Add support for .pgpass to PostgreSQL (#3593)

Implements https://www.pivotaltracker.com/story/show/182582924

CHANGELOG.md

@@ -164,6 +164,8 @@
 - [Added `line_endings` and `comment_character` options to
   `File_Format.Delimited`.][3581]
 - [Fixed the case of various type names and library paths][3590]
+- [Added support for parsing `.pgpass` file and `PG*` environment variables for
+  the Postgres connection][3593]
 
 [debug-shortcuts]:
   https://github.com/enso-org/enso/blob/develop/app/gui/docs/product/shortcuts.md#debug
@@ -260,6 +262,7 @@
 [3581]: https://github.com/enso-org/enso/pull/3581
 [3588]: https://github.com/enso-org/enso/pull/3588
 [3590]: https://github.com/enso-org/enso/pull/3590
+[3593]: https://github.com/enso-org/enso/pull/3593
 
 #### Enso Compiler
 

distribution/lib/Standard/Base/0.0.0-dev/src/System.enso

@@ -50,6 +50,10 @@ nano_time = @Builtin_Method "System.nano_time"
 os : Text
 os = @Builtin_Method "System.os"
 
+## Check if the operating system is UNIX.
+is_unix : Boolean
+is_unix = @Builtin_Method "System.is_unix"
+
 ## PRIVATE
    Returns the default line separator for the platform that the program is
    currently running on.

distribution/lib/Standard/Base/0.0.0-dev/src/System/Environment.enso

@@ -1,6 +1,6 @@
 from Standard.Base import all
 
-polyglot java import java.lang.System
+polyglot java import org.enso.base.Environment_Utils
 
 ## ALIAS Read Environment
    UNSTABLE
@@ -18,4 +18,24 @@ polyglot java import java.lang.System
 
          example_get = Environment.get "PATH"
 get : Text -> Text | Nothing
-get key = System.getenv key
+get key = Environment_Utils.get_environment_variable key
+
+## UNSTABLE
+
+   Returns a value of a specified environment variable or the provided default
+   value if such variable is not defined.
+
+   Arguments:
+   - key: The name of the environment variable to look up.
+   - default: The default fallback value.
+
+   > Example
+     Look up the value of the `FOOBAR` environment variable.
+
+         import Standard.Base.System.Environment
+
+         example_get_or_else = Environment.get_or_else "FOOBAR" "my default"
+get_or_else : Text -> Text -> Text
+get_or_else key ~default = case get key of
+    Nothing -> default
+    value -> value

distribution/lib/Standard/Base/0.0.0-dev/src/System/File.enso

@@ -2,6 +2,7 @@ from Standard.Base import all
 
 import Standard.Base.System.File.Option
 import Standard.Base.System.File.Existing_File_Behavior
+import Standard.Base.System.File.File_Permissions
 import Standard.Base.Error.Problem_Behavior
 import Standard.Base.Data.Text.Matching_Mode
 import Standard.Base.Data.Text.Text_Sub_Range
@@ -368,9 +369,30 @@ type File
        Builtin method that gets this file's last modified time.
        Recommended to use `File.last_modified_time` instead which handles
        potential exceptions.
-    last_modified_time_builtin : File -> ZonedDateTime
+    last_modified_time_builtin : ZonedDateTime
     last_modified_time_builtin = @Builtin_Method "File.last_modified_time_builtin"
 
+    ## Gets the POSIX permissions associated with the file.
+
+       > Example
+         Check if the file is readable by the user's group.
+
+             import Standard.Examples
+
+             example_permissions = Examples.csv.posix_permissions.group_read
+    posix_permissions : File_Permissions
+    posix_permissions =
+        File_Permissions.from_java_set self.posix_permissions_builtin
+
+    ## PRIVATE
+
+       Builtin method that gets this file's POSIX permissions as a Java Set.
+       Recommended to use `File.posix_permissions` instead which handles
+       potential exceptions and converts an Enso representation of the
+       permissions.
+    posix_permissions_builtin : Set
+    posix_permissions_builtin = @Builtin_Method "File.posix_permissions_builtin"
+
     ## Checks whether the file exists and is a directory.
 
        > Example

distribution/lib/Standard/Base/0.0.0-dev/src/System/File/File_Permissions.enso

@@ -0,0 +1,104 @@
+from Standard.Base import all
+
+polyglot java import java.nio.file.attribute.PosixFilePermission
+
+type Permission
+    ## Permission for read access for a given entity.
+    type Read
+
+    ## Permission for write access for a given entity.
+    type Write
+
+    ## Permission for execute access for a given entity.
+    type Execute
+
+type File_Permissions
+    ## Access permissions for a file.
+    type File_Permissions (owner : Vector Permission) (group : Vector Permission) (others : Vector Permission)
+
+    ## Converts the Enso atom to its Java enum counterpart.
+    to_java : Vector PosixFilePermission
+    to_java =
+        result = Vector.new_builder
+        if self.owner.contains Read then
+            result.append PosixFilePermission.OWNER_READ
+        if self.owner.contains Write then
+            result.append PosixFilePermission.OWNER_WRITE
+        if self.owner.contains Execute then
+            result.append PosixFilePermission.OWNER_EXECUTE
+        if self.group.contains Read then
+            result.append PosixFilePermission.GROUP_READ
+        if self.group.contains Write then
+            result.append PosixFilePermission.GROUP_WRITE
+        if self.group.contains Execute then
+            result.append PosixFilePermission.GROUP_EXECUTE
+        if self.others.contains Read then
+            result.append PosixFilePermission.OTHERS_READ
+        if self.others.contains Write then
+            result.append PosixFilePermission.OTHERS_WRITE
+        if self.others.contains Execute then
+            result.append PosixFilePermission.OTHERS_EXECUTE
+        result.to_vector
+
+    ## Checks if the given file can be read by the owner.
+    owner_read : Boolean
+    owner_read = self.owner.contains Read
+
+    ## Checks if the given file can be written by the owner.
+    owner_write : Boolean
+    owner_write = self.owner.contains Write
+
+    ## Checks if the given file can be executed by the owner.
+    owner_execute : Boolean
+    owner_execute = self.owner.contains Execute
+
+    ## Checks if the given file can be read by the group.
+    group_read : Boolean
+    group_read = self.group.contains Read
+
+    ## Checks if the given file can be written by the group.
+    group_write : Boolean
+    group_write = self.group.contains Write
+
+    ## Checks if the given file can be executed by the group.
+    group_execute : Boolean
+    group_execute = self.group.contains Execute
+
+    ## Checks if the given file can be read by others.
+    others_read : Boolean
+    others_read = self.others.contains Read
+
+    ## Checks if the given file can be written by others.
+    others_write : Boolean
+    others_write = self.others.contains Write
+
+    ## Checks if the given file can be executed by others.
+    others_execute : Boolean
+    others_execute = self.others.contains Execute
+
+## Converts a Java `Set` of Java `PosixFilePermission` to `File_Permissions`.
+from_java_set java_set =
+    owner = Vector.new_builder
+    group = Vector.new_builder
+    others = Vector.new_builder
+
+    if java_set.contains PosixFilePermission.OWNER_READ then
+        owner.append Read
+    if java_set.contains PosixFilePermission.OWNER_WRITE then
+        owner.append Write
+    if java_set.contains PosixFilePermission.OWNER_EXECUTE then
+        owner.append Execute
+    if java_set.contains PosixFilePermission.GROUP_READ then
+        group.append Read
+    if java_set.contains PosixFilePermission.GROUP_WRITE then
+        group.append Write
+    if java_set.contains PosixFilePermission.GROUP_EXECUTE then
+        group.append Execute
+    if java_set.contains PosixFilePermission.OTHERS_READ then
+        others.append Read
+    if java_set.contains PosixFilePermission.OTHERS_WRITE then
+        others.append Write
+    if java_set.contains PosixFilePermission.OTHERS_EXECUTE then
+        others.append Execute
+
+    File_Permissions owner.to_vector group.to_vector others.to_vector

distribution/lib/Standard/Base/0.0.0-dev/src/System/Platform.enso

@@ -26,6 +26,10 @@ type Os
 os : Os
 os = from_text System.os
 
+## Check if the currently running platform is a UNIX platform.
+is_unix : Boolean
+is_unix = System.is_unix
+
 ## PRIVATE
 
    Create an Os object from text.

distribution/lib/Standard/Database/0.0.0-dev/src/Connection/Postgres.enso

@@ -1,12 +1,15 @@
 from Standard.Base import all
 
+from Standard.Base.Data.Numbers import Parse_Error
+
 import Standard.Database.Data.Dialect
 import Standard.Database.Connection.Connection
 from Standard.Database.Connection.Credentials as Credentials_Module import Credentials
 import Standard.Database.Connection.Connection_Options
 import Standard.Database.Connection.SSL_Mode
 from Standard.Database.Connection.SSL_Mode import all
 import Standard.Database.Connection.Client_Certificate
+import Standard.Database.Internal.Postgres.Pgpass
 
 polyglot java import org.postgresql.Driver
 
@@ -20,7 +23,7 @@ type Postgres
        - credentials: The credentials to use for the connection (defaults to PGPass or No Authentication).
        - use_ssl: Whether to use SSL (defaults to `Prefer`).
        - client_cert: The client certificate to use or `Nothing` if not needed.
-    type Postgres (host:Text='localhost') (port:Integer=5432) (database:Text='') (credentials:(Credentials|Nothing)=Nothing) (use_ssl:SSL_Mode=Prefer) (client_cert:(Client_Certificate|Nothing)=Nothing)
+    type Postgres (host:Text=default_postgres_host) (port:Integer=default_postgres_port) (database:Text=default_postgres_database) (credentials:(Credentials|Nothing)=Nothing) (use_ssl:SSL_Mode=Prefer) (client_cert:(Client_Certificate|Nothing)=Nothing)
 
     ## Build the Connection resource.
 
@@ -42,11 +45,22 @@ type Postgres
     jdbc_properties : [Pair Text Text]
     jdbc_properties =
         credentials = case self.credentials of
-            Nothing -> Postgres.read_pgpass self.host self.port self.database
+            Nothing ->
+                env_user = Environment.get "PGUSER"
+                env_password = Environment.get "PGPASSWORD"
+                case Pair env_user env_password of
+                    Pair Nothing Nothing ->
+                        Pgpass.read self.host self.port self.database
+                    Pair Nothing _ ->
+                        Error.throw (Illegal_State_Error "PGPASSWORD is set, but PGUSER is not.")
+                    Pair username Nothing ->
+                        Pgpass.read self.host self.port self.database username
+                    Pair username password ->
+                        [Pair 'user' username, Pair 'password' password]
             Credentials username password ->
                 [Pair 'user' username, Pair 'password' password]
 
-        ssl_properties = Postgres.ssl_mode_to_jdbc_properties self.use_ssl
+        ssl_properties = ssl_mode_to_jdbc_properties self.use_ssl
 
         cert_properties = if self.client_cert.is_nothing then [] else
             self.client_cert.properties
@@ -57,31 +71,30 @@ type Postgres
     dialect : Dialect
     dialect = Dialect.postgres
 
-    ## PRIVATE - static
-       Read the .pgpass file from the User's home directory and obtain username
-       and password. https://www.postgresql.org/docs/current/libpq-pgpass.html
-
-       Arguments:
-       - host: The hostname of the database server.
-       - port: The port of the database server.
-       - database: The database to connect to.
-    read_pgpass : Text -> Integer -> Text -> [Pair Text Text]
-    read_pgpass _ _ _ =
-        ## ToDo: Code not part of the design document.
-        ## host port database
-        []
-
-    ## PRIVATE - static
-       Given an `SSL_Mode`, create the JDBC properties to secure a Postgres-based
-       connection.
-    ssl_mode_to_jdbc_properties : SSL_Mode -> [Pair Text Text]
-    ssl_mode_to_jdbc_properties use_ssl = case use_ssl of
-        Disable -> []
-        Prefer -> [Pair 'sslmode' 'prefer']
-        Require -> [Pair 'sslmode' 'require']
-        Verify_CA cert_file ->
-            if cert_file.is_nothing then [Pair 'sslmode' 'verify-ca'] else
-                [Pair 'sslmode' 'verify-ca', Pair 'sslrootcert' (File.new cert_file).absolute.path]
-        Full_Verification cert_file ->
-            if cert_file.is_nothing then [Pair 'sslmode' 'verify-full'] else
-                [Pair 'sslmode' 'verify-full', Pair 'sslrootcert' (File.new cert_file).absolute.path]
+## PRIVATE
+   Given an `SSL_Mode`, create the JDBC properties to secure a Postgres-based
+   connection.
+ssl_mode_to_jdbc_properties : SSL_Mode -> [Pair Text Text]
+ssl_mode_to_jdbc_properties use_ssl = case use_ssl of
+    Disable -> []
+    Prefer -> [Pair 'sslmode' 'prefer']
+    Require -> [Pair 'sslmode' 'require']
+    Verify_CA cert_file ->
+        if cert_file.is_nothing then [Pair 'sslmode' 'verify-ca'] else
+            [Pair 'sslmode' 'verify-ca', Pair 'sslrootcert' (File.new cert_file).absolute.path]
+    Full_Verification cert_file ->
+        if cert_file.is_nothing then [Pair 'sslmode' 'verify-full'] else
+            [Pair 'sslmode' 'verify-full', Pair 'sslrootcert' (File.new cert_file).absolute.path]
+
+## PRIVATE
+default_postgres_host = Environment.get_or_else "PGHOST" "localhost"
+
+## PRIVATE
+default_postgres_port =
+    hardcoded_port = 5432
+    case Environment.get "PGPORT" of
+        Nothing -> hardcoded_port
+        port -> Integer.parse port . catch Parse_Error (_->hardcoded_port)
+
+## PRIVATE
+default_postgres_database = Environment.get_or_else "PGDATABASE" ""

distribution/lib/Standard/Database/0.0.0-dev/src/Connection/Redshift.enso

@@ -7,8 +7,7 @@ import Standard.Database.Connection.Connection_Options
 import Standard.Database.Connection.SSL_Mode
 from Standard.Database.Connection.SSL_Mode import all
 import Standard.Database.Connection.Client_Certificate
-
-import Standard.Database.Connection.Postgres
+import Standard.Database.Internal.Postgres.Pgpass
 
 polyglot java import com.amazon.redshift.jdbc.Driver
 polyglot java import java.util.Properties
@@ -53,7 +52,7 @@ type Redshift
     jdbc_properties : [Pair Text Text]
     jdbc_properties =
         credentials = case self.credentials of
-            Nothing -> Postgres.Postgres.read_pgpass self.host self.port self.schema
+            Nothing -> Pgpass.read self.host self.port self.schema
             AWS_Profile db_user profile ->
                 [Pair 'user' db_user] + (if profile == '' then [] else [Pair 'profile' profile])
             AWS_Key db_user access_key secret_access_key ->
@@ -75,15 +74,15 @@ type Redshift
 
 type AWS_Profile
     ## Access Redshift using IAM via an AWS profile.
-    
+
        Arguments:
        - db_user: Redshift username to connect as.
        - profile: AWS profile name (if empty uses default).
     type AWS_Profile db_user:Text profile:Text=''
 
 
     ## Access Redshift using IAM via an AWS access key ID and secret access key.
-    
+
        Arguments:
        - db_user: Redshift username to connect as.
        - access_key: AWS access key ID.