Minimum IAM Policy/Role Permissions to deploy Serverless.com (assuming you pre-created the deployment bucket)

minimum_serverless_iam_policy_for_deployment.json

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "cloudformation:Describe*",
                "cloudformation:List*",
                "cloudformation:Get*",
                "cloudformation:PreviewStackUpdate",
                "cloudformation:CreateStack",
                "cloudformation:UpdateStack",
                "cloudformation:DeleteStack"
            ],
            "Resource": [
              "arn:aws:cloudformation:*:<ACCOUNT_ID_HERE>:stack/<SERVICE_NAME>-<SERVICE_STAGE>/*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "cloudformation:ValidateTemplate"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "s3:ListAllMyBuckets",
                "s3:GetBucket*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "s3:ListBucket"
            ],
            "Resource": [
                "arn:aws:s3:::<EXISTING_S3_DEPLOYMENT_BUCKET>"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "s3:*"
            ],
            "Resource": [
                "arn:aws:s3:::<EXISTING_S3_DEPLOYMENT_BUCKET>/serverless/*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "logs:DescribeLogGroups"
            ],
            "Resource": "arn:aws:logs:*:<ACCOUNT_ID_HERE>:log-group::log-stream:*"
        },
        {
            "Action": [
                "logs:CreateLogGroup",
                "logs:CreateLogStream",
                "logs:DeleteLogGroup",
                "logs:DeleteLogStream",
                "logs:DescribeLogStreams",
                "logs:FilterLogEvents",
                "logs:PutRetentionPolicy"
            ],
            "Resource": "arn:aws:logs:*:<ACCOUNT_ID_HERE>:log-group:/aws/lambda/<SERVICE_NAME>*:log-stream:*",
            "Effect": "Allow"
        },
        {
            "Effect": "Allow",
            "Action": [
                "iam:GetRole",
                "iam:PassRole",
                "iam:CreateRole",
                "iam:DeleteRole",
                "iam:DetachRolePolicy",
                "iam:PutRolePolicy",
                "iam:AttachRolePolicy",
                "iam:DeleteRolePolicy"
            ],
            "Resource": [
                "arn:aws:iam::<ACCOUNT_ID_HERE>:role/<SERVICE_NAME>*-lambdaRole"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "apigateway:GET",
                "apigateway:POST",
                "apigateway:PUT",
                "apigateway:DELETE"
            ],
            "Resource": [
                "arn:aws:apigateway:*::/restapis"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "apigateway:GET",
                "apigateway:POST",
                "apigateway:PUT",
                "apigateway:DELETE"
            ],
            "Resource": [
                "arn:aws:apigateway:*::/restapis/*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "lambda:CreateFunction",
                "lambda:DeleteFunction",
                "lambda:UpdateFunctionConfiguration",
                "lambda:UpdateFunctionCode",
                "lambda:ListVersionsByFunction",
                "lambda:PublishVersion",
                "lambda:CreateAlias",
                "lambda:DeleteAlias",
                "lambda:UpdateAlias",
                "lambda:GetFunctionConfiguration",
                "lambda:AddPermission",
                "lambda:RemovePermission",
                "lambda:InvokeFunction",
                "lambda:GetPolicy",
                "lambda:ListTags",
                "lambda:TagResource",
                "lambda:UntagResource",
                "lambda:*"
            ],
            "Resource": [
                "arn:aws:lambda:*:<ACCOUNT_ID_HERE>:function:<SERVICE_NAME>*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeSecurityGroups",
                "ec2:DescribeSubnets",
                "ec2:DescribeVpcs"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "events:Put*",
                "events:Remove*",
                "events:Delete*",
                "events:Describe*"
            ],
            "Resource": "arn:aws:events:*:<ACCOUNT_ID_HERE>:rule/<SERVICE_NAME>*"
        }
    ]
}