration = conn.latest_run_migration_version()?;
+        let latest_id = if let Some(migration) = latest_migration {
+            self.0
+                .binary_search_by_key(&migration.as_str(), |mig| mig.name)
+                .map(|id| id + 1)
+                .map_err(|_| Error::NotFound)?
+        } else {
+            0
+        };
+
+        let to_run = &self.0[latest_id..];
+        for migration in to_run {
+            conn.transaction(|| {
+                migration.run(conn, path)?;
+                conn.insert_new_migration(migration.name)
+                    .map_err(Error::from)
+            })?;
+        }
+        Ok(())
+    }
+
+    pub fn is_pending(&self, conn: &Connection) -> Result<bool> {
+        let latest_migration = conn.latest_run_migration_version()?;
+        if let Some(migration) = latest_migration {
+            Ok(self.0.last().expect("no migrations found").name != migration)
+        } else {
+            Ok(true)
+        }
+    }
+
+    pub fn rerun_last_migration(&self, conn: &Connection, path: &Path) -> Result<()> {
+        let latest_migration = conn.latest_run_migration_version()?;
+        let id = latest_migration
+            .and_then(|m| self.0.binary_search_by_key(&m.as_str(), |m| m.name).ok())?;
+        let migration = &self.0[id];
+        conn.transaction(|| {
+            migration.revert(conn, path)?;
+            migration.run(conn, path)
+        })
+    }
+}
+
+pub const IMPORTED_MIGRATIONS: ImportedMigrations = {
+    import_migrations! {}
+};