File contents can now be only strings

Allowing file contents to be represented with lists added
unnecessary complexity also in UI implementations.

docs/source/backends/openwrt.rst

@@ -202,8 +202,8 @@ dictionary is structured as follows:
+===================+================+==========+==========================================================+
| ``path``          | string         | yes      | path of the file in the tar.gz archive                   |
+-------------------+----------------+----------+----------------------------------------------------------+
| ``contents``      | string or list | yes      | | *string*: plain text contents of the file              |
|                   |                |          | | *list*: lines of strings representing lines of file    |
| ``contents``      | string         | yes      | plain text contents of the file, new lines must be       |
|                   |                |          | encoded as `\n`                                          |
+-------------------+----------------+----------+----------------------------------------------------------+
| ``mode``          | string         | no       | permissions, if omitted will default to ``0644``         |
+-------------------+----------------+----------+----------------------------------------------------------+

netjsonconfig/backends/openwrt/schema.py

@@ -297,10 +297,8 @@
                        "type": "string"
                    },
                    "contents": {
                        "anyOf": [
                            {"type": "string", "format": "textarea"},
                            {"type": "array"}
                        ]
                        "type": "string",
                        "format": "textarea"
                    },
                    "mode": {
                        "type": "string",

tests/openwrt/test_backend.py

@@ -284,10 +284,8 @@ def test_file_inclusion(self):
            "files": [
                {
                    "path": "/etc/crontabs/root",
                    "contents": [
                        '* * * * * echo "test" > /etc/testfile',
                        '* * * * * echo "test2" > /etc/testfile2'
                    ]
                    "contents": '* * * * * echo "test" > /etc/testfile\n'
                                '* * * * * echo "test2" > /etc/testfile2'
                },
                {
                    "path": "/etc/dummy.conf",
@@ -304,7 +302,7 @@ def test_file_inclusion(self):
        # first file
        crontab = tar.getmember('etc/crontabs/root')
        contents = tar.extractfile(crontab).read().decode()
        self.assertEqual(contents, '\n'.join(o.config['files'][0]['contents']))
        self.assertEqual(contents, o.config['files'][0]['contents'])
        self.assertEqual(crontab.mtime, 0)
        self.assertEqual(crontab.mode, 420)
        # second file
@@ -314,27 +312,6 @@ def test_file_inclusion(self):
        self.assertEqual(dummy.mode, 420)
        tar.close()

    def test_file_inclusion_list_contents(self):
        o = OpenWrt({
            "files": [
                {
                    "path": "/root/.ssh/authorized_keys",
                    "contents": [
                        "key1 user@machine1",
                        "key2 user@machine2",
                        "key3 user@machine3",
                    ]
                }
            ]
        })
        tar = tarfile.open(fileobj=o.generate(), mode='r')
        self.assertEqual(len(tar.getmembers()), 1)
        # check file
        crontab = tar.getmember('root/.ssh/authorized_keys')
        contents = tar.extractfile(crontab).read().decode()
        self.assertEqual(contents, '\n'.join(o.config['files'][0]['contents']))
        tar.close()

    def test_file_permissions(self):
        o = OpenWrt({
            "files": [